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The IPCC Fourth Assessment Report (AR4) is a report on climate change created with the help of a large number of contributors, both scientists and governmental representatives. Issues have been raised, both about the specific content of the report, as well as the process undertaken to complete the report.

Content issues

Some observers have identified issues in which the peer-reviewed science suggests outcomes more severe than outlined by the report, while other observers have noted that some conclusions in the report are not satisfactorily supported by the peer-reviewed science.

Arctic sea ice extent

According to a study conducted by the National Center for Atmospheric Research and the National Snow and Ice Data Center, Arctic Sea ice is melting faster than predicted by climate models. The study concludes that the 18 models on which the IPCC has based its current recommendations could already be out of date, and that the retreat of the ice could already be 30 years ahead of the IPCC's worst case scenario, possibly leading to an ice-free summer Arctic by the end of the 21st century.

Glacial dynamics

The IPCC AR4 estimates explicitly exclude the influence of the melting of ice sheets. These ice sheets include most notably the Greenland ice sheet, and both the east and west Antarctic ice sheets, as well as numerous glaciers. This may result in a major underestimate of the upper limit for sea level rise in the long term. Due to Arctic melting the Greenland ice sheet is particularly vulnerable, and a study by climatologist James E. Hansen states that "we cannot rule out large changes on decadal time-scales once wide-scale surface melt is underway.", the melting of the Greenland ice sheet would result in an increase in sea level rise of over 7m . Melting of the west Antarctic ice sheet would cause a similar, if slightly smaller rise in sea levels due to being grounded below sea level, whilst the effect of the melting of the east Antarctic, although less probable would be an order of magnitude greater.

In a lecture he gave at the University of California, Santa Barbara, James E. Hansen criticised the IPCC for its description of future sea level rise. Hansen has also written on this issue:

The IPCC (2007) midrange projection for sea level rise this century is 20–43 cm (8–17 inches) and its full range is 18– 59 cm (7–23 inches). The IPCC notes that they are unable to evaluate possible dynamical responses of the ice sheets, and thus do not include any possible ‘rapid dynamical changes in ice flow’. Yet the provision of such specific numbers for sea level rise encourages a predictable public response that the projected sea level change is moderate, and smaller than in IPCC (2001). Indeed, there have been numerous media reports of ‘reduced’ sea level rise predictions, and commentators have denigrated suggestions that business-as-usual greenhouse gas emissions may cause a sea level rise of the order of meters

The IPCC is doing a commendable job, but we need something more. Given the reticence that the IPCC necessarily exhibits, there need to be supplementary mechanisms. The onus, it seems to me, falls on us scientists as a community.

In a lecture given at Princeton University, IPCC author Michael Oppenheimer admitted that the IPCC report could have better explained the contribution of melting ice sheets in predictions of sea level rise. Oppenheimer said that the IPCC Working Group II Summary of Policymakers (quoted below) managed this better than the Working Group I Summary of Policymakers:

There is medium confidence that at least partial deglaciation of the Greenland ice sheet, and possibly the West Antarctic ice sheet, would occur over a period of time ranging from centuries to millennia for a global average temperature increase of 1-4°C (relative to 1990-2000), causing a contribution to sea-level rise of 4-6 m or more.

Projected date of melting of Himalayan glaciers

A paragraph in the 938-page 2007 Working Group II report (WGII) included a projection that Himalayan glaciers could disappear by 2035. This projection was not included in the final summary for policymakers which highlighted the importance of the glaciers for freshwater availability, and stated that "Widespread mass losses from glaciers and reductions in snow cover over recent decades are projected to accelerate throughout the 21st century". Late in 2009, in the approach to the Copenhagen climate summit, the 2035 date was strongly questioned in India. On 19 January 2010 the IPCC acknowledged that the paragraph was incorrect, while reaffirming that the conclusion in the final summary was robust. They expressed regret for "the poor application of well-established IPCC procedures in this instance" and their vice-chairman Jean-Pascal van Ypersele said that the reviewing procedures would have to be tightened.

The WGII report ("Impacts, Adaptation and Vulnerability"), chapter 10, page 493, includes this paragraph:

Glaciers in the Himalaya are receding faster than in any other part of the world (see Table 10.9) and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate. Its total area will likely shrink from the present 500,000 to 100,000 km by the year 2035 (WWF, 2005).

