The Intergovernmental Panel on Climate Change ( IPCC ) has concluded that " of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.

Thus methane has a potential of 25 over 100 years but 72 over 20 years ; conversely sulfur hexafluoride has a GWP of 22, 800 over 100 years but 16, 300 over 20 years ( IPCC TAR ).

Even the most credible international assessment body, the Intergovernmental Panel on Climate Change ( IPCC ), has refused to attempt subjective probabilistic estimates of future temperatures.

The IPCC has informed the UNFCCC process in determining what constitutes " dangerous " human interference of the climate system.

The IPCC has broken down current and future impacts of climate change into a range of " key vulnerabilities ", e. g., impacts affecting food supply, as well as five " reasons for concern ", shown opposite.

The IPCC has received the Nobel Peace Prize in 2007 " for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change.

Despite its short atmospheric half life of 7 years, methane has a global warming potential of 62 over 20 years and 21 over 100 years ( IPCC, 1996 ; Berner and Berner, 1996 ; vanLoon and Duffy, 2000 ).

He has been Chair or co-chair of other international scientific assessments, including the IPCC Working Group II, the United Nations Environment Programme / World Meteorological Organization ( UNEP / WMO ), and the UNEP Global Biodiversity Assessment. Professor of Environmental Sciences ; Director of Strategic Development, Tyndall at the University of East Anglia,

* IPCC Third Assessment Report, has extensive coverage of cloud-climate interactions: See, in particular, chapter 7. 2.

In Northern Ireland the Police Ombudsman for Northern Ireland has a similar role to that of the IPCC and PCCS.

Rajendra Kumar Pachauri ( born 20 August 1940 ) has served as the chairperson of the Intergovernmental Panel on Climate Change ( IPCC ) since 2002, which was awarded the Nobel Peace Prize in 2007 during his tenure.

Following the retraction of a flawed projection regarding glacier melt in the IPCC AR4 working group II report, there were calls for him to step down as head of the IPCC, which he has rejected.

When this allegation became public following an unauthorised disclosure, Scotland Yard issued a statement claiming that the officer alleged to have believed this " has categorically denied this in his interview with, and statement to, the IPCC investigators ".

In December 2007, the General Assembly of the Polish Academy of Sciences (), which has not been a signatory to joint national science academies ' statements issued a declaration endorsing the IPCC conclusions, and stating:

The situation has been handed over to the IPCC for consideration.

The term " radiative forcing " has been used in the IPCC Assessments with a specific technical meaning, to denote an externally imposed perturbation in the radiative energy budget of Earth ’ s climate system, which may lead to changes in climate parameters.

More widely, he has contributed to raising awareness to the consequences of global climate change through involvement in the Intergovernmental Panel on Climate Change ( IPCC ).

While Zillman has contributed to the IPCC, unlike others on the IPCC, he has made public comments that indicate his respect for the IPCC process and has defended it from attack:

# Global average temperature and sea level are projected to rise under all IPCC SRES scenarios.

Intensities are also used in projecting possible future scenarios such as those used in the IPCC assessments, along with projected future changes in population, economic activity and energy technologies.

According to IPCC ( 2011 ) estimates of annual losses have ranged since 1980 from a few billion to above 200 billion USD ( in 2010 dollars ), with the highest value for 2005 ( the year of Hurricane Katrina ).

The Intergovernmental Panel on Climate Change ( IPCC ) provides the generally accepted values for GWP, which changed slightly between 1996 and 2001.

Under the Kyoto Protocol, the Conference of the Parties decided ( decision 2 / CP. 3 ) that the values of GWP calculated for the IPCC Second Assessment Report are to be used for converting the various greenhouse gas emissions into comparable CO < sub > 2 </ sub > equivalents when computing overall sources and sinks.

Thousands of scientists and other experts contribute ( on a voluntary basis, without payment from the IPCC ) to writing and reviewing reports, which are reviewed by representatives from all the governments, with summaries for policy makers being subject to line-by-line approval by all participating governments.

** IPCC AR4 WG1 Report Available for Purchase

*** Summaries for Policymakers ( SPMs ) of the IPCC Fourth Assessment Report:

He was a Coordinating Lead Author in Working Group II IPCC TAR and was engaged as a co-anchor of the Key Vulnerabilities Cross-Cutting Theme for the Fourth Assessment Report ( AR4 ) at the time of his death.

* Received a collective Nobel Peace Prize for his joint efforts with the IPCC ( Intergovernmental Panel on Climate Change ) ( 2007 ).

Predictions tools made significant progress during the decade, UN-sponsored organisations such as the IPCC gained influence, and studies such as the Stern report influenced public support for paying the political and economic costs of countering climate change.

