WASHINGTON - August 12 - A number of extreme weather events have been happening around the world this summer, including record flooding in Pakistan that has killed more than 1,000 people and displaced millions of others; the worst drought in Russia in decades, which has triggered wildfires and doubled the daily death rate in Moscow to about 700; and torrential rains in China, which have caused massive flooding and triggered landslides that have killed more than 3,000 people.
 
Meanwhile, here at home, residents in more than 15 states have been sweltering from heat waves that flared in June. Several East Coast cities experienced record-breaking heat last month, which was the hottest one on record in Rhode Island and Delaware.

The devastating heat, fires and floods we are seeing around the world this summer are consistent with trends that scientists say are caused by global warming, including temperature increases, increases in heavy precipitation in some parts of the world, and droughts in others.

The scientists who have been analyzing data over centuries to determine shifts in climate have determined that the Earth’s average temperature has been increasing, mainly due to a build up of heat-trapping emissions caused by burning fossil fuels. According to NASA, 2010 is on track to be the hottest year ever recorded. And the last decade—from 2000 through 2009—was the hottest recorded decade since worldwide record-keeping began more than 100 years ago.

While it may seem counterintuitive, a warming planet generates more precipitation in regions that typically experience rain or snow. That is because a warmer atmosphere absorbs and retains more water from the soil and water bodies—lakes, rivers and oceans. Where storm clouds gather, the atmosphere typically has more water to dump, producing heavier-than-normal storms.

The U.S. Global Change Research Program and U.N. Intergovernmental Panel on Climate Change have found that the heaviest rainstorms and snowstorms are depositing more precipitation today than decades ago. For example, the heaviest storms are now dumping on average 67 percent more precipitation in the Northeast and 31 percent more in the Midwest.

“Climate scientists have been warning for years about the potential for intense heat waves, droughts and drenching rains in various parts of the world,” said Brenda Ekwurzel, a climate scientist with the Union of Concerned Scientists (UCS). “This intense weather is consistent with well-documented climate change trends over the past several decades. Unless we significantly reduce global warming emissions, we’ll likely see even more extreme weather events.”

See a related August 9 Reuters story and a Canadian television evening newscast featuring Brenda Ekwurzel.