— WGII p. 493

At the start of December 2009 J. Graham Cogley of Trent University, Ontario, described the paragraph as wildly inaccurate. The rates of recession of Himalayan glaciers were not exceptional, but their disappearance by 2035 would require a huge acceleration in rate. The first sentence of the IPCC WGII report, including the date of 2035, came from the cited source, "(WWF, 2005)". This was a March 2005 World Wildlife Fund Nepal Program report, page 29:

In 1999, a report by the Working Group on Himalayan Glaciology (WGHG) of the International Commission for Snow and Ice (ICSI) stated: “glaciers in the Himalayas are receding faster than in any other part of the world and, if the present rate continues, the livelihood of them disappearing by the year 2035 is very high”.

— WWF p. 29

On page 2, the WWF report cited an article in the 5 June 1999 issue of New Scientist which quoted Syed Hasnain, Chairman of the International Commission for Snow and Ice (ICSI), saying that most of the glaciers in the Himalayan region "will vanish within 40 years as a result of global warming". That article was based on an email interview, and says that "Hasnain's four-year study indicates that all the glaciers in the central and eastern Himalayas could disappear by 2035 at their present rate of decline." Both the article and the WWF report referred to Hasnain's unpublished 1999 ICSI study, Report on Himalayan Glaciology, which does not estimate a date for the disappearance of Himalayan glaciers.

The second sentence of the questionable WGII paragraph which states "Its total area will likely shrink from the present 500,000 to 100,000 km by the year 2035" could not refer to the Himalayan glaciers, which cover about 33,000 km. Cogley said that a bibliographic search indicated that it had been copied inaccurately from a 1996 International Hydrological Programme (IHP) report by Kotlyakov, published by UNESCO, which gave a rough estimate of shrinkage of the world's total area of glaciers and ice caps by 2350.

The extrapolar glaciation of the Earth will be decaying at rapid, catastrophic rates– its total area will shrink from 500,000 to 100,000 km² by the year 2350.

— IHP p. 66

Cogley suggested that the "2035" figure in the second sentence of the WGII paragraph was apparently a typographic error. He concluded, "This was a bad error. It was a really bad paragraph, and poses a legitimate question about how to improve IPCC’s review process. It was not a conspiracy. The error does not compromise the IPCC Fourth Assessment, which for the most part was well reviewed and is highly accurate."

Statements very similar to those made in both sentences of the WGII paragraph appeared as two successive paragraphs in an April 1999 article in Down to Earth , published in the India Environment Portal (IEP). This included the substitution of 2035 for 2350 as stated in the IHP study. New Scientist has drawn attention to Hasnain's claim about the timing of glaciers disappearing:

"Glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 is very high," says the International Commission for Snow and Ice (ICSI) in its recent study on Asian glaciers. "But if the Earth keeps getting warmer at the current rate, it might happen much sooner," says Syed Iqbal Hasnain of the School of Environmental Sciences, Jawaharlal Nehru University, New Delhi. Hasnain is also the chairperson of the Working Group on Himalayan Glaciology (WGHG), constituted in 1995 by the ICSI. "The glacier will be decaying at rapid, catastrophic rates. Its total area will shrink from the present 500,000 to 100,000 square km by the year 2035," says former icsi president V M Kotlyakov in the report Variations of snow and ice in the past and present on a global and regional scale (see table: Receding rivers of ice ).

— IEP

The question of whether it was acceptable to use material which had not been peer reviewed has been disputed. IPCC rules permit the use of non-peer-reviewed material, subject to a procedure in which authors are to critically assess any source that they wish to include, and "each chapter team should review the quality and validity of each source before incorporating results from the source into an IPCC Report."

The official statement issued by the IPCC on 20 January 2009 noted that "a paragraph in the 938-page Working Group II contribution to the underlying assessment refers to poorly substantiated estimates of rate of recession and date for the disappearance of Himalayan glaciers. In drafting the paragraph in question, the clear and well-established standards of evidence, required by the IPCC procedures, were not applied properly." It emphasised that the paragraph did not affect the conclusion in the final summary for policymakers in the 2007 report, which it described as "robust, appropriate, and entirely consistent with the underlying science and the broader IPCC assessment", and reaffirmed a commitment to absolute adherence to the IPCC standards. The IPCC also stated that it did not change the broad picture of man-made climate change. This was confirmed by Wilfried Haeberli, who announced the latest annual results of the World Glacier Monitoring Service. He stated that the important trend of 10 years or so showed "an unbroken acceleration in melting" and on expected trends, many glaciers will disappear by mid century. Glaciers in lower mountain ranges were the most vulnerable, and while those in the Himalayas and Alaska could grow in the short term, in a realistic mid-range warming scenario they would not last many centuries.

