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Environment B‑class

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nb: many of the comments here were written before the move to the current name of "attribution of recent climate change".

Old stuff

I think this entry is superfluous; the political aspects of anthropogenic global warming are just about identical to the political aspects of all (man+nature) global warming, since we can't do anything about natural global warming. A better place might be with greenhouse gases. --TheCunctator

I also find it somewhat confusing; the Democratic party is said to consider anthropogenic global warming a huge threat, but then it goes on to describe how not a single Democrat politician supported the Kyoto protocols. And then there's that odd reference to Enron. I don't know if this article is biased in any particular direction, but it feels that way somehow. To make you feel better, very few politicians supported Kyoto initially, regardless of being right or left.

Responding to the unsigned paragraph above

1. Democratic support and non-support is puzzling (but real). Perhaps there is a political strategy involved. I'm not sure whether we should analyze and comment on the Clinton Administration's strategy, but the 95-0 Senate vote is a fact and should be reported.

I'm glad the bit about Enron came out: it was only breaking news, and really of a political or financial nature. This article should be scientific.

Ed Poor

This article seems to be totally focused on the US political aspects of an international issue, and in any case, if every single Democrat voted against the Kyoto protocols, then it is clearly not the case that "the Democratic Party" supports it. I think this article gives the Democrats much more credit for being progressive and pro-environment on this issue than they deserve. soulpatch

Ah, but the Democrats didn't vote against it. The treaty never was submitted to the Senate for ratification. What was actually voted was a resolution -- not the treaty itself. If you check around, you'll see that Democrats are adamant supporters of the treaty, ratified or not. Go and talk to some people, or check out campaign literature or visit some websites. Or dip into Gore's Earth in the Balance. But you're right about the "more credit...than they deserve"; I think they only rode the issue to get votes in 2000. --Ed Poor

My understanding is that those who opposed the treaty, held that position partly because of China and India (and their rapidly growing economies) are excluded and because of widespread emissions trading. Brian Pearson 01:46, 6 January 2007 (UTC)

Editors who question "The science working group of the IPCC Third Assessment Report (TAR) recognizes that the climate models in the IPCC Second and Third Assessment Reports are seriously flawed." should read the Executive Summary in the IPCC Scientific basis document about physical climate processes . -- SEWilco 16:26, 24 Aug 2003 (UTC)

Info on IPCC and SEPP

The UN created the Intergovernmental Panel on Climate Change, an organization which aims to be objective, but its opponents assert that it has misrepresented scientific reports because of political pressure. The IPCC says its role is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.

SEPP, an organization which claims to be non-partisan, presents a number of objections to interpretation of the available data on global warming. In particular, they point out that temperature measurements from weather balloons show no warming whatsoever in the 1979 to 1996 period when land-based thermometers show record-breaking rises (they won't tell you that the longer-term balloon record from 1958 matches the land-based record well). Also, they present evidence that rising temperatures cause sea level to fall (not rise, as orthodox global warming theory predicts) although this is widely disbelieved. However, the oil corporation ExxonMobil is one of SEPP's sponsors.

I don't think the above 2 paragraphs are really relevant to the Anthropogenic global warming article. But where should they go? William, Martin, Eloquence, SEWilco, what do you think?

(William M. Connolley 19:27, 11 Sep 2003 (UTC)) In some logical world, this page would hold the anthro aspects of GW. But in fact the GW page has most of the stuff, because you can't separate the two (ie, you can't quantify the anthro without some idea of the natural; and vice versa). So this page is doomed to be an orphan. Perhaps it should be reduced further.

(SEWilco 20:37, 11 Sep 2003 (UTC)) I agree. At the moment it (and anthropogenic global cooling) should just state the definition of the term and direct people to global warming for details of all the issues. When the anthro effects can be identified, they can be described here.

Merge proposal

If "global warming" means not just any period in which the air temperature went up, but "the theory that emissions have been heating the air too much" -- then anthropogenic GW isn't really a separate article.

I propose the following division of articles:

articles about how warm or cool the air has been

• global temperature record -- multiple articles, this link might be wrong
• Little Ice Age -- a long cold spell
• Medieval Climate Optimum -- put the "green" in Greenland

articles about what cause the air to heat up or cool down

• urban heat island -- cities keep getting bigger and hotter
• solar variability -- more light, more heat?
• global warming hypothesis -- CO2 makes the air heat up too much

The above list is not complete, so let's work on it together. --Uncle Ed 16:26, 9 Aug 2004 (UTC)

(William M. Connolley 17:33, 9 Aug 2004 (UTC)) OK, if you haven't seen it already it would be worth you looking at: User:William_M._Connolley/Wiki_pages_related_to_climate_change which is my classification of what we have now.

What you are proposing for surface air temperature (at least, you recently created sat, so I presume you had some use for it... not glob t rec) is already covered in historical temperature record. Its not clear why you want a new page - see my message on your talk page. Following on from that is t-rec-of-the-last 1000 years. Etc etc. Errrm... anyway, you clearly haven't looked through what we have yet. *This* current page is about attribution, which is not covered anywhere else. Arguably it should be renamed, but not merged. A lot of the v old talk above should be archived: it talks about a page that no longer exists.

Yer right, boss. Our conversations are getting scattered all over the place. But since we are working together, that's okay. We seem to find each other's scattered comments okay.

I hadn't seen your classification scheme, so obviously my little attempt is amateurish. But hey, what can I say? I always read the Amateur Scientist section of Scientific American, and now I'm an amateur journalist! --Uncle Ed

Solar/Cosmic rays and climate

(William M. Connolley 18:36, 17 Nov 2004 (UTC)) AFAIK the solar/cosmic-ray climate connection is all up in the air at the moment. There are various theories and mechanisms, none command any wide acceptance. I've qualified S's recent addition to reflect that viewpoint. Presenting that paper in science as the-state-of-the-debate would be wrong.

Probably, that stuff is worth its own page: there is a lot of it, far more than just the science paper, and it can't all go on this page.

New Articles: Global climate change and Climate forcings

Please read the new articles and consider commenting on them and/or moving some material to either one. Note that climate forcings is not specific to global climate forcings, so if it makes sense to create a separate section please do.

I hope this helps get this part of Misplaced Pages sorted out.

Posted to all discussion pages listed in the "See Also" section of global climate change. --Ben 03:48, 2 Dec 2004 (UTC)

Njau

(William M. Connolley 20:30, 7 Feb 2005 (UTC)) I consider the Njau refs somewhat desparate. Renewable energy isn't a climate journal. The 1999 paper has been cited 7 times... all by Njau. Never by anyone else. The abstract is gobbledegook. In 1999 Njau published 5 other papers - all in Renewable energy (actually one other, in the well known Nuovo Cimento. Only he has ever cited it). One of them has never been cited by anyone, even him. Of the other 4, only one has ever been cited by anyone but Njau, and that only once. He is clearly a minor author peddling his pet theories, but no-one is listening.

The 2005 paper hasn't been published yet - at least Elsevier lists it for april so I don't think it should be in there. It contains 17 refs... 9 of which are to his own papers. Reading the abstract for that paper it is clear why its published in such a minor journal - its clearly dubious stuff.

Here's an example of the sort of rubbish he is writing:

A previous publication by the author predicted that global temperature patterns will switch from the sinusoidal (amplitude-modulation) state into which it has been since 1944 into a node-antinode (amplitude-modulation) state somewhere over the 1997-2012 period. Here we present record-backed evidence which shows that the state change just mentioned is apparently in the process of starting up. By its very nature, this imminent (node-antinode) state is expected to make global temperature vary significantly above and below a common mean which itself may be approximately constant or may at certain times undergo relatively slow drifts. Furthermore we present a historical example in which records of temperature-sensitive indicators show that at least some regional temperature patterns have at least once switched from the sinusoidal (amplitude-modulation) state to the node-antinode state under global climate conditions that were fairly similar to those of the present. Finally we propose possible physical causes of the latter historical switch from sinusoidal state to node-antinode state.

Thats from a 2000 paper, cited by... nobody.

He publishes something you disagree with and you immediately engage in ad hominem attacks? As for the April 2005 publication date, that journal is already available on the web, as I read it a few hours ago. So I don't think it qualifies as "not published yet". — Cortonin | Talk 21:18, 7 Feb 2005 (UTC)

(William M. Connolley 22:27, 8 Feb 2005 (UTC)) Stop eveading the issue: his work is cited by no-one and published exclusively in minor journals. Neither is an ad-hom. Nor is describing the abstract above as rubbish.

Best answers

What part of "Misplaced Pages does not endorse a best answer, source it to someone or remove it" do you not understand??? It's straight out of NPOV policy, follow it! — Cortonin | Talk 17:12, 22 Apr 2005 (UTC)

I think you'll find that's one of the problems with True Believers, they don't see their opinions as anything but absolute fact. In their eyes, it isn't POV because they absolutely know it to be true. What does one do in this situation? --JonGwynne 17:23, 22 Apr 2005 (UTC)

Some POV problems

1. The phrase "The current best answer is..." is incredibly POV and inappropriate for this article. While it is true that some people may believe that it is "the best answer", that doesn't necessarily mean it is and it certainly should be reported as fact when it is opinion.

3. It is absolutely inappropriate to discuss the issue of greenhouse gas emission in the second paragraph without including discussion of the fact that the majority of greenhouse gas emissions has taken place AFTER the reported increase in global temperatures. Anything else is POV pushing.

3. "A summary of climate research may be found in the IPCC assessment reports". That isn't either accurate or sufficient. The IPCC doesn't summarize all climate research, it creates its own summary. So this phrase must be changed to reflect this fact. I suggest something like "An IPCC summary of climate research may be found in their assessment reports".

JGs: Removed POV paragraph - not only does it violate wiki policy, it isn't relevant to the article

(William M. Connolley 21:16, 22 Apr 2005 (UTC)) This has got to be one of the worst edits I've seen for a long while, with the edit summary Removed POV paragraph - not only does it violate wiki policy, it isn't relevant to the article. The para itself is well balanced, and how can it possibly be regarded as not relevant? It seems perfectly clear that JG has essentially degnerated to vandalising the articles.

Here are some facts for you William: The statement "The current best answer is, roughly, most of the warming observed over the last 50 years is attributable to human activities" is grotesquely POV. First of all, it fails to mention who is responsibole for deciding the "best answer". I'll assume that since you're such a big fan of this statement, that the IPCC is somehow responsible for it. However, the statement is unattributed. Second, the statement is completely subjective. Even if this is the IPCC's official opinion as to what the best answer is, then it still isn't an absolute fact it is opinion and, therefore, POV. In other words, it isn't relevant to the discussion and it is a clear violation of wikipedia policy with regard to POV - as you have been repeatedly informed. So, the real question is why do you insist on pushing unattributed POV when you know it is a violation of wikipedia policy to do so? --JonGwynne 00:01, 23 Apr 2005 (UTC)

Sockpuppetry?

(William M. Connolley 22:09, 23 Apr 2005 (UTC)) I've just reverted what I suspect is a JonGwynne sockpuppet, User:Springmourning44. Oddly, this new entrant to the debate has chosen to re-do a JG revert, with no explanation. Whoever it may be, its been blocked anyway.

I think the sound of black helicopters you were talking about earlier may be confusing you William, I don't use sock-puppets. BTW, since you bring them up, what interest do you think your personal, unfounded suspicions hold for other people here? --JonGwynne 22:32, 23 Apr 2005 (UTC)

National Academy of Sciences

Don't forget that the US National Academy of Sciences concurred with the IPCC conclusion that the majority of the temperature rise last century was most likely due to anthropogenic influences. If the IPCC is to be cited explicitly as a source of this scientific opinion, then so too should the NAS, and perhaps also all the other scientists who did not take part in either IPCC or NAS reports but have arrived at the same conclusion. It would seem to be biased to attribute that conclusion only to a subset of those who hold it. Daniel Collins 22:47, 23 Apr 2005 (UTC)

Then list it as both. Such evaluations must be sourced and attributed. — Cortonin | Talk 03:45, 24 Apr 2005 (UTC)

expressed / according to

(William M. Connolley 13:28, 27 May 2005 (UTC)) JG changed "expressed" to "according to". This was a pointless tweak, but makes the sense worse, by implying the views are restricted to those bodies; whereas they are merely expressing the general consensus. Hence reverted.

Meaning of 20C

"20C temperature trends (including early 20C changes, where solar forcing is non-negligible) there is no obvious need for a high sensitivity to solar forcing. Indeed, a significantly higher sensitivity to solar forcing would make early 20C"

I'm unsure if this is saying 20th century or 20 degrees Celsius. I assume century, but if someone who knows could fix them one way or the other, that would be good.

Wikibofh 8 July 2005 16:12 (UTC)

Century. Sorry... I'll fix it. William M. Connolley 2005-07-08 16:57:05 (UTC).

Other factors to consider

What should be in this article is a link to Axial_tilt. That and the related Arctic_Circle and Antarctic_circle need a bit of numbers disambiguation on the variation in how much Earth's axial tilt changes.

Climate change is driven by BOTH variations in solar output and the continously varying tilt of Earth's axis, which at present is decreasing. Think about the effect that has on the amount of surface area that's in constant darkness from 24 hours to six months per year, and how that affects the net heat loss. See also Solar_variation.

I never see or hear anyone talking about these two things _combined_. It's always "It's all THIS that's the cause!".

Discovery Channel's recent documentary on "The Little Ice Age" hit upon just about every possible factor _except_ axial tilt change, and nobody on the show proposed any theory combining more than one factor. They were all "THIS caused it. Those other things? Piffle! Irrelevant!".

It's time for people who study each of these things to get together, get their (bleep) together and quit butting heads over who's "right" and realize that none of their pet theories works in isolation!

North Shore Alaska/Antarctic Western Ice Shelve?

Is there a better place to find out what has caused these regions to warm? Is there a ball of CO2 hovering over them? Or is the cause of regional rise and falls of temperature completely unrelated to the rise or fall of global temperature? Should I be asking this some place else or on a different article?

I doubt this is the right place. First, we don't do original research, and secondly, this article primarily deals with global temperature. Changes in regional climates are not unrelated to global temperature, but neither is it a simple, monotone correlation. One of the famous questions is what happens to northern European climate when the North Atlantic Drift shuts down due to melting of polar ice... --Stephan Schulz 20:48, 10 May 2006 (UTC)

indeed?

No citation is provided for the "indeed" sentence I deleted. The sentence is probably an erroneous statement of the idea of trying to explain all 20th century warming with solar and without GHGs. That would require enough solar in the latter half century to overshoot the warming in the first half. However, this explanation is not what the indeed text says, and the indeed text is false. There could be a "significant" increase in sensitivity to solar that compatible with the first half century, there is room for reallocation of forcing to solar there. That "significant" increase in sensitivity to solar would not be enough to fully explain the latter half of the 20th century, but more would be attributed to solar than the TAR, and probably even Stolt did. --Poodleboy 13:37, 10 June 2006 (UTC)

PB edit

PB added:

However, the models may have significant errors in their representation of surface albedo. Positive albedo biases due to inaccuracies in representing snow cover and desert albedos would have the effect of reducing model sensitivity to solar forcing.

To me this looks like more of his obsession with albedo in models. Havin looked at his refs, I don't see any of them addressing the question of model sensitivity to solar forcing.

