The IPCC Fourth Assessment Report (AR4) has been subjected to both scientific and non scientific (process based) criticism. The Intergovernmental Panel on Climate Change first assessment report was completed in 1990 and served as the basis of the United Nations Framework Convention on Climate The Intergovernmental Panel on Climate Change supplementary report of 1992 was published to contribute to the debate on the United Nations Framework Convention on Climate The Second Assessment Report (SAR of the Intergovernmental Panel on Climate Change was published in 1995 The IPCC Third Assessment Report, Climate Change 2001, is an assessment of available scientific and socio-economic information on climate change by an intergovermental panel Climate Change 2007, the Fourth Assessment Report (AR4 of the United Nations Intergovernmental Panel on Climate Change ( IPCC) is the fourth Annex I and Annex II Countries and Developing Countries Signatories to the UNFCCC are split into three groups Annex I countries (industrialized countries The UN Environment Programme (or UNEP) coordinates United Nations environmental activities assisting developing countries in implementing environmentally sound policies Climate Change 2007, the Fourth Assessment Report (AR4 of the United Nations Intergovernmental Panel on Climate Change ( IPCC) is the fourth Scientific criticism can broadly be broken down into criticism that the report either greatly understates or greatly overstates the dangers of climate change. Process criticism does not concern the science, but it can affect the science.

Scientific criticism

Scientific criticism can broadly be broken down into criticism that the report is too conservative or that it overstates the dangers of climate change. In this case, the view that the IPCC is conservative means the IPCC did not go far enough, it understated the state of the science or the consequences of global warming. Global warming is the increase in the average measured temperature of the Conversely, those who view the IPCC as alarmist, think that the IPCC overstated the state of the science and oversold the consequences of global warming. In addition, some scientists are concerned about potential biases of IPCC lead authors, who have been shown to favor their own research rather than opposing views.

AR4 is too conservative

Scientists at the National Snow and Ice Data Center (NSIDC) and the National Center for Atmospheric Research (NCAR) found that satellite and other observations show the Arctic ice cover is retreating more rapidly than estimated by any of the eighteen computer models used by the Intergovernmental Panel on Climate Change (IPCC) in preparing its 2007 assessments.

• Scientists, including former U.S. Department of Energy member Joseph Romm, have claimed that the report underestimates positive feedbacks that could lead to a runaway greenhouse effect, thus greatly underestimating the future warming and its effects. The United States Department of Energy ( DOE) is a Cabinet -level department of the United States government responsible for energy policy Joseph J Romm (born June 27 1960) is an American author lecturer and scientist who concentrates on solutions related to reducing Greenhouse gas emissions Positive feedback, sometimes referred to as "cumulative causation" is a Feedback loop system in which the system responds to perturbation in the same direction The Greenhouse effect refers to the change in the Thermal equilibrium temperature of a planet or moon by the presence of an Atmosphere containing gas that absorbs The report is also said to be out of date because it omits recent observations such as the release of greenhouse gases, including methane, from thawing tundra. ^[1]

The actual report gives a warning that positive feedbacks could release more carbon dioxide in a yet uncertain magnitude, but it does not mention gases with an even greater global warming potential like methane: "Climate-carbon cycle coupling is expected to add carbon dioxide to the atmosphere as the climate system warms, but the magnitude of this feedback is uncertain. Global warming potential (GWP is a measure of how much a given mass of Greenhouse gas is estimated to contribute to Global warming. This increases the uncertainty in the trajectory of carbon dioxide emissions required to achieve a particular stabilization level of atmospheric carbon dioxide concentration. " ^[2]

• Arctic Sea ice is melting faster than predicted by climate models. This article is about the theories and mathematics of climate modeling Research conducted by the U. S. -based National Center for Atmospheric Research and the National Snow and Ice Data Center demonstrates 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. The National Center for Atmospheric Research ( NCAR) is a non-governmental U The National Snow and Ice Data Center, or NSIDC, is a United States information and referral center in support of polar and cryospheric ^[3]

AR4 overstates the dangers of climate change

• Shortly after publication of the AR4 Summary for Policymakers, The libertarian Fraser Institute issued an alternative "Independent Summary for Policymakers" (ISPM) drawing skeptical conclusions ^[4]: There is no evidence provided by the IPCC in its Fourth Assessment Report that the uncertainty can be formally resolved from first principles, statistical hypothesis testing or modeling exercises. The Fraser Institute is Conservative and Libertarian Think tank based in Canada that espouses Free market principles Consequently, there will remain an unavoidable element of uncertainty as to the extent that humans are contributing to future climate change, and indeed whether or not such change is a good or bad thing. RealClimate describes it as "profoundly ignorant" of IPCC processes, and contends that there were "so many bizarre statements in the Fraser Institute report that some of us think that spotting them could serve as a good final exam in an elementary course on climate change. RealClimate is a commentary site ( Blog) on Climatology by a group of climate scientists for the interested Public and Journalists It aims to " ^[5].

• The American Association of Petroleum Geologists referred to AR4 as "wildly distorted and politicized. The American Association of Petroleum Geologists (or AAPG) is one of the world's largest professional geological societies with over 31000 members as of 2007 "^[6] However, organization members "have threatened to not renew their memberships if the AAPG does not alter its position on global climate change," according to president Lee T. Billingsley. ^[7]

Process criticism

• Critics contend 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. ^[8]

• 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. Christopher Landsea, formerly a research Meteorologist with Hurricane Research Division of Atlantic Oceanographic & Meteorological Laboratory at NOAA, is now the Science 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"^[9].

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". Dr Kevin E Trenberth is head of the Climate Analysis Section at the National Center for Atmospheric Research. He has stated that the process of producing the Fourth Assessment Report is "motivated by pre-conceived agendas" and "scientifically unsound". ^[9]

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. "

Further information: Politics of global warming

References