A Large and Persistent Carbon Sink in the World’s Forests

Abstract

The terrestrial carbon sink has been large in recent decades, but its size and location remain uncertain. Using forest inventory data and long-term ecosystem carbon studies, we estimate a total forest sink of 2.4 ± 0.4 petagrams of carbon per year (Pg C year(-1)) globally for 1990 to 2007. We also estimate a source of 1.3 ± 0.7 Pg C year(-1) from tropical land-use change, consisting of a gross tropical deforestation emission of 2.9 ± 0.5 Pg C year(-1) partially compensated by a carbon sink in tropical forest regrowth of 1.6 ± 0.5 Pg C year(-1). Together, the fluxes comprise a net global forest sink of 1.1 ± 0.8 Pg C year(-1), with tropical estimates having the largest uncertainties. Our total forest sink estimate is equivalent in magnitude to the terrestrial sink deduced from fossil fuel emissions and land-use change sources minus ocean and atmospheric sinks.

Protected areas’ role in climate-change mitigation

“…The TEM estimates for the major global scale land-atmosphere carbon fluxes, including N L , land sink strength, agree well with the mean annual values of the other estimates for the 2000s (Table 4). Some of the estimates are made with processbased models, while others are primarily inventory based (Pan et al 2011; summarized by Le Quéré et al 2014). TEM's global land sink estimate is 2.5 Pg C year -1 for the early 2000s.…”

“…During the first decade of the twenty-first century, between 0.9 and 1.3 Pg C per year were released from the land due to deforestation activities, largely in the tropics (Pan et al 2011;Le Quéré et al 2014;Ballantyne et al 2015). Concurrently, an estimated 2.3-2.5 Pg C per year were sequestered in land ecosystems, primarily in actively growing forests across the globe (Pan et al 2011;Le Quéré et al 2014;Ballantyne et al 2015).…”

Evaluation on the carbon pools of China’s forest ecosystems―current status, capacities and sinks and studies on the mechanisms

“…缓大气中CO 2 等温室气体浓度上升以及维持全球气 候稳定等方面具有不可替代的作用 (Kauppi et al, 1992;Dixon et al, 1994;Pan et al, 2011Pan et al, , 2013 Science, 263, 185-190. Du H, Zeng FP, Song TQ, Wen YG, Li CG, Peng WX, Zhang H, Zeng ZX (2016).…”

How harmful is burning logging residues? Adding economics to the emission factors for Nordic tree species

“…Apart from being a huge carbon pool, forests also play a significant role in the global carbon cycle, since they act as both major contributors and sinks of atmospheric CO 2 . Even though deforestation in tropical regions continues at a substantial rate, forests worldwide still serve as net carbon sinks (Pan et al, 2011). IPCC (2007) also recognizes that if properly implemented forests could offer an effective way to mitigate climate change through sequestration of carbon.…”