by P. Homewood, August 26, 2020 in NotaLotofPeopleKnowThat
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It’s Not About The Climate
Nobody denies climate change is occurring and playing a role in warmer temperatures and heatwaves. Keeley notes that, since 1960, the variation in spring and summer temperatures explain 50% of the variation in fire frequency and intensity from one year to the next.
But the half-century since 1960 is the same period in which the U.S. government promoted, mostly out of ignorance, the suppression of regular fires which most forests need to allow for new growth.
For much of the 20th Century, U.S. agencies and private landowners suppressed fires as a matter of policy. The results were disastrous: the accumulation of wood fuel resulting in fires that burn so hot they sometimes kill the forest, turning it into shrubland.
The US government started to allow forests in national parks to burn more in the 1960s, and allowed a wider set of forests on public lands to burn starting in the 1990s.
“When I hear climate change discussed it’s suggested that it’s a major reason and it’s not,” Scott Stevens of the University of California, Berkeley, told me.
Redwood forests before Europeans arrived burned every 6 to 25 years. The evidence comes from fire scars on barks and the bases of massive ancient trees, hollowed out by fire, like the one depicted in The New York Times photograph.
“There was severe heat before the lightning that dried-out [wood] fuel,” noted Stevens. “But in Big Basin [redwood park], where fire burned every seven to ten years, there is a high-density of fuel build-up, especially in the forests.”
