Using satellite images, the researchers found the total breadth of these fires has grown by a rate of nearly 90,000 acres per year—roughly equivalent to the size of Nevada.
This increasing problem is most likely tied to rising temperatures and extreme drought related to climate change, according to the report, which will be published in Geophysical Research Letters by the American Geophysical Union.
"These trends suggest that large-scale climate changes, rather than local factors, could be driving increases in fire activity," the scientists write. "The study stops short of linking the rise in number and size of fires directly to human-caused climate change. However, it says the observed changes in fire activity are in line with long-term, global fire patterns that climate models have projected will occur as temperatures increase and droughts become more severe in the coming decades due to global warming."