The contribution of China’s Grain to Green Program to carbon sequestration

Forests play an important role in regulating atmospheric carbon dioxide concentration and mitigating the greenhouse effect. The Grain to Green Program (GGP) is one of the largest ecological programs in China, and it aims at converting croplands on steep slopes to forests. However, the magnitude and distribution of carbon sequestration induced by GGP remain unknown. In this study, we estimated the changes in carbon fluxes and stocks caused by forests converted from croplands under the GGP using a process-based ecosystem model (i.e., IBIS). Our results showed that the converted areas from croplands to forests under the GGP program could sequester 110.45 Tg C by 2020, and 524.36 Tg C by the end of this century. The sequestration capacity showed substantial spatial variations with large sequestration in southern China. The economic benefits of carbon sequestration from the GGP were also estimated according to the current carbon price. The estimated economic benefits ranged from $8.84 to $44.20 billion from 2000 through 2100, which may exceed the current total investment ($38.99 billion) on the program. As the GGP program continues and forests grow, the impact of this program will be even larger in the future, making a more considerable contribution to China’s carbon sink over the upcoming decades.