For the first time, data show that cataclysmic infernos are increasing in frequency and intensity globally.

The frequency at which extreme fires occur around the world has more than doubled during the past two decades, according to an analysis of satellite data1. The trend is driven by the exponential growth of extreme fires across vast portions of Canada, the western United States and Russia, researchers say.

The results provide the first solid evidence to support a nagging suspicion that many scientists and others have had as they watch a seemingly endless series of cataclysmic infernos scorch ecosystems and communities: wildfires have increased somehow, and climate change is almost certainly a factor.