Intergovernmental Panel on Climate Change

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IPCC
Assessment reports:
First (1990)
1992 sup.
Second (1995)
Third (2001)
Fourth (2007)
UNFCCC | WMO | UNEP

The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), to evaluate the risk of climate change brought on by humans, based mainly on peer reviewed and published scientific/technical literature.^[1] The Panel is open to all members of the WMO and UNEP.

IPCC reports are widely cited in almost any debate related to climate change.^[2][3] National and international responses to climate change generally regard the UN climate panel as authoritative.^[4]

Contents 1 Aims 2 IPCC Reports 2.1 IPCC Fourth Assessment Report: AR4 2.2 IPCC Third Assessment Report: Climate Change 2001 2.2.1 Debate over Climate Change 2001 2.2.1.1 Economic growth estimates 2.2.1.2 Physical modeling 2.3 IPCC Second Assessment Report: Climate Change 1995 2.3.1 Debate over Climate Change 1995 2.4 IPCC supplementary report, 1992 2.5 IPCC First Assessment Report: 1990 3 Operations 3.1 Contributors 4 Activities 5 Publications 6 Criticism of IPCC 6.1 Christopher Landsea resignation 6.2 Unavailability of Supporting Data 6.3 Emphasis of the "Hockey Stick" Graph 6.4 History and studies suggesting a conservative bias, under-stating dangers 6.5 IPCC processes 7 See also 8 Notes and references 9 External links

[edit] Aims

The principles of the IPCC operation^[5] are assigned by the relevant WMO Executive Council and UNEP Governing Council resolutions and decisions as well as on actions in support of the UN Framework Convention on Climate Change process.

The role of the IPCC 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. IPCC reports should be neutral with respect to policy, although they may need to deal objectively with scientific, technical and socio-economic factors relevant to the application of particular policies.

Review is an essential part of the IPCC process. Since the IPCC is an intergovernmental body, review of IPCC documents should involve both peer review by experts and review by governments.^[5]

The stated aims of the IPCC are to assess scientific information relevant to:

1. human-induced climate change,
2. the impacts of human-induced climate change,
3. options for adaptation and mitigation.

The history of the IPCC is described in a brochure (PDF).

[edit] IPCC Reports

The IPCC published a first assessment report in 1990, a supplementary report in 1992, a second assessment report (SAR) in 1995, and a third assessment report (TAR) in 2001. A fourth assessment report (AR4) is currently underway. Each of the assessment reports is in three volumes from the working groups I, II and III. Unqualified, "the IPCC report" is often used to mean the WG I report.

[edit] IPCC Fourth Assessment Report: AR4

This documents a current event. Information may change rapidly as the event progresses.

Main article: IPCC Fourth Assessment Report

Work on the fourth assessment report (AR4) is well underway^[6].

The Working Group I Summary for Policymakers (SPM) was published on February 2, 2007^[7]. Its key conclusions were that^[8]:

• Warming of the climate system is unequivocal
• Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely (greater than 90% likely) due to the observed increase in anthropogenic (human) greenhouse gas concentrations
• Hotter temperatures and rises in sea level "would continue for centuries" no matter how much humans control their pollution.^[9], although the likely amount of temperature and sea level rise varies greatly depending on the fossil intensity of human activity during the next century (pages 13 and 18)^[10]
• The probability that this is caused by natural climatic processes alone is less than 5%
• World temperatures could rise by anything between 1.1 and 6.4°C (1.98 and 11.52°F) during the 21st century (table 3) and that:
  • Sea levels will probably rise by 18 to 59 cm (7.08 to 23.22 in) [table 3]
  • It is more than 90% certain that there will be frequent warm spells, heat waves and heavy rainfall
  • It is more than 66% certain that there will be an increase in droughts, tropical cyclones and extreme high tides.
• Both past and future anthropogenic carbon dioxide emissions will continue to contribute to warming and sea level rise for more than a millennium.
• Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values over the last 650,000 years.

Working Group II and Working Group III reports are scheduled for early April and early May, respectively. The AR4 Synthesis Report (SYR) is expected to be finalized during the last quarter of 2007.

Author lists and a chapter outline of the WGI report are available^[11].