As for stronger-solar-makes-early-20th-C inexplicable, I admit thats unreferenced but it seems obvious: if you can explain the T from current models, with no solar amplification, there seems to not too much room for solar amplification. Unless you turned down the solar forcing in the reconstructions William M. Connolley 13:37, 10 June 2006 (UTC)

No, you would turn down the GHG sensitivity. Since less solar would be being reflected into space, it would be contributing a larger share of the warming and the heat storage in the ocean. Note that Gregory in his climate sensitivity analysis, found positive forcing in the late 19th century that would already commit some warming in the 20th. Presumably with climate models without positive albedo bias, he would find even greater committed warming and solar heat storage in the oceans. Roesch addresses the positive albedo bias, the increased solar radiative flux absorption is obvious.--Poodleboy 14:37, 10 June 2006 (UTC)

Consider forcing, F = F_solar + F_GHG + F_volcanic, etc. Your position seems to be based on the assumption that T(t) is proportional to F(t) , and hence to get the right temperature history T(t) we basically have a specified total forcing history that we have to match. And consequently if F_solar is underestimated then F_GHG is probably overestimated, etc. Is this basically your logic? I.e. A fixed amount of forcing that needs to be partitioned among causes?

If so, then your problem is basically that attribution studies don't assume this. It is too hard and the models simply aren't good enough to make those matches without noticable systematic errors in both total T and F. So instead the focus is on how much each forcing has changed in time. Saying that ΔF = ΔF_solar + ΔF_GHG + ΔF_volcanic, etc, allows researchers to minimize the effects of any systematic errors that are present at both the beginning and end of their studies. For example, if albedo is 0.01 too high in 1900 and 0.01 too high in 2000, then F_solar is underestimated by ~3-4 W/m^2 at all times, but the associated error in ΔF_solar will be less than 0.1 W/m^2. Focusing on the change in forcing, as most attribution studies do, allows us to estimate the impact of that change even in the face of considerable systematic biases. Dragons flight 15:58, 10 June 2006 (UTC)

I agree that a lot of past work has focused on how much forcing has changed in time, basically attempting signal detection. Signal detection is valuable on geologic time scales, with low frequency signals and a lot of data to analyze, but the thermal inertial of the ocean dampens high frequencies. If you want to attribute warming of the last 30 years, you can't assume that solar is contributing nothing to the temperature increase or the heat storage in the ocean, just because the solar pattern of cyclic forcing has essentially remained the same for that period. Solar forcing is at highs that have not equilibrated yet (recall the Solanki references), in fact the equilibration to this recent 60+ year long plateau of solar forcing was only just beginning 30 years ago because volcanic aerosol forcing actually was strong enough to override the solar and impose a period of cooling.

With the advent of models coupled with the oceans, that can impose conservation-of-energy constraints, the energy budget has to balance. Nearly everything in the models are highly parameterized. It is tough enough to do ab initio physics on large molecules, you are not doing it on a global climate system. The models are parameterized to the known observations, and the hope is that they become useful for gaining insight and making predictions. If the models are matching the record of heat storage in the ocean, and it is discovered they were doing while throwing away 10 to 20 watts/m^2 (orthogonal to the sun) of energy. They must have been getting that energy elsewhere. The GHGs act cheifly to blanket the earth, reducing the radiation of heat into space at certain parts of the spectrum and retaining that warmth in the atmosphere. They are the most likely place for the "correcting" error that balanced the energy budget. They work off of solar energy after all, with very little of the energy budget being geothermal, with less solar energy absorbed, the models had be parameterized to do a better job retaining it to match the temperature and heat storage. Of course, the budget can be being balanced elsewhere, perhaps modeling less negative feedback to counter the GHG forcing. The net result is a higher model sensitivity to GHG forcing than would result with proper attribution of solar forcing, and unfortunately less appreciation for the contribution of natural solar variation and more extreme predictions from GHGs scenerios.

You are wrong about attribution studies and underestimate the quality of our models, with the advent of coupled models they are balancing energy budgets and producing realistic qualitative climate behavior, this process of creeping improvements in the parameterizations will eventually yield tools of predictive value. The importance of spectrally correct parameterization of the albedo was just unappreciated until recently and the cumulative size of the errors in all the major models is a new result. When the albedos are fixed, there will be a big jump in credibility and a lot of interesting new science. The hope is that there isn't more errors of similar magnitude left to be discovered. The understanding and parameterization of the cloud physics, will I suspect be the final major frontier. Incremental improvements in realism will be the story after that.

Frankly, I am extremely excited about the science. Because the solar forcing is distributed so differently than the GHG forcing, this may explain some of the troubling problems the models have had replicating the multi-decadal climate modes and certain aspects of the ocean circulation, and result in better convergence of model results. Perhaps with these corrections, we will gain more insight into these aspects of the climate. The next few years should yield real insight into the climate, current, past and future. --Poodleboy 03:05, 11 June 2006 (UTC)

If you want to attribute warming of the last 30 years, you can't assume that solar is contributing nothing to the temperature increase or the heat storage in the ocean - I don't understand this. There is no such assumption. Also, I reiterate my unanswered point that PB is reading too much into his refs: the assertion of a bias in sensitivity is his own, not in the refs William M. Connolley 07:26, 11 June 2006 (UTC)

Yes, there is that assumption. Dragons Flight proposed focusing only on ΔF. The solar activity is has not significantly changed in the last 30 years, so his approach would not attribute any warming to solar for that period. The bias is in albedo, unless you contend that the models will still match the heat stored in the ocean even after their albedo bias is corrected then, then they have an error elsewhere they have to correct to match the energy budget. But the conclusion of a bias in sensitivity can be arrived at by other means also. The models have different sensitivities, so most of them must be biased.--Poodleboy 08:52, 11 June 2006 (UTC)

I've reverted, cos your refs still don't support your text. You say search the first reference for the word "bias", you will find what you seem to be missing, well the first ref contains the word bias, but nothing I can see about climate sensitivity. So Positive albedo biases due to inaccuracies in representing snow cover and desert albedos would have the effect of reducing model sensitivity to solar forcing. seems to be purely your own; it shouldn't have your refs following it, pretending to back it up, cos they don't. Also, as DF has pointed out, the errors in solar forcing implied by the albedo errors are tiny, and (I think) don't rate a mention. None of the models are perfect William M. Connolley 09:05, 11 June 2006 (UTC)

I forgot I had written about sensitivity to "solar" forcing, I had been responding here as if I had written about sensitivity to "GHG" forcing. But how can you question this solar forcing statement at all. If the albedos are bias high, then more solar energy is being reflected into space than in the models than in the observations. Since albedo is a proportion, the higher the forcing is the higher the bias is. Negative results, unfortunately usually don't get publish. The biases reported in the abstract are significant. The values DF and I have been discussing are on the order of the well mixed GHG forcing, do you consider that insignificant?--Poodleboy 09:34, 11 June 2006 (UTC)

No, the values you have been discussing, as DF says above, are less than 0.1 w/m2. Thats small. I don't know what you mean about "-ve results": a result that all model sensitivities were too high, or biased high, would be publishable. But oddly, the people writing the albedo papers *haven't* drawn the conclusions from them that you've jumped to William M. Connolley 14:04, 11 June 2006 (UTC)

No, DF and I were discussing the impact of an albedo error of 0.01. That was over 10 watts/m^2 orthogonal, or 3.5 watts/m^2 mapped to the earth's surface. I.e., equivilent to the GHG forcings.--Poodleboy 06:45, 12 June 2006 (UTC)

No, thats the *total* solar. You need to factor in, as DF did, the change in solar, which reduces your number by 100 at least and probably more William M. Connolley 07:32, 12 June 2006 (UTC)

The total solar is on the order 1364 watts/m^2, so that is not what DF and I were talking about. This is not about the "change" in solar, it is about the difference in solar reflected by the models vs the solar reflected into space as observed. We were analyzing the implications of a 0.01 albedo error. I don't think you have been paying attention to the discussion.--Poodleboy 09:36, 12 June 2006 (UTC)

Sigh. *total* solar is 136x; per unit area its 350-ish; albedo err of 0.01 is then 3.5 w/m2. But thats not the *forcing* number; what you then need is the *change* in the forcing; which is 1% of that. This is what DF and I have patiently been trying to explain to you with little success so far William M. Connolley 11:04, 12 June 2006 (UTC)

No, the 3.5 watts is the globally averaged change in forcing (an increase in forcing in this case) to bring the models in conformance with the observed albedo. Of course, the actual changes will be locally much greater than 3.5 watts/m^2 in the land areas where the positive biases have actually identified. You have applied the 0.01 twice once explicitly, and then again as 1%--Poodleboy 09:58, 13 June 2006 (UTC)

No, there are two separate 0.01's. The first is the albedo err (which we're talking of as assumed definite; I'm by no means convinced); the second is the change in solar forcing (??? 1% is far too large anyway, at least over 20th C). As DF wrote above: ΔF = ΔF_solar + ΔF_GHG + ΔF_volcanic. Since pre-industrial, ΔF_GHG is about 2.4 w/m2; ΔF_solar is... about 0.1. If you care about attributing to the various components, then the models, presumably, introduce an error of ΔF_solar*albedo error. The F_solar*albedo error is subsumed elsewhere. the 3.5 watts is the globally averaged change in forcing (an increase in forcing in this case) to bring the models in conformance with the observed albedo is a component that doesn't matter for attribution, because its a constant William M. Connolley 18:43, 13 June 2006 (UTC)

No, it does matter, because the extra 3.5 watts/m^2 extra radiation that was being reflected into space was energy the models were erronenously finding elsewhere since they were matching the energy stored in the ocean. In other words, they were finding that energy to store in the ocean with an error elsewhere in their model. The models are constrained by observations, and one of those observations is the energy budget with energy being stored in the ocean, i.e., the rise in sea level. The new observations they have to match is the globally averaged spectral albedo, and hopefully also the local albedo details.--Poodleboy 22:46, 13 June 2006 (UTC)

Sure, there is an extra 3.5 (lets say). But its a constant. It doesn't matter that much where it comes from; it doesn't affect the attribution much. The models are constrained by observations - not quite sure what you mean by that William M. Connolley 13:13, 15 June 2006 (UTC)

The Earth as Modified by Human Action

• "The Earth as Modified by Human Action", 1868, George P. Marsh assumes anthropogenic change as given fact: "The object of the present volume is: to indicate the character and,approximately, the extent of the changes produced by human action in the physical conditions of the globe we inhabit..." This book gives an extremely thorough description of the multiple ways in which humans have most definitely and observably contributed to climate change.

I've moved this to talk. I don't think its very relevant to attribution of GW William M. Connolley 06:18, 15 June 2006 (UTC)

Views of Roger Pielke

Removed from article by William:

The range of views held by working climate scientists does not show up in the political version of the debate, according to Roger Pielke Jr., a University of Colorado political scientist who studies the politics of climate science.

Isn't this a well-referenced view? Why did you remove it? --Uncle Ed 17:26, 2 August 2006 (UTC)

While I can't speak for William, you seem to be misrepresenting Pielke's position. You placed that quote under a section heading "Is there a consensus?", but the truth is that Pielke believes there is a scientific consensus. His complaint is that the political debate is being mischaracterized as a battle between caricatured positions (e.g. "alarmist" vs. "contrarian"), neither of which reflect the nuanced and detailed consensus within the climate community. Dragons flight 18:55, 2 August 2006 (UTC)

Oh, sorry. Perhaps I've confused the views of father and son. Pielke senior is a scientist, did you mean him? Or did I miss something specific you can point me to (hint, hint)? --Uncle Ed 19:00, 2 August 2006 (UTC)

Pielke, Jr: "Like Oreskes, I am happy to take the IPCC as the best assessment of state of climate science, and its conclusions as an accurate measure of the central tendency of views among the climate science community. The work of the IPCC, including its certainties and uncertainties, is plenty good enough for the development and promulgation of a steady stream of policy options on climate." The linked page also elaborates on his views both in the main post and through a serious of comments made below it. He is not absolutist and acknowledges that a diversity of nuanced opinion exists, but he argues that a consensus defined by the "central tendency" of climate scientists supports the IPCC and policy action to address global warming. Dragons flight 19:23, 2 August 2006 (UTC)

I think you're reading too much into this. I'd like the passage restored, with attribution to John whoever, the guy who wrote it.

Despite the high esteem in which I hold you, my anonymous friend, your opinion carries no weight here. I mean, I'd love to cite you as a source, but unless you're planning to out yourself you're a published author it's not gonna happen. --Uncle Ed 20:37, 2 August 2006 (UTC)

Ed, when was the last time you looked at my user page? Dragons flight 20:41, 2 August 2006 (UTC)

Sorry, confusing you with someone else, Robert. --Uncle Ed 21:30, 2 August 2006 (UTC)

You're expecting Ed to have read up on things...? Anyway: I removed it because (a) even if correct, its a bizarre lead-in to the section (b) its not correct. The is the attribution page, and its about science, not the politicial view of the science, which (as RR (thats a hint, Ed) has pointed out) is what RP Jr is talking about William M. Connolley 20:53, 2 August 2006 (UTC)

Ed still seems to be on his one-man campaign to challenge the view that there *is* a consensus. I don't think thats tenable - Lindzen may well disagree with the consensus, for example, but not with its existence. Indeed, thats what he is railing against. How else does According to some global warming skeptics like Richard Lindzen, Patrick Michaels, and Sallie Baliunas, scientists whose views and positions run counter to scientific consensus have found it more difficult to secure funding and publish their work, alleging that their difficulties are the result of an intentional suppression of intellectual dissent against "mainstream" theories make any sense? Oh, and Peiser is (a) wrong (and Ed, before you ask for a source for that, do please check all the previous sources you've been given) and (b) not published William M. Connolley 21:45, 2 August 2006 (UTC)

I believe there are too many people giving too much weight to "consensus". Assuming there is some degree of consensus, it doesn't follow that they are right about it. Brian Pearson 01:26, 6 January 2007 (UTC)

Statistics!

In the section Detection and Attribution, Detection is defined to be a specific demonstration of statistical significance, but then we go on to claim implicitly that there is no uncertainty, or "margin of error" to be dealt with when discussing Detection:

Detection does not imply attribution, and is easier than attribution. Unequivocal attribution would require controlled experiments with multiple copies of the climate system, which is not possible. Attribution, as described above, can therefore only be done within some margin of error.

There most certainly is uncertainty in Detection! We are dealing with experimental (and therefore uncertain) data, and unproven (in a strict sense, as all theoretical models are, strictly) (and therefore uncertain) models. Statistical significance itself is a somewhat arbitrary thing (5% significance level? 10% level? 0.5% level?). Thus the implication that Detection does not entail any uncertainty is a gross abuse of statistics, is very misleading to those not familiar with statistics, and should be remedied! Jon Wilson 24.162.120.52 01:47, 31 August 2006 (UTC)

I don't understand your interpretation. As you say, detection is done to some level of stat sig. There is nothing in what you quote that asserts or implies absolute certainty in det William M. Connolley 21:40, 2 September 2006 (UTC)

My reading of this concern is that, while detection might be 'easier', in that statistically significant results are more readily obtained, even a statistically significant result is still subject to uncertainty (or "a margin of error", even if that margin of error is statistically small). There still exists uncertainty in many (most?) relevant areas of climate science and ignoring that uncertainty risks assigning certainty to an inherently uncertain understanding of a complex system. Statisticians understand the nature of statistics. Many others don't and might interpret words like 'consensus' and 'statistically significant' as meaning that there exists absolute certainty where uncertainty still exists. Hope this helps. Ofomamad 16:19, 8 February 2007 (UTC)Ofomamad

That was a bit wordy - apologies. Structure of the wording in question is: 'D is easier than A. Unequivocal A would require X, which is not possible. A therefore can only be done within a margin of error.' Implies Unequivocal D can be obtained, either using X or some other way, without a margin of error, which is false. D is not unequivocal - it is also "done within some margin of error", but the opposite is implied here. Hope that's more clear. Ofomamad 17:29, 8 February 2007 (UTC)Ofomamad

Cosmic rays cause global cooling

Svensmark's recent research on cosmic rays is certain to gain many followers, but I just found a very interesting article written in 2004 that predicted global cooling by 2006 because of increased cosmic rays. The fact temperatures were down in 2006 says something, although I have not yet found proof that cloud or cosmic rays were increased (I would not doubt it). The article itself is only on google cache, so the charts and images do not show. RonCram 13:48, 10 January 2007 (UTC)

Erm...2006 is the warmest year on record for the US, and the 6th-warmest worldwide. And that despite the fact that for the first half of the year ENSO was in El Nina. Where did you get the "fact" that temperatures were down? --Stephan Schulz 19:40, 10 January 2007 (UTC)

Stephan, we are talking about global temperatures - not US temperatures. Hansen, Jones and others had predicted that 2006 would be the warmest ever globally, breaking the record of 1998. It didn't happen. In fact, temperatures were down significantly from 2005. Your comment regarding La Nina is incorrect. Conditions changed from La Nina to El Nino in February, 2006. RonCram 01:23, 22 January 2007 (UTC)

"Most fiercely contested"?