He was Chairman of the Global Environment Facility's Scientific and Technical Advisory Panel from 1991 to 1994, Chair of the Intergovernmental Panel on Climate Change ( IPCC ) from 1997 to 2002 and Board co-chair for the Millennium Ecosystem Assessment from 2000 to 2005.

In April 2002 the United States pressed for and won his replacement by Rajendra Pachauri as IPCC chair.

However, as of March 2012, the latest IPCC report on extreme events SREX states that " there is low confidence in any observed long-term ( i. e., 40 years or more ) increases in tropical cyclone activity ( i. e., intensity, frequency, duration ), after accounting for past changes in observing capabilities.

In 2007, more than 20 PNNL scientists were recognized for their contributions to the Intergovernmental Panel on Climate Change ( IPCC ) that received the 2007 Nobel Peace Prize in equal parts with former Vice President Al Gore.

Similarly the IPCC do not classify peat amongst renewable biomass or biofuels, due to the length of time for peat to re-accumulate after harvesting, but as a fossil fuel.

* Dr. Adil Najam, member of the United Nations ' Intergovernmental Panel on Climate Change ( IPCC ) which was awarded the 2007 Nobel Prize for Peace.

These models are the basis for sophisticated model predictions of future climate, such as are discussed by the IPCC.

* Summary for policymakers, a summary of the IPCC reports intended to aid policymakers

" He described the full 2001 IPCC report as " an admirable description of research activities in climate science " although he criticized the Summary for Policymakers.

The IPCC Fourth Assessment Report found that the instrumental temperature record for the past century included urban heat island effects but that these were primarily local, having a negligible influence on global temperature trends ( less than 0. 006 ° C per decade over land and zero over the oceans ).

The scientific consensus is reflected in, for example, reports by the Intergovernmental Panel on Climate Change ( IPCC ) and US Global Change Research Program.

Singer responded with a letter to Science saying the IPCC report had presented material selectively.

He said the leaked e-mails showed that the " surface temperature data that IPCC relies on is based on distorted raw data and algorithms that they will not share with the science community.

This EPA estimate is based on methodologies agreed to by the Conference of Parties of the UNFCCC, with 100-year global warming potentials from the IPCC Second Assessment Report used in estimating GHG emissions as carbon dioxide equivalents.

In the mid-1980s, a 500-page report ( Brundtland Report ) which Bolin was involved with contributed to the setting up of the Intergovernmental Panel on Climate Change ( IPCC ).

Under his chairmanship ( from 1988 to 1997 ), the IPCC produced its First Assessment Report ( 1990 ) and Second Assessment Report ( 1995 ), contributing to the IPCC sharing the 2007 Nobel Peace Prize with former US Vice President Al Gore.

The Intergovernmental Panel on Climate Change ( IPCC ) stated in its Fourth Assessment Report ( AR4 ) that the temperature rise over the 100 year period from 1906 – 2005 was 0. 74 ° C to 0. 92 ° C with a confidence interval of 90 %.

The IPCC shared the 2007 Nobel Peace Prize with former U. S. Vice President Al Gore, who had earlier criticised Pachauri when he was first elected in 2002.

The two Mann, Bradley & Hughes studies, together with, and others formed a major part of the IPCC Third Assessment Report's conclusion that " the rate and magnitude of global or hemispheric surface 20th century warming is likely to have been the largest of the millennium, with the 1990s and 1998 likely to have been the warmest decade and year ".

This list of scientific bodies of national or international standing, that have issued formal statements of opinion, classifies those organizations according to whether they concur with the IPCC view, are non-committal, or dissent from it.

Following the IPCC Fourth Assessment Report, the declaration states, " It is unequivocal that the climate is changing, and it is very likely that this is predominantly caused by the increasing human interference with the atmosphere.

He was a member of the IPCC jointly awarded the Nobel Peace Prize with Al Gore in 2007.

Serious complaints regarding SOCA are dealt with by the Independent Police Complaints Commission ( IPCC ).

The same logarithmic formula applies for other greenhouse gases such as methane, N < sub > 2 </ sub > O or CFCs, with coefficients that can be found e. g. in the IPCC reports.

In a 2007 ruling in a trial relating to automobile emission regulation in Vermont, U. S. District Court Chief Judge William K. Sessions wrote, " Plaintiffs ’ own expert, Dr. Christy, agrees with the IPCC ’ s assessment that in the light of new evidence and taking into account remaining uncertainties, most of the observed warming over the last fifty years is likely to have been due to the increase in GHG concentrations.

: The IPCC is not, as ... many appear to have been led to believe, some ideologically committed group of scientists with a particular position or perspective on the science which they seek to promote.

: In order to avoid the risk of having the IPCC reports made vulnerable to charged of political influence, the IPCC Chairman and the WG Co-chairmen were meticulous in insisting that the final decision on whether to accept particular review comments should reside with chapter Lead Authors.