Policy Documents

Global Climate Change Impacts in the United States

September 27, 2012

This report--an addendum to a 2009 document--notes climate change impacts by sector:  water resources, energy supply, transportation, agriculture, ecosystems, human health, and society.  It also notes regional climate change impacts:  northeast, southeast, midwest, great plains, northwest, and Alaska.

The reports shows that there have been two periods of planetary warming in the past 160 years. However, there has been no significant warming since 1997, and the overall importance of this to global warming science is unclear at this time. The report concludes that reducing "U.S. emissions of carbon dioxide, even by over 80 percent, will have no measurable effect on global mean surface temperature or other climate-change-related phenomena within any policy-forseeable timeframe." Part of the reason for this is because of emissions in China, India, and the developing world.