In a paper published this week as a research article in the journal Science, Niels Andela and coauthors show that global burned has declined by nearly a quarter over the past two decades. The loss of fire was greatest in savanna and grassland ecosystems across northern Africa, the Eurasian steppe, Latin and South America, and some areas of Southeast Asia and Australia. Taking fire as an indicator of ecosystem health, the rapid decline in burning points to a profound, human-driven transformation of savanna and grassland ecosystems over the past 20 years. The authors show that significant increases in population, livestock density and cropland areas are important contributors to the decline in fire activity, and that the changes in fire are modifying atmospheric composition and ecosystem structure. State-of-the-art prognostic fire models could not reproduce the magnitude of the declining trends, suggesting that more research is needed to understand how land use change modified fire dynamics. Niels is a UCI postdoctoral scholar and NASA research scientist who works at Goddard Space Flight Center. He is co-advised by Douglas Morton and Jim Randerson. News reports about the study include articles in the Washington Post and Popular Science. NASA and UC Irvine released additional information about the study.
Figure caption: Expansion of crop production has fragmented many savanna landscapes, restricting fires to remaining patches of natural vegetation. This false-color Landsat8 image from the Brazilian Cerrado shows an actively burning fire in a fragment of remaining savanna vegetation, surrounded by agricultural fields. Fire scars from other recent burns appear maroon (Douglas Morton, NASA).
The study was funded by the Gordon and Betty Moore Foundation, NASA, and other sources. The data we used in the study can be found at: