IPCC 4th Assessment Report: Working Group I Report “The Physical Science Basis” (2007). This working group contribution to the IPCC 4th Assessment Report describes progress in understanding the human and natural drivers of climate change, observed climate change, climate processes and attribution, and estimates of projected future climate change. See also IPCC 4th Assessment Report: Summary for Policymakers.
Policy Implications of Warming Permafrost, United Nations Environment Program (Nov. 27, 2012). This report finds that thawing of permafrost found in colder climates may potentially accelerate the pace of global warming through 2100 and beyond by releasing vast amounts of carbon dioxide and methane stored beneath the Earth's surface. This could result in a loop known as permafrost carbon feedback, as emissions released from the subsurface layer increase Earth's surface temperature, which then accelerates further thawing of the permafrost. The report recommends a special assessment of the topic by the U.N. Intergovernmental Panel on Climate Change and the creation of national monitoring networks and adaptation plans to deal with potential impacts.
U.N. Weather Agency Says Concentrations of Greenhouse Gases Reach New Record in 2011, World Meteorological Organization (Nov. 20, 2012). Concentrations of greenhouse gases in the atmosphere reached another record high in 2011, with growth in atmospheric carbon dioxide continuing to increase at a steady rate, according to the WMO’s annual Greenhouse Gas Bulletin. The report finds that concentrations of carbon dioxide, methane, and nitrous oxide, the main greenhouse gases contributing to global warming, all increased in 2011. WMO Secretary-General Michel Jarraud said in a release that the figures provide further evidence that global warming is in line with the “worst case” scenario outlined by the Intergovernmental Panel on Climate Change (IPCC) in its 2007 report. That scenario projected an increase in global average temperatures of between 2.4 and 6 degrees Celsius by the end of the century.
Climate Change Science Compendium 2009, U.N. Environment Programme (September 2009). This report provides a review of major scientific findings, interpretations, ideas, and conclusions related to earth systems and climate released through peer-reviewed literature or from research institutions since the close of research for consideration by the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. The report examines evidence of unexpected rates of change in Arctic sea ice extent, ocean acidification, and species loss and finds that many of the predictions at the upper end of the IPCC's forecasts are becoming increasingly likely.