NOAA: Severe wildfire seasons more likely

A Dec. 15 National Oceanic and Atmospheric Administration (NOAA) report shows that the likelihood of a severe fire season in Alaska, similar to 2015 when more than 5.1 million acres burned, has risen significantly (34-60%) due to human-caused climate change. The 2015 Alaska fire season burned the second largest number of acres in Alaska since records began in 1940.

The report is part of a 153-page NOAA report focusing on extreme weather-related phenomenon from across the globe and part of a special edition of the Bulletin of the American Meteorological Society. The fifth edition of Explaining Extreme Events from a Climate Perspective includes 25 peer-reviewed research papers that examine episodes of extreme weather from 2015 over five continents and two oceans, according to a press release issued by NOAA.

The report features the research of 116 scientists from 18 countries analyzing both historical observations and changing trends. It also included model results to determine whether and how climate change may have influenced the event.

The strongest evidence for a human influence was found for temperature-related events – the increased intensity of numerous heat waves, diminished snowpack in the Cascades, record-low Arctic sea ice extent in March and the extraordinary extent and duration of Alaska wildfires, according to the report. The report stated the Alaska 2015 fire season in Alaska was remarkable for its early-season total acres burned.

Report authors concluded , the wildfires resulted from fuel flammability due to the warm and dry conditions of May and June, and lightning-induced ignitions in June. authors concluded in the research paper. It stated mid-summer rains likely prevented a new record for area burned in Alaska in 2015. Here in the Mat-Su, the mid-June 2015 Sockeye Fire near Willow burned more than 7,200 acres over an approximate five-week period. It destroyed a reported 55 residences, numerous outbuildings, and killed a number of pets and livestock.

“An attribution analysis indicates that 2015’s fuel conditions reached a level that is 34%–60% more likely to occur in today’s (human influenced) climate than in the past. The major uncertainty in such an attribution assessment is the as-yet unknown relationship between climate change and the major lightning events that ignite widespread fires,” the report stated .”

Despite an early start to the state’s 2016 wildfire season, Alaska’s Division of Forestry (ADF) reported the number of burned acres ended up well below normal. A total of 558 blazes burned just over a half-million acres, making it the 36th largest fire season on record dating back to 1939 when statistics began. Alaska averages about 500 fires annually which consume an average of one million acres, according to ADF.

ADF reported, as is usually the case, the majority of wildfires in Alaska in 2016 were human caused. Fifty-nine percent of wildfires (331) were caused by humans and 41 percent (227) were started by lightning.

Alaska Division of Forestry Fire Behavior Analyst Robert ‘Zeke’ Ziel, along with meteorologists Sharon Alden and Heidi Strader from the Alaska Interagency Coordination Center, were contributing authors for the research paper titled, “An Assessment of the Role of Anthropogenic Climate Change in the Alaska Fire Season of 2015.” They worked with scientists and researchers from the National Weather Service and University of Alaska Fairbanks to develop the paper.

To read the full report or the research paper on the 2015 Alaska fire season, go to:

https://www.ametsoc.org/ams/index.cfm/publications/bulletin-of-the-american-meteorological-society-bams/explaining-extreme-events-from-a-climate-perspective/