The causes of California’s megafires: Climate change or 150 years of Euro-American mismanagement? Yes and yes.

In a very frank and data-rich webinar, fire ecologist Hugh Safford (USDA Forest Service and research faculty at Department of Environmental Science and Policy at UC Davis) offers “Some ruminations on fire and vegetation trends in California”. He explains the causes of the dramatic increase in megafires and what can be done about it.

A 2,500 year-old tree at Sequoia National Park now needs protection from fires.

The webinar was co-sponsored by the Yolo Interfaith Alliance for Climate Justice and Cool Davis and presented on May 5, 2021.

Safford’s presentation starts at 13:23 of the video. The equally enlightening Q&A session begins at 48:20.

Here is a summary of some of the key points:

  • The annual burned area has been rising rapidly since the 1980s, almost entirely in northern California.
  • This is largely due to fire exclusion caused by the removal of Native Americans as land managers and increased drought and record vegetation dryness caused by climate change.
  • Since 1999, burning over a million acres/yr now occurs regularly; this had not happened before 1999.
  • Pre-EAS (Euro-American Settlement) burning by Native Americans totaled up to FOUR million acres/year (but these were low severity fires that primarily burned the understory and smaller trees).
  • “Euro-Americans, when they showed up in the 1850s, and for that matter today, had no idea how important fire was to the functioning of these ecosystems and they feared it and felt like it was something they needed to stop. After a hundred years of that, it’s really biting us in the butt now because now we have jungles of fuels, we’ve cut most of the big fire-resilient trees out of the system, and when we get the ignitions start we can’t stop the fires anymore. Until about the 1990s, it was easy to put fires out in the forests.”
More mature trees are burning; the acres burned by high severity fires (where more than 90% of trees die) have increased 7x since 2001 in northern Sierra Nevada. 35% of the area of current fires are severe (burn most of the trees); under regular Native burning, this was 5-15%.
  • Pre-EAS forests were at least 40% old growth; current forests are only 6% old growth and highly vulnerable to high severity fires, as they are 4-5x denser than pre-EAS.
  • “Every single fire projection we found in the literature predicts bigger fires, more fires, and more severe fires, basically until we’ve burned so much of California that there actually isn’t much woody vegetation left to burn.”
  • Expect the loss of conifers and an increase in non-native grassland.
  • Changes already underway: loss of blue oak woodland, ponderosa, yellow pine, and subalpine pine; increase in hardwoods. Loss of sage scrub and chaparral in southern California. Many burned areas are quickly invaded by non-native grasses and will not recover. Incense cedar and white fir may become more dominant trees in California forests.
  • Fires in the Coast Range are now destroying chamise and blue oaks with limited evidence of re-sprouting.
  • In the short run, there’s not a lot we can do to manage climate, but there’s a lot we can do to manage fuels.
  • There’s been a huge renaissance, especially among Native tribes, to use controlled burns to manage forests. California’s new fire resilience plan supports the use of controlled burns. Northern Australia has had great success allowing Aboriginies to manage forests. Opportunities are limited, however, because of development.
  • The combination of drought cause megafires in the Sierra to produce “Hiroshima-type landscapes”, burning old growth.
  • How to stop fires: Forest thinning is critical, but it’s not economical to harvest small trees, so the government will have to subsidize it. For example, we can use the cut trees for biomass energy, as it done in Scandinavia. This is the only way to save large old growth trees and healthy forests.  “We have to cut a lot of trees. We don’t have a choice…. We can create forests that can handle large fires, or we can sit around and watch it all vaporize.”

3 thoughts on “The causes of California’s megafires: Climate change or 150 years of Euro-American mismanagement? Yes and yes.

  1. Thanks, Steve. I missed this webinar, grateful to have your summation. Do I detect a glimmer of hope? I have to believe all is not lost.

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    • Janet, Sorry about false hope. Safford does have a solution (massive govt subsidized thinning) but I don’t think our govt is capable of that. Regardless, it’s too late– about a third of the west side of the Sierra has burned in recent years, and I think EVERY canyon on the east side of the Coast Range between the Bay and Redding just burned– and with climate change regrowth will be limited to the north faces of deep canyons. Arizonification is happening quickly. Oregon is next.

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  2. Yes, thanks for this very interesting analysis. A lot of us have been wondering what’s going on in California [and similar burning in Canada’s British Columbia where I suspect much of what you say also applies].

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