Wildfires Got Better Before They Got Worse

(Bloomberg Businessweek) -- One evening in 1861, Samuel Clemens, aka Mark Twain, started a cooking fire along the Nevada shore of Lake Tahoe that jumped to the surrounding forest. In his memoir Roughing It, Twain described how he retreated to his boat just offshore and watched the flames spread “till as far as the eye could reach the lofty mountain-fronts were webbed as it were with a tangled network of red lava streams.”

It’s a reminder, if perhaps a somewhat embellished one, that giant wildfires of the sort tormenting California and other Western states this summer are not a new thing. Wildfires appear to have been far more widespread in the 19th and early 20th centuries than they are now. The National Interagency Fire Center cautions that its pre-1983 numbers aren’t entirely reliable, but its plot of acres burned since the 1920s is consistent with both anecdotal accounts and scientific research: One recent study of sedimentary charcoal concluded that wildfire incidence in the Western U.S. hit a 3,000-year low in the late 20th century.

None of this, though, is inconsistent with the impression that wildfires have been getting worse. The number of acres burned each year dropped sharply starting in the 1930s, mainly because firefighting efforts grew more aggressive and successful—so successful that there’s now far more fuel available to burn. As the climate has warmed, with average annual temperatures across the West about 2 degrees higher than they were in the 1980s, the average annual acreage burned has crept back up. More than twice as much land has been blasted by wildfires since 2010 than in the 1980s and ’90s combined.

Wildfires Got Better Before They Got Worse

● The Big One
At 3 million acres burned across three states and British Columbia, the Great Fire of 1910 was the biggest wildfire in U.S. history, spurring an increase in budgets for fire suppression.
● America’s Next Top Wildfire
The Oakland firestorm of 1991 was the worst for property damage, with economic losses of $2.75 billion in 2018 dollars. But last year’s Tubbs Fire (also in California) is likely to surpass that: Insurance claims for Sonoma County alone exceed $7 billion.
● Spending Soars
Increase in federal spending on fire suppression from 1985 to 2017, adjusted for inflation: 435 percent.
● To Clear or Not to Clear?
Some experts say reduced logging on federal lands since the 1980s has increased wildfire danger, but the science is mixed—large, healthy trees tend to be the least susceptible to fire. —Fox is a business columnist for Bloomberg Opinion

To contact the editor responsible for this story: Jillian Goodman at jgoodman74@bloomberg.net

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