Hydrological and biogeochemical constraints on terrestrial carbon cycle feedbacks
OPEN ACCESS
Loading...
Author / Producer
Date
2017-01
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
OPEN ACCESS
Data
Rights / License
Abstract
The feedbacks between climate, atmospheric CO2 concentration and the terrestrial carbon cycle are a major source of uncertainty in future climate projections with Earth systems models. Here, we use observation-based estimates of the interannual variations in evapotranspiration (ET), net biome productivity (NBP), as well as the present-day sensitivity of NBP to climate variations, to constrain globally the terrestrial carbon cycle feedbacks as simulated by models that participated in the fifth phase of the coupled model intercomparison project (CMIP5). The constraints result in a ca. 40% lower response of NBP to climate change and a ca. 30% reduction in the strength of the CO2 fertilization effect relative to the unconstrained multi-model mean. While the unconstrained CMIP5 models suggest an increase in the cumulative terrestrial carbon storage (477 PgC) in response to an idealized scenario of 1%/year atmospheric CO2 increase, the constraints imply a ca. 19% smaller change. Overall, the applied emerging constraint approach offers a possibility to reduce uncertainties in the projections of the terrestrial carbon cycle, which is a key determinant of the future trajectory of atmospheric CO2 concentration and resulting climate change.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
12 (1)
Pages / Article No.
14009
Publisher
IOP Publishing
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
CMIP5 models; CO2 fertilization; Emergent constraints; Evapotranspiration; Terrestrial carbon cycle feedbacks
Organisational unit
03778 - Seneviratne, Sonia / Seneviratne, Sonia
03731 - Gruber, Nicolas / Gruber, Nicolas