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