Can Planted Forests Counteract Increasing Atmospheric Carbon Dioxide?

Establishing new forests has been widely suggested as a means to prevent, reduce, or delay fossil fuel‐driven increases in CO2 concentrations in the atmosphere. This analysis examines the potential magnitude of C storage in biomass, emphasizing the amount of land area that could be planted to trees, the rates of C storage in developing forest plantations, and the fate of material harvested from forests. I conclude that while converting old‐growth forests to plantations is a losing proposition, there may be sufficient formerly forested land and the possibility of sufficiently high rates of C storage in young tree plantations that reforestation could remove substantial quantifies of C from the atmosphere (≥1 Pg yr−1). However, rapid net C storage is a short‐lived phenomenon, and it is unlikely that a substantial fraction of material harvested from plantations can go into long‐term storage on land. Therefore, new tree plantations designed to store C can at best cause a brief delay in the accumulation of CO2 in the atmosphere. Forest plantations designed to produce energy from biomass would represent a longer‐term contribution to reducing rates of CO2 accumulation—as long as they replaced fossil fuel‐derived energy.