This is an excerpt from EERE Network News, a weekly electronic newsletter.

August 04, 2010

Past Decade was Warmest on Record, According to Scientists in 48 Countries

The Earth has been growing warmer for the past 50 years, and the past decade was the warmest on record, according to a new report from the National Oceanic and Atmospheric Administration (NOAA). State of the Climate in 2009, released on July 28, draws on the contributions of more than 300 scientists from 160 research groups in 48 countries. The report examined 10 key climate indicators, which all indicate that the world is warming. Seven indicators are rising: air temperatures over land, sea-surface temperatures, air temperatures over oceans, sea levels, ocean heat contents, humidity, and temperatures in the troposphere, the active weather layer of the atmosphere that is closest to the Earth's surface. The three declining indicators are arctic sea ice, glaciers, and spring snow cover in the Northern Hemisphere. The report finds not only that the 2000s was the hottest decade on record but also that each of the last three decades was much warmer than the previous decade. The report concludes that the world is moving toward a new climatic state that is consistently warmer, making it more likely for some areas to see more extreme events like severe drought, torrential rain, and violent storms. See the NOAA press release, the 2009 State of the Climate report Web site, and the NOAA Climate Services Web site.

Meanwhile, a new report from Stanford University finds that heat waves and extremely high temperatures could be commonplace in the United States within 30 years. The study drew on two dozen climate models to project what would happen in the United States if increased carbon dioxide emissions raised the Earth's temperature by another 1.8°F, to 3.6°F hotter than the pre-industrial era, a scenario considered likely by the International Panel on Climate Change. The study projects that from 2030 to 2039, most areas of Arizona, Colorado, New Mexico, and Utah could endure at least seven seasons equally intense as the hottest season ever recorded between 1951 and 1999. The climate modeling, which used unprecedented high-resolution simulations, found that an intense heat wave was likely to occur as often as five times between 2020 and 2029, and that the following decade would be even hotter. The study found persistent hot, drier conditions over most of the United States by the 2030s, posing serious risks to human health and agriculture and leading to more droughts and wildfires. DOE provided partial support for the study. See the Stanford University press release.