The Intergovernmental Panel on Climate Change (IPCC), whose workings were probed in a report published in New York on Monday, is the top scientific authority on global warming.
Set up in 1988 by the UN's World Meteorological Organisation (WMO) and Environment Programme (UNEP), the IPCC comprises around 3,000 atmospheric scientists, oceanographers, ice specialists, economists, public-health specialists and other experts.
Their task is to give policymakers a neutral and balanced update, known as an assessment report, of the latest knowledge about climate change and its impacts.
The IPCC comprises three working groups of men and women, nominated by governments and international organisations, whose full-time job is usually at research institutes and universities.
They trawl through thousands of peer-reviewed and published literature and summarise these findings; the IPCC does not conduct research of its own.
Working Group 1 deals with the pure scientific evidence for global warming and its effect on climate; Working Group 2, with the impacts of climate change; and Working Group 3, with how to tackle the problem.
Each group submits a draft summary that undergoes a two-stage review by outside assessors and governments. The document is then submitted to a plenary, when it can be vetted line-by-line or even word-by-word before the final version is approved by consensus.
The IPCC proudly describes it as the biggest and most frequently updated peer-review process in the world, although it has also been criticised for being cumbersome and outmoded in its working methods.
The 938-page Fourth Assessment Report, which appeared in 2007, gave the most emphatic warning yet about the threat from greenhouse gases.
The shock unleashed political momentum that culminated in the December 2009 Copenhagen Summit, attended by more than 120 leaders in the search for a post-2012 pact on greenhouse gases.
The conference was the biggest summit in UN history, although it veered close to fiasco.
The IPCC, meanwhile, shot to fame. It won the 2007 Nobel Peace Prize; along with former US vice president Al Gore, and its chairman, Rajendra Pachauri, supped with heads of state and shook the hands of rock stars and Hollywood actors.
But the panel's rise, and Pachauri's management style, also earned it closer scrutiny, especially from climate skeptics and fossil-fuel lobbyists.
First came "Climategate," or the assertion, derived from intercepted emails from among key British scientists, that evidence had been skewed in favour of alarm.
The scientists were cleared by a parliamentary inquiry and an independent review, but they were also criticised for lacking openness towards public requests for information.
Then came potentially far more damaging criticism on the grounds of accuracy and working methods.
Working Group 2's section in the Fourth Assessment Report was found to have erroneously predicted Himalayan glaciers, which provide water to a billion people, could be lost by 2035.
The reference was found to have come from a press article, not from a scientific journal, a mistake the IPCC has admitted.