Four main reasons that California and other Western states are particularly prone to deadly blazes, which are intensifying as the world warms. All fires need fuel and a spark. In the West, fuel is plenty, with flammable pine needles, shrubs and grasses that can ignite easily. And while the region’s dry vegetation has always made it prone to fires, climate change is intensifying wildfires and lengthening fire season. There’s not necessarily an increase in the number of fires in the West, “but the fires are bigger, more severe, and last longer so the total area burned per year is rapidly increasing,” said Morgan Tingley, an ecologist at the University of California, Los Angeles, who studies the effects of wildfire on Western ecosystems. …There are four key factors. Climate and landscape. …Climate change. …Fire suppression. …Human settlement. (to access the full story a NY Times subscription is required).