U.S. Forests and Carbon | Issues In Ecology
Issues in Ecology is a publication of the Ecological Society of America. The spring 2010 issue offers "A Synthesis of the Science on Forests and Carbon for U.S. Forests" (pdf). Lead author is Forest Service ecologist Mike Ryan.
From the Conclusions and Recommendations:
U.S. forests and forest products currently offset 12-19% of U.S. fossil fuel emissions, largely owing to recovery from past deforestation and extensive harvesting. Increased nitrogen deposition and atmospheric CO2 compared to historical levels may also be contributing to increased forest growth, but the science supporting their contribution is uncertain because of a limited number of experiments and the difficulty in assessing change over the diverse forests of the U.S.
How long will U.S. forests remain a carbon sink? Since 1940, forest regrowth in the U.S. has recovered about a third of the carbon lost to the atmosphere through the deforestation and harvesting that occurred from 1700-1935. To recover the remaining two-thirds of the carbon that was lost would require reestablishing forests in a significant portion of what is now agriculture and pasture land. However, reforesting this part of the U.S. (almost all land east of the Mississippi) is not feasible from an economic and food-security perspective. Today’s recovery from the forest clearing and wood-based economy of the 1800s and early 1900s will likely sustain carbon storage rates at the current rate for decades, but not indefinitely.
But, forest carbon storage only gets us part of the way. Even under the best scenarios, the amount of carbon storage potential is finite. Strategies that combine increased use of forest products to offset fossil fuel use (such as use of biomass energy and substitution), in conjunction with increasing carbon storage on forested landscapes, are likely to produce the most sustainable forest carbon benefits.
