The smoky haze Minnesotans experienced earlier this week was the result of an unusually high number of wildfires burning in Alaska and western Canada.
On this week's Climate Cast, we looked at how climate change contributes to these fires in boreal forests and is also fueled by them in what MPR Meteorologist calls a feedback loop.
"There has been a fairly significant increase in fire activity in the North American boreal region over the past four to five decades," said Eric S. Kasischke, a professor of geographical sciences at the University of Maryland.
More late-season fires are also problematic to the environment, he said on MPR News with Kerri Miller.
"That actually adds more carbon dioxide to the atmosphere because you're burning deep organic soils that are present in these boreal forests that contain large amounts of carbon," Kasischke said.
The larger amounts of carbon develop in these forests because of the permafrost that prevents organic matter from decomposing. When fires hit these forests later in the season, the soil is thawed and burns deeper, he said.