Do Humans Contribute to Increased Fire in Southcentral Alaska?

A pair of new 2021 papers take different tracks to assess the impact of human activities and anthropogenic climate warming, on fire season in south central Alaska. We still remember how smoke choked the Kenai and Matsu boroughs in 2019, for most of June-August. A University of Alaska team tallies the impacts–in $$, losses, and human health, while also placing the season in a historical context to look for anthropogenic influence. They deemed human influences thus far were less important than weather, but would become more of a factor by mid-century. An important finding was that heating seemed to overpower increased precipitation (over longer timescales): “The effect of warming temperatures dominates the effect of enhanced precipitation in the trend towards increased fire risk.” Read the full paper HERE: Uma S. Bhatt, et al. 2021. Emerging Anthropogenic Influences on the Southcentral Alaska Temperature and Precipitation Extremes and Related Fires in 2019. Land. 2021; 10(1):82.

A second team, led by Princeton scientist Yan Yu, did a different type of analysis and tried to incorporate other factors such as anthropogenic ignitions, population density, and increased conifer biofuels. Although the increased fuels may be largely an assumption in their paper, at least for the Kenai region it is validated by Carson Baughmann’s (USGS) 2020 study: Four decades of land-cover change on the Kenai Peninsula, Alaska: detecting disturbance-influenced vegetation shifts using Landsat Legacy data. Yu’s team asserts there is evidence that part of the increase in fire risk is human-caused: “The . . . model indicates a threefold increased risk of Alaska’s [southcentral region] extreme fires during recent decades due to primarily anthropogenic ignition and secondarily climate-induced biofuel abundance.” Read their paper HERE: Yan Yu, et al. 2021. Increased Risk of the 2019 Alaskan July Fires due to Anthropogenic Activity, Bulletin of the American Meteorological Society 102(1): s1-s7.