Improved estimates of net carbon emissions from land cover change in the tropics for the 1990s

TLDR

Recent estimates of tropical forest cover change are used to calculate carbon fluxes, and these estimates are corroborated by independent global, Amazonian, and Southeast Asian CO₂ observations. The authors applied their humid‑tropics deforestation data, supplemented by published dry‑tropics figures, to biomass measurements to generate new net carbon emission estimates. The study estimates global tropical land‑use change emissions at 1.1 ± 0.3 Gt C yr⁻¹, comprising 71 % from forest conversion, 20 % from soil loss, 4.4 % from degradation, 8.3 % from 1997‑98 Indonesian fires, and a −3.3 % sink from regrowth.

Abstract

Recent figures on net forest cover change rates of the world's tropical forest cover are used for the calculation of carbon fluxes in the global budget. By applying our deforestation findings in the humid tropics, complemented by published deforestation figures in the dry tropics, to refereed data on biomass, we produced new estimates of net carbon emissions. These estimates are supported by recent, independent estimations of net carbon emissions globally, over the Brazilian Amazon, and by observations of atmospheric CO 2 emissions over Southeast Asia. Our best estimate for global net emissions from land‐use change in the tropics is at 1.1 ± 0.3 Gt C yr −1 . This estimate includes emissions from conversion of forests (representing 71% of budget) and loss of soil carbon after deforestation (20%), emissions from forest degradation (4.4%), emissions from the 1997–1998 Indonesian exceptional fires (8.3%), and sinks from regrowths (−3.3%).