African crop yield projections

Chapter 9 of the Working Group II report states that "In other countries, additional risks that could be exacerbated by climate change include greater erosion, deficiencies in yields from rain-fed agriculture of up to 50% during the 2000-2020 period, and reductions in crop growth period (Agoumi, 2003)." This claim was also included in the AR4 Synthesis Report, and has been mentioned in speeches by IPCC Chairman Rajendra Pachauri and UN Secretary-General Ban Ki-Moon. The source cited in the report for this claim is a non-peer reviewed policy paper published by International Institute for Sustainable Development, a Canadian think tank. Chris Field, the new lead author of the IPCC's climate impacts team, questioned the claim, telling the Sunday Times that "I was not an author on the Synthesis Report but on reading it I cannot find support for the statement about African crop yield declines". Former IPCC chairman Robert Watson said "Any such projection should be based on peer-reviewed literature from computer modelling of how agricultural yields would respond to climate change. I can see no such data supporting the IPCC report."

Proportion of Netherlands below sea level

The Working Group II: Impacts, Adaption and Vulnerability report states that "The Netherlands is an example of a country highly susceptible to both sea-level rise and river flooding because 55% of its territory is below sea level". This was based on data it had received from the Netherlands Environmental Assessment Agency PBL. When the Dutch government raised questions, the PBL acknowledged in a statement that it had sent incomplete wording to the IPCC, "It should have said 55 percent of the Netherlands is vulnerable to floods; the 26 percent of the Netherlands that is below sea level and another 29 percent can suffer when rivers flood." Martin Parry, climate expert and co-chair of the IPCC working group II, said that various different figures could have been used, depending on how the issue was defined. The figure of 60% of land which lies below high water level during storms is used by the Dutch Ministry of Transport, while the figure of 30% referring to land below mean sea level is used by others.

Process issues

Richard Black, an environmental reporter for the BBC, once observed that the IPCC is an unusual organisation in that the evidence is supplied by scientists, but the summaries of its reports are agreed between scientists and representatives of governments.

Dismissal of concerns

In January 2005, Dr. Chris Landsea who was already an author on the 2001 report (TAR), withdrew his participation in the Fourth Assessment Report claiming that the portion of the IPCC to which he contributed had become "politicized" and that the IPCC leadership simply dismissed his concerns. He published an open letter explaining why he was resigning and to "bring awareness to what I view as a problem in the IPCC process".

The conflict centers around Dr. Kevin Trenberth's public contention that global warming was contributing to "recent hurricane activity", which Landsea described as a "misrepresentation of climate science while invoking the authority of the IPCC". He has stated that the process of producing the Fourth Assessment Report is "motivated by pre-conceived agendas" and "scientifically unsound". Landsea writes that "the IPCC leadership said that Dr. Trenberth was speaking as an individual even though he was introduced in the press conference as an IPCC lead author."

Uncertainty

The 2007 IPCC Working Group I Report quantified the effect of anthropogenic aerosols on the climate in terms of their radiative forcing. Radiative forcing measures the influence a particular factor has on changing the Earth-atmosphere-system energy balance. The effect of aerosols was assessed to be the dominant uncertainty in radiative forcing.

A 2008 Report for the US Climate Change Science Program (CCSP) suggested that the IPCC report may have been 'overconfident' with its uncertainty estimate for the total aerosol forcing. This was based on an earlier 2006 paper that elicitated the judgement of twenty-four experts on aerosol forcing. The CCSP Report went on to say:

expert judgment is not a substitute for definitive scientific research. Nor is it a substitute for careful deliberative expert reviews of the literature of the sort undertaken by the IPCC. However, its use within such review processes could enable a better expression of the diversity of expert judgment and allow more formal expression of expert judgments, which are not adequately reflected, in the existing literature. It can also provide insights for policy makers and research planners while research to produce more definitive results is ongoing. It is for these reasons that Moss and Schneider have argued that such elicitations should become a standard input to the IPCC assessment process

Recommended procedural change

In 2007, economist and former IPCC author Richard Tol wrote a paper on the IPCC Working Group III Report. Tol said that the quality of the Working Group III Report had declined. He made several criticisms of the Report's content, and suggested changes in procedure that could improve the quality of future IPCC assessments:

It would be much better to shift the IPCC from UNEP and the environment ministries to ICSU and the ministries of research and higher education. Academic quality should be guiding principle in selecting authors. As a check, the committees that nominate and select authors should publish their proceedings. The review editors should become more independent, and gain the right to reject chapters that are not properly revised. The alternative is a gradual erosion of the quality, prestige and, eventually, influence of the IPCC.

