by Forests are an essential part of the Earth’s operating system. They reduce the amount of carbon dioxide trapped as heat in the atmosphere from fossil fuel burning, deforestation and land degradation by 30% each year. This slows global temperature increases and the resulting changes in climate. In the US, forests absorb up to 12% of the nation’s greenhouse gas emissions each year and store the carbon long-term in trees and soils.
Mature and old-growth forests, which have larger trees than younger forests, play an extremely large role in storing carbon and keeping it out of the atmosphere. These forests are especially resistant to wildfires and other natural disturbances as the climate warms.
Most of the forests in the continental US have been harvested many times. Today, only 3.9% of timberland across the US, in both public and private hands, is over 100 years old, and most of these areas have little carbon relative to their potential.
The Biden administration is moving to improve protection for old-growth and mature forests on federal land, which we see as a welcome step. But this involves regulatory changes that will take several years to complete. Meanwhile, the existing forest management plans that allow the logging of these large and important trees are still in place.
As scientists who have spent many years studying forest ecosystems and the effects of climate change, we believe it is essential to start protecting carbon storage in these forests. In our opinion, there is sufficient scientific evidence to justify an immediate moratorium on the logging of mature and old-growth forests on federal lands.
Federal action to protect mature and old-growth forests
A week after his inauguration in 2021, President Joe Biden issued an executive order setting a goal of conserving at least 30% of US lands and waters by 2030 to address a “profound climate crisis.” In 2022, Biden recognized the climate importance of mature and old-growth forests for a healthy climate and called for their preservation on federal lands.
Most recently, in December 2023, the US Forest Service announced that it was evaluating the effects of revised management plans for 128 US national forests to better protect mature and old-growth stands – the first time any administration has done so. such an activity.
These actions attempt to make existing old-growth forests more resilient; to preserve the ecological benefits they provide, such as habitat for threatened and endangered species; establish new areas where old growth conditions can be developed; and monitor the condition of forests over time. The revised national forest management plans would also prohibit the felling of old-growth trees primarily for economic purposes – that is, to produce timber. Harvesting of trees would be allowed for other reasons, such as thinning to reduce fire intensity in hot, dry regions where fires occur more frequently.
Interestingly, however, logging is barely factored into the Forest Service’s initial analysis, even though studies show it causes more carbon loss than wildfires and pest infestations.
In one analysis across 11 western US states, researchers calculated the total above-ground tree carbon loss from logging, beetle infestation and fire between 2003 and 2012 and found that logging accounted for half of it. Across the states of California, Oregon and Washington, harvest-related carbon emissions between 2001 and 2016 averaged five times those from wildfires.
A 2016 study found that total carbon emissions from logging nationwide, between 2006 and 2010, were comparable to emissions from all US coal plants, or direct emissions from the entire construction sector.
