Wildfire is a natural and beneficial part of many of California’s ecosystems. However, the size and severity of California wildfires have increased over the past 40 years resulting in high economic and human costs. A new synthesis study by Southwest CASC-supported authors, including Southwest CASC Deputy Director Carolyn Enquist, in the International Journal of Wildland Fire investigated the complex factors responsible for changing wildfire regimes in California – including climate change, land cover change, and historical land management.  

Authors show that the increase in land burned each year is related to increasing temperatures and dryness) along with shorter winter wet seasons. These hotter and dryer conditions create dryer plant materials that ignite more easily to start and spread fire. There are also site-specific drivers, for instance locations where there has been long-term suppression of traditional Indigenous burning practices, changes to logging practices, or aggressive fire management. While many factors are responsible for wildfire conditions, over 90% of wildfire ignitions in California have been human-caused.  

This Southwest CASC-supported study provides information that can be used to tailor local collaborative solutions to the wildfire challenges across the state of California.