Journal Article

Historical Carbon Dioxide Emissions Caused by Land-Use Changes are Possibly Larger than Assumed

Fader, M., Pongratz, J., Ciais, P., Gasser, T., Li, W., Bayer, A. D., Arneth, A., Sitch, S., Nabel, J. E. M. S., Pugh, T. A. M., Chini, L. P., Robertson, E., Lindeskog, M., Calle, L., Viovy, N., Poulter, B., Friedlingstein, P., Kato, E., Bondeau, A., Stocker, B. D., Yue, C., Zaehle, S.

2017

Overview

The terrestrial biosphere absorbs about 20% of fossil-fuel CO2 emissions. The overall magnitude of this sink is constrained by the difference between emissions, the rate of increase in atmospheric CO2 concentrations, and the ocean sink. However, the land sink is actually composed of two largely counteracting fluxes that are poorly quantified: fluxes from land-use change andCO2 uptake by terrestrial ecosystems. Dynamic global vegetation model simulations suggest that CO2 emissions from land-use change have been substantially underestimated because processes such as tree harvesting and land clearing from shifting cultivation have not been considered. As the overall terrestrial sink is constrained, a larger net flux as a result of land-use change implies that terrestrial uptake of CO2 is also larger, and that terrestrial ecosystems might have greater potential to sequester carbon in the future. Consequently, reforestation projects and efforts to avoid further deforestation could represent important mitigation pathways, with co-benefits for biodiversity. It is unclear whether a larger land carbon sink can be reconciled with our current understanding of terrestrial carbon cycling. Our possible underestimation of the historical residual terrestrial carbon sink adds further uncertainty to our capacity to predict the future of terrestrial carbon uptake and losses.

• Publisher: Macmillan Publishers,Nature Publishing Group UK,Nature Publishing Group
• Subject: 704/172/169/824 / 704/2151/209 / 704/2151/215 / Biosphere / Carbon cycle / Carbon dioxide / Carbon dioxide emissions / Carbon sequestration / Carbon sinks / Climate change / Deforestation / Earth and Related Environmental Sciences / Earth science / Earth Sciences / Earth System Sciences / Emissions / Environment Pollution / Environmental science / Environmental Sciences / Fossil fuels / Geochemistry / Geography / Geology / Geophysics/Geodesy / Geovetenskap och relaterad miljövetenskap / Land clearing / Land use / Miljövetenskap / Natural Sciences / Naturvetenskap / perspective / Reforestation / Sciences of the Universe / Shifting cultivation / Terrestrial ecosystems / Terrestrial environments / Vegetation