Grey literature

The report was also criticized by The Sunday Telegraph for using grey literature. Examples given included the use of non-peer reviewed sources from the International Union for Conservation of Nature and the World Wildlife Fund regarding amazon rainforest predictions, and the use of student dissertations to source reports of ice cover in the Andes, in the Alps and in African mountain ranges. IPCC rules permit the use of non-peer-reviewed material, subject to critical assessment and review of the quality and validity of each source. In many cases allegations against IPCC findings have been based on the idea that the IPCC could not use "grey literature" such as reports from campaign groups and governments. Martin Parry, co-chair of the IPCC, stated, "many such reports are intensively reviewed, both internally and externally. Even if not peer-reviewed, there are reports that contain valuable information."

References

1. "Arctic melt worse than predictions". CNN.com. 2007-05-02. Retrieved 2010-02-03.
2. This contrasts with the IPCC AR3, which included earlier estimates of these ice dynamics, and had a higher top end sea level rise estimate, although much lower than some new estimates. The report states that recent observations suggest that ice flow dynamics could lead to additional rise: "Dynamical processes related to ice flow not included in current models but suggested by recent observations could increase the vulnerability of the ice sheets to warming, increasing future sea level rise. Understanding of these processes is limited and there is no consensus on their magnitude."
3. Climate change and trace gases. By James Hansen, Makiko Sato, et.al. Phil.Trans.R.Soc.A (2007)365,1925–1954, doi:10.1098/rsta.2007.2052. Published online 18 May 2007,
4. Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) . Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 881pp. ,, and .
5. Hansen, J.E. (26 March 2007). "How Can We Avoid Dangerous Human-Made Climate Change". UCTV – University of California Television. Retrieved 2009-05-20.
6. Hansen, J.E. (2007). "Scientific reticence and sea level rise". Environ. Res. Lett. doi:10.1088/1748-9326/2/2/024002. Retrieved 2009-05-20. {{cite journal}}: Check |doi= value (help); Unknown parameter |doi_brokendate= ignored (|doi-broken-date= suggested) (help)
7. Oppenheimer, M. (1 April 2008). "Ice Sheets and Sea Level Rise: How Should IPCC Handle Deep Uncertainty?". Princeton University, Woodrow Wilson School of Public and International Affairs. Retrieved 2009-05-20.
8. M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds. (2007). "IPCC, 2007: Summary for Policymakers. In: Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change" (PDF). Cambridge University Press. Retrieved 2009-05-20.{{cite web}}: CS1 maint: multiple names: authors list (link)
9. Mukherjee, Krittivas and Alister Doyle (Agence France-Presse), "U.N. panel re-examines Himalayan glacier thaw report", NewsDaily, January 18, 2010.
10. ^ Richard Black (19 January 2010). "UN climate body admits 'mistake' on Himalayan glaciers". BBC News. Retrieved 2010-01-23.
11. ^ "IPCC statement on the melting of Himalayan glaciers" (PDF). 20 January 2010. Retrieved 2010-01-23.
12. ^ Cruz, R.V., H. Harasawa, M. Lal, S. Wu, Y. Anokhin, B. Punsalmaa, Y. Honda, M. Jafari, C. Li and N. Huu Ninh (2007), "10 Asia", Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (PDF), Cambridge University Press, pp. 469–506{{citation}}: CS1 maint: multiple names: authors list (link)
13. ^ Pallava Bagla (5 December 2009). "Himalayan glaciers melting deadline 'a mistake'". BBC News. Retrieved 2010-01-26.
14. ^ "web.hwr.arizona.edu" (PDF). Retrieved 2010-01-28. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
15. ^ An Overview of Glaciers, Glacier Retreat, and Subsequent Impacts in Nepal, India and China (PDF), World Wide Fund for Nature, 2005, pp. 2, 29
16. Fred Pearce (2010-01-13). "Sifting climate facts from speculation". New Scientist. Retrieved 2010-01-27. and it turns out that our article is the primary published source
17. ^ Fred Pearce (2010-01-13). "Debate heats up over IPCC melting glaciers claim". New Scientist. Retrieved 2010-01-26.
18. Fred Pearce (1999-06-05). "Flooded out". New Scientist. Retrieved 2010-01-28.
