Global Study Finds Fire Intensity is Growing at Night
Decades ago, nighttime provided relief for firefighters; temperatures cooled and humidity levels increased, which slowed the spread of blazes. But as the world warms, progressively drier and hotter weather has made nighttime deadly. According to a new study, night fires have become 7.2% more intense globally from 2003 to 2020. In the Western US specifically, night fires have become a whopping 28% more intense.
"Our nights have been warming more than our days…as a function of human-caused climate change, and that’s having a direct impact on fires," said Jennifer Balch, a lead author of the study, to the Washington Post. We're losing the brakes on fires in terms of the cooling and moisture accumulation that happens at night.”
Guardian: The climate science behind wildfires - why are they getting worse?, August 20, 2021.
Why This Matters
Fire-prone communities used to count on cool, wet winters and humid nights to quell fire season, but climate change has made these conditions rare. The ongoing megadrought in the Western US has made winter wildfires -- once a rarity -- more commonplace. In December of last year, Colorado was hit with the Marshall Fire, the most severe wildfire in the state's history. This year, California has already had three fires, including an active fire that broke out Wednesday in Inyo county and has already burned through 3900 acres as of Thursday morning with 10-15 mph winds working against fire fighters’ efforts. Last week, wind and downed power lines resulted in a 159-acre fire along the northern coast of Laguna Beach; and in January, another winter wildfire burned more than 700 acres across the coast north of Big Sur.
Reuters: Scientist says climate change worsened Colorado fire, January 3, 2022.
"Fighting Fires 24/7"
To gather data about how fire spreads at night, scientists used satellite imagery and hourly climate data from 81,000 fires worldwide to calculate the vapor-pressure deficit (VPD). The study found higher VPD overall, adding that there was also a 36% increase of flammable nighttime hours between 1979 and 2020, while daytime flammable hours increased by 27% in the Western US. These conditions make firefighters' jobs even harder. Injuries are more common since it is harder to see dangers like falling trees. And low visibility at night means firefighters have fewer resources, including aircraft, to back them up.
"The fact that firefighters aren't getting a break at night," said Balch, "means that firefighters are fighting fires 24/7."
MSNBC: Climate Change Is Our Greatest Existential Threat, January 3, 2022.
Verge: Why wildfire season never stops, July 2018.
WW0: Dr. Alex Hall & Dr. Mustafa Santiago Ali Discuss the California Fires and Climate Change, September 30, 2020.