Human-Induced Climate Change to Blame for the Increasing Forest Fire in the US

A new study from the University of Idaho and Columbia University's Lamont-Doherty Earth Observatory (LDEO) revealed that human-induced climate change is responsible for the increasing area affected by forest fires in the western United States over the last 30 years.

The study, published in the journal Proceedings of the National Academy of Sciences, suggests that the drying effect of the warming climate has doubled the area affected by forest fires in the western US, causing fires to spread an additional 16,000 square miles.

"No matter how hard we try, the fires are going to keep getting bigger, and the reason is really clear," said Park Williams, a bioclimatologist at Columbia University's Lamont-Doherty Earth Observatory and co-author of the study, in a statement. Climate is really running the show in terms of what burns. We should be getting ready for bigger fire years than those familiar to previous generations."

For the study, the researchers used eight different systems for rating forest aridity to measure the effect of warming climate to the forest in western U.S. The researchers then compared their measurement with observations of actual fires and large-scale models that estimated human-induced warming.

The researchers found strong link between increasing dryness of the forests due to warming climate and the area of land affected by forest fires. The researchers also discovered that human-induced climate change could be responsible for about 55 percent increase in fuel aridity that led to forest fires.

Warmer air sucks moisture from the plants, making plants, trees and dead vegetation in the ground to be drier and more prone to fires. Researchers noted that the average temperature of forests areas in western U.S. has reached 2.5 degrees Fahrenheit since 1970. As the average temperatures in the western U.S. continue to intensify and droughts are more frequent and longer than usual, the researchers expect a larger area of the forest to be drier than usual and at risk of forest fire.