Terrestrial ecosystems play a significant role in global carbon and water cycles because of the substantial amount of carbon assimilated through net primary production and large amount of water loss through evapotranspiration (ET). Using a process-based ecosystem model, we investigate the potential effects of climate change and rising atmospheric CO2 concentration on global terrestrial ecosystem water use efficiency (WUE) during the twenty-first century. Future climate change would reduce global WUE by 16.3% under high-emission climate change scenario (A2) and 2.2% under low-emission climate scenario (B1) during 2010–2099. However, the combination of rising atmospheric CO2 concentration and climate change would increase global WUE by 7.9% and 9.4% under A2 and B1 climate scenarios, respectively. This suggests that rising atmospheric CO2 concentration could ameliorate climate change-induced WUE decline. Future WUE would increase significantly at the high-latitude regions but decrease at the low-latitude regions under combined changes in climate and atmospheric CO2. The largest increase of WUE would occur in tundra and boreal needleleaf deciduous forest under the combined A2 climate and atmospheric CO2 scenario. More accurate prediction of WUE requires deeper understanding on the responses of ET to rising atmospheric CO2 concentrations and its interactions with climate.
|Number of pages
|International Journal of Digital Earth
|Published - Jun 3 2018
Bibliographical noteFunding Information:
This research was supported by National Science Foundation (NSF) Grants (1243232, 121036), Chinese Academy of Sciences STS Program (KFJ-STS-ZDTP-010-05). We thank the previous members in the Ecosystem Dynamics and Global Ecology (EDGE) Laboratory who made great contributions to the improvements and developments of the DLEM and associated geo-referenced data set in the past decades. We also appreciate the precious comments and suggestions from the reviewers.
This research was supported by National Science Foundation (NSF) Grants (1243232, 121036), Chinese Academy of Sciences STS Program (KFJ-STS-ZDTP-010-05).
© 2017 Informa UK Limited, trading as Taylor & Francis Group.
- Climate change
- net primary productivity
- water use efficiency
ASJC Scopus subject areas
- Computer Science Applications
- Earth and Planetary Sciences (all)