Rising temperatures caused by climate change increased the number of wildfires in the Western United States over the past 34 years, destroying 6.5 times more land than in the 1970s.

Among other factors like land-use changes or forest management practices, the changing climate was the most important factor driving a four-fold increase in the average number of large wildfires in the Western United States since 1970, said a research study seen here on Friday.

The study found that the average fire season has grown more than two months longer, while fires have become more frequent, longer-burning and harder to extinguish.

The average spring and summer temperatures were more than 1.5 degrees higher in Western states between 1987 and 2003 than during the previous 17 years, said the study conducted by researchers at the Scripps Institution of Oceanography in La Jolla, California and the University of Arizona.

Last year was the worst wildfire season on record, with over 8. 53 million acres burned nationwide by the end of December. So far this year, more than 60,000 wildfires have charred almost 3.9 million acres - twice the number of fires during the same period last year, according to the National Interagency Fire Center in Boise, Idaho.

Wildfires cost more than 1 billion dollars a year in federal firefighting expenses, plus untold property damages.

In the first detailed study of its kind, scientists analyzed 34 years of wildfire activity, temperature records, snow-melt trends, stream flows and other climate-related data.

Source: Xinhua