Compensatory water effects link yearly global land CO 2 sink changes to temperature

Research output: Contribution to journalArticle

Abstract

Large interannual variations in the measured growth rate of atmospheric carbon dioxide (CO 2) originate primarily from fluctuations in carbon uptake by land ecosystems. It remains uncertain, however, to what extent temperature and water availability control the carbon balance of land ecosystems across spatial and temporal scales. Here we use empirical models based on eddy covariance data and process-based models to investigate the effect of changes in temperature and water availability on gross primary productivity (GPP), terrestrial ecosystem respiration (TER) and net ecosystem exchange (NEE) at local and global scales. We find that water availability is the dominant driver of the local interannual variability in GPP and TER. To a lesser extent this is true also for NEE at the local scale, but when integrated globally, temporal NEE variability is mostly driven by temperature fluctuations. We suggest that this apparent paradox can be explained by two compensatory water effects. Temporal water-driven GPP and TER variations compensate locally, dampening water-driven NEE variability. Spatial water availability anomalies also compensate, leaving a dominant temperature signal in the year-to-year fluctuations of the land carbon sink. These findings help to reconcile seemingly contradictory reports regarding the importance of temperature and water in controlling the interannual variability of the terrestrial carbon balance. Our study indicates that spatial climate covariation drives the global carbon cycle response.

Details

Authors
  • Martin Jung
  • Markus Reichstein
  • Christopher R. Schwalm
  • Chris Huntingford
  • Stephen Sitch
  • Almut Arneth
  • Gustau Camps-Valls
  • Philippe Ciais
  • Pierre Friedlingstein
  • Fabian Gans
  • Kazuhito Ichii
  • Atul K. Jain
  • Etsushi Kato
  • Dario Papale
  • Ben Poulter
  • Botond Raduly
  • Christian Rödenbeck
  • Gianluca Tramontana
  • Nicolas Viovy
  • Ying-Ping Wang
  • Ulrich Weber
  • Sönke Zaehle
  • Ning Zeng
Organisations
External organisations
  • Max Planck Institute for Biogeochemistry
  • Friedrich Schiller University Jena
  • Centre for Ecology & Hydrology
  • University of Exeter
  • Karlsruhe Institute of Technology
  • Japan Agency for Marine-Earth Science and Technology
  • National Institute for Environmental Studies of Japan
  • University of Illinois at Urbana-Champaign
  • University of Tuscia
  • NASA Goddard Space Flight Center
  • CSIRO Oceans and Atmosphere, Canberra
  • University of Maryland
  • Woods Hole Research Center
  • University of Valencia
  • Laboratoire des Sciences du Climat et de l'Environnement
  • Institute of Applied Energy (IAE)
  • Sapientia – Hungarian University of Transylvania
  • Institute of Atmospheric Physics, Chinese Academy of Sciences
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Climate Research
Original languageEnglish
Pages (from-to)516-520
Number of pages5
JournalNature
Volume541
Issue number7638
Publication statusPublished - 2017 Jan 26
Publication categoryResearch
Peer-reviewedYes