While scientists have long hypothesized that climate change could cause wildfires in the western US to worsen, they had no way of quantifying the increase in damage – until now, thanks to a new study published Monday in the Proceedings of the National Academy of Sciences.
Now, researchers have determined human-driven climate change has doubled the amount of land burned by wildfires over the last three decades – an increase of 16,000 square miles, or about the same size as Massachusetts and Connecticut combined, according to the Los Angeles Times.
“No matter how hard we try, the fires are going to keep getting bigger, and the reason is really clear,” study coauthor Park Williams, a bioclimatologist at Columbia University in New York, explained 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.”
“A lot of people are throwing around the words climate change and fire – specifically, last year fire chiefs and the governor of California started calling this the ‘new normal,’ lead author John Abatzoglou, a professor of geography from the University of Idaho, added. “We wanted to put some numbers on it.”
Trend expected to worsen over the next ‘three to four decades’
Abatzoglou, Williams and their colleagues used wildfire data, large-scale climate models and eight established techniques for measuring forest aridity, the Times explained. They determined that between 1979 and 2015, climate change increased the dryness of this land by 55%. Half as much land would have burned if these changes never took place.
Furthermore, the researchers discovered the role of climate in increasing the aridity of wildfire fuel has increased since 2000 and would continue to do so. In short, as the Washington Post said, they found a strong link between increased dryness and how much land impacted by forest fires, that more than 75% of the changes in burned area over the past 30 years was due to dryness.
Forest fires in California have been a huge problem for the state as droughts increase in frequency and intensity (Credit: Thinkstock)
They then turned their attention to see what percentage of those changes were the direct result of human-caused climate change. They found that warming caused by our activities caused slightly more than half of observed increase in fuel dryness, and that the other half could be attributed to natural climate variations, according to the Post. Nonetheless, their findings indicate that humans were responsible 16,000-plus square miles of additional forestland being burned since 1984.
This summer, approximately three million acres of forest have burned throughout the US, with most of that taking place in the western states. While that’s a significant amount, the authors are quick to note that it is not a record – although some scientists believe that the worst may be yet to come, as in some locations, the most dangerous conditions take place during the last four months of the year, when desert winds interact with increasingly dry environments.
Some experts believe that eventually forests will become too few and far between for wildfires to spread easily. However, Williams believes that “there’s no hint we’re even getting close to that yet. I’d expect increases to proceed exponentially for at least the next few decades.” In fact, he told the Post that there was “a very high likelihood” that wildfires “in the next three to four decades” would be “dwarfing the fires that we see today.”
—–
Image credit: Thinkstock
Comments