The North American west is burning. Millions of acres of forests and grassland burn, and the fires threaten homes. NPR has a nice summary of some abnormal fires in Washington. But what is the cause? The finger is most often pointed at climate change (or just “the drought” by skeptics), but invasive beetles, poor forest management strategies, and lightning also get some credit. So what is most to blame for the increased wildfires? We can’t blame lightning, because that hasn’t changed much. A recent paper shot down the evidence that forests killed by beetles actually resulted in more fires. This leaves climate change and management strategies as the most likely culprits.
I was lucky enough to work with a fire prevention crew in the stunning Ponderosa Pine forests above Lake Tahoe for one summer in 2012. With the Nevada Conservation Corps, I strapped on a chainsaw, grew a beard and some flannels, and hiked into the hilly terrain to thin out dead trees and smaller firs. You can see me here “expertly” walking down a dangerously leaning tree here. The objective of the summer was to reduce the fuel load, not to prevent all fires, but to prevent crown fires (fires that reach the tops of trees). The Tahoe region before it was settled relied on small fires called ground fires about every seven years to reduce fuel buildup and understory growth. The region fits into the “Understory fires every 0-34 years” category on this fascinating map. In the early 20th century, the entire basin was logged, and the fire prevention regime began. Dead trees built up. Firs that would normally be killed by ground fires grew to compete with the tall, fire-resistant Jeffrey and Ponderosa pines. This is the perfect recipe for a stand-destroying crown fire: the fire starts in the dry, dead tinder around, gains heat from the copious dead logs, then catches the sappy, medium-height firs, which gives the flames a ladder to reach the crowns of the pines. The thick, layered bark protects most pines in this regions from fire, but once the fire is in the crown, all it takes is a breeze to kills thousands of acres of trees. We were tasked with preventing that from happening by cutting off those “ladder” trees.
Management like this is effective, but there are many millions of acres of forests in the American west. We were tasked to Tahoe because it is an area with money to pay to protect its forests for tourism and to protect the expensive homes in the area. The forests most at risk have little money nor and less support. We can prioritize high-risk areas, but that is where climate change comes in. The above map was written for a climate that will change. I am not one to blame every drought or even blizzard on climate change. Extreme weather events have been happening since the Big Bang, but we now know for certain that they will be more frequent. As our weather regime shifts, it seems increasingly likely that we can expect more forest fires. And don’t forget, forest fires release carbon dioxide on a massive scale. The American and Canadian governments need more money to spend on fire prevention so that they do not need to spend millions on excessively dangerous wildland firefighting. Please support programs like the Nevada Conservation Corps, programs that teach young people about conservation and cost a minuscule fraction of the costs of fighting a fire. And remember, climate change is real, climate change is expensive, and climate change is coming to your town.
Learn more about wildfires: Forest Service Wildfire Guide
Recent wildfires: NPR
Video credit: Daniel Burch a.k.a. BURCH!