Estimating the carbon sequestration potential of tree planting campaigns on existing forest land in the United States

Several tree planting campaigns (e.g., Trillion Trees Initiative, 1t.org) have been proposed as a means to mitigate climate change as well as maintain, restore, and establish forest ecosystems. These initiatives, in addition to proposed legislative efforts, have both inspired and been inspired by global assessments of tree and forest attributes and their past, present and future contributions to emissions offsets. Here we describe, using data from more than 130,000 national forest inventory plots, the contribution of nearly 1.4 trillion trees on forest land in the conterminous US to mitigate emissions through carbon uptake. Forests offset more than 14 percent of carbon dioxide emissions in the US each year; however, there are both opportunities and challenges on public and private forest land to increase emissions offsets from forests. We provide context and estimates from the US to inform assessments of the potential contributions of trees and forests in climate change mitigation associated with tree planting initiatives.