The article reads "The most fiercely-contested question in current climate change research is over attribution of climate change to either natural/internal or human factors..." -- most significant perhaps, but most fiercely contested seems misleading given that there is a consensus... --Nethgirb

Attribution goes beyond whether any human contribution is estimated to be zero or non-zero. If the human component were non-zero but very small, then arguably the optimal response might be to do nothing (as warming might happen at roughly the same rate over much the same period anyway). If any human component were relatively very large, then that might be suggestive of the need for a response to any anthropogenic forcing, with the magnitude of the response positively related to the magnitude of the attribution (as action might make an important difference over meaningful timeframes if any athropogenic contribution were estimated to be relatively very large). On this reading, there does not seem to be a consensus surrounding attribution, although the IPCC use of the word "most" appears to imply that there exists a consensus that any human component is > 50%. Does anyone have references for supporting evidence of this implied consensus of > 50% attribution? Ofomamad 16:00, 8 February 2007 (UTC)Ofomamad

I'm not sure I understand the question. The IPCC is very clear in stating that "Most of the observed increase in globally averaged temperatures since the mid-20th is very likely due to the observed increase in anthropogenic greenhouse gas concentrations". If you read the SPM leading up to this, you get a fairly detailed discussion of the different radiative forcings. Greenhouse gases are responsible for most of the positive forcings, but the effect is reduced by some negative forcings like aerosols. I find >50% a bit misleading, because it they attribute much more than half of the positive forcings to greenhouse gases, but it certainly is not incorrect (and the forcings cannot simply be added up and divided anyways). --Stephan Schulz 18:09, 8 February 2007 (UTC)

It is precisely because "forcings cannot be simply added up and divided" that creates the problem of explicitly attributing "most" (i.e. >50%) of ΔT to anthropogenic variables. The statistical relationship may be stronger for the anthropogenic (Y) variables than the non-anthropogenic (non-Y) variables modelled, but that is not the same as an empirically determined attribution of X% (where X>50%). I have found no published evidence of X>50% (only that the statistical power is higher for Y than for the non-Y variables modelled), thus am seeking assistance finding such evidence to validate the claim made in the IPCC's SPM.

It seems you're assuming that attribution is done by statistical regression, which isn't the case (please clarify if otherwise). Read the SPM and supporting chapters in the full report for details. Raymond Arritt 15:43, 24 May 2007 (UTC)

Actually I was just reading chp2 of the AR4 and it will explain forcings for you rather well. ~ UBeR 18:19, 24 May 2007 (UTC)

Bratcher and Giese

I took out:

* Bratcher and Giese, "Tropical Pacific decadal variability and global warming" published in 2002, points to oceanic events (with a four year lag in temperatures) causing climate shifts - a 1972 event caused a climate shift resulting in warmer temperatures from 1976 until 2002. An event in 2002 caused Giese to predict a climate shift and cooler temperatures beginning in 2006. Giese's prediction came true when 2006 temperatures were cooler than 2005 even though 2006 was an El Nino year. Giese concludes the results of his study "indicate that the human forced portion of global warming may be less than previously described."

because I don't see that it fits the description of *important* results. Also its badly misrepresented: B+G don't predict cooling, they say: If tropical Pacific SST responds to these subsurface changes in a similar way, then it could be an indication of a climate regime shift to pre-1976 conditions. Given the considerable effect that tropical Pacific SST has on global atmospheric circulation, a climate shift to pre-1976 conditions could lessen the warming trend that has existed since 1976. which is very different. Also they make no specific predictions about 2006 that I can see. William M. Connolley 20:29, 21 January 2007 (UTC)

William, of course you don't see it as *important* since it conflicts with your POV, but that does not change the fact it is important. The specific prediction for 2006 results from the four year lag from their observation in 2002. Giese predicted a return to pre-1976 conditions which was a period of global cooling. You did not quote the entire passage. "A similar situation existed in the early 1940’s when SST records show an equatorial Pacific cooling with the period from 1942–1976 generally cooler than the period following the 1976 climate shift ." If you think my wording overstates the case, feel free to edit my wording. But the entry needs to stay. RonCram 20:55, 21 January 2007 (UTC)

Why is it important? Has it gained wide notice? No. There was no specific prediction (let alone of 2006): note the "*If* tropical Pacific SST responds..." and a lessened warming trend - not a cooling.

As for the Schmidt thing... that seems so far from reality that I'm baffled you put it in. Schmidt, of course, is with RC and won't agree with your Original interpretation of his work. Nor is C12/13 the major reason to attribute CO2 to humans. Please get real William M. Connolley 21:34, 21 January 2007 (UTC)

William, you know as well as I that people use the C13 to C12 ratio to attempt to prove mankind is responsible for increased CO2 in the atmosphere. Read this bit from RealClimate. The NASA piece proves that the ratio widens and tightens by purely natural mechanisms, mechanisms which are impossible for us to measure. My entry did not claim that Schmidt was a skeptic, only that this report proves that isotopes cannot be used to blame mankind.RonCram 01:11, 22 January 2007 (UTC)

As it sez on RC: There are actually multiple, largely independent lines of reasoning, discussed in some detail in the IPCC TAR report, Chapter 3. One of the best illustrations of this point, however, is not given in IPCC. Indeed, it seems not all that well appreciated in the scientific community, and is worth making more widely known. So no, you can't use RC to prove that we don't know that CO2 is anthro, since we don't. Asserting that the CO2 increase is not known to be anthro pushes you out onto the wild fringes of skepticism and destroys your credibility. And I don't even see why the Schidt piece you linked to makes your point William M. Connolley 09:45, 22 January 2007 (UTC)

The argument seems to be as follows: Development of the C12/C13 ratios are consistent with the massive influx of carbon from fossil resources and hence confirm what we expect in the first place (given that we introduce massive amounts of fossil carbon into the atmosphere). Therefore the only reason we have to believe that we introduce massive amounts of fossil carbon is the change in the C12/C13 ration. But 55 million years ago, another event changes the C12/C13 ratio (over about 100000 years) and hence we know nothing anymore... --Stephan Schulz 10:08, 22 January 2007 (UTC)

William and Stephan - First of all, Real Climate is wrong. The IPCC does discuss the C13 to C12 ratio and says it points to the burning of fossil fuels. Second, the characteristic isotopic signatures of fossil fuel (its lack of 14C, and depleted content of 13C) leave their mark in the atmosphere. The article I linked to proves that this line of reasoning is bogus. 13C can be "depleted" by purely natural mechanisms. Seeing the hand of man where it is not necessarily active is poor science. These guys are jumping to conclusions that are not warranted. Recent studies show this line of argument is no longer valid. RonCram 03:52, 23 January 2007 (UTC)

Ron, you start being unneccesarily dense. The primary reason for our knowledge of man's contribution to the CO2 increase is the fact that we do release massive amounts of CO2 - in fact, we release about 2 times more than shows up in the atmosphere, with much of the rest currently absorbed by the oceans and biosphere. The C in the CO2 we release also has a very distinct isotopic signature - essentially no C14 and very reduced amounts of C13. And this very change is reflected in the atmosphere. What is your explanation? Squirrels collecting the CO2 we produce, and storing it underground while at the same time some other source of fossil Carbon is convenienty converted to CO2 at just the right rate to fool us? Science does not do absolute proof, but this is as close as it can possibly get. --Stephan Schulz 08:17, 23 January 2007 (UTC)

Stephan, I think this whole line of argument is way oversold. I would think that to get an accurate measure of man's contribution based on isotopes, you would need a stable baseline of the isotopes. When this line of argument was first advanced to me, I was told nature did provide a stable baseline. Now I learn it does not. Is it possible to decipher man's contribution in a scenario with a changing baseline? Perhaps, but it seems to me that arguing from the total change makes much more sense than an argument based on isotopes. Regardless of my thoughts, I am ready to concede the point. RonCram 00:54, 24 January 2007 (UTC)

William, you deleted my entry on Giese again. He predicted a return to pre-1976 conditions after 4 years from his study. His study was 2002. Temperatures did cool in 2006. The entry is correct. RonCram 19:38, 26 January 2007 (UTC)

William, you are reverting without any comment. You have not demonstrated any inaccuracy in my entry. And you are deleting two entries at the same time. RonCram 19:49, 26 January 2007 (UTC)

RC continues to misrepresent B+G. First of all, I maintain my doubt that its important enough to list. But even past that, RC has it wrong: RC added:

Bratcher and Giese, "Tropical Pacific decadal variability and global warming" published in 2002, points to oceanic events (with a four year lag in temperatures) causing climate shifts - a 1972 event caused a climate shift resulting in warmer temperatures from 1976 until 2002. An event in 2002 caused Giese to predict a climate shift to pre-1976 conditions by 2006. Giese's prediction came true when 2006 temperatures were cooler than 2005 even though 2006 was an El Nino year. No climate model considers oceanic events as a climate forcing. Giese concludes the results of his study "indicate that the human forced portion of global warming may be less than previously described."

The lag is *about* 4 years, and the paper says this, not precisely 4. The paper cannot possibly be about an event in 2002 - "An event in 2002 caused..." is an invention by RC - because it was received in March 2002 by GRL, which means it must have been begun in early 2002 at best. Fig 1 shows temperatures to 2000 and 5-y smoothed ENSO to 2001. The paper does say if negative anomalies follow a pattern similar to the positive anomalies in the mid–1970’s, then a cool tropical Pacific SST anomaly may soon weaken the global warming signal. but note the if, the may, and the lack of a timescale. And later: If tropical Pacific SST responds to these subsurface changes in a similar way, then it could be an indication of a climate regime shift to pre-1976 conditions. Given the considerable effect that tropical Pacific SST has on global atmospheric circulation, a climate shift to pre-1976 conditions could lessen the warming trend that has existed since 1976 - again, note the if, the could be, the could. And that it ends with "lessen the warming trend" - not *cooling*. Adn there is no 4-y timescale given.

In short, RC has misread the paper William M. Connolley 19:54, 26 January 2007 (UTC)

William (ie. Kim), your excessive obfuscating is growing wearisome. So the cooling trend began in late 2005. Is that really significant to readers of an encyclopedia? If you insist, we can quote the entire Giese paper. But nothing you have said above indicates that Giese's study is not appropriate for this section of the article. The main point is Giese's conclusion: The results presented here do not preclude the possibility that anthropogenic sources of greenhouse gases have contributed to global warming. However the results do indicate that the human forced portion of global warming may be less than previously described. Instead of trying to make the entry better, you have just deleted the information, proving that you care more for censoring science than you do for an accurate encyclopedia. Using Kim to do you your dirty work only makes you look bad.RonCram 14:55, 27 January 2007 (UTC)

I don't know what this "ie Kim" nonsense is. You kept insisting that B+G was abou an event in 2002. I point out this was impossible; it clearly means you didn't both read the paper but only read into it what you wanted to see. Thankfully you've removed that, but the never version is still very bad: No climate models consider oceanic events as a climate forcing - what does this mean? All climate models had predicted 2006 would set record temperatures - this is complete nonsense - where did you get it from? And in all, the paper remains of no particular importance. The main point is... - its certainly the main point to you, but thats not enough William M. Connolley 15:31, 27 January 2007 (UTC)

William, my comment was to you but it was Kim that deleted my entry. Again, he did it without any effort to make the entry better or to prove it didn't belong - he just deleted it. Your claim I did not read the paper is completely bogus. I read the paper carefully. The timing of the observations and the cooling is just a smokescreen for your POV. An encyclopedia is not expected to use the same careful wording of a scientific paper, especially when discussing annual temperature averages. So the observations probably happened in 2001 and were published in early 2002, resulting in cooler temps in late 2005 but really affected the 2006 annual avg temps much more. This is the "about" four years I was talking about. Nothing you have said has debunked anything I wrote. "No climate models consider oceanic events as a climate forcing" means exactly what it says. Climate models consider CO2, solar variability, and other factors. Climate models do not factor in the conditions and observations of Dr. Giese. This is why Dr. Giese concludes "the results do indicate that the human forced portion of global warming may be less than previously described." Regarding the point that 2006 was predicted to be the warmest year ever, I could find lots of such predictions - Hansen, Jones, Mann. All in all, the paper is of extreme importance. Just as Einstein was recognized as great because his theory was proven correct, so too is Giese's prediction proving to be correct. That is the main point. RonCram 15:49, 27 January 2007 (UTC)

Nothing you have said has debunked anything I wrote: except you have at last admitted that the even could not possibly have been in 2002, as you had previously repeatedly insisted. Regarding the point that 2006 was predicted to be the warmest year ever...: no, you actually wrote, and have left in the article, All climate models had predicted 2006 would set record temperatures. Are you now backing away from that to asserting that someone predicted it? Do please provide several climate models that predict such, or take the sentence out of the article. This is the "about" four years I was talking about - no, you did *not* write "about" 4 years - you insisted on exactly 4 years. B+G does not make any prediction - it is far too hedged with ifs and buts, and contains no specific dates - it is only you who have arbitrarily decided that B+G meant 2006, based on your invention of an event in 2002. On your logic, B+G could have meant 2001, and therefore predicted a cold 2005, but you need to insist on 2005 being warm. No climate models consider oceanic events as a climate forcing - this is in essence wrong. GCMs contain oceans, which are fully able to provide forcing as in the real world. Its clear that what you are writing is your own OR based on B+G. BTW, given this is B+G, why do you insist on using the second author? William M. Connolley 16:15, 27 January 2007 (UTC)

William, IMHO the word "about" was not required in an encyclopedia when talking about averaged annual temperatures. If you thought it was required, you could have added the word instead of deleting the entire entry. If you think you can find a climate model which includes the observations and predictions Giese made, please provide a link and I will agree to remove the sentence. If not, and you still think some change to the wording is required - feel free to make the change in wording. If I do not find your change acceptable, we can discuss it. Regarding B+G, I mention both in the entry. However, Dr. Giese is the professor and Batcher was only a Ph.D. candidate. RonCram 17:56, 27 January 2007 (UTC)

You are shifting and turning, but cannot hide the fact that your additions are wrong. You have inserted into the article All climate models had predicted 2006 would set record temperatures. This appears to be a fact entirely of your own invention, and completely sourceless, as well as being wrong (assuming you really mean climate models). a climate model which includes the observations and predictions Giese made - what does this mean? A climate model that includes predictions? IMHO the word "about" was not required in an encyclopedia when talking about averaged annual temperatures - sheer revisionism. You needed it to be exactly 4 years to make your fantasy prediction make any sense. I've reverted it again to remove your falsehoods William M. Connolley 19:06, 27 January 2007 (UTC)

RonCram, yes... i deleted the entry, and William has summed up my opposition quite accurately. As you may remember this paper was discussed on the Talk:List_of_scientists_opposing_global_warming_consensus - so i do know the paper. And i cannot say that your entry in any way is representative of it. I didn't edit it - because there wasn't anything to salvage. --Kim D. Petersen 23:45, 27 January 2007 (UTC)

I revised the entry to read as below.

