Climate Sensitivity Controls Uncertainty in Future Terrestrial Carbon Sink

Summary, in English

For the 21st century, carbon cycle models typically project an increase of terrestrial carbon with increasing atmospheric CO₂ and a decrease with the accompanying climate change. However, these estimates are poorly constrained, primarily because they typically rely on a limited number of emission and climate scenarios. Here we explore a wide range of combinations of CO₂ rise and climate change and assess their likelihood with the climate change responses obtained from climate models. Our results demonstrate that the terrestrial carbon uptake depends critically on the climate sensitivity of individual climate models, representing a large uncertainty of model estimates. In our simulations, the terrestrial biosphere is unlikely to become a strong source of carbon with any likely combination of CO₂ and climate change in the absence of land use change, but the fraction of the emissions taken up by the terrestrial biosphere will decrease drastically with higher emissions.

• Author: Guy Schurgers; Anders Ahlström; Almut Arneth; Thomas A.M. Pugh; Benjamin Smith
• Department/s: Dept of Physical Geography and Ecosystem Science; MERGE: ModElling the Regional and Global Earth System; eSSENCE: The e-Science Collaboration
• Publishing year: 2018-05-16
• Language: English
• Pages: 4329-4336
• Publication/Series: Geophysical Research Letters
• Volume: 45
• Issue: 9
• Links: http://dx.doi.org/10.1029/2018GL077528
• Document type: Journal article
• Publisher: American Geophysical Union (AGU)
• Topic: Geosciences, Multidisciplinary
• Keywords: Carbon cycle; Climate change; Climate sensitivity; Ecosystem modeling; Land carbon sink
• Status: Published
• ISBN/ISSN/Other: ISSN: 0094-8276