Reduction in global area burned and wildfire emissions since 1930s enhances carbon uptake by land

How can we use earth system models to provide policy-makers with better tools to address wildfires?

New research by Environment and Climate Change Canada scientists Vivek Arora and Joe Melton, based in Victoria, British Columbia, helps to answer that question.

In their recent article “Reduction in global area burned and wildfire emissions since 1930s enhances carbon uptake by land” published in the April 2018 edition of Nature Communications, Arora and Melton show that there has been a net increase in carbon dioxide (CO2) absorbed by land from 1960 to 2009. As CO2 is emitted into the atmosphere, about half is taken up by the land and the oceans, and they have found that this figure has been increasing as a result of a decrease in fires.

Research by Environment and Climate Change Canada scientists Vivek Arora and Joe Melton looks at how we can use earth system models to provide policy-makers with better tools to address wildfires

Research by Environment and Climate Change Canada scientists Vivek Arora and Joe Melton looks at how we can use earth system models to provide policy-makers with better tools to address wildfires

While increased population leads to more human-caused fires, it simultaneously suppresses the number of wildfires. This occurrence is in part due to the suppression of wildfires by human activities. For example, increased cropland results in a net decrease in total area burned, since managed landscapes burn less than natural landscapes. In addition, a fragmented landscape suppresses fires, hindering their spread. Therefore, the net effect of increasing population densities globally has been a reduction in wildfires since the 1930s.

Arora and Melton use the land component of the Canadian Earth System Model to illustrate the role of wildfires in affecting carbon uptake over land, which provides a global picture. However, the story changes when we look at certain parts of the world, notably Canada. There has been an increase in fires in our boreal forests, not a decrease, as is seen on a global scale. The authors hope to eventually use the Model to project how fires in Canada may change in the future and predict fire prevalence for the next 50 to 100 years.

Arora says this knowledge will be important to policy- and decision-makers for their consideration in responding to and preparing for wildfires. “For example, how much money do we need to spend to fight fires in future?”

Learn more about the work of Environment and Climate Change Canada’s Canadian Centre for Climate Modelling and Analysis here.