File this one under “the more you know.” It can also be cross filed under “we told you so.” Also, there’s plenty of scientific evidence and research out there that would refute much of what Idaho State Forester David Groeschl says below.
From the Associated Press:
BOISE, Idaho (AP) — The amount of carbon dioxide being released into the atmosphere from forest fires in the U.S. West is being greatly overestimated, possibly leading to poor land management decisions, researchers at the University of Idaho said.
Researchers in the study published last week in the journal Global Change Biology say many estimates are 59% to 83% higher than what is found based on field observations.
Healthy forests are carbon sinks, with trees absorbing carbon and reducing the amount in the atmosphere contributing to global warming. Forest fires can release that carbon.
“Part of the reason we’re talking about this is that there’s a narrative that has circumvented science,” said Jeff Stenzel, the lead author and a doctoral student at the university. “What that can lead to is management decisions that can exacerbate rather than mitigate greenhouse gas emissions.”
The study used field data from a 2002 wildfire in southern Oregon and a 2013 wildfire in central California that, the authors of the paper said, included one of the largest pre- and post-fire data sets available.
Typically, the study found, about 5% of the biomass burned in a forest fire as opposed to other estimates of 30% and public perceptions of 100%.
Former Interior Secretary Ryan Zinke in late 2018 cited carbon released from forest fires as a result of poor forest practices on federal land and a need to increase various management practices.
Forest fires usually leave behind standing dead trees, the study said, that could be mistakenly counted as releasing carbon in other estimates. The carbon remains in those trees and is slowly released over decades. Even then, the study found, much of that carbon is recaptured in new growth following the forest fire.
Overall, the study found, forest fires in the U.S. West in the last 15 years have emitted about 250 million tons of carbon, about half of many estimates.
Idaho State Forester David Groeschl said carbon emissions are a consideration when it comes to making decisions about forests on the 2.4 million acres (987,000 hectares) the state manages, but so are other factors.
In deciding where to log, Groeschl said, the state considers weather and climate, insect and disease, fire frequency and severity, milling technology, and local, regional and global economics.
When a forest is logged, the resulting wood products retain that carbon, he noted. When a fire moves through state-owned forests, he said, salvage logging removes standing dead trees and trees likely to die and so captures that carbon in wood products rather than allowing it to be slowly released over several decades.
He also said that forest restoration efforts following logging or a fire speed up the return of a forest that otherwise could take decades.
“We get carbon sequestration going as quickly as possible,” he said.
Wildfires have become more frequent and more severe in the last 20 to 30 years, Groeschl said, which is also a factor when it comes to logging state lands.
“The longer we grow it, the greater the risk of loss and carbon emission happening,” he said.
10 thoughts on “NEW STUDY: CO2 released from wildfires in western U.S. is being overestimated, leading to poor land management decisions”
Of course, there was no mention of the more powerful GHGs being produced by dead and dying trees, as they decompose, BEFORE they eventually lose ALL of their carbon in the next inevitable wildfire, human-caused, or not.
Also, I wonder how much carbon is released by other aspects of ‘doing nothing’.
Most decomposition in forests is aerobic and releases C02.
Wood products that end up in landfills release methane.
In the LA Basin, vast amounts of trees did, indeed, end up in landfills. Since the nearest lumber mill is too far away, the economics doesn’t work out. Dead trees, in the huge numbers we are seeing, have to have other emissions, besides the incredible amounts of CO2 being emitted.
Matthew, if study b disagrees with study a, about something as site specific and full of assumptions as carbon accounting, why would you assume that b is correct and a is incorrect.
Another, perhaps more scientific, interpretation might be “studies came to different conclusions, I wonder why?” If other scientists found out something, that’s not a “narrative that circumvents science” , that’s a legitimate scientific disagreement based on different data sets and different assumptions.
I also thought it interesting that “Forest fires usually leave behind standing dead trees, the study said, that could be mistakenly counted as releasing carbon in other estimates. The carbon remains in those trees and is slowly released over decades. Even then, the study found, much of that carbon is recaptured in new growth following the forest fire.” I can’t imagine anyone assuming that standing dead trees have released all their carbon (or they should have their “carbon accounting” license rescinded ?) But wouldn’t new growth capture the same amount of carbon whether trees are removed or not? Unless there are more seedlings one could argue because a) snags provide shelter or b) no snags means more light for seedlings. But this is a reforestation/seedling plant physiology question, not a carbon accounting question.
The scientist’s (a doctoral student’s) statement that “What that can lead to is management decisions that can exacerbate rather than mitigate greenhouse gas emissions” makes the assumption that people who make management decisions care totally about GHGs. But clearly they don’t and have other concerns. As with Groeschl says very clearly.
Question.. do people studying forest management practices at the University of Idaho actually talk to people doing forest management in Idaho? I thought that that was the point of the land grant system.. to link practitioners and researchers via the mission of education, extension and research. Or maybe Idahoans make decisions one way and Californians another? Anyway if I were Queen of Science, research papers that state that they have management implications would be peer reviewed by groups that include managers. It’s way to easy to pontificate about how important a piece of research is without any ground- truthing..
Thanks for sharing this paper, thinking about carbon sequestration implications for forest management is an area I’ve long had an interest in, and I’m always glad to see more research published that could help guide managers. I’m curious what you meant when you said there is researching refuting what Groeschl says. His statements appear pretty bland to me, except maybe the idea that replanting accelerates carbon sequestration. I could see that being debated but I’d be curious to see any research that has addressed that question!
See: The Carbon Value of Wood Products is Over-Estimated.
Conor, just so you know, there is much scientific debate on this topic. Personally, I can’t say that one side is “right” or “wrong” but they proceed from different framings (what are the alternatives?) and different assumptions, including about the future (who the heck knows?), use different data as input and so on. IMHO if people really wanted to know, someone would establish a commission of scientists to outline why and how they disagree, but so far there are no widely -used institutional mechanisms for scientific conflict resolution. Others: please chime in if you know of any.
People give papers that say different things.. claim that managers aren’t following “science” and there we all are. I do remember Jerry Franklin saying something like “you geneticists should get your act together, I don’t know whom to believe!” so it’s not just managers with this difficulty.
Sharon, I would agree that “there is much scientific debate on this topic.”
That’s why I stated that there’s plenty of scientific evidence and research out there that would refute much of what Idaho State Forester David Groeschl said in the news article.
But it seems like you have no problem with State Forester Groeschl providing just “one side” of the story, which he believes in “right”…even if there is plenty of evidence that counters that opinion.
I see Groeschl outlining how he makes decisions. You can’t “refute” that with scientific studies. As many have said, scientific information can tell us the impacts of certain activities (if conducted at the right scale, etc.) but it cannot tell us what governments or people should do.
Science tells us that if soils are damaged by high intensity wildfires (incinerating all the organic matter out of the top soil horizons), those soils cannot support the previous amount of carbon sequestration until those soils have been replenished. Such a process may take many decades. If re-burn occurs, that wait will take much longer. We should not be pretending that such issues don’t need to be addressed. The water-holding capacity of soils is key to forest reproduction and carbon sequestration, in our dry western forests.