How Wildfires Have Changed Over the Last 20 Years
Climate Change Series:
Consistent with a warming climate, wildfire season has lengthened across a quarter of the world’s vegetated surface.
Rising temperatures create drier conditions, drier conditions result in forest fires, forest fires produce carbon emissions, more carbon in the atmosphere results in higher temperatures … and so the circle goes.
This summer many countries across the globe are experiencing the worst wildfires in years of recorded history, with entire towns like Lytton, British Columbia almost totally consumed along with massive swaths of land.
According to the Global Fire Emissions Database, over the 1997 – 2016 period, the average annual fire emissions were 2.2 picograms of carbon (PgCyr-1).
Fires in Different Regions – Global
The relative impact of different regions or continents globally, however, varies depending on what is being considered, the burned area, carbon emissions, or trace gas emissions.
For instance, Equatorial Asia, though responsible for only 0.6% of the global burned area, accounts for 8% of carbon emissions and 23% of methane (CH4) emissions.
Fires in Different Regions – Regional
According to the World Resources Institute, emissions from wildfires in 2020 were 3 times higher than usual in California, Oregon and Washington.
However, scientists at Europe’s Copernicus Atmosphere Monitoring Service (CAMS) note that though fire activity hot spots such as experienced in the western U.S. reached new extremes, global fire emissions have decreased since they began to measure them in 2003, due to better fire management and mitigation measures.
Although one hopes this global trend continues, some of the worst fires in 2021 have occurred in the Siberian Yakutia region, with almost 4.2 million hectares burned so far this year and CAMS stated that as of August 4th, fires in this area had unleashed 505 megatonnes of carbon dioxide equivalent, surpassing the 2020 record of 450 megatonnes for the entire fire season.
GFED – Global Fire Emissions Database
Pg Cyear-1 – picograms of carbon per year; one picogram is equal to 1000 teragrams
Tg Cyear-1 – teragrams of carbon per year; one teragram is equal one trillion grams