[edit] IPCC Third Assessment Report: Climate Change 2001

Main article: IPCC Third Assessment Report

The Third Assessment Report (TAR) consists of four reports, three of them from the Working Groups:

• Working Group I: The Scientific Basis^[12]
• Working Group II: Impacts, Adaptation and Vulnerability^[13]
• Working Group III: Mitigation^[14]
• Synthesis Report^[15]

The "headlines" from the summary for policymakers^[16] in The Scientific Basis were:

1. An increasing body of observations gives a collective picture of a warming world and other changes in the climate system (The global average surface temperature has increased over the 20th century by about 0.6°C; Temperatures have risen during the past four decades in the lowest 8 kilometres of the atmosphere; Snow cover and ice extent have decreased)
2. Emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate (Anthropogenic aerosols are short-lived and mostly produce negative radiative forcing; Natural factors have made small contributions to radiative forcing over the past century)
3. Confidence in the ability of models to project future climate has increased (Complex physically-based climate models are required to provide detailed estimates of feedback and of regional features. Such models cannot yet simulate all aspects of climate (e.g., they still cannot account fully for the observed trend in the surface-troposphere temperature difference since 1979) and there are particular uncertainties associated with clouds and their interaction with radiation and aerosols. Nevertheless, confidence in the ability of these models to provide useful projections of future climate has improved due to their demonstrated performance on a range of space and time-scales^[17].)
4. There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities
5. Human influences will continue to change atmospheric composition throughout the 21st century
6. Global average temperature and sea level are projected to rise under all IPCC SRES scenarios

The TAR estimate for the climate sensitivity is 1.5 to 4.5 °C; and the average surface temperature is projected to increase by 1.4 to 5.8 Celsius degrees over the period 1990 to 2100, and the sea level is projected to rise by 0.1 to 0.9 metres over the same period. The wide range in predictions is based upon several different scenarios that assume different levels of future CO₂ emissions. Each scenario then has a range of possible outcomes associated with it. The most optimistic outcome assumes an aggressive campaign to reduce CO₂ emissions, while the most pessimistic is a "business as usual" scenario. The more realistic scenarios fall in between.

IPCC predictions are based on the same models used to establish the importance of the different factors in global warming. These models need data about anthropogenic emissions of greenhouse gases and aerosols. These data are predicted from economic models based on 35 different scenarios. Scenarios go from pessimistic to optimistic, and predictions of global warming depend on the kind of scenario considered.

IPCC uses the best available predictions and their reports are under strong scientific scrutiny. The IPCC concedes that there is a need for better models and better scientific understanding of some climate phenomena, as well as the uncertainties involved. Critics assert that the available data is not sufficient to determine the real importance of greenhouse gases in climate change. Sensitivity of climate to greenhouse gases may be overestimated or underestimated because of some flaws in the models and because the importance of some external factors may be misestimated. The predictions are based on scenarios, and the IPCC did not assign any probability to the 35 scenarios used.

[edit] Debate over Climate Change 2001

[edit] Economic growth estimates

Castles and Henderson asserted that the IPCC has been using inflated economic growth rates, which result in increased emission estimates^[18]. This was incorrect because IPCC growth and emissions rates were based upon several factors and not only GDP, as rebutted by Nebojsa Nakicenovic et al.

[edit] Physical modeling

See also: global climate model

A few participants in IPCC Working Group I (Science) do not agree with the IPCC reports (of the 120 lead authors, 2 have complained [3]).

A particularly active critic, MIT physicist Richard Lindzen, expressed his unhappiness about those portions in the Executive Summary based on his contributions in May 2001 before the U.S. Senate Committee on Commerce, Science and Transportation:

The summary does not reflect the full document... For example, I worked on Chapter 7, Physical Processes. This chapter dealt with the nature of the basic processes which determine the response of climate, and found numerous problems with model treatments – including those of clouds and water vapor. The chapter was summarized with the following sentence: 'Understanding of climate processes and their incorporation in climate models have improved, including water vapour, sea-ice dynamics, and ocean heat transport.'

The "Summary for Policymakers" of the WG1 reports does include caveats on model treatments: Such models cannot yet simulate all aspects of climate (e.g., they still cannot account fully for the observed trend in the surface-troposphere temperature difference since 1979) and there are particular uncertainties associated with clouds and their interaction with radiation and aerosols. Nevertheless, confidence in the ability of these models to provide useful projections of future climate has improved due to their demonstrated performance on a range of space and time-scales. [4].

These statements are in turn supported by the executive summary of chapter 8 of the report, which includes:

• Coupled models can provide credible simulations of both the present annual mean climate and the climatological seasonal cycle over broad continental scales for most variables of interest for climate change. Clouds and humidity remain sources of significant uncertainty but there have been incremental improvements in simulations of these quantities.

