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Friday, Jul 17, 2026

Are more than 80% of wildfires started by humans?

Cassis Tingley, The Colorado Sun
yes

Humans cause roughly 84% of wildland fires in the U.S., University of Colorado researchers found in a 2017 review of more than two decades of wildfire data. 

Human-caused fires account for 44% of total land area burned each year, extending the natural fire season by over 100 days and damaging ecosystems that don’t naturally experience burning, the researchers found. Natural wildfires are typically started by lightning.

The average annual wildfire count across the U.S. has decreased in recent decades, dropping from 80,303 between 1991-2000 to 62,435 from 2015-2025. However, the average annual burn area has doubled, rising from 3.7 million acres to 7.6 million acres during those same periods.

Colorado saw 620 fires burn 265,000 acres this year through July 15, eclipsing the annual state average of 268 fires with 58,000 acres burned since 2020. 

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