A Human-Driven Decline in Global Burned Area

NASA satellite data provide a consistent global record of fire activity. Years with more fire (red) and less fire (blue) highlight how different biomes respond to climate variability. In forests and the humid tropics, most burning occurs in dry years. In more arid savannas, wetter years increase burned area—more rainfall grows more grass, adding fuel for future fires.

During 1998-2015, global burned area declined by nearly 25%. The trend map shows strong declines in burned area (blue) across the savannas and grasslands of Africa, the Eurasian Steppe, and South America. A rapid increase in agriculture, livestock, and population reduced burning in these highly flammable ecosystems. Less burning has benefits, including improved air quality and increasing the land carbon sink. However, less frequent burning may convert open savannas into shrublands or woodlands, eliminating habitat for many endemic species, including iconic lions, elephants, and other large mammals.