Viewpoint: Forest thinning intensifies global warming
Michael Hoyt
Most Forest Service project proposals include variations of the following: “The project’s primary purpose is to reduce the risk of a stand-replacing wildfire . . . Proposed project treatments include prescribed fire, noncommercial thinning, and commercial harvesting.”
Despite Earth’s rapidly warming climate being humanity’s most serious problem, agency proposals seldom include consequential explanations of how a project may reduce or contribute to global warming.
Each molecule of carbon dioxide (CO2) added to the atmosphere increases global warming. Once CO2 is added to the atmosphere, it hangs around for a long time—between 300 and 1,000 years. Because of its long life in the atmosphere, any increase in the amount of atmospheric CO2 is cumulative. Every additional amount counts, no matter how small.
A simple thought experiment exposes how Forest Service thinning projects affect global warming.
Research revealed that forest thinning immediately reduces the amount of carbon being stored in live trees, understory plants, and the soil (Coulston 2023). It typically requires 20 or more years for the remaining trees to be able to sequester the same amount of carbon that was being annually sequestered before thinning. Most of the thinned material is burned, an activity which immediately releases stored carbon into the atmosphere as CO2.
Each consumed gallon of gasoline used during a thinning project produces 19.7 pounds of CO2, each gallon of diesel produces 22.4 pounds of CO2. But even when the amount of fossil fuels used during a thinning project is ignored—typical agency practice—the amount of stored carbon immediately released into the atmosphere (by burning residue) and the reduced capacity of the forest to sequester carbon contribute to increased global warming. Therefore, forest thinning projects intensify global warming.
In addition to contributing to global warming, thinning projects damage natural ecosystems, decrease a forest’s capacity to store and filter water, harm wildlife habitat, reduce biodiversity, increase stream sediment, and negatively affect the human environment—not just for people living in the U.S., but for every person on the planet.
The Forest Service’s oft-repeated allegation that thinning reduces the risk of stand-replacing wildfire is disingenuous. The agency’s declaration that thinning reduces the risk of stand-replacing wildfire assumes that fire will occur in a thinned area.
However, research (Rhodes & Baker 2008; Barnett et al 2016; Morris 2023) showed that areas receiving fuel treatments have a 1% to 8% possibility of encountering wildfire during the assumed 20-year period of reduced fuels. Spending tax dollars to reduce a risk already approaching zero is ill-advised and worsens global warming.
Scientific research has established that wind is the main driver of wildfire, not high fuel loads, not drought, and not dense forests (Coen 2018). Particularly disturbing is the fact that two decades ago, Forest Service fire scientists determined that work, not in the wildland-urban interface (WUI) but within 100 feet of homes and structures, is the most effective way to reduce infrastructure damage from wildfire (Cohen 1995).
Questions must be answered. Why does the Forest Service insist on an ever-increasing number of thinning projects when scientific research refutes the efficacy of such procedures? Why does the agency continue to conceal how vegetation management (forest thinning) worsens global warming? Rather than performing meaningless management activities in the WUI, miles from where people live, why isn’t the Forest Service focused exclusively on hardening homes and important infrastructure?
Because any increase in atmospheric CO2 intensifies global warming, government agencies that insist on pouring more CO2 into the atmosphere, are committing crimes against humanity. It is far past time for the Forest Service to explain why it continues to propose thinning projects that exacerbate global warming.