A large and persistent carbon sink in the world's forests

Authors: Pan Y, RA Birdsey, J Fang, R Houghton, PE Kauppi, WA Kurz, OL Phillips, A Shvidenko, SL Lewis, JG Canadell, P Ciais, RB Jackson, S Pacala, AD McGuire, S Piao, A Rautiainen, S Sitch, D Hayes

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.

science2011.pdf