• Bratcher and Giese, "Tropical Pacific decadal variability and global warming" published in 2002, observed conditions that "could be an indication of a climate regime shift to pre-1976 conditions." (The Earth was in a cooling trend from 1945 to 1975 and then saw warmer temperatures from 1976 through 2002.) Climate models cited by IPCC TAR did not consider as a climate forcing the conditions and possible climate regime shift that Giese predicted. Giese concludes: The results presented here do not preclude the possibility that anthropogenic sources of greenhouse gases have contributed to global warming. However the results do indicate that the human forced portion of global warming may be less than previously described."

The climate forcings considered by IPCC TAR can be seen on the graphic on this article. It should be clear that no climate model has considered a regime shift such as that predicted by Giese prior to his paper. While I expect future climate models will include Giese's observations and predictions, I do not believe (as yet) that any climate models have. I have asked William (or anyone) to provide evidence any climate models have considered Giese's observations and predictions and no such evidence has been forthcoming. Certainly this will happen. It will be interesting to see how these models react. RonCram 19:24, 29 January 2007 (UTC)

William, you quote me and then comment: IMHO the word "about" was not required in an encyclopedia when talking about averaged annual temperatures - sheer revisionism. You needed it to be exactly 4 years to make your fantasy prediction make any sense. I've reverted it again to remove your falsehoods. Sheer hogwash. "About 4 years" could be 3.5 to 4.5 years. When you factor in the time required to write and publish the study and factor in the fact the data set is averaging annual temperatures, such approximations disappear into insignificance. The entire "four year" argument you are putting forward is nothing but a red herring. I have completely removed it, not because it was wrong but because it was inconsequential. The main point is that the IPCC's climate models do not consider an important theory of climate shifts. RonCram 19:34, 29 January 2007 (UTC)

Still you shift and turn. You have, finally, removed the blatant untruths from your text. However now B+G are no longer predicting anything, still less anything that has come true, there is no obvious claim for notability - other than it including the quote you like. Now you are left with your main point being OR: that GCMs don't consider climate shifts. You bolster this with your reading of climate forcings, but yet again you are wrong. The regime shift that B+G consider is internal to the ocean-atmos system (well, mostly in the ocean) not an *external* forcing at all. So yes, coupled GCMs contain the same physics and may well have such regime shifts. Without some backup, your assertion that these *aren't* considered is nothing but OR on your part. I am not required to demonstrate the falsity of words you add: you are required to add only verifiable sourced material: which your "main point" isn't William M. Connolley 19:38, 29 January 2007 (UTC)

William, B+G's observations led them to write that oceanic events "could be an indication of a climate regime shift to pre-1976 conditions." Most people will understand that to be a prediction. Giese's "climate shift" is not considered by any computer model considered by the IPCC since it was published after the TAR. This is self-evident, not OR. I have restored the entry. Everything in the entry itself is well-sourced and not OR. As to your argument of importance, Giese's study is far more important than Barnett which has already been disproved. RonCram 21:18, 29 January 2007 (UTC)

You are completely shameless. You have made claim after claim for this article that you've been forced to withdraw. Now you shift to the idea that Barnett has been disproven, which is yet more OR on your part. This is self-evident, not OR is the claim of the OR-ist time after time, its not even original :-). This is a scientific paper, to be read by scientists, not "most people". You have Climate models cited by IPCC TAR did not consider as a climate forcing the conditions and possible climate regime shift that Giese predicted - this is B+G and you should *not* be writing G - there is no prediction. You have continually misrepresented this paper and you still are William M. Connolley 21:49, 29 January 2007 (UTC)

William, you are shameless. Your reputation for being among the most POV editors on wikipedia is evidently well-deserved. IMHO Barnett's thesis has been disproven since the oceans have been cooling since 2003. However, my opinion is not in the entry. You are merely attempting to change the subject. You admitted there were no errors in my entry and you have not identified any errors now. You complain that I should be naming both B+G and not just G. Very well. I will be happy to make that change (even though B was only a graduate student at the time). However, your claim there is no prediction is wishful thinking. B+G wrote that what they observed "could be an indication of a climate regime shift to pre-1976 conditions." This is a prediction to anyone - scientist or not - who is not intentionally blind to anything contrary to the IPCC. Regardless of any of this, your main goal is to keep their conclusion out of the article - namely, that the IPCC has overestimated the role of mankind in climate change. William, you should be ashamed of yourself. You are evidently incapable of doing the right thing. I suggest we bring in other editors to decide this dispute. Hopefully, we can find some editors who are not subject to the same kind of groupthink as some of your followers. RonCram 23:55, 29 January 2007 (UTC)

Took out the predicted bit as I don't see a prediction in their paper. Mainly just a caution regarding uncertainties in observed natural cycles and they point out a ...similar, but opposite in sign, pattern as that seen prior to the 1976 climate shift and emphasize the importance of understanding the separation between natural variability and anthropogenic forcing in the climate system. Let's not read more into the article than is there. Vsmith 02:24, 30 January 2007 (UTC)

Um. Now essentially everything of RC's is stripped out, we return to: why is this paper significant? According to RC, the main point is that the IPCC's climate models do not consider an important theory of climate shifts. I don't believe that; you've removed it. With the main point gone, why does the entry remain? William M. Connolley 09:46, 30 January 2007 (UTC)

Don't know 'bout the significance - it can go as far as I'm concerned, the paper was an interesting read but important to this article? - doubt it. Vsmith 12:45, 30 January 2007 (UTC)

Now i just reread the B+G paper - and am i correct in stating that the hypothesised return should have happened around 3-4 years ago - according to the hypothesis? If so - then the "prediction" has actually already been falsified by current data. --Kim D. Petersen 01:20, 31 January 2007 (UTC)

Kim, to answer your question, you are incorrect. The study was performed in 2001 or very early 2002 and changes in the climate regime was expected "about" four years later (late 2005 or early 2006). 2005 was a warm year and 2006 was significantly cooler than expected since it was an El Nino year. RonCram 00:32, 3 February 2007 (UTC)

RonCram, but unfortunatly for that argument, the observations are about subsurface temperature anomalies in the tropical Pacific, which is according to the hypothesis correlated with air temperature by a lag of 7 years. At the time of publication it was around 7 years since the subsurface tropical pacific temp started to fall - so the effect should have been noticeable around 3-4 years ago - as i said - it is not the publication date that sets the timeline - but the observation. --Kim D. Petersen 02:54, 6 February 2007 (UTC)

I'm not sure how you determine their timescales. But since the "main point" was removed, I've taken out the entry again, as its obviously pointless William M. Connolley 09:44, 31 January 2007 (UTC)

William, I am restoring it. The point is that "subsequent to the TAR" research has been done that concluded "that the human forced portion of global warming may be less than previously described." There is no way you can claim this is pointless as it goes to the very heart of the debate. As I stated before, I think we need to bring in some outside editors to help resolve this conflict. RonCram 23:26, 31 January 2007 (UTC)

RC, your shifting of ground is amazing! A direct quote from you is The main point is that the IPCC's climate models do not consider an important theory of climate shifts just above. Now that this bit has been removed, you have changed your "main point" yet again (previous shifts, you'll recall, include the "prediction" that wasn't). The entry remains non-notable; removed William M. Connolley 10:03, 1 February 2007 (UTC)

William, IMHO the ground is not shifting. I may not have expressed myself well in the earlier post, but my position is unchanged. The main point stated as: "IPCC do not consider the Giese study" is pretty much the other side of the coin of the point just above: "Giese disagrees with the IPCC." I am not sure why you do not see those two as related. They are two sides of the same coin. I am restoring the entry.RonCram 00:02, 3 February 2007 (UTC)

RC wrote: main point is that the IPCC's climate models do not consider an important theory of climate shifts (the sentence doesn't really make sense from a modelling viewpoint but no matter). TO state that your position is unchanged is nonsense. I think you have *now* finally come to your true "main point": you want someone disagreeing with the IPCC. But just disagreeing with IPCC is not enough to make this notable (unless you are asserting that there are so few paper disagreeing that one that does is automatically notable? Its a possible viewpoint, but not one I'd expect from you) William M. Connolley 16:35, 3 February 2007 (UTC)

I'm not a science scholar, but just wanted to add my opinion as someone who came to this article looking to understand the causes to climate change. I wanted to add my support to the B+G section staying. Even if it isn't notable on its own, I think it's important to have opposition opinions (or a criticism) section in an article like this. --Bill.matthews 17:16, 3 February 2007 (UTC)

Bill, thanks for your input. William, it is notable because the observations B+G made caused them to make a prediction of a climate shift to pre-1976 conditions (a cooling period even though we had rising CO2). B+G stated there would be a four year lag from the observations to lower surface temperatures. All of this has proven out. The oceans started cooling in 2003 resulting in lower than expected temperatures in 2006. The standard argument for any pro-AGW person is that "any" evidence that contradicts the IPCC is not notable. Such an argument is intellectually bankrupt. The IPCC has dramatically toned down their catastrophic warnings about AGW (see the analysis of Lord Monckton below) showing they were way off base to begin with. RonCram 17:44, 3 February 2007 (UTC)

Now we're going round in circles: now you've shifted gorund yet again to it being the prediction thats notable. Your text used to have "prediction" in it, but was removed by me and by Vsmith who both can't see any prediction there. If you think there is a prediction, and its part of its importance, then the text you add needs to have that in. Now you're back at "4 year lag" having previously admitted to "about"; we also don't even know what its "about 4 year" *from* - please do point to the date in the paper that you expect (about/exactly) a 4 year lag from. Without this, how can any "prediction" be evaluated? Bill - the text at the start of this section reads Some important results include: - if you think B+G is worth having but not notable, you need to revise that text. For my part, I'd rather have it only list important things. As to Mocktons anaylsis - its trash. IPCC hasn't toned itself down - Monckton has simply got his figures wrong. But I don't suppose you bothered to check them, you just took him on trust? William M. Connolley 20:15, 3 February 2007 (UTC)

Monckton's analysis of 4AR

Lord Monckton has a very readable analysis. Here are some excerpts:

FIGURES in the final draft of the UN’s fourth five-year report on climate change show that the previous report, in 2001, had overestimated the human influence on the climate since the Industrial Revolution by at least one-third.

Also, the UN, in its 2007 report, has more than halved its high-end best estimate of the rise in sea level by 2100 from 3 feet to just 17 inches. It suggests that the rate of sea-level rise is up from 2mm/yr to 3mm/year – no more than one foot in a century.

UN scientists faced several problems their computer models had not predicted. Globally, temperature is not rising at all, and sea level is not rising anything like as fast as had been forecast. Concentrations of methane in the air are actually falling.

The Summary for Policymakers was issued February 2, 2007, but the report on which the Summary is based will not be published until May. This strange separation of the publication dates has raised in some minds the possibility that the Summary (written by political representatives of governments) will be taken as a basis for altering the science chapters (written by scientists, and supposedly finalized and closed in December 2006).

The draft of the science chapters, now being circulated to governments for last-minute comments, reveals that the tendency of computers to over-predict rises in temperature and sea level has forced a major rethink.

The report’s generally more cautiously-expressed projections confirm scientists’ warnings that the UN’s heavy reliance on computer models had exaggerated the temperature effect of greenhouse-gas emissions.

You can read the full report here. RonCram 01:00, 3 February 2007 (UTC)

Why would you want to? Better read William M. Connolley 19:10, 3 February 2007 (UTC)

IPCC assessment

I'd like to avoid using the term "consensus" in contexts that imply that all scientists agree or that "the science is settled" - as this is the position advocated by Kyoto Protocol supporters in the global warming controversy, a proposition which I believe Misplaced Pages should not take a stand on.

So I propose using phrases like "IPCC assessment of the latest scientific research". This wording is, I believe, neutral. It does not say that there is (or is not) a consensus. It doesn't even say whether the IPCC's assessment is correct. The reader can visit the IPCC article to determine in his own mind whether he should accept their report as authoritative. Just about everyone does, I guess. But I want that to be something we leave up to the reader, instead of telling them that they must believe what that intergovermental panel says. --Uncle Ed 13:03, 18 February 2007 (UTC)

This has been brought up before. The problem is that the consensus goes much beyond the IPCC, with essentially all major scientific organizations (e.g. the G8 Science Academies, the AGU, the AAAS, the AMetS...) having issued explicit statements supporting it. Consensus does not imply unanimity. --Stephan Schulz 13:08, 18 February 2007 (UTC)

Indeed. People are free to disagree, or to otherwise conclude that the consensus view is in error, but it would be heavily POV to try to conceal that there is such a consensus. There is a majority view, and then there are some significant minority views, and the article should reflect that. Mishlai 17:02, 18 February 2007 (UTC)

This is a very useful clarification! I'm getting from this discussion, the idea that "consensus" can mean anything between "majority" and "unanimity". Perhaps I had misconstrued the term in the past, thinking it implied a commitment by the minority to support the majority (as in consensus decision-making). Come to think about it, this "objection to the word consensus" might be a partisan view of the anti-AGW side.

In that case, it might be better discussed at talk:Global warming controversy, as in "proportion of scientists agreeing with AGW". --Uncle Ed 11:22, 19 February 2007 (UTC)

Or we could use the normal term for it, which is scientific consensus. Mishlai 17:44, 19 February 2007 (UTC)

Sorry to disturb but :

Search for "recent", "recently" in Misplaced Pages the recent encyclopedia lead to this page amongst others.

Shall the recent climate change still be "recent" when it gets its climax and Misplaced Pages begins to melt too ?

I agree that the most common term used in the recent world is similar to the title of this article. But it shall have to change one day. -- DLL 21:07, 2 March 2007 (UTC)

On a geologic time scale.

I am afraid "recent" will continue to describe the time period since the Little Ice Age until the next one. —The preceding unsigned comment was added by RonCram (talk • contribs) 21:10, 2 March 2007 (UTC).

New Evidence on Channel 4 (UK) March 2007?

