Forests

The North American forest carbon sink of 217 Tg C reported in this chapter represents about 20% of the global net forest carbon sink (Pan et al., 2011) on forest area that is 18% of the global total (FAO 2016b). Most of the North American carbon sink is in temperate U.S. forests that are managed relatively intensively for wood products and other services, indicating that managed forests typically are maintained with a lower stand density and lower carbon stocks than mature forests but have potentially higher growth rates. Current carbon stocks of North American forests average 155.4 Mg C per hectare, which is about 69% of the average for global forests (Pan et al., 2011), indicating higher-than-average carbon uptake and substantial capacity to increase average carbon stocks. According to the most comprehensive global estimates (FAO 2016a; Nabuurs et al., 2007), the mitigation potential of North American forests represents about 15% of the global forest mitigation potential for forestry activities according to “bottom-up” studies, sufficient to offset 2% of global CO₂ emissions (Le Quéré et al., 2015). The main mitigation activities for North American forests include reducing deforestation, increasing afforestation, and improving forest management—activities that are most viable in tropical and temperate biomes (FAO 2016a; Nabuurs et al., 2007).