Logging dominates U.S. tree cover loss
Forest area lost to wildfire pales compared to timber harvests
To hear the Republican administration talk about how the United States should produce more timber, you might imagine U.S. forests would remain pristine except for the wildfires racing through them.
In fact, logging consistently takes down more than triple the forest area as wildfires in this country.
That’s based on an interactive website, Global Forest Watch, launched in 2014 by the World Resources Institute—an organization I’ve long admired for their World Resources Reports highlighting global issues. The latest synthesis covers sustainable cities.
In this era of large-scale surveillance, it’s nice to know satellite imagery is moving us toward a realistic understanding of how our planet’s forest cover is changing.
Tree cover declining overall
There’s no way to hide from the reality depicted by the eyes in the sky—at least once canopy cover is removed.
Researchers with the World Resources Institute and the University of Maryland partnered with Google and a smattering of other institutions to develop the methods for many of the Global Forest Watch datasets.
Nancy Harris, the institute’s research director for Global Forest Watch, recommended by email yesterday using the data with five different drivers of tree cover loss to compare wildfire and timber harvesting activities.
Across the 23 years from 2001 through 2023, U.S. tree cover loss from wildfire totaled about 1.1 million acres a year, while loss due to apparent timber harvesting averaged 3.8 million acres a year.
That’s right. For more than two decades, “forestry” activities—which include clearcutting, selective harvesting and any other logging practices that kill or remove swaths of trees taller than 16 feet on public and private land—sheared more than three times as much area as wildfire damage.
The interactive website uses the term “tree cover loss” rather than “deforestation” to acknowledge stands might regrow in time. In fact, Global Forest Watch also records gains, if tree cover re-establishes.
This research effort involved the Landsat pixel resolution of 30 meters, or roughly 100 feet on a side—about the size of a baseball diamond. A tree cover of 30 percent or more qualified as forest.
“The people who study tropical forests were really happy, right? We have this very consistent 30-meter product of where tropical deforestation is happening,” Harris explained during a December presentation at the American Geophysical Union’s annual conference.
Global Forest Watch even uses the information to share daily deforestation alerts for tropical forests.
“Another subset of the world was really unhappy with us,” she said. “The data we were releasing on Global Forest Watch ran completely counter to the standard narrative that deforestation was a tropical problem, that we are not losing forests in the global north.”
A salvage logging project harvests wood from Oregon’s Mount Hood National Forest. Photo by David Herasimtschuk
Forest cover gains and losses
As with any effort to monitor landscape changes, challenges arise when combining or comparing different approaches, in part due to differing definitions of forests and tree maturity.
Global Forest Watch hosts three distinct data sets, which vary in resolution, spatial coverage and time frames, as well as other details. (For instance, minimum qualifying tree cover ranges from 10 to 30 percent, and the cutoff point for tree heights from about 10 to 16 feet.)
The data comparing the five drivers of tree cover loss do not tally gains made when forests recover, but another dataset available on the website does. With this data, gains register when enough trees in an area reach heights of about 10 feet or more to qualify as forest cover. Losses detail areas where trees have been sheared, leaving behind shorter trees, if any.
For the five countries with the most gains reported, which include the United States, and the world as a whole, here’s the spread for the 21 years spanning 2000 to 2020:
The United States lost 8.6 million acres overall, with the 34.6 million acres of regrowth covering less area than the 43.2 million acres of tree cover lost. Overall tree cover dropped by 1.2 percent.
While Russia seems like a leader in forest regrowth, with 91.9 million acres gained during this time frame, it pretty much broke even after accounting for losses, mainly due to logging and wildfire. About 92.4 million acres of tree cover loss offset gains, leaving it more precisely with an estimated overall loss of 435,000 acres, or 0.023% of its forest cover.
Brazil experienced a net loss of 69.4 million acres, with 19.9 million acres of regrowth dwarfed by 89.2 million acres of tree cover loss. Overall, the country containing most of the Amazon rainforest lost 5.9 percent of tree cover.
Canada experienced a net loss of 20.3 million acres, with 42 million acres in regrowth and 62.3 million acres lost. Unlike the United States, a large portion of Canada’s tree cover loss related to wildfires. This includes 91 percent of its astounding 21.2-million-acre loss in 2023, largely from the smoke-filled summer that carried emissions far beyond its borders.
China gained 16.5 million acres of forest, but lost 11.2 million acres, leaving it with a net gain of 5.3 million acres in tree cover—about a 1 percent gain in land cover. China’s forest regrowth helped stabilize global carbon drawdown, according to Yude Pan, lead author of a 2024 Nature paper documenting carbon dynamics.
Globally, the world experienced a net loss close to 250 million acres, with 324 million acres of regrowth and 571 million acres of tree cover loss. Overall, tree cover declined by about 2.4 percent, slightly less than Canada’s 2.8 percent drop.
No denying role of humans
It might be tempting to blame wildfires for the loss of tree cover in the United States and the world as a whole.
The U.S. president’s executive order to boost timber production in our public lands and efforts by Congress to pass a deceptively named Fix Our Forests Act are examples of attempts to blame wildfire for ongoing tree cover loss and boost logging on our public lands.
But that blame game doesn’t hold up to a scientific analysis of forest dynamics.
What’s more, loss of tree cover translates to a loss in forests’ ability to lock up some of the heat-trapping carbon dioxide plucked from the air and stored in wood.
“The conclusion remains that most emissions of carbon dioxide from global tree cover loss—more than 80 percent—are driven by human activities,” Harris said. “Our human footprint on the Earth continues to grow.”
As humans, we use “footprint” to give ourselves the stature of a boot suitable in size to the eyes in the sky.
It makes sense here, given the baseball-diamond-sized imprints under analysis.
In reality, our imprints, viewed from a satellite perch in orbit, resemble the activity of termites more than giants.
Well, maybe giant termites.
Environmental scientist and writer Dr. Melanie Lenart publishes Eco-Logic perspectives three times a week. To receives email notices about posts, please subscribe. It’s free! Paid subscribers also welcome. Or if you like today’s public post, please share it.