Have there been any responses to the claims made by the contributers to 'The Great Global Warming Swindle' on Channel 4, UK, on the 9th of March 2007? Such as that temperature change has always led carbon change by a gap of 800 years? This would make it impossible for Carbon to be causing temperature changes. Another point made was that CO2 makes up 0.54% of the atmosphere and that human CO2 emissions are 6 gigatons per annum of that, whilst animals and plants create 130 gigatons and still more is produced by either volcanoes or the ocean than human activity. I really think that a lot of people will turn to Misplaced Pages for answers to these sorts of questions, but it was difficult to see them clearly laid out in this article.--82.43.176.137 16:24, 9 March 2007 (UTC)

The problem is that nothing in that article makes any sense. Wiki climate articles don't spend much time on non-science. The T-CO2 lag is covered at http://www.realclimate.org/index.php/archives/2004/12/co2-in-ice-cores/ if you want William M. Connolley 17:11, 9 March 2007 (UTC)

ty, I had a lot of strong reactions from people both where I agreed or disagreed with GW, so any help is much appreciated.--82.43.176.137 18:37, 9 March 2007 (UTC)

There is now a section on the 800 year ice core lag thing (which I did think was one of the programme's stronger arguments). The argument about CO2 only being 0.54% of the atmosphere was just meaningless. Who cares? Plutonium makes up a very small part of the mass of the Earth, but that doesn't mean we want any more of it, as it is lethal at the level of microgrammes. The absolute amount of CO2 is completely irrelevant, what matters is the effect that _increasing_ the level of CO2 has. To be honest it reduced my respect for the programme that it used arguments such as these (which are obviously fallacious). Subsequent research into the producer of the programme, and Wunsch's very public complaint about how they used his interview, have reinforced this. --Merlinme 10:49, 14 March 2007 (UTC)

I agree that there was a lot of information presented in the Channel 4 programme that is not mainstream knowledge and should have representation in wikipedia articles so as to present a balanced view. I couldn't find information anywhere in wikipedia on the % of CO2 attributable to human activities (directly or indirectly) so that kind of thing should be added somewhere.... Think Merlinme has made a good start by putting in the section on ice core stuff. Will henderson 14:47, 15 March 2007 (UTC)

Hey, that was my section, though rewrote it :-). As to CO2: the answer is about 200%; in that only 1/2 the human-emitted CO2 stays in the atmosphere. Its Carbon_dioxide#Atmospheric_concentration there William M. Connolley 15:08, 15 March 2007 (UTC)

B+G

I dont see where B+G say "Bratcher and Giese claim the Earth was in a cooling trend from 1942 to 1975 and then saw warmer temperatures from 1976 through 2002." I don't think there is such a trend. B+G say "A similar situation existed in the early 1940’s when SST records show an equatorial Pacific cooling with the period from 1942–1976 generally cooler than the period following the 1976 climate shift ." If you want them to say 42-76 (why do you say 75?) was cooler than 76 on then I'm happy with that, obviously. But if you want them to say a *global* cooling trend from 42-75/6 please quote them here William M. Connolley 22:44, 9 March 2007 (UTC)

William, throughout the article (starting in paragraph 1) B&G talk about the warming trend that began in 1976. They also predict a return to pre-1976 conditions which they describe as "cooler." I understand pre-1976 as 1975. If you think the statement should read "from 1942 to 1976," I'm okay with that. Regarding the issue of whether this is global, that is the topic of the article. Here is one example: "Given the considerable effect that tropical Pacific SST has on global atmospheric circulation, a climate shift to pre-1976 conditions could lessen the warming trend that has existed since 1976." They also write: "However the results do indicate that the human forced portion of global warming may be less than previously described." Also, "The purpose of this paper is to bring attention to the similar, but opposite in sign, pattern as that seen prior to the 1976 climate shift and emphasize the importance of understanding the separation between natural variability and anthropogenic forcing in the climate system." The "similar, but opposite in sign" climate shift could only refer to cooling. Notice the trend from 1940s to 1970s in this temperature chart that GISS published in 1999. There really is not much point in trying to argue against a cooling trend if that is your goal. RonCram 23:21, 9 March 2007 (UTC)

On the contrary, I do indeed argue against 1942-1975/6 being a cooling trend. I would see it as a small peak around 194x, followed by a plateau. However the results do indicate that the human forced portion of global warming may be less than previously described - this is fair enough, and supports your (other) point. But the "pattern" stuff: no. They don't say cooling trend; and you're having to torture their words to get it out. Try replacing it with something they did actually say William M. Connolley 23:40, 9 March 2007 (UTC)

William, I am not torturing their words. They discussed the warming trend that started in 1976. They indicate a similar climate shift is happening in 2002 but with the opposite sign. That can only mean the beginning of a cooling trend. Your argument for a plateau is not in accord with the B&G. Neither is it in accord with the temperature record in which the 1930s were as warm or warmer than the 1990s (if you consider the temperature record prior to the unwarranted adjustments that were made in 2001 in time for the TAR). Did you even look at the temperature chart I linked to? If you insist on using the unreliable temperature records that are currently in vogue, the trend is still visible. This website will provide you with annual U.S. temperatures for the years being discussed. RonCram 00:33, 10 March 2007 (UTC)

Why did you link to the *US* dta rather than the global? But the point is not to argue about the interpretation of 1940-70 here: clearly we disagree. The point is, what do B+G say, since we're reporting on them. And the answer is, they say nothing of a cooling trend from 42-75/6. Don't put words in their mouths William M. Connolley 08:44, 10 March 2007 (UTC)

'Myths of attribution'

This heading (and hence possibly this section) is clearly POV. I have marked it as such. Ben Finn 23:44, 12 March 2007 (UTC)

Errrmmm... so what do you suggest? William M. Connolley 09:48, 13 March 2007 (UTC)

I've renamed the section "Arguments which dispute attribution to CO2", and discussed the argument in more detail. I think it's worth exploring at length, because I can understand why it can be a persuasive argument, and we need to understand it if we are to understand why it is fallacious. Given that I now think the argument is reasonably presented, I've also removed the POV tag. Merlinme 10:03, 14 March 2007 (UTC)

Strong objections to 'Arguments which dispute attribution to CO₂' section

This section is completely POV. It makes a bunch of unsubstantiated "rebuttals" with the only source being (IMHO very bias) realclimate.org, which in turn links to a single source. This section needs to be vastly improved and IMHO I think a separate article should be created that discusses the lag. In the following I'll provide a list of what I think is wrong with this section:

The main error with this argument is that it ignores whether increased CO2 levels should cause increased global temperatures, and in fact, no-one seriously disputes this (although they may dispute the level of climate sensitivity to CO2). Although other factors must have been at work in starting the period of global warming identified in these ice cores, therefore, the CO2 would have increased its effects.

• I'm not so sure about this claim that no-one seriously disputes more CO2 in the atmosphere leads to an increase in global temperature. Where is the evidence to back this up (that no-one seriously believes this)? And I don't think that it is being ignored, I believe that what is being said is that we aren't even sure how an increase in CO2 affects temperature.

Pretty well everyone agrees CO2=warming (including Lindzen, Michaels, etc); the only dispute is how much (as it says) William M. Connolley 22:32, 18 March 2007 (UTC)

From studying all the available data (not just ice cores), the probable sequence of events at a termination goes something like this. Some (currently unknown) process causes Antarctica and the surrounding ocean to warm. This process also causes CO2 to start rising, about 800 years later. Then CO2 further warms the whole planet, because of its heat-trapping properties. This leads to even further CO2 release. So CO2 during ice ages should be thought of as a "feedback" . (emphasis mine)

• Before quoting realclimate.org, the argument was made that Although other factors must have been at work in starting the period of global warming identified in these ice cores, therefore, the CO2 would have increased its effects. However, even the realclimate.org article says that this is only probable.

Probable only refers to the starting bit. The CO2 feedback is... basic physics William M. Connolley 22:32, 18 March 2007 (UTC)

• I would like to further dispute this argument since taking a look at this graph one can see that in fact temperature starts to drop before CO2 starts dropping. How can you attribute temperature rise to "feedback" when temperature starts falling before CO2 does?

Its not terribly clear to me from that graph; but even granting you the assertion, its the same thing in reverse: falling T lowers CO2 then we're into the same feedback cycle as before. Whats new? William M. Connolley 22:32, 18 March 2007 (UTC)

The other error with this argument is that it ignores what is widely believed to be the cause of recently observed warming (that is, warming since about 1960), which is increased CO2 levels. Models which give a significant amount of weight to increased CO2 levels when attempting to explain recent temperature rises match the observed data far better than those which do not. It is from this (and other observations) that the IPCC concluded that humans (because of CO2 emissions) were 90% likely to be the cause of the recently observed warming. (emphasis mine)

• My question is, how can we conclude that it is in fact CO2 that is causing the latest increase in temperature if what we know about the past doesn't agree with this assessment?

Nothing we know about the past disagrees with this assessemnt William M. Connolley 22:32, 18 March 2007 (UTC)

• Hmm the models give a significant amount of weight to the CO2 increase? Why? Shouldn't they be considering every other source? It says that models that did were able to predict better, where is the source for this claim? What else did the models consider? More information is needed for such a claim.

Models have all the known sources put into them. People don't just say "we'll assume CO2 causes X warming and put that into the models..." the models contains the best physics they can, for CO2; and for solar William M. Connolley 22:32, 18 March 2007 (UTC)

To put it another way, while there must have been another cause than CO2 for the initial global warming at the times in history indicated in the ice core record, it does not follow from this that there is such a cause now. In fact there is strong evidence that CO2 is the cause now.

• Huh? How did this get concluded? There was a probable sequence of events and now you get such a strong conclusion? Huh?

What its trying to say is that the entire argument is a non-sequitor William M. Connolley 22:32, 18 March 2007 (UTC)

Anyways, here is more information. Codingmonkey 23:21, 16 March 2007 (UTC)

Very nice, I'm sure. In return, you may have William M. Connolley 22:32, 18 March 2007 (UTC)http://www.copernicus.org/EGU/cp/cpd/3/435/cpd-3-435.pdf

Unknown Process

Having read through the (current) final section of this article something struck me about the line:

"Some (currently unknown) process causes Antarctica and the surrounding ocean to warm. This process also causes CO2 to start rising, about 800 years later. Then CO2 further warms the whole planet, because of its heat-trapping properties."

If the initial 'unknown' process started the periods of global warming how do we know that it didnt cause all the warming and the CO2 had no real effect ? If the source is unknown then it could be a short or long term driver of climate and could be relatively strong or weak compared to other factors since it is 'unknown' and its characteristics are not understood. Just a thought.... 194.6.79.200 21:33, 18 March 2007 (UTC)

For one, because the events are (as far as is known) triggered by orbital variations which provide too small a forcing. For two, because in the process CO2 is released, which causes yet more radiative forcing. Unless you have some magic reason for believing that CO2 to have no radiative effect, its natural to suppose it does have one. William M. Connolley 22:16, 18 March 2007 (UTC)

And what was the magic reason that stopped the CO2 radiative effect? It is natural to suppose that something has stopped it. Ccwelt 21:09, 21 March 2007 (UTC)

No, its more likely that there is some reservoir that gets exhausted. However, no-one really knows why CO2 peaks out at 280 in interglacials - a Nobel prize awaits you! William M. Connolley 21:34, 21 March 2007 (UTC)

So let me get this straight, you don't know what caused the temperature to rise in the first place, you think/believe (=don't know) that the CO2 reservoir got exhausted which lead to stopping the temperature increase. But once the CO2 peaked out, something had to have a cooling effect? And I guess you don't know what the cooling effect was.

For me the more rational explanation would be that CO2 is driven by temperature and that something else is driving temperature. This ] simply seems much more plausible than something that nobody understands and that could earn me a Noble prize if I understand it - because I would be the first person to understand it. Ccwelt 12:02, 22 March 2007 (UTC)

You can think what you like. The current CO2 is definitely *not* driven by temperature - we know its human caused. Try to keep the ice age and now situations separate, because they are, as far as anyone can tell.

How nice of you to allow me to think what I like. I do not dispute that the level of CO2 is rising, but the fact I hear all the time is that in historic scale, CO2 drives temperature. Can I take it from your annoyed factless answer that indeed CO2 has not been driving temperatures in historic times? A simple "Yes" would be enough. Of course, you can say "No" if you like (you have the same liberty as I to think what you like), but I would like to hear some facts, please. Ccwelt 20:04, 28 March 2007 (UTC)

I cut out:

It is argued that another influence are the changes in the solar wind and the Sun's magnetic flux. These changes are causing an increased solar wind and stronger magnetic field, which lead to an decrease of the cosmic rays striking the Earth's atmosphere. As cosmic rays affect formation of clouds and clouds are responsible for a considerable amount of the Earth's albedo, the solar wind could have a major influence on Earth's climate. See: Solar variation

Firstly because its badly broken - it doesn't distinguish any kind of time scales; it asserts that CR *do* affect clouds when this is only speculation at the moment; etc. But more than that... this is already done higher up the page, considerably better. This is an unfortunate consequence of the name-change of this section :-( William M. Connolley 12:28, 22 March 2007 (UTC)

Arguments which dispute- solar system warming

I thought we were a bit hasty to delete in full the following which had been added in the "Arguments which dispute" section:

"Climate change elsewhere in the solar system In recent years warming has been observed on Mars , Jupiter , Pluto , and Neptune's largest moon Triton . This points to a solar explanation for the recent warming on Earth."

It is an argument which disputes, so surely it would be better to discuss in full, rebutting where reasonable? In fact most of the articles linked to gave strong arguments why this wasn't thought to indicate a single solar irradiance cause (as opposed to e.g. changes in orbits, local climate changes, etc.)

The one I would take out would be Jupiter, where it was far from clear to me from the article linked to whether we were talking about global warming, or local warming caused by changes in Jupiter's atmosphere. --Merlinme 13:17, 19 March 2007 (UTC)

Maybe. It was more or less reflexive on my behalf, as I've seen this 15 times and over refuted crapmisinformation introduced over and over again in the various articles. --Stephan Schulz 13:33, 19 March 2007 (UTC)

This can go in, as long as its clear that the evidence is against this having anything to do with Earth GW. As the plotu folk say: Jay Pasachoff, an astronomy professor at Williams College, said that Pluto's global warming was "likely not connected with that of the Earth. The major way they could be connected is if the warming was caused by a large increase in sunlight. But the solar constant--the amount of sunlight received each second--is carefully monitored by spacecraft, and we know the sun's output is much too steady to be changing the temperature of Pluto.". Ditto Neptune. In fact, when you look around there is *no* evidence for solar-caused warming on any planet William M. Connolley 13:36, 19 March 2007 (UTC)

Also, of course, the evidence for "global" warming is very scant in most of these cases. --Stephan Schulz 14:10, 19 March 2007 (UTC)

New version seems fair enough. Note, BTW, that as far as I know there are no actual temperature measurements involved (there are ?some? on Mars but even there the ice caps seem to be the main evidence). Pluto for example is done by some ?reliable? measures of the atmospheric density William M. Connolley 14:26, 19 March 2007 (UTC)

I don't know about any direct measurements, even on Mars. Pluto's "global temperature" is derived from three occultation events in 1988, 2002 and 2006. There should probably also be a note that we know about the existance of Triton for about one (1) Neptunian year, and about the existance of Pluto for about 1/3rd Plutonian year. --Stephan Schulz 15:06, 19 March 2007 (UTC)

All the planets seem to be getting warmer - there seems to be a reason given why each one is not due to more heat from the sun ( isn't it strange that they are all getting hotter at the samr time - well coordinated dust storms, and human activity and just the right tilt, the planets must all have a good communications director). Are there any planet/s that are getting cooler?159.105.80.141 19:09, 8 May 2007 (UTC)

One might assume that all the planet should be warming if solar output was increasing (or cooling less than what would be expected given natural variations), but I don't think this is being observed. So far, the only warming I've seen argued to be connected with Earth's is Neptune's. ~ UBeR 19:51, 8 May 2007 (UTC)

Ice cores changes

On the whole I like the changes, although they perhaps make it a little heavy-going for your average lay person. However, I'm not sure about the "death spiral" bit. I thought there were processes which are believed to have eventually reduced CO2 levels because of changed atmospheric properties, e.g. rock weathering. Do the changes really help explain the ice core argument? --Merlinme 16:43, 20 March 2007 (UTC)

Death spiral is no good. And of course the feedback does work in reverse, or at least its no great surprise if it does William M. Connolley 16:57, 20 March 2007 (UTC)

Numbers

It is weak page.

