Climate impacts of US forest loss span net warming to net cooling

Storing carbon in forests is a leading land-based strategy to curb anthropogenic climate change, but its planetary cooling effect is opposed by warming from low albedo. Using detailed geospatial data from Earth-observing satellites and the national forest inventory, we quantify the net climate effect of losing forest across the conterminous United States. We find that forest loss in the intermountain and Rocky Mountain West causes net planetary cooling but losses east of the Mississippi River and in Pacific Coast states tend toward net warming. Actual U.S. forest conversions from 1986 to 2000 cause net cooling for a decade but then transition to a large net warming over a century. Avoiding these forest conversions could have yielded a 100-year average annual global cooling of 0.00088 degrees C. This would offset 17% of the 100-year climate warming effect from a single year of U.S. fossil fuel emissions, underscoring the scale of the mitigation challenge.

Automated summary

The study finds that forest loss in different regions of the United States has varying effects on the climate, impacting the magnitude of global climate change. Forest conversions may initially lead to temporary net cooling, but over the long term can transition to net warming, posing challenges in offsetting the climate warming effects of fossil fuel emissions.