Importance of Vegetation Processes for Model Spread in the Fast Precipitation Response to CO2 Forcing

TitleImportance of Vegetation Processes for Model Spread in the Fast Precipitation Response to CO2 Forcing
Publication TypeJournal Article
Year of Publication2016
AuthorsDeAngelis, Anthony M., Qu Xin, and Hall Alex
JournalGeophysical Research Letters
Volume43
Pages12550-12559
Date Published12/2016
Abstract / Summary

In the current generation of climate models, the projected increase in global precipitation over the 21st century ranges from 2% to 10% under a high-emission scenario. Some of this uncertainty can be traced to the rapid response to carbon dioxide (CO2) forcing. We analyze an ensemble of simulations to better understand model spread in this rapid response. A substantial amount is linked to how the land surface partitions a change in latent versus sensible heat flux in response to the CO2-induced radiative perturbation; a larger increase in sensible heat results in a larger decrease in global precipitation. Model differences in the land surface response appear to be strongly related to the vegetation response to increased CO2, specifically, the closure of leaf stomata. Future research should thus focus on evaluation of the vegetation physiological response, including stomatal conductance parameterizations, for the purpose of constraining the fast response of Earth’s hydrologic cycle to CO2 forcing.

URLhttp://onlinelibrary.wiley.com/doi/10.1002/2016GL071392/full
DOI10.1002/2016GL071392
Journal: Geophysical Research Letters
Year of Publication: 2016
Volume: 43
Pages: 12550-12559
Date Published: 12/2016

In the current generation of climate models, the projected increase in global precipitation over the 21st century ranges from 2% to 10% under a high-emission scenario. Some of this uncertainty can be traced to the rapid response to carbon dioxide (CO2) forcing. We analyze an ensemble of simulations to better understand