If you want to attribute something you should also put out the numbers as to the percentage of the change that is attributed to that cause.

Doesn't the graph give the necessary information? Apart from anything else, I imagine it depends which model you use. Given that this is one of the most heavily disputed areas, I'm not entirely sure what numbers you are looking for. It seems pointless to me, to be very precise about things which have a large level of uncertainty. --Merlinme 17:52, 21 March 2007 (UTC)

There is an awful lot of technical details in the TAR if you feel like reading it William M. Connolley 19:57, 21 March 2007 (UTC)

The ice core bit - Dwc

Dwc144 added . I regard this as dubious:

This account of a self-reinforcing dynamic primarily involving temperature and CO₂ concentrations does carry with it an increased burden of explaining the abrupt cessation of global warming during all prior prehistoric episodes.

Why? No other explanation is asked to explain itself. The T-causes-CO2 doesn't explain the changes at all - not why they start, how big they are or why they stop.

This is not the place for a detailed explanation of glacial-interglacial CO2 changes: that would belong on ice age I guess William M. Connolley 20:24, 22 March 2007 (UTC)

DWC144's reply: cf. Paillard, 2001, "Glacial Cycles", Reviews of Geophysics, 39, 3 / August 2001: "The classical Milankovitch theory needs to be revised to account both for the traditional peculiarities of the records, like the 100-kyr cyclicity and the stage 11 problem, and for the recent observational evidence of abrupt climatic changes, in association with the main terminations." (Emphasis added) Paillard uses the term "abrupt" or derivatives more than 25 times in this piece, and for good reason. The Vostok data shows transient peaks, which still need to be explained, particularly the implied sudden reversals off the tops, if the data is as straightforward as it seems. Intuitively, conjoint, positive feedback dynamics (e.g. T-->CO2-->T-->CO2-->T etc. posited as the comeback in this section) add to the momentum of systems. It is not that this makes it impossible to explain the previous reversals off the tops, but let us agree that the mutual positive feedback thesis does make proving up an explanation (Heinrich events??) more urgent, and perhaps more complex. In the interim, this combination does properly add slightly to the case for doubt. (That is, along the lines of pondering what would be the slope of those curves during the next millenium even in the hypothetical absence of anthropogenic global warming--which of course is to be taken for granted. Can we really rule out a relatively steep slope--one way or the other--in that hypothetical absence, given the demonstrated potential for nonlinear dynamics in the system? Even in the top horizontal band on the chart, where we currently find our planet?) I'd have rather given a brief nod to this question, and I also see no problem with identifying the boundaries of current knowledge in the Misplaced Pages. In response to your other comment, the section appears already to be addressing "glacial-interglacial" CO2 changes; perhaps it is bound to, because of the prominence given to the ice-core data by Gore's film, and the potential relevance of the longer term context for appraising modern developments. The record of edits shows that I tried several times to inject an element of the forgoing in the piece--I would have been happy with even a sentence--but I will concede now that my colleagues here are unprepared to build on this. I'll leave it to you to determine the rightful bounds of proper discussion in the article, but I would appreciate it if you could at least leave these comments here, on the discussion page.

—The preceding unsigned comment was added by 74.99.153.7 (talk • contribs) 02:39, 28 March 2007.

Of course we'll leave your comments on the talk page. As both WMC and I have said in our comments and on this talk page, it's not the information you're adding per se we're objecting to, it's where you're adding it. I simply don't see why the "abrupt changes" are relevant to an argument about temperature leading CO₂. WMC suggested that you add the information e.g. in the article on ice ages. You may be able to find a better place for it. If you can find a source which uses it as an argument against anthropocentric global warming caused by CO₂, perhaps it could even be given its own section. But I don't see it as relevant to the "Warming sometimes leads CO2 increases" section. --Merlinme 09:08, 28 March 2007 (UTC)

The relevance is to the response given in the section (positive feedback), and specifically a clear complication the thesis entails. If not for the temperature-leading observations and abruptness in the ice core data, and the recourse to a positive feedback explanation, we'd have a much simpler presumed dynamic through geological history (e.g. orbital forcing --> T and/or CO2 -->T), which would present much less background noise to disentangle from modern anthropogenic contributions. Now we have an inherently unbounded feedback loop, offered in the section, combined with data showing abrupt reversals at the tops of peaks that have generally been transient in the past. Not only that, but we are currently situated in line with the peak temperatures on the chart. From a modelling perspective, even conceptually, this is not a happy situation. Parsimony is a core value of scientific endeavor; see Occam's razor. And I would add that when the data take us far beyond parisimony we need to provide a little alert to the effect that "we now departing from the world of parsimonious explanation; we've gotta do this, but we gotta acknowledge now that this makes our answers more tentative." Positive feedback may not be wrong, and it is probably the most reasonable account, but it is not parsimonious in the broader context of this data. Let's be honest. Even Gore was willing to say that the ice core data is "complex." The difference between a scientist and a hack is in the willingness to be open about the difficulties presented by his/her own explanations. Do we aspire to be scientists or hacks here? —The preceding unsigned comment was added by Dwc144 (talk • contribs) 14:09, 28 March 2007 (UTC).

Well no. For a start, we have the obs record, which clearly isn't compatible with a orbital linear forcing assumption. And then we have the fact that the orbital forcing is too small. Please don't confuse things with D-O events. This section is about why the CO2/T lags leads shown in the ice cores don't impact modern attribution studies, from a scientific point of view - please try and hang on to that (or, alternatively, please try to find a single paper asserting it) William M. Connolley 14:17, 28 March 2007 (UTC)

Thanks for your comments. If you don't like the Paillard, I'll find another paper when I have a chance (not this week). A reasonable suggestion. Note that I did not suggest orbital forcing alone, above. And incidentally, I'd prefer to rephrase one of your comments and suggest instead that "This section is about evaluating the extent to which the ice core data, particularly the CO2/T lags/leads in conjunction with the transients and abrupt terminations of that data, complicate or do not complicate modern attribution studies, from a scientific point of view." However, on the Misplaced Pages it seems that the one with the less expansive concept has a natural advantage, for it is easier and more defensible to hit the delete key than to add.Dwc144 15:03, 28 March 2007 (UTC)

I'm really sorry, but I find your writing style very unclear sometimes. As far as I can understand it, you seem to be saying that abrupt reversals in temperature when CO₂ levels were very high, argue against the normal understanding that CO₂ causes warming. Please correct me if I'm wrong. If this is a true observation (and I have no idea, not being a climate scientist myself), then it is interesting, and certainly I think it is fair to say that there are questions which need answering about why greenhouse warming in the past was eventually reversed. As I understand it the normal explanation is that when CO₂ levels get very high, ocean acidity increases and calcium carbonate gets dissolved, increasing the ocean's capacity to absorb CO₂. In the long term, chemical weathering of silicate rocks then permanently removes CO₂ from the atmosphere. This was the best link I could find on it, about the Paleocene-Eocene Thermal Maximum (PETM):

Anyway, there may well be a place for a discussion of all this on Misplaced Pages, and a place for your arguments (assuming they are sourced and not Original Research). However, the argument being described in this section is specifically about CO₂ leading temperature change in the ice core record; it says absolutely nothing about abrupt changes in the ice core dataset. If you want to talk about that argument (or whatever your argument is, apologies if I've misunderstood), you are in the wrong section; you can't simply rewrite a completely different argument so it allows you to make your point. Either find a more appropriate section for it, or create a new section (assuming you can find a source). --Merlinme 17:30, 28 March 2007 (UTC)

Let me try to be even clearer, and I do appreciate your bearing with me. Here is a collection of a few key points, including current ones from the ice core bit, that could be registered in a section on this page. (a) The ice core data does not present a reason to discount the impact of anthropogenic CO2 on the climate, but simply a reason to believe that T and CO2 often work in tandem; (b) The abrupt reversals in that data during the past 500 k years suggest that knock-on effects or events (e.g. loss of ice cover, disruptions to ocean currents??) are likely also at work at least from time to time; (c) Given that the planet is currently in a temperature range in which such reversals have previously occurred, it is conceivable that it is currently subject to the effects of such intermittent feedbacks; (d) These feedbacks, and the rudimentary state of our knowledge about them, increase the level of difficulty involved in global climate modelling; (e) Most critically, these complications limit the ‘’precision’’ with which causation can be attributed within those models. For example, while we can likely state “mostly anthropogenic causes” with confidence, we likely cannot yet state 51% or 74% or 84.5%. (f) More research is required to understand better the feedback effects (not before acting, but just because). This line of thought is not original, but it can be referenced to very mainstream sources (e.g. the IPCC, in large part, I'm thinking). It is also squarely about the question of the page, attributing modern climate change. What’s the motivation? I think it is useful to highlight the longer term potential for disastrous, naturally caused/aggravated climatic change, because the question of how to mitigate those risks is even broader than the question of how to minimize the human footprint on the climate. (Notwithstanding that, we clearly start by simply minimizing that footprint now.)

--Dwc144 20:02, 28 March 2007 (UTC)

Well no: Given that the planet is currently in a CO2 and temperature range in which such reversals have previously occurred is wrong: the planet hasn't been in this CO2 range for 10's of millions of years, and we have no good T or CO2 records back that far. If you want to rephrase that bit, we can go on to the rest... William M. Connolley 23:13, 28 March 2007 (UTC)

Okay... I was looking at this graph: , the actual ice-core data under discussion. But I take your point that this excludes the directly measured, recent data (the bit that Gore used the Sky-Jack for in his film). Anyway, that point is moot for my argument; correction made.

--Dwc144 01:02, 29 March 2007 (UTC)

Image:Carbon Dioxide 400kyr.png is the one you want, as you've realised. Now I don't know what you mean by "abrupt reversals". Within the ice core context that usually means D-O events but you're not seeing them in that record, you're seeing events that look abrupt but only because of the timescale that they are being plotted on. But point (e) is simply wrong: the ice age stuff has no impact on attribution of present day warming (or being tediously precise has next to no impact) William M. Connolley 07:53, 29 March 2007 (UTC)

Fair warning about the scale, so help me understand this. Let's take the transient peak during the interglacial at 240k years as a numerical example. I don't have the raw data, so this will be a crude, back of the envelope. Let's say that the slope (dT/dt) during the preceding warming period was 8 degrees C / 4000 years, or 0.2 degrees C/100 years. Then, let's take the first part of the cooling, during which dT/dt is, say, -2 degrees C / 1000 years, hence -0.2 degrees C / 100 years. Furthermore, let's say that the change from the warming to the cooling mode occurred during 500 years. That implies an average rate of change in dT/dt of -0.4 degrees C per 500 years, and perhaps a peak rate of twice that at a century resolution. With even higher resolution data (e.g. decadal), though this will remain total speculation, one might expect to find multiple-higher rates of change, assuming that shorter term transient feedbacks are superimposed on this "background" signal. I don't know what you get to, but is the established view that first and second degree noise of this order of magnitude is still insignificant compared to the rates of climate change ("signal strength") being seen in modern GW? Also, don't we need to invoke factors other than solar insolation to understand these abrupt changes, particularly since we're working against the T-CO2 feedback loop? The insolation chart looks distinctly smoother assuming no artifacts from estimation. Hasn't the scientific interest in esoteric missing pieces (e.g. ocean current disruptions, ice cover, low level clouds, divine intervention--just kidding) been catalyzed somewhat by this general line of thinking out of paleoclimatology? Also, have observations such as these been sufficient in your view to induce some degree of caution in modern climate modellers as to the precision of their models?

--Dwc144 14:29, 29 March 2007 (UTC)

0.2/100y is considerably smaller than the current warming, by a factor of 3 at least. Yes, we do need to invoke other factors than solar - as you say, the solar is smooth. And (less obviously) the 100kyr cycle is very weak - so you need to invoke non-linear feedbacks in the ice sheets, etc etc, to understand a 100kyr cycle. I'm not saying that studying this is irrelevant - just that if you look at attribution of recent climate change you'll see its not very relevant. But it would be a good idea to read that (and the TAR) to see what *is* relevant William M. Connolley 14:39, 29 March 2007 (UTC)

After all that hot air on my part, you're seriously positing 0.2/100y (or, say, 0.1/50y) as a representative *very high* rate of change during, say, 50 year periods during previous interglacials? Wouldn't you expect there to be a hefty right tail (in the distribution of 50 years temperature changes) given the nonlinearities (perhaps acting at different timescales) you say are likely in there? And why do you suggest that the "ice age stuff" of prior peak interglacials, which scientists are still trying to conceive of and define, is necessarily a completely different bag of tricks to what's been going on during the past 500 years? (If because the GCMers get a great fit with just CO2 a little insolation, and a couple of readily available other series thrown in to be nice, isn't there a little wedge of concern about the extremely high degree of colinearity between CO2 and temperature in the broader 500 k year picture?) To be clear, my point is not to dispute AGW; it is rather to raise the question about the degree of precision that can be claimed for the models. And I won't reiterate the reasons, stated above, why I believe this matter of precision could usefully be reflected on the page. In any case, I'll let you have the last word on this and will take it upon myself to do some more (secondary!) research in my spare time, as you suggest.

--Dwc144 15:28, 29 March 2007 (UTC)

Don't let me give you the impression that I fully understand all this. I don't. No-one does. But if you're interested in the GCMs, this isn't the place to start. They don't run over these timescales anyway William M. Connolley 15:40, 29 March 2007 (UTC)

Section: Warming sometimes leads CO₂ increases

This entire section seems to be someones opinion and synthesis (ie. does the BAS hold this view? its the only source..). My questions here are:

• is there really such a dispute?
• who is disputing it?
• Is the dispute scientifical?
• why isn't there a large section in Global warming controversy about it if its a big controversy? (where it belongs if its real?)
• The size of this section (compared to the rest) seems to indicate that this is an important controversy or is it WP:Undue_weight?

