Human activities since the industrial revolution have affected the amount of biomass burned in wildfires. A study published online this week in Nature Geoscience reports that biomass burning rose steadily after 1750, before declining abruptly around 1870.
Jennifer Marlon, Patrick Bartlein and colleagues compiled records of natural charcoal deposited in lakes and peat swamps for the past two millennia. They found that until 1750, global biomass burning patterns closely follow climate variations. However, beginning around the time of the industrial revolution, the amount of burning began to increase, which the researchers associate with increasing population and the use of slash and burn farming techniques. They link the subsequent decline with increased agriculture and livestock grazing, as well as active fire suppression. The changes since 1750 are generally not consistent with climate changes reported for the time, which the team considers as evidence for the increasing influence of human activities.
In an accompanying News and Views article, Andrew Scott writes that this work “is an important contribution to our understanding of the relationship between fire and climate”.