Eastern US heading for 110 degree summers

Stan Beer
Friday, 11 May 2007 07:35

Science - Climate

Greenhouse gas induced global warming looks set to turn the eastern region of the US into a sweltering hotbox within decades, with cities such as Chicago and Washington DC baking under 110 degree Fahrenheit (43.3C) summers, according to a new study.

The study conducted by NASA scientists predict that global warming may raise average summer temperatures across the eastern region of the US by 10 degrees Fahrenheit over the next 70 years.

Average summer temperatures currently fall in the low to mid 80 degrees range. By 2080, typical summers in eastern US will average 90 degrees plus, according to the report. And the heating effect will be more pronounced in summers where rainfall is lower than usual. If the predictions are correct, an average day in Chicago, Washington or Atlanta during July and August would see temperatures max out between 100 and 110 degrees.

The prediction is based on 30 years of observed temperature and rainfall data and computer simulations based on a widely used weather prediction model which took into account soil, atmospheric, and oceanic conditions and projected changes in greenhouse gases.

According to the report, the predicted higher temperatures are linked to both lower rainfall and ocean surface temperatures in a feedback loop.

"Relatively cool waters in the eastern Pacific often result in stubborn summer high-pressure systems over the eastern states that block storms, reducing the frequency of precipitation below normal,” according to study co-author Richard Healy of the Woods Hole Oceanographic Institution.

"Less frequent storms result in higher surface and atmospheric temperatures that then feedback on the atmospheric circulation to further reduce storm frequency and raise surface temperatures even more."