Forests help to offset carbon emissions by trapping carbon within trees, and when scientists and policy makers discuss emissions goals, they take this fact into consideration, hedging on forests to help offset what we produce. Unfortunately, according to a new study by the Forest Service, here in the United States, forests aren’t going to be as much help over the next 25 years as we’d been hoping.

american forest

Over a series of simulations, the researchers discovered that over the next quarter of a century, the ability of American trees to sequester carbon, to remove it from the air, will reduce across the board. The levels will vary according to different parts of the continent though.

In the East there should be only a gradual decline. In the Rocky Mountain region though, that rate declines much faster, down to 0 by 2037. Worse, those trees could actually become a source of new carbon due to forest fires and insects. The Pacific Northwest is expected to fluctuate but to even out as forests that were harvested in the past continue to grow back.

All the simulations based on current or projected land use showed a decline in carbon sequestration. North American forests are by and large too old to soak up all that much more carbon. Trees grow more slowly as they age, and younger trees eat up more carbon. With that in mind, they also looked at potential outcomes of planting additional forests here in the United States. They found that planting 19.1 million acres of forest over the next 25 years would result in significant gains, allowing for much greater overall carbon sequestration. That number may seem high, but past efforts by the USDA Conservation Reserve Program give the researchers confidence that such an undertaking would be possible.