A significant body of research suggests that the likelihood and impact of wildfires today may be greater as a result of climate change. Let’s examine some of the specific trends regarding the size and frequency of wildfires in more detail.
1. Wildfires are Definitely Getting Larger
While a variety of factors — including human behaviors, wind levels, vegetation, humidity levels, and more — contribute to the likelihood of wildfires, the impact of climate change is becoming increasingly apparent.
It’s a fact that six of California's largest fires in history ignited in 2020, and the damage and toxic smoke exposure extended far beyond state lines.
The massive August Complex fire in 2020 also developed to become the largest fire in the state's history, period:
Before these record-breaking wildfires, scientists were already grabbing headlines in 2019 by stating that wildfires in California had become 500% larger since 1972 as a result of climate change.
These trends aren’t unique to the U.S:
Europe: In 2017, fires burned nearly three times more than the historic rate of 1,500 square miles in the EU.
Australia: In 2019, Australia’s NSW Rural Fire Service went on record as stating that the New South Wales 2019 fires were unprecedented for that point of the fire season.
Fire authorities across Australia in 2019 also highlighted the shocking continental-scale nature of the threat they were facing and underlined how the geographic range of fires that they were facing all at once was something entirely new.
Siberia: Reports state that in 2020, wildfires in Russia burned down an area larger than the size of Greece, prompting an emotional plea from Greenpeace’s Russia Wildfire Unit Head Grigory Kuksin:
“Russia’s sprawling Siberia region became a climate hotspot, heating up much faster than the rest of the planet. This summer has already brought extreme heat waves, oil spills caused by thawing permafrost, and raging forest fires – what next before we finally act on climate?
2. Wildfire Seasons Are Getting Longer
Fire seasons vary in duration based on location. However, lengthening fire seasons may be due in large part to climate change. As winter snowpacks melt earlier, forests’ dry periods are stretched longer.
One study based on 35 years of meteorological data revealed that fire seasons around the globe had become longer than ever before. In particular, their findings were:
The average wildfire season length has increased by nearly 19% between 1978 and 2013.
Parts of the western United States, Mexico, Brazil, and East Africa now undergo wildfire seasons that are more than a month longer than they were 35 years ago.
Lengthening wildfire seasons also held true for European countries: Scandinavia experienced significant growth in the length of their wildfire seasons, Sweden witnessed a 41% increase in fire season length while Norway suffered a staggering 288% increase.
US Firefighters Transition from ‘Fire Seasons’ to ‘Fire Years’
In America, increasingly common wildfires have prompted USDA Forest Service employees to reconfigure the way they speak and learn about wildfires: Where once they spoke of 'fire seasons' which typically occurred at certain points of the year, many now prepare for wildfires as an all-year-round event.
3. More Heatwaves Means More Fires
As droughts become more common, so too do adjacent heatwaves.
Meteorologists predicted that in June 2019, temperatures would climb above 40 degrees Celsius (104 degrees Fahrenheit) across large stretches of Europe and they were correct: In the summer of 2019, two extreme heatwaves hit Western Europe - historical records were smashed in a number of locations.
In August 2020, California’s record-breaking wildfire season began with nearly 14,000 lightning strikes over a 72 hour period, setting off more than 900 fires that month. After a hot, dry summer, there was little rain to quell the fires and according to the New York Times, in some cases the heat caused the rain to evaporate before it even hit the ground.
Unfortunately, increasingly common heatwaves like this spell trouble both for human health and for wildfires, as hotter, drier conditions function as a key contributor to the proliferation of wildfires.
The Verdict? Pretty Likely
Some argue against a clear link between climate change and forest fires. Some deny climate change at all. However, these views are not commonly accepted positions within the wider scientific community.
In August 2020, Daniel Swain, a climate scientist at UCLA and the National Center for Atmospheric Research, stated in no uncertain terms;
“at this point, it’s certainly clear climate change is increasing the intensity and frequency everywhere….even in very different kinds of geographies and climates. The blackouts rolling across the state over the weekend would be far less likely if temperature remained just a few degrees lower”.
Whatever the wider debate surrounding wildfires and how best to prevent and handle their fallout, all signs point to a strong connection to climate change. It is likely that our changing climate will continue to play a huge role in our understanding & preparing for wildfires for the coming months, years, and decades.