19. Syed Hasnain (1999), An Overview of Glaciers, Glacier Retreat, and Subsequent Impacts in Nepal, India and China (PDF), Jawaharlal Nehru University, New Delhi: ICSI working group on Himalayan Glaciology
20. J. Graham Cogley (20 January 2010). "Science/AAAS | Science Magazine: Published E-Letter responses for Bagla, 326 (5955)". Tracking the Source of Glacier Misinformation. pp. 924–925. Retrieved 2010-01-28. {{cite web}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
21. V.M. Kotlyakov (1996), Variations of Snow and Ice in the past and at present on a Global and Regional Scale, UNESCO, pp. 469–506 {{citation}}: Text "http://unesdoc.unesco.org/images/0010/001065/106523E.pdf" ignored (help)
22. John Nielsen-Gammon (December 22, 2009). "By the way, there will still be glaciers in the Himalayas in 2035". Chron.com - Houston Chronicle. Retrieved 2010-01-28.
23. ^ Fred Pearce (21 January 2010). "Climate chief admits error over Himalayan glaciers - environment". New Scientist. Retrieved 2010-01-27. This week Hasnain has claimed, for the first time, that he was misquoted by New Scientist in 1999. New Scientist stands by its story and was not the only news outlet to publish Hasnain's claim.
24. "Glaciers beating retreat". Down to Earth Vol: 7 Issue: 19990430. India Environment Portal. April 1999. Retrieved 2010-01-28.
25. ^ "Appendix A to the Principles Governing IPCC Work" (PDF). IPCC. 2003. p. 14. Retrieved 2010-01-31.
26. Juliette Jowit (2010-01-25). "World's glaciers continue to melt at historic rates | Environment". The Guardian. Retrieved 2010-01-26.
27. "IPCC Fourth Assessment Report - Working Group II Chapter 9" (PDF). Intergovernmental Panel on Climate Change. Retrieved 2010-02-07. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
28. "IPCC AR4 synthesis report" (PDF). Intergovernmental Panel on Climate Change. Retrieved 2010-02-07. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
29. ^ "Top British scientist says UN panel is losing credibility". Sunday Times. Retrieved 2010-02-07. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
30. Johnson, Keith (2010-02-08). "Panel on Climate Faces Challenges". The Wall Street Journal. Retrieved 2010-02-13.
31. "Pachauri's IPCC report faces fresh questions". Times of India. Retrieved 2010-02-07. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
32. "AR4 WGII Chapter 12: Europe - 12.2.3 Current adaptation and adaptive capacity". Retrieved 2010-02-15.
33. "nrc.nl - International - New mistake found in UN climate report". NRC Handelsblad. 4 February 2010. Retrieved 2010-02-15. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
34. ^ David Adam (14 February 2010). "Climate scientist says Himalayan glacier report is 'robust and rigorous' | Environment". The Guardian. Retrieved 2010-02-14.
35. Black, Richard (2007-04-06). "Stark picture of a warming world". BBC. Retrieved 2010-01-27.
36. ": Chris Landsea Leaves IPCC (dead link)".
37. Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.) (2007). "IPCC, 2007: Summary for Policymakers. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change". Cambridge University Press. Retrieved 2009-12-07. {{cite web}}: |author= has generic name (help)CS1 maint: multiple names: authors list (link)
38. Granger Morgan, H. Dowlatabadi, M. Henrion, D. Keith, R. Lempert, S. McBrid, M. Small, T. Wilbanks (eds.) (2009). "Best practice approaches for characterizing, communicating, and incorporating scientific uncertainty in decisionmaking. Final Report, Synthesis and Assessment Product 5.2". US Climate Change Science Program website. Retrieved 2009-12-07. {{cite web}}: |author= has generic name (help)CS1 maint: multiple names: authors list (link)
39. Tol, R.S.J. (2007). "Biased Policy Advice from the Intergovernmental Panel on Climate Change" (PDF). Energy & Environment. 18 (7+8): 929–936. Retrieved 2009-05-20.
40. Gray, Richard (06 Feb 2010). "New errors in IPCC climate change report". Telegraph Media Group. Retrieved 14 February 2010. {{cite web}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)

Further reading

• "A critique of the Stern and IPCC analyses of CO2 mitigation: Consumer-capitalist society cannot solve the problem" Ted Trainer, The International Journal of Inclusive Democracy, vol 4, no 4, October 2008.

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