NEWS

The western U.S. heats up faster—report

03/28/2008

Christa Marshall, ClimateWire reporter

Temperatures in the Colorado River Basin soared twice as fast than those in the rest of the world over the past five years, according to a new report summarizing data from the National Oceanic and Atmospheric Administration.

From 2003-2007, the basin—which provides water to swaths of the western United States and is in the middle of a stifling drought—experienced temperatures 2.2 degrees Fahrenheit higher than the 20th century historical average, compared to about a 1 degree increase worldwide over the same time period.

"The speed of warming and mounting economic damage make clear the urgent need to limit global warming pollution," said Theo Spencer of the Natural Resources Defense Council, which released the report with the Rocky Mountain Climate Organization (RMCO), a coalition of local governments, businesses and nonprofits.

Along with assessing the basin’s climate, the report’s authors examined temperature data from 11 Western states and found they witnessed temperatures 1.7 degrees higher than the 20th century average over the same five-year period.

‘Science doesn’t have a complete answer’

"Science doesn’t have a complete answer" for why temperatures are soaring at a faster rate in the West than in the rest of the United States, said Martin Hoerling, a NOAA meteorologist at the Earth System Research Laboratory in Boulder.

A naturally occurring drought, along with warming attributed to carbon dioxide emissions, has exacerbated the problem, he said.

Hoerling said that some of the consequences of warming in the West described in the report could worsen, as scientific projections indicate temperature could rise as high as 4 degrees by the middle of the 21st century.

Those effects in the West include increased wildfires, heat waves, melting glaciers in Montana and a raging bark beetle epidemic that is killing pine trees and threatening the nut supply of grizzly bears in Yellowstone National Park.

The Colorado River provides water to millions of people in some of the fastest-growing cities in the United States, including Denver, Las Vegas, Phoenix and San Diego.