Researchers from the Earth Institute at Columbia University have concluded that many, though not all, California wildfires are a result of a warming climate.
The study, published in Earth’s Future, analyzed the factors known to promote wildfires and concluded that recent summer fires have a connection to dry ground conditions brought on by increased heat. Average summer temperatures in California have risen 3.25 degrees Fahrenheit since 1896, with three-quarters of that rise occurring since the 1970s.
Study lead author Park Williams said it’s hard to give a single reason for wildfires across California, especially given the wide-ranging variability of the state’s forests. Williams’ 2016 study showed that arid conditions increased the size of the wildfires, but further research was needed to determine how the fires began. Williams’ most recent study aimed to understand if dry conditions were responsible.
The researchers analyzed fire data from the last 100 years and found that growing temperature-induced arid ground conditions accounted for nearly all the growth in forest fires from 1972-2018.