Fourth Assessment Report

Fourth Assessment Report
Name	Fourth Assessment Report
Caption	Summary cover of the report
Author	Intergovernmental Panel on Climate Change
Country	United Nations member states
Language	English
Subject	Climate change assessment
Publisher	IPCC
Pub date	2007

Fourth Assessment Report

The Fourth Assessment Report was a comprehensive evaluation produced in 2007 by the Intergovernmental Panel on Climate Change, synthesizing research from the United Nations Framework Convention on Climate Change, contributions by World Meteorological Organization, and studies from institutions such as National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, Hadley Centre for Climate Science and Services, and Lawrence Livermore National Laboratory. It integrated peer-reviewed literature from research groups at Massachusetts Institute of Technology, Stanford University, University of Cambridge, University of Oxford, and Chinese Academy of Sciences to inform policy deliberations at meetings like the Bali Conference and the Copenhagen Summit.

Overview

The report was coordinated by the IPCC with inputs from hundreds of authors affiliated with European Commission, National Science Foundation, Russian Academy of Sciences, Indian Institute of Science, and Commonwealth Scientific and Industrial Research Organisation, and was presented to representatives of member states including delegations from United States, China, India, Brazil, and South Africa. It provided assessments used by decision-makers at forums such as the G8 summit and the Group of 77 consultations, and influenced negotiations under the Kyoto Protocol and subsequent processes related to the Paris Agreement dialogues.

Key Findings

The assessment presented conclusions on observed warming, attribution, projections, and impacts that drew on data from observatories like Mauna Loa Observatory, reconstructions such as those by Michael E. Mann and teams at University of East Anglia, and satellite records from European Space Agency, JAXA, and NOAA. It reported that warming of the climate system was unequivocal, linked to increases in greenhouse gases identified by analyses at Scripps Institution of Oceanography, Max Planck Institute for Meteorology, and Potsdam Institute for Climate Impact Research. Projections used scenarios developed by groups including International Institute for Applied Systems Analysis, IIASA, and the Intergovernmental Panel on Climate Change's scenario teams, citing potential outcomes discussed by researchers at IPSL and NCAR. The report also assessed sea level rise, ice-sheet dynamics studied at Columbia University, permafrost thaw observed by teams from University of Alaska Fairbanks, and impacts on ecosystems evaluated by United Nations Environment Programme researchers alongside conservation bodies like World Wildlife Fund.

Methodology and Structure

Methodology combined model intercomparisons from projects such as Coupled Model Intercomparison Project and evaluations using observational networks maintained by Global Climate Observing System, International Arctic Research Center, and Antarctic Treaty System research stations. The structure comprised three Working Group reports and a Synthesis Report, following procedures established at IPCC plenaries attended by delegates from United Nations Environment Programme, World Health Organization, International Maritime Organization, and national academies including the Royal Society and National Academy of Sciences. Peer review cycles engaged experts from institutions like Harvard University, Yale University, Australian National University, and University of Cape Town.

Working Group Contributions

Working Group I addressed physical science basis with lead authors from NOAA, Met Office Hadley Centre, Max Planck Institute for Meteorology, Russian Academy of Sciences, and Chinese Academy of Sciences using output from centers such as GFDL and ECMWF. Working Group II examined impacts, adaptation, and vulnerability with contributors affiliated to International Council for Science, World Bank, Asian Development Bank, European Environment Agency, and universities including University of Nairobi and Universidad Nacional Autónoma de México. Working Group III evaluated mitigation options drawing on analyses from International Energy Agency, OPEC-adjacent research, Petroleum Institute studies, and energy modeling teams at Princeton University and Tsinghua University. The Synthesis Report integrated cross-cutting findings for policymakers from multilateral bodies like United Nations Framework Convention on Climate Change meetings and regional conferences such as the Arctic Council.

Reception and Impact

The report received attention from governments including the European Union institutions, the United States Congress, and cabinets in Japan and Australia, influencing legislation and commitments discussed in parliaments of Canada and Germany. It informed reports by World Bank, shaped research funding at agencies like European Research Council, and prompted scientific collaborations among centers such as Potsdam Institute for Climate Impact Research and Stockholm Environment Institute. Media coverage by outlets including BBC, The New York Times, and The Guardian amplified its findings, and civil society organizations such as Greenpeace and Sierra Club used it in advocacy related to policies discussed at the G8 and COP meetings.

Criticisms and Controversies

Controversies involved debates over paleoclimate reconstructions associated with work by Michael E. Mann and exchanges with researchers at University of East Anglia; policy commentators in publications such as The Wall Street Journal and analyses by think tanks like Heritage Foundation raised questions about uncertainties and model projections from centers including Hadley Centre. Scientific critique involved independent assessments by experts at National Academy of Sciences and investigations into editorial practices at research centers including the University of East Anglia Climatic Research Unit. Discourse in national legislatures and hearings in bodies such as the United States Senate reflected contested interpretations of conclusions and uncertainty statements debated among panels including members of Royal Society and panels convened by InterAcademy Council.

Category:Intergovernmental Panel on Climate Change reports