Last week, Working Group I of the Intergovernmental Panel on Climate Change (IPCC) adopted the Summary for Policymakers of the first volume of "Climate Change 2007," also known as the Fourth Assessment Report. The report assesses the current scientific knowledge of the natural and human drivers of climate change, observed changes in climate, the ability of science to attribute changes to different causes, and projections for future climate change. It concludes that the Earth is unequivocally warming, and that the observed temperature increase since the mid-20th century is very likely due to greenhouse gas emissions caused by human activities. The report—produced by some 600 authors from 40 countries—concludes that human influences can now be discerned in ocean warming, larger temperature extremes, and changing wind patterns. The report also hones its determination of the climate's sensitivity to greenhouse gas emissions, concluding that a doubling of carbon dioxide concentrations from pre-industrial levels is likely to increase temperatures by 2 to 4.5 degrees Celsius. See the IPCC press release and the Summary for Policymakers (PDF 2.2 MB). Download Adobe Reader.
Energy Secretary Samuel Bodman welcomed the IPCC report and noted the contributions of U.S. scientists and technologies to the report. In a press conference featuring Secretary Bodman; EPA Administrator Samuel Johnson; and Vice Admiral Conrad Lautenbacher, Administrator of the National Oceanic and Atmospheric Administration (NOAA), the officials noted that the U.S. federal government has invested nearly $29 billion in climate-related science, technology, international assistance, and incentive programs. Because of those efforts, the United States is well on track to meet the President's goal of reducing greenhouse gas intensity by 18 percent by 2012.
Meanwhile, two new reports point the way to using renewable energy and energy efficiency to drastically cut the world's greenhouse gas emissions. A report from Greenpeace International and the European Renewable Energy Council asserts that renewable energy and energy efficiency can meet half the world's energy needs by 2050. The report, called "energy [r]evolution," claims that the United States could cut its greenhouse gas emissions by nearly 75 percent in the same timeframe, and that it will be economically beneficial to do so. That conclusion is supported by a similar report from the American Solar Energy Society (ASES), which asserts that the United States could cut its greenhouse gas emissions between 60 and 80 percent by 2050 through the use of energy efficiency and renewable energy.
