Researchers: Climate change increases fire season severity

FAIRBANKS, Alaska (KTVF) - The 2015 Alaska fire season burned the second largest number of acres since records began in 1940.

According to University of Alaska researchers, human-induced climate change may have increased the risk of a fire season of that severity by 34 to 60 percent.

A report published over the winter by eight university of Alaska researchers concludes that climate change has strongly increased the prospects of a massive wildfire season like the one Alaska experience in 2015, which burned 5.1 million acres throughout the state.

"There was a big lightning burst in mid-June, and it ignited about 300 fires that grew very, very rapidly at a pace that we have never seen before," said Alison York of the Alaska Fire Science Consortium.

The Alaska wildfire study looked at the probability of climate change contributing to another fire season on the scale of 2015.

"The models show us that compared to a pre-industrial period which is a model time when the cO2 in the atmosphere, the amount of carbon dioxide, was in lower concentration," said Peter Bieniek, research associate at the International Arctic Research Center. "Compared to that period, temperatures are actually warmer, but also wetter. When we look at fire indexes, that blend actually tells us that such extreme fire seasons are more likely in the present climate thanks to climate change, thanks to human induced climate change."

The model predicts that Alaska temperatures will rise by 1 to 2 degrees Celsius by 2050, added warmth that will offset an anticipated 15 to 30 percent increase in precipitation.

"When we use these fire weather indexes that actually takes into account temperature, humidity, moisture, all of that and compares that with fuel moisture, the real moisture in the plants and stuff that burns. That integration between those processes tell us that actually the warmer and wetter leads to higher fire risk and higher risk of these types of extreme fire years," said Bieniek.

The report also indicates there is a lot of variability from year to year to make a big fire season.

"Records for the fire season in Alaska are not that long. This research group is still grappling with the question of how definitive can we be in generally saying that climate change has increased extreme fire seasons in recent years. Although at the same time, I think our gut feeling is that, yes, it has," said York.