--Kim D. Petersen 07:52, 28 March 2007 (UTC)

Errrm, so why the factual-accuracy tag? But to answer your Qs: this isn't a scientific dispute, its a septic talking point (see TGGWS). Its here because its an issue with attribution. This section was smaller; its grown perhaps too much William M. Connolley 08:31, 28 March 2007 (UTC)

The tag should probably be something else (i appologize) - i selected it because the POV flag defined the whole article (which i didn't intend). Change it to something more appropriate. The section does seem to indicate a dispute (by being in a section called "Arguments which dispute attribution to CO2" - since it doesn't and isn't scientific - shouldn't the section either be labelled something else ("common misunderstandigs"? *grin*) - i think i understand the purpose as being some kind of FAQ then? --Kim D. Petersen 08:46, 28 March 2007 (UTC)

Sorry my english deteriorates when i'm tired --Kim D. Petersen 08:48, 28 March 2007 (UTC)

Try looking back at the original . But - why this fad for tagging stuff nowadays? Whatever happened to just talking about things first? I prefer myths William M. Connolley 08:54, 28 March 2007 (UTC)

This section was created to handle the following: people look to Misplaced Pages for information about Global Warming; in particular they look to Misplaced Pages to understand arguments used for and against Global Warming; there are arguments used against Global Warming which are not particularly scientific, but they do exist and should be discussed; where they should they be discussed in Misplaced Pages? The original title of the section was something like "Myths of global warming", but this was felt to be rather a long way from NPOV, so it was given the title it currently has. If you have a good suggestion for how this should be handled differently, we will of course consider it, but I have to agree with WMC: this should be discussed on the talk page first. I'll remove the tag now. --Merlinme 09:01, 28 March 2007 (UTC)

Merlinme, i was tired and probably overreacted. Sorry. Myth is better than the current title (how about "common misconceptions"? --Kim D. Petersen 09:52, 28 March 2007 (UTC)

Sorry about tagging it (i agree with your sentiment). I'm probably a bit to tired to edit anything today. --Kim D. Petersen 09:52, 28 March 2007 (UTC)

Don't worry, its no problem William M. Connolley 10:09, 28 March 2007 (UTC)

Lets discuss the logic here. "By amplifying each other’s response, this “positive feedback” can turn a small initial perturbation into a large climate change. There is therefore no surprise that the temperature and CO2 rose in parallel, with the temperature initially in advance". Initial rise is one thing but the subsequent falls and rises also had the co2 lag. If the feedback had been of greater importance than the main driver then it would have begun to dominate which doesn't happen. Also since this is a time slice there is no initial rise. The fact is that very little can be concluded from the graph except that there is a correlation and that co2 lags temperature. Anything else is useless speculation. The whole argument is illogical and erroneous. I'd remove it but it would just be put back again. jg17JG17 10:02, 4 May 2007 (UTC)

Initial rise is one thing but the subsequent falls and rises also had the co2 lag - are you sure about this? As I understand it the lag is only really well established for deglaciation, and 800+/-600 is not too precise even there. very little can be concluded from the graph except that there is a correlation and that co2 lags temperature - two things. Firstly, as pointed out, people are attempting to conclude from the graph that CO2 can't be causing T rise. I'm glad to see you denying thats possible, but not everyone has realised it. Secondly, various scientists who have studied it *ahve* concluded various things from the graph: why should we prefer your interpretation to theirs? William M. Connolley 10:13, 4 May 2007 (UTC)

William: You assume "people are attempting to conclude from the graph that CO2 can't be causing T rise". I don't see that at all. To me it seems sceptics use the time lag as a rebuttal of the idea that CO2 caused temperature swings in the past when the reverse corrollory is equally plausible and indeed more likely. No one can seriously claim though that the past CO2-T relationship proves anything about current climate either pro or against AGW. Any attempt to do so by postulating that the CO2-T feedback is shown to be a driver in the past is surely accepting second or even third best interpretation of the graph and that the most logical conclusion if there is a CO2 lag - which everyone seems now to accept - is that the original driver of temperature in the past is more important than any CO2 feedback. I don't ask you to accept my point of view but I ask you to think about it yourself and conclude whether it is worthy of inclusion in Misplaced Pages or is it just more uncorroborated noise in the debate? Do you not feel that inclusion of this poorly thought-out theory makes even non-scientists strongly wonder about the thinking ability of the people who assert it and hence weakens their case? JG17 09:35, 5 May 2007 (UTC)

Sadly you are wrong: there really are people stupid enough to make this claim (see TGGWS) and people stupid enough to believe it. I could find you various comments from such people if required William M. Connolley 21:02, 5 May 2007 (UTC)

Are you saying that the flawed logic of the feedback argument is acceptable just to counter the flawed logic of the sceptics? Where does the truth stand in all of this? Too inconvenient? Maybe you should ask your colleagues how they explain the cooling periods with this feedback theory before it comes to court or before someone embarrasses them on CNN or Newsnight. Maybe the CO2 is sucked into a black hole at the end of the heating period thereby allowing the climate to start from scratch? JG17 09:57, 7 May 2007 (UTC)

The feedback argument isn't flawed. The argument isn't that it initiates change, only amplifies it. Hence it can explain cooling or warming, as long as they are triggered by something else William M. Connolley 10:12, 7 May 2007 (UTC)

It is flawed since if it worked there would be instances in the record where CO2 initiated warming. I mean one supposes that this feedback doctrine is at least possible. But you have no evidence for it so its misleading to be telling people that its a real effect.

In that case "positive feedbacks from CO2 concentrations amplify warming initially caused by other factors" should have "or cooling" inserted after "warming" and "temperature and CO2 rose in parallel" should be "rose and fell in parallel." In that case the idea of removing CO2 from the air as mooted on the IPCC website and encouraged by the Gore/Branson prize should be discouraged forthwith because the climate is clearly such a delicate system that if we remove too much CO2 we'll initiate a catastrophic ice age. But then you don't really believe that do you? Oh what a tangled web we weave.... JG17 16:07, 7 May 2007 (UTC)

Since the text mostly focusses on the lag where its best understood, ie deglaciations, ie T rise, the current text is probably OK. We'd need to remove an awful lot of CO2 from the air to get towards glacial type levels... certainly below 300 ppmv, and we're at 380+ and climbing William M. Connolley 20:29, 7 May 2007 (UTC)

Ah what the heck - throw it into the article. 90% certainty, given all the approximations etc in the theory, probably means more like maybe not for sure. When the Vikings were farming in Greenland did the CO2 precede or follow the icecap?159.105.80.141 19:13, 8 May 2007 (UTC)

Talk:Global_warming/FAQ#It_was_obviously_much_warmer_when_the_Norse_settled_Greenland--Stephan Schulz 19:29, 8 May 2007 (UTC)

Section: Natural Climate Variation and justification for inaction

Point to consider?

People often say that climate change is natural and use that as a counter argument to attempts at mitigation. However, I don't believe that argument in itself is a valid counter argument to undertaking mitigation. Even if climate change is mostly natural, it is still a situation that our civilisation needs to contend with. Of course one of the ways to deal with it is to reduce greenhouse gas emissions (the science behind that is not disputed at all as far as I'm aware - correct me if you have better information though). Simply saying that climate change is natural (even though it is not believed to be so) is not a counter argument against reducing greenhouse gas emission. I would almost go so far as to say that using the 'climate change is natural' argument is irrelevant to the entire debate.

I am sort of new to this so sorry if the format or section placing of this point is wrong. I wonder whether there is a case for putting a section like this into this article (or a more appropriate one? Open to suggestions). Anyway what do people think?... Gaz —The preceding unsigned comment was added by 129.242.31.43 (talk • contribs) 12:40, 14 May 2007.

The argument is as follows: If climate change is natural, then it is not caused by (anthropogenic) CO2 emissions and hence we do not need to reduce them. Mitigation using other means than reducing human interference with the climate system is a much less understood and potentially much more controversial topic. --Stephan Schulz 13:02, 14 May 2007 (UTC)

Climate models

The reference says:

"A climate model can be used to simulate the temperature changes that occur both from natural and anthropogenic causes. The simulations represented by the band in (a) were done with only natural forcings: solar variation and volcanic activity. Those encompassed by the band in (b) were done with anthropogenic forcings: greenhouse gases and an estimate of sulphate aerosols, and those encompassed by the band in (c) were done with both natural and anthropogenic forcings included. From (b), it can be seen that inclusion of anthropogenic forcings provides a plausible explanation for a substantial part of the observed temperature changes over the past century, but the best match with observations is obtained in (c) when both natural and anthropogenic factors are included. These results show that the forcings included are sufficient to explain the observed changes, but do not exclude the possibility that other forcings may also have contributed."

The article says:

"Climate models forced by natural factors and increased greenhouse gases and aerosols reproduce the observed global temperature changes; those forced by natural factors alone do not."

I changed this to "...reproduce the observed global temperature changes better than those forced by natural factors alone."

I thought this was a better summary of the reference, however WMC has reverted it. WMC knows the science much better than I do, and rereading the reference, the inference is that graph a) (with no GHG forcing) doesn't explain the observed changes. However, I still think Misplaced Pages's claim is too strong: to me, "reproduce the observed global temperature changes" suggests that there's a near perfect match, and that's surely not the case. How about: ""Climate models forced by natural factors and increased greenhouse gases and aerosols produce the best match to the observed global temperature changes; those forced by natural factors alone do not produce a good match."? --Merlinme 12:50, 7 June 2007 (UTC)

Sorry, I could have been a bit more polite here. Your last version is OK-ish; the briefer version you put in, to my mind, didn't downplay the nat-only match enough. How about "The observed patterns of warming, including greater warming over land than over the ocean, and their changes over time, are only simulated by models that include anthropogenic forcing" from the AR4 SPM? William M. Connolley 13:39, 7 June 2007 (UTC)

Sounds good to me. Presumably you'll need to change the reference as well. --Merlinme 13:45, 7 June 2007 (UTC)

"That Complicates"

Although others may disagree, I feel that in a section where problems with the CO2 theory are being listed, this choice of wording seems awfully biased, eg. by someone who is convinced by the CO2 theory and wants to hide the problems, or even "slip them under the rug", wanting those reading to ignore this section. I suggest that it is changed from "that complicates" to "that may contradict to", not any further though (eg. not to "disproves", for that is simply bias in the wrong direction). I know it may seem a subtle change, but to me "complicates isn't very neutral". TJ 16:28UTC 07/06/07

• note, I in fact agree with the CO2 theory, but feel that there should always be some form of proper Critisism page, not trying to convince people otherwise.

• I agree, I don't like "that complicates". It implies that the theory is still 100% true, just more complicated. I'm not sure what it should be changed to. "may contradict" or "may challenge"? --Bill.matthews 16:05, 7 June 2007 (UTC)

There have been various attempts to get a better wording for this. I'm not convinced by "that may contradict", as this implies they have significant weight, when very few (no?) scientists give them any weight at all. Previous efforts include "Myths of climate change attribution" and "Attempts to disagree with CO2 attribution" (or words to that effect). I think the current wording gets the balance reasonably well. --Merlinme 16:13, 7 June 2007 (UTC)

(ec) People often fall into the trap of thinking the issue is either-or. But it isn't. Nobody who knows anything about the science doubts that there are roles for both CO2 and natural variations. Results that show natural variations play a larger role than presently thought (even by a factor of 2 or 3) would not "contradict" the role of CO2. "Complicate" may not be be the best word, but it's more accurate than "contradict" or "challenge." Raymond Arritt 16:18, 7 June 2007 (UTC)

How about "Frequently asked questions" - thats really what this section is William M. Connolley 16:15, 7 June 2007 (UTC)

Yes, possibly something along the lines of Talk:Global warming/FAQ might work better. Then the countertheories could be phrased as questions and answered in a less tortuous way. --Merlinme 16:58, 7 June 2007 (UTC)

"contradicts basic results in physics"

This sentence: "However, a strictly "one-way" view of the relationship between CO2 and temperature contradicts basic results in physics, specifically the fact that the absorption and emission of infrared radiation by CO2 increases as its atmospheric concentration increases." is horrendously POV, OR, and absolutely cannot remain in the article without a source. It doesn't require a source for the greenhouse effect, but rather a source that a one-way view of CO2 causality "violates basic physics." Taking a position that some reputable scientists hold and saying it contradicts basic physics without a source is exactly the kind of statement Misplaced Pages can't make. Oren0 07:50, 11 June 2007 (UTC)

There are no reputable scientists who argue that increasing CO2 has no effect (name one) William M. Connolley 08:44, 11 June 2007 (UTC)

From what I recall from TGGWS, though I don't remember who said it (I could look it up later), the argument goes that CO2 only follows temperature on a global scale, and that the GHE is more of a local phenomenon. If nobody is making this one-way argument, why is this straw man here? Oren0 16:38, 11 June 2007 (UTC)

Any way to verify this? Saying that the greenhouse effect is a local phenomenon is just as nonsensical as saying the effect is one-way; it would be helpful to know which flavor of nonsense was being served. The "one-way" argument is, sadly, quite common in the popular press and has been mentioned by one or two self-styled experts, so it deserves to be mentioned here. Raymond Arritt 17:07, 11 June 2007 (UTC)

I'm pretty sure that TGGWS narrator said that CO2 strictly follows T, not the other way round. Its a stupid thing to say, and no sensible scientist would say it, of course. Oh, and since you've just asserted that reputable scientists say it, its hardly a strawman William M. Connolley 19:23, 11 June 2007 (UTC)

You're having it both ways. You're saying that no reasonable scientist holds this position, therefore it can be refuted without a source. But it isn't a strawman because some scientists do hold this view. Don't you see the contradiction? Either some reasonable scientist holds this view, in which case a source is needed to refute it, or no reasonable scientist holds this view, in which case it shouldn't be on the page. I honestly don't know what the answer is, but I've read it enough places to be inclined towards the former. Oren0 01:50, 12 June 2007 (UTC)

The answer is "some unreasonable scientists hold this view." The fact that it's unquestionably contradictory to basic physics doesn't prevent someone from holding the view. One truth of this world is that there is no shortage of people willing to make pronouncements on topics of which they know nothing. Raymond Arritt 02:28, 12 June 2007 (UTC)

You may call them unreasonable, but that does not make it so. If this view is really so unquestionable, then find a source and this debate is over. 02:57, 12 June 2007 (UTC)

"And how much is absorbed by carbon dioxide? Eight hundredths of one percent. One one-thousandth as important as water vapor. You can go outside and spit and have the same effect as doubling carbon dioxide." - Reid Bryson. You did ask for a reputable scientist. Clearly the question is not whether it has an effect but by how much it has an effect; the effect of a spit isn't much is it? JG17 15:04, 12 June 2007 (UTC)

Not really- I googled that quote, and at (which is, in any case, not a particularly reliable source, being a blog), the article goes on to say: "Bryson says the data fed into the computers overemphasizes carbon dioxide and accounts poorly for the effects of clouds—water vapor." That's overemphasizes carbon dioxide. Which is not the same as "carbon dioxide has no effect". --Merlinme 15:41, 12 June 2007 (UTC)

Also, see: Greenhouse_gas#The_role_of_water_vapor --Merlinme 15:45, 12 June 2007 (UTC)

Bryson is emeritus William M. Connolley 16:14, 12 June 2007 (UTC)

Ok, I found the original article/ interview at: Bryson is fairly clear that he really does think CO2 has very little effect (although that is still not the same as no effect, and he does not deny that temperature is going up, and in fact he is proud of the fact that he was one of the first people to suggest that human activity could affect climate). However, although I'm sure he is a distinguished man, WMC's point is that Bryson is emeritus, i.e. retired. That doesn't necessarily stop you being a scientist, but it does tend to mean that your research may not be up to date. If this were published in a peer reviewed journal it wouldn't be an issue, because we would know that his work had been considered critically by other scientists. But while "Wisconsin Energy Cooperative News" seems a perfectly respectable publication, it's focus is "rural, non-rural, and statewide issues that affect electric cooperatives". A peer reviewed scientific journal it is not. People say a lot of things when they're waxing lyrical in response to interviewing, that they wouldn't say in a scientific article (or at least, they would have to justify if they said it in a scientific article). I'm not sure one newspaper interview with an 86 year old scientist (who does not even specifically deny that CO2 has an effect) justifies altering the current Misplaced Pages article, therefore. --Merlinme 16:38, 12 June 2007 (UTC)

None of that stops this being a strawman argument. No-one argues the possible amplification effect so no-one argues against basic physics, but the extent of amplification cannot be determined at all from the ice-core records. Bryson says the effect of CO2 is negligible and he is by no means alone. Ian Clarke among many others say that the lag means that clearly CO2 did not drive climate in the past. Do you realise that this "feedback theory" is not published or peer-reviewed either? It seems to have first appeared on the realclimate.org blog and it is only endorsed on other blogs or webpages. How many people really believe this nonsense is quite unknown. I don't think many would actually like to debate it because it's a stone cold loser of a motion. Look at the graphs. What do you see? Do you just see what you want to see? This is a hobbyhorse the Misplaced Pages authors should not have got on. (JG17 17:49, 12 June 2007 (UTC))

