Historical carbon dioxide emissions due to land use changes possibly larger than assumed

Research output: Contribution to journalArticle

Authors

  • Almut Arneth
  • Stephen Sitch
  • Julia Pongratz
  • Benjamin Stocker
  • Philippe Ciais
  • Anita Bayer
  • Alberte Bondeau
  • Leonardo Calle
  • Louise Chini
  • Thomas Gasser
  • Marianell Fader
  • Piere Friedlingstein
  • Etoshi Kato
  • Wei Li
  • Mats Lindeskog
  • Julia Nabel
  • Eddy Robertson
  • Nicholas Viovy
  • Chao Yue
  • Sönke Zaehle

Colleges, School and Institutes

External organisations

  • Max Planck Institut fur Biogeochemie Jena

Abstract

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 and CO2 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.

Details

Original languageEnglish
Pages (from-to)79-84
JournalNature Geoscience
Volume10
Early online date30 Jan 2017
Publication statusPublished - 2017