• Confidence in the ability of models to project future climates is increased by the ability of several models to reproduce the warming trend in 20th century surface air temperature when driven by radiative forcing due to increasing greenhouse gases and sulphate aerosols. However, only idealised scenarios of only sulphate aerosols have been used.

[edit] IPCC Second Assessment Report: Climate Change 1995

Main article: IPCC Second Assessment Report

Climate Change 1995, the IPCC Second Assessment Report (SAR) was finished in 1996. It is split into four parts:

• A synthesis to help interpret UNFCCC article 2.
• The Science of Climate Change (WG I)
• Impacts, Adaptations and Mitigation of Climate Change (WG II)
• Economic and Social Dimensions of Climate Change (WG III)

Each of the last three parts was completed by a separate working group, and each has a Summary for Policymakers (SfP) that represents a consensus of national representatives. The SfP of the WG I report contains headings:

1. Greenhouse gas concentrations have continued to increase
2. Anthropogenic aerosols tend to produce negative radiative forcings
3. Climate has changed over the past century (air temperature has increased by between 0.3 and 0.6 °C since the late 19th century; this estimate has not significantly changed since the 1990 report).
4. The balance of evidence suggests a discernible human influence on global climate (considerable progress since the 1990 report in distinguishing between natural and anthropogenic influences on climate, because of: including aerosols; coupled models; pattern-based studies)
5. Climate is expected to continue to change in the future (increasing realism of simulations increases confidence; important uncertainties remain but are taken into account in the range of model projections)
6. There are still many uncertainties (estimates of future emissions and biogeochemical cycling; models; instrument data for model testing, assessment of variability, and detection studies)

[edit] Debate over Climate Change 1995

Most scientists involved in climate research believe that the IPCC reports accurately summarise the state of knowledge. Few scientists have objected and made public comments to that effect.

The report formed the basis of negotiations over the Kyoto Protocol.

A December 20, 1995, Reuters report quoted British scientist Keith Shine, one of IPCC's lead authors, discussing the Policymakers' Summary. He said: "We produce a draft, and then the policymakers go through it line by line and change the way it is presented.... It's peculiar that they have the final say in what goes into a scientists' report". It is not clear, in this case, whether Shine was complaining that the report had been changed to be more skeptical, or less, or something else entirely.

Dr. Frederick Seitz, president emeritus of Rockefeller University and past president of the National Academy of Sciences, has publicly denounced the IPCC report, writing "I have never witnessed a more disturbing corruption of the peer-review process than the events that led to this IPCC report". He opposed it in the Leipzig Declaration of his Science and Environmental Policy Project.

In turn, Seitz's comments were vigorously opposed by the presidents of the American Meteorological Society and University Corporation for Atmospheric Research, who wrote about a systematic effort by some individuals to undermine and discredit the scientific process that has led many scientists working on understanding climate to conclude that there is a very real possibility that humans are modifying Earth's climate on a global scale. Rather than carrying out a legitimate scientific debate... they are waging in the public media a vocal campaign against scientific results with which they disagree [5].

S. Fred Singer disseminated a letter about what he learned about changes to Chapter 8, interpretations of the IPCC Summary's key conclusion, and some policy implications [6]:

1. Chapter 8 was altered substantially in order to make it conform to the Summary;
2. Three key clauses — expressing the consensus of authors, contributors, and reviewers — should have been placed into the Summary instead of being deleted from the approved draft chapter;
3. The ambiguous phrase "the balance of evidence suggests a discernible human influence on global climate" has been (mis)interpreted by policymakers to mean that a major global warming catastrophe will soon be upon us;
4. The IPCC report and its authors are being (mis)used by politicians and others to push an ideologically based agenda.

Dr. Benjamin D. Santer, Convening Lead Author of Chapter 8 of 1995 IPCC Working Group I Report, replied [7]:

1. All revisions were made with the sole purpose of producing the best-possible and most clearly-explained assessment of the science, and were under the full scientific control of the Convening Lead Author of Chapter 8.
   • Changes were made in direct response to:
     • Written comments made by governments and non-governmental organizations (NGOs) during October and November 1995.
     • Comments made by governments and NGOs during the plenary sessions of the IPCC meeting that was held in Madrid from November 27-November 29, 1995.
   • Post-Madrid changes to Chapter 8 were made solely in response to review comments and/or in order to clarify scientific points.
2. After receiving much criticism of the redundancy of a concluding summary (Section 8.7) in October and November 1995, the Convening Lead Author of Chapter 8 decided to remove it. About half of the information in the concluding summary was integrated with material in Section 8.6.
3. The bottom-line assessment of the science in the October 9 draft of Chapter 8 was "Taken together, these results point towards a human influence on climate".
   • The final assessment in the now-published Summary for Policymakers is that "the balance of evidence suggests that there is a discernible human influence on global climate".
     • The latter sentence, which is entirely consistent with the earlier October 9 sentence, was unanimously approved at the Madrid meeting by delegates from nearly 100 countries.
4. None of the changes were politically motivated.

[edit] IPCC supplementary report, 1992

The 1992 supplementary report was an update, requested in the context of the negotiations on the Framework Convention on Climate Change at the Earth Summit (United Nations Conference on Environment and Development) in Rio de Janeiro in 1992.

The major conclusion was that research since 1990 did "not affect our fundamental understanding of the science of the greenhouse effect and either confirm or do not justify alteration of the major conclusions of the first IPCC scientific assessment". It noted that transient (time-dependent) simulations, which had been very preliminary in the FAR, were now improved, but did not include aerosol or ozone changes.

[edit] IPCC First Assessment Report: 1990

The IPCC first assessment report was completed in 1990, and served as the basis of the United Nations Framework Convention on Climate Change (UNFCCC).

The executive summary of the policymakers summary of the WG I report includes:

• We are certain of the following: there is a natural greenhouse effect...; emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases: CO₂, methane, CFCs and nitrous oxide. These increases will enhance the greenhouse effect, resulting on average in an additional warming of the Earth's surface. The main greenhouse gas, water vapour, will increase in response to global warming and further enhance it.

• We calculate with confidence that: ...CO₂ has been responsible for over half the enhanced greenhouse effect; long-lived gases would require immediate reductions in emissions from human activities of over 60% to stabilise their concentrations at today's levels...

• Based on current models, we predict: under [BAU] increase of global mean temperature during the [21st] century of about 0.3 ^oC per decade (with an uncertainty range of 0.2 to 0.5 ^oC per decade); this is greater than that seen over the past 10,000 years; under other ... scenarios which assume progressively increasing levels of controls, rates of increase in global mean temperature of about 0.2 ^oC [to] about 0.1 ^oC per decade.

• There are many uncertainties in our predictions particularly with regard to the timing, magnitude and regional patterns of climate change, due to our incomplete understanding of: sources and sinks of GHGs; clouds; oceans; polar ice sheets.

• Our judgement is that: global mean surface air temperature has increased by 0.3 to 0.6 ^oC over the last 100 years...; The size of this warming is broadly consistent with predicion of climate models, but it is also of the same magnitude as natural climate variability. Thus the observed increase could be largely due to this natural variability; alternatively this variability and other human factors could have offset a still larger human-induced greenhouse warming. The unequivocal detection of the enhanced greenhouse effect is not likely for a decade or more.

[edit] Operations

The current Chair of the IPCC is Rajendra K. Pachauri, elected in May 2002; previously Robert Watson headed the IPCC.

The IPCC Panel is composed of representatives appointed by governments and organizations. Participation of delegates with appropriate expertise is encouraged. Plenary sessions of the IPCC and IPCC Working Groups are held at the level of government representatives. Non Governmental and Intergovernmental Organisations may be allowed to attend as observers. Sessions of the IPCC Bureau, workshops, expert and lead authors meetings are by invitation only.^[19] Attendance at the 2003 meeting included 350 government officials and climate change experts. After the opening ceremonies, closed plenary sessions were held.^[20] The meeting report ^[21] states there were 322 persons in attendance at Sessions with about seven-eighths of participants being from governmental organizations.^[22]

The IPCC is led by government scientists, but also involves several hundred academic scientists and researchers. It synthesises the available information about climate change and global warming, has published four major reports reviewing the latest climate science, as well as more specialized reports.

The IPCC does not carry out research nor does it monitor climate related data or other relevant parameters. It bases its assessment mainly on peer reviewed and published scientific/technical literature.^[23]

There are several major groups:

• IPCC Panel: Meets in plenary session about once a year and controls the organization's structure and procedures. The Panel is the IPCC corporate entity.
• Chair: Elected by the Panel.
• Secretariat: Oversees and manages all activities. Supported by UNEP and WMO.
• Bureau: Elected by the Panel. Chaired by the Chair. 30 members include IPCC Vice-Chairs, Co-Chairs and Vice-Chairs of Working Groups and Task Force.
• Working Groups: Each has two Co-Chairs, one from the developed and one from developing world, and a technical support unit.
  • Working Group I: Assesses scientific aspects of the climate system and climate change.
  • Working Group II: Assesses vulnerability of socio-economic and natural systems to climate change, consequences, and adaptation options.
  • Working Group III: Assesses options for limiting greenhouse gas emissions and otherwise mitigating climate change.
• Task Force on National Greenhouse Gas Inventories

The IPCC receives funding from UNEP, WMO, and its own Trust Fund for which it solicits contributions from governments.

[edit] Contributors

according to a flash animation on the front page of the IPCC's website, the people contributing to the IPCC 4AR include:

• 2500+ scientific expert reviewers
• 850+ Contributing authors
• 450+ lead authors

from over 130 countries, contributing for the last 6 years.

of these, the contributors to the Working group 1 report (including the summary for policy makers) included [8]

• 600 authors from 40 countries
• Over 620 expert reviewers
• a large number of government reviewers
• Representatives from 113 governments

[edit] Activities

The IPCC concentrates its activities on the tasks allotted to it by the relevant WMO Executive Council and UNEP Governing Council resolutions and decisions as well as on actions in support of the UN Framework Convention on Climate Change process.^[5]

As of April 2006, the IPCC was in the process of preparing the IPCC Fourth Assessment Report or AR4;^[24] Reports of the workshops held so far are available at the IPCC website.^[25]

• Working Group I [9]:
  • Report is due to be finalised during February of 2007 [10].
  • As of May 2005, there have been 3 AR4 meetings, with only public information being meeting locations, an author list, one invitation, one agenda, and one list of presentation titles.
  • As of December 2006, governments are reviewing the revised summary for policy makers.
• Working Group II [11]:
  • Report is due to be finalised in mid-2007.
  • As of May 2005, there have been 2 AR4 meetings, with no public information released.
  • One shared meeting with WG III has taken place, with a published summary.
• Working Group III [12]:
  • Report is due to be finalized in mid-2007.
  • As of May 2005, there has been 1 AR4 meeting, with no public information released.

If it is decided to prepare one the AR4 Synthesis Report (SYR) would be finalised during the last quarter of 2007. Documentation on the scoping meetings for the AR4 are available [13] as are the outlines for the WG I report [14] and a provisional author list [15].

While the preparation of the assessment reports is a major IPCC function, it also supports other activities, such as the Data Distribution Centre [16] and the National Greenhouse Gas Inventories Programme [17], required under the UNFCCC. This involves publishing default emission factors, which are factors used to derive emissions estimates based on the levels of fuel consumption, industrial production and so on.

The IPCC also often answers inquiries from the UNFCCC Subsidiary Body for Scientific and Technological Advice (SBSTA).

[edit] Publications

The IPCC reports are a compendium of peer reviewed and published science. Each subsequent IPCC report notes areas where the science has improved since the previous report and also notes areas where further research is required.

Authors for the IPCC reports are chosen from a list of researchers prepared by governments, and participating organisations and the Working Group/Task Force Bureaux, and other experts as appropriate, known through their publications and works ([18], 4.2.1,2). The composition of the group of Coordinating Lead Authors and Lead Authors for a section or chapter of a Report is intended to reflect the need to aim for a range of views, expertise and geographical representation (ensuring appropriate representation of experts from developing and developed countries and countries with economies in transition).

There are generally three stages in the review process [19]:

• Expert review (6-8 weeks)
• Government/expert review
• Government review of:
  • Summaries for Policymakers
  • Overview Chapters
  • Synthesis Report

Review comments are in an open archive for at least five years.

There are several types of endorsement which documents receive [20]:

• approval: Material has been subjected to detailed, line by line discussion and agreement.
  • Working Group Summaries for Policymakers are approved by their Working Groups.
  • Synthesis Report Summary for Policymakers is approved by Panel.
• adoption: Endorsed section by section (and not line by line).
  • Panel adopts Overview Chapters of Methodology Reports.
  • Panel adopts IPCC Synthesis Report.
• acceptance: Not been subject to line by line discussion and agreement, but presents a comprehensive, objective, and balanced view of the subject matter.
  • Working Groups accepts their reports.
  • Task Force Reports are accepted by the Panel.
  • Working Group Summaries for Policymakers are accepted by the Panel after group approval.

The Panel is responsible for the IPCC and its endorsement of Reports allows it to ensure they meet IPCC standards. The Panel's approval process has been criticized for changing the product of the experts who create the Reports. On the other hand, not requiring Panel re-endorsement of Reports has also been criticized, after changes required by the approval process were made to Reports.

[edit] Criticism of IPCC

[edit] Christopher Landsea resignation

In January 2005 Christopher Landsea resigned from work on the IPCC AR4, saying that he viewed the process as both being motivated by pre-conceived agendas and being scientifically unsound because of Kevin Trenberth's public contention that global warming was contributing to recent hurricane activity Chris Landsea Leaves. Roger A. Pielke who published Landsea's letter writes: How anyone can deny that political factors were everpresent in the negotiations isn't paying attention, but notes that the actual report maintain[s] consistency with the actual balance of opinion(s) in the community of relevant experts [21]. See IPCC Fourth Assessment Report for more details.

[edit] Unavailability of Supporting Data

Stephen McIntyre, an IPCC reviewer on the IPCC AR4, found that portions of the report were based on unpublished data. When he attempted to obtain this data, the IPCC threatened to remove his accreditation as an IPCC expert reviewer. McIntyre recommends that the "IPCC should require authors who submitted papers for citation to consent to provide data." The IPCC has declined to do so saying that this would interfere with the journals.^[26]

[edit] Emphasis of the "Hockey Stick" Graph

Main article: Hockey stick controversy

The third assessment report (TAR) prominently featured^[27] a graph labeled "Millennial Northern Hemisphere temperature reconstruction" from a paper by Mann, Bradley and Hughes (MBH98^[28]) often referred to as the "Hockey Stick Graph". This graph differed radically from a schematic in the first assessment report which depicted much larger global temperature variations over the past 1000 years, and higher temperatures during the the Medieval Warm Period than the present day. The appearance of MBH98 in the TAR was widely construed as demonstrating that the current warming period is exceptional in comparison to temperatures between 1000 and 1900. From 2001 to 2005 the graph was heavily promoted by groups advocating the immediate reduction of carbon emissions, often with the error bars removed. By 2005, the methodology used to produce this graph was the target of many criticisms^[29]. In a 2006 letter to Nature, Bradley, Hughes and Mann pointed out that their original article had said that more widespread high-resolution data are needed before more confident conclusions can be reached and that the uncertainties were the point of the article. Critics of the IPCC claim that it has damaged its credibility by promoting this graph as proof of historically unusual climate change.

[edit] History and studies suggesting a conservative bias, under-stating dangers

Other critics have pointed to conservative biases and influences over IPCC which suggest that IPCC, far from being prone to exaggerations, is actually more prone to underestimating dangers, under-stating risks, and reporting only the "lowest common denominator" findings which make it through the bureaucracy. These sort of problems are almost inevitable with such a large organisation representing such a large number of bodies with differing postitions. There is an enormous amount of careful negotiation on the content of the text. As noted by the History News Network,

The Reagan administration wanted to forestall pronouncements by self-appointed committees of scientists, fearing they would be 'alarmist.' Conservatives promoted the IPCC’s clumsy structure, which consisted of representatives appointed by every government in the world and required to consult all the thousands of experts in repeated rounds of report-drafting in order to reach a consensus. Despite these impediments the IPCC has issued unequivocal statements on the urgent need to act.

– HNS.

On February 1st, 2007, the eve of the publication of IPCC's major report on climate, a new study was published in the peer-review journal Science, in which research by an international group of scientists suggests that temperatures and sea levels have been rising at or above the maximum rates proposed during the last IPCC report in 2001.^[30] The study compared IPCC 2001 projections on temperature and sea level change with what has actually happened. Over the six year span of time, the actual temperature rise was near the very top (in the top 10%) of the "range" given by IPCC's 2001 projection. In the case of sea level rises, the actual rise was above even the top of the range IPCC had given.

There are many additional examples of scientific research which has indicated that previous estimates by the IPCC, far from overstating dangers and risks, have actually under-stated them (this may be due, in part, to the expanding human understanding of climate, as well as to the conservative bias, noted above, which is built into the IPCC system). Examples include a study on projected rises in sea levels. When the researchers' analysis was "applied to the possible scenarios outlined by the Intergovernmental Panel on Climate Change (IPCC), the researchers found that in 2100 sea levels would be 0.5–1.4m above 1990 levels. These values are much greater than the 9–88cm as projected by the IPCC itself in its Third Assessment Report, published in 2001."^[31][32]

A "conservative" bias in the sense of right-wing, pro-corporate leanings and influences has been documented by the release of a famous Memo by ExxonMobil to the Bush Whitehouse, and its effects on the IPCC's leadership. The memo led to strong Bush administration lobbying, evidently at the behest of ExxonMobil, to oust Robert Watson, one of the world's leading climate scientists, from the IPCC chairmanship, and to have him replaced by Pachauri, who was seen at the time as much more soft-stated, mild-mannered, and more industry-friendly in his rhetoric^[33][34]. Notwithstanding the Exxon memo and the intentions it states for selecting him as more soft-spoken, Pachauri's language has become stronger since taking the IPCC chairmanship as the scientific evidence has mounted.

In response to criticism by respected scientific experts that IPCC's then impending January 2007 report under-states certain risks, particularly sea level rises, an AP story acknowledged that

[IPCC] a consensus-building structure that routinely issues scientifically cautious global warming reports, scientists say and quotes Stefan Rahmstorf, a physics and oceanography professor at Potsdam University in Germany, that it is perhaps a "strength" of IPCC, but that yes, IPSS is "very conservative and cautious".

In his December 2006 book, Hell and High Water: Global Warming, and in an interview on Fox News on January 31, 2007, energy expert Joseph Romm noted that the IPCC Fourth Assessment Report is already out of date and omits recent observations and factors contributing to global warming, such as the release of greenhouse gases from thawing tundra.^[35]

These recent reports and publications are in marked contrast to some media portrayals of IPCC's reports as possibly over-stating dangers to humankind posed by climate change.

[edit] IPCC processes

UK House of Lords Science and Economic Analysis and Report on IPCC for the G-8 Summit, July 2005:

We have some concerns about the objectivity of the IPCC process, with some of its emissions scenarios and summary documentation apparently influenced by political considerations. There are significant doubts about some aspects of the IPCC’s emissions scenario exercise, in particular, the high emissions scenarios. The Government should press the IPCC to change their approach. There are some positive aspects to global warming and these appear to have been played down in the IPCC reports; the Government should press the IPCC to reflect in a more balanced way the costs and benefits of climate change. The Government should press the IPCC for better estimates of the monetary costs of global warming damage and for explicit monetary comparisons between the costs of measures to control warming and their benefits. Since warming will continue, regardless of action now, due to the lengthy time lags.

– UK Parliament, PDF.

Interestingly, the Stern Review ordered by the UK government, whose findings were released in October 2006, made a stronger economic argument in favor of urgent action to combat human-made climate change than previous analyses, including some by IPCC.

[edit] See also

• Global warming
• G8+5
• Climate tourists
• Summary for policymakers
• Avoiding Dangerous Climate Change international conference

[edit] Notes and references

[edit] External links

• The IPCC web site
  • IPCC organisation
  • IPCC Principles
• IPCC article at the Encyclopedia of Earth - General overview of the IPCC
• Sherwood Rowland (Nobel Laureate for work on ozone depletion) discusses climate change and the IPCC recorded in 2006 Freeview video provided by the Vega Science Trust.
  • Second Assessment "Synthesis" Report (pdf)
  • Second Assessment Summaries for Policymakers: Working Group I (Science), Working Group II (Impacts, Adaptation, and Mitigation), Working Group III (Socio-economics)
  • Third Assessment Report
    • A non-authorized summary of the Third Assessment Report by GreenFacts.

• The IPCC Controversy - from the Science & Environmental Policy Project
• climate change - What is the IPCC by Jean-Marc Jancovici
• Climate Change Freeview Video Interview 2006 - Sherwood Rowland, Nobel Laureate (1995) for work on Ozone Depletion discusses Climate Change. Provided by the Vega Science Trust.

Part of a series on Global Warming

Subtopics

Scientific opinion • Attribution of causes • Effects • Mitigation • Adaptation • Controversy • Politics • Economics

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Climate change • Deforestation • Global climate modelling • Global cooling • Global dimming • Greenhouse effect • Greenhouse gases Intergovernmental Panel on Climate Change • Kyoto Protocol • Peak Oil • Renewable energy • Temperature data