JG, lets get this straight right now: Clarke is correct - everyone agrees about that one (and also that its misleading). Climate in the past was not driven by CO2. Where you get things wrong is by assuming that because this is correct, the opposite cannot be true. Its a chicken/egg thing, Temperature can drive CO2 and CO2 can drive temperature. CO2 can both be a feedback and a forcing. --Kim D. Petersen 17:59, 12 June 2007 (UTC)

Well I'm glad everyone agrees about Clarke being correct because Clarke doesn't believe in this new interpretation of the time-lag so who is misleading who? The Swindle documentary was just negating Al Gore's misleading presentation and they used Clarke (amongst others) to denounce Gore. Yes CO2 can be a feedback and a forcing but the extent of the feedback may be negligible (as Bryson argues). The extent most certainly cannot be determined from the ice-core studies: The most obvious interpretation of which is that the initial driver remains the main driver otherwise the onset of the cooling periods cannot be explained. Any other theory is guesswork.(JG17 11:07, 13 June 2007 (UTC))

Ah, so many errors, so little patience to respond. For a start, the derided "feedback theory" has indeed been published in numerous peer-reviewed publications -- as you could easily have found had you bothered to take two seconds with Google Scholar. The whole one-way argument is silly and based on fundamentally flawed logic (as Kim implies). Does heat cause fire, or does fire cause heat? Raymond Arritt 18:19, 12 June 2007 (UTC)

You are confusing the original feedback theory with this new "feedback theory" which was composed specifically to explain the CO2 time lag in the ice-core graphs (ie. reread the article please) and proposes that the CO2 feedback thence became the main heating component of climate change in the past. Anyway the one-way argument is not the issue -- as you could easily have found had you bothered to take two seconds to read my actual words. The issue is that one-way has never been argued, not even in the Swindle documentary. What has been argued is just that the data demonstrates the feedback effect to be negligible. Even the phrase "it seems to be almost completely one-way" wouldn't violate basic physics so the sentence in it's current form is clearly a strawman. If you don't want to respond then please don't. Your snark is not welcome.(JG17 11:07, 13 June 2007 (UTC))

From a transcript to The Great Global Warming Swindle: ": So obviously Carbon Dioxide is not the cause of that warming. In fact we can say that the warming produced the increase in Carbon Dioxide. CO2 clearly cannot be causing temperature changes. It's a product of temperature - it's following temperature changes." They seem to be pretty strong claims to me that warming produces more CO2, and that CO2 cannot be causing temperature changes. I don't really understand why you're getting so worked up about this, to be honest. TGGWS used the ice cores lag as an argument that CO2 does not cause warming, it follows it. This is misleading, because although there must have been some non CO2 related initial cause at the points shown in the ice core record, it ignores the expected effect on global temperature after the CO2 has been released. If you believe that CO2 has a negligible effect, then the onus is surely on you to find an alternative scientific mechanism for the recently observed warming. While it would be foolish to believe that we have perfect understanding of the atmosphere, the fact is that theories which give a significant weight to CO2 have a much better explanatory power than those which don't. As far as I can tell, very few scientists have time for the alternative "cosmic rays" theory suggested by TGGWS. See, for example, Alan Thorpe in the New Scientist: "that the presence or absence of cosmic rays in Earth's atmosphere is a better explanation for temperature variation than the concentration of CO2 and other gases. This is not a new assertion and it is patently wrong: there is no credible evidence that cosmic rays play a significant role." Until someone comes up with a better theory, I will tend to believe the theory that CO2 is a significant contributor, because I trust the large body of scientists who agree with it. --Merlinme 12:27, 13 June 2007 (UTC)

You are wandering off from the point. I said that no-one rejects the idea of positive feedback, including Bryson, Singer, Lindzen, Clarke, etc: They only query the extent of the effect. To test theories you must use real world data. The ice-core data timelag in the heating half-cycle does not disprove the theory but the completely in-step onset of the cooling cycles conclusively shows that any feedback effect was negligible in the past. Without nitpicking the transcript you must surely realise that is what was meant. Check these scientists various writings' to confirm it if you like. Hence no-one in the world is arguing against basic physics so the text in this article is deliberately wrong ie. a strawman. If I appear worked up it is because I see this particular issue as a litmus test for the credibility of global warming science: That is do you allow dogma or data to guide you? I am not against reducing our CO2 output but I do like the truth. Perhaps I have seen the "large majority of scientists" be wrong more often than you - and wrong on so many issues and in so many areas I'd be hard put to list them all. Scientists are very, very often wrong and they are usually wrong en masse and usually when they trust theory over real data. I repeat what do you see in the ice core data? Does the argument posed in this article make any sense to you? (JG17 14:36, 13 June 2007 (UTC))

"the completely in-step onset of the cooling cycles conclusively shows that any feedback effect was negligible in the past" -- oh dear, back to the chicken-and-egg argument again. Raymond Arritt 14:54, 13 June 2007 (UTC)

A poor analogy disproves nothing. But even if you believe in this flawed feedback-becomes-driver theory, do you suppose that the GCM's have a 1000 year time-lag in the feedback, or even 100 years? (JG17 14:35, 15 June 2007 (UTC))

"If you believe that CO2 has a negligible effect, then the onus is surely on you to find an alternative scientific mechanism for the recently observed warming." I don't know who "you" is supposed to be in this sentence, but it's clearly an argument from ignorance. Lots of scientists fall into this camp and I think it's a perfectly reasonable position to hold. "We don't know" is not at all a sign of failure in science, and it is a position scientists have held and continue to hold on many issues. The assumption that CO2 must be causing global warming because we haven't found something else to explain it is a fallacy. That being said, do we have a source that anyone is indicating that CO2 has zero effect on temperature, as the article states? Oren0 17:23, 13 June 2007 (UTC)

I'm sorry, but your statement "the assumption that CO2 must be causing global warming because we haven't found something else to explain it" displays an unsettling lack of familiarity with the scientific literature on the topic. It's not an assumption; rather, it's the most parsimonious explanation for a broad range of theoretical and observational evidence. The onus really is on the skeptics in this case -- the supposed alternate explanations often involve a great deal of speculation (e.g., a mysterious amplification mechanism for tiny solar variations) and in general have no coherent theme ("it's cosmic rays...no, it's ocean circulation....no, it's natural variability...oh please dear Lord, let it be anything but CO2"). Raymond Arritt 18:38, 13 June 2007 (UTC)

Like many people in this debate you assume that disagreement with the conclusions of the scientific literature means unfamiliarity with it. That is just conceit. Most, if not all, of the so-called "evidence" consists of nothing more than someone's biased opinion based on ambiguous, incomplete data, poor statistics or guesswork-inspired modeling. The only real evidence is the retreat of the arctic and glaciers. But several specialists in those fields argue that these are a natural recovery from the little ice age. Who are we to argue?(JG17 14:35, 15 June 2007 (UTC))

I'm not nitpicking the transcript; those two quotes follow each other directly, and surely the implication is clear. Durkin probably did selectively edit the participants (he has a history of doing so), but his intention is clearly to imply that CO2 is a consequence, not a cause of global warming. Anyway, I agree that scientists are often wrong; in fact I'd say they're almost invariably wrong, because any scientific theory is only 'right' until contradictory data and a better theory come along. By all means look at the data and the theories critically, however you can't go from this to saying that the theory supported by the majority of scientists is usually rubbish. The theory supported by the majority of scientists should hopefully be the best fit for the data currently available. You've latched onto the ice core data, which I will confess that I initially found very convincing. Has correlation been confused with causation? If the only counter argument was that this was all a feedback loop, I would personally find it rather unconvincing; it seems a little neat, to explain away the lag by saying that A caused B but then B causes A to some extent, honest. However, this is not the only counter argument. We know that a) CO2 should increase global temperature and b) that giving significant weight to CO2 provides a better match for 20th century temperature than giving it a low weight. Given that we must literally have millions more data points for 20th Century temperature than we do for Antarctic temperatures hundreds of thousands of years ago, I find this persuasive. The heating mechanism that causes the initial temperature rise in ice cores remains to be explained; but that does not mean that CO2 cannot be causing temperature rises right now. --Merlinme 17:31, 13 June 2007 (UTC)

CO2 production is a consequence of global warming: That is what feedback means. Durkin only summarised the scientists and they have never discounted CO2 feedback - they are physicists after all - but it appears to have had negligible effect on past temperatures they say. You should also be wary of the argument that only CO2 can explain current warming. This originally comes from Hadley centre's climate modeling team. Since most of the model parameters were guessed and hence very variable; they tuned them all until the model nearly mapped the surface temperature records. It is circular reasoning with no actual supporting data and quite frankly it is appalling science. Google "Craig Bohren USA today" for a good perspective from the inside. Yes another emeritus! They are the people you can really trust because they don't make money from either side.(JG17 14:35, 15 June 2007 (UTC))

First, you've wandered quite a bit from the original point, which was the argument that temperature affects CO2 but CO2 does not affect temperature. Also, I don't think you understand how the models work. Finally, Bohren makes a number of statements that are flat-out wrong, e.g. "in the atmospheric sciences it is difficult to get grants unless you can somehow tie your work to global warming" (which a quick glance at lists of NSF or NOAA awards will show to be false). Raymond Arritt 14:56, 15 June 2007 (UTC)

The Bohren article is interesting, and seems reasonably well balanced. I'm still not completely sure why you would take the views of a couple of retired professors over the views of dozens of active, researching professors though. Anyway, at no point does Bohren say that he doesn't think global warming doesn't exist. His main point is that he is sceptical of doomsday scenarios, having seen plenty of them fail to happen, which is fair enough. I don't personally believe we're going to get a superstorm going to swallow up entire cities or anything. However, I do believe we're going to get changed weather patterns happening in a fairly short space of time, which will increase stresses on human populations, notably in the third world, and will probably lead to greater problems with migration and conflict over things like water and grazing rights. Bohren implies that he thinks that there are more serious risks than global warming, which is an arguable case. However, he seems unnecessarily defeatist about the possibility of keeping consumption of fossil fuels down- is there no point in even trying? He is also rather dismissive of computer modelling, which he admits is a personal bias; is this a reasonable bias, based on knowledge and experience, or simply that of an old man who did most of his research before computers were everywhere, doesn't like them particularly and doesn't understand people who spend their lives with them? To return to the analogy I use quite a lot, how much do the people who program weather models understand each individual data point? Does that make their weather predictions invalid?

When Borhen admits his bias against modelling, he lists things which he finds more convincing, e.g. longer growing seasons. At no point does he say whether he sees or does not see evidence of this. Really, I'd describe his whole viewpoint as "somewhat sceptical of global warming, sceptical of what we can do about it, and very sceptical of doomsday scenarios". At no point does he say he doesn't think global warming exists. The sentence: "Fortunately , I'll be dead before the consequences of global warming become dire, if indeed they do" is essentially saying he would like to see more conclusive evidence. He doesn't even entirely rule out the possibility that the consequences of global warming will be dire. --Merlinme 17:31, 15 June 2007 (UTC)

At no point have I disagreed about global warming either, or with man's current contribution. Perhaps the arctic is melting too quick and perhaps it's our fault. I'm just arguing against clearly unscientific and unsound logic from a web page, not a paper, being repeated here. I explained why I trusted retired professors - precisely because they can be trusted. (JG17 18:10, 2 July 2007 (UTC))

Yes I wandered off the point. However, the GISS model can be downloaded from their site and it is far less complex than the mathematical models which I work with on a daily basis. Actually I criticise fatigue crack growth modeling for exactly the same reason - too many fudge factors make accuracy impossible. Furthermore, most of these climate factors don't seem to be based on hard data and they are admitted to be poorly or very poorly understood. Anyone expressing full certainty in the models, as Hadley centre does, is engaging in pure PR, not science. Bohren obviously meant grants in his own field of climatology. Whether it is false or not I'd suspect he is far more able to say than you.(JG17 18:10, 2 July 2007 (UTC))

Bohren even repeats the tired old global cooling nonsense William M. Connolley 17:37, 15 June 2007 (UTC)

I vividly remember the ice-age stories. It may have been before your time, and it may have been nonsense but it most certainly had a following among certain journalists. It didn't go anywhere only because the earth started warming up. That there were few papers is probably due to the fact that there were very few climatologists then. Bottom line: Bohren was there - you weren't. (JG17 18:10, 2 July 2007 (UTC))

You're welcome to your stories and to your journalism. I'm talking about the science, and I'd hope that Bohren was, too. If you're interested in the science (the state of it then) tehn I recommend the global cooling article which you might find interesting. Bottom line: I've read the science papers from then; you haven't; it looks like Bohren hasn't either William M. Connolley 19:23, 2 July 2007 (UTC)

Sven

I don't believe "Previous research has demonstrated a reduction in cosmic rays between 1920 and 1980, when measurements were stopped. ". Reading the ref (I presume this ) says "Fair-weather potential gradient (PG) observations in Scotland and Shetland show a previously unreported annual decline from 1920 to 1980, when the measurements ceased." which is entirely different. CR measurements continue William M. Connolley 21:10, 12 June 2007 (UTC)

In fact I cut the whole Sven para: "Henrik Svensmark at Danish National Space Center contends that low-level clouds (which cool the Earth) are formed when cosmic rays come into the low atmosphere. ." - the Royal Soc stuff is new, but the rest isn't; and the Royal Soc stuff *doesn't* support the text - only the press release does; but thats nothing post-TAR William M. Connolley 21:10, 12 June 2007 (UTC)

"Warming elsewhere in the solar system"

I demand this section be rewritten from a NPOV standpoint. Articles written so as to convey the impression that one side is more credible than the other must not be tolerated. If reference was not good enough, then please someone else rewrite the section, or fix the context in which the reference was used. James Callahan 19:34, 24 June 2007 (UTC)

You're not going to win anybody over by making demands and saying what will and will not "be tolerated." Instead, perhaps try to be bold and make changes to make the article better. I incorporated your reference and rewrote part of the section, but it's clear that the balance of scientific opinion is currently against this theory, and the section has to reflect that. Oren0 20:16, 24 June 2007 (UTC)

"Dismissed" seems a bit strong. From NASA:

"Since the late 1970s, the amount of solar radiation the sun emits, during times of quiet sunspot activity, has increased by nearly .05 percent per decade, according to a NASA funded study.

"This trend is important because, if sustained over many decades, it could cause significant climate change,"

...

"Historical records of solar activity indicate that solar radiation has been increasing since the late 19th century. If a trend, comparable to the one found in this study, persisted throughout the 20th century, it would have provided a significant component of the global warming the Intergovernmental Panel on Climate Change reports to have occurred over the past 100 years," ()

See also: Sun more active than for more than a millenium, Oren0 20:45, 24 June 2007 (UTC)

"Dismissed" is entirely accurate. We have other scientists going on record as saying things like "that's nuts", which is extremely unusual in scientific discourse. His speculations simply aren't taken seriously. Raymond Arritt 20:57, 24 June 2007 (UTC)

Do you believe that opinion should be more important than data? Saying "That's nuts" is unusual in most scientific discourses but it seems commonplace in this particular area. Why is that? Are climate scientists particularly uncivil? Seems so! (JG17 18:10, 2 July 2007 (UTC))

If you like data rather than opinions, you could provide some. As far as can be told - see solar variation - there is no long-term upwards trend in solar over the last 30 y so its a poor candidate for explaining the warming. Nor is there any sfc T signal corresponding to the (far larger than any trend) 11-y solar cycle. You can also look at fig 4 of the SPM for some attribution stuff comparing natural (inc solar) and GHG forcing William M. Connolley 19:21, 2 July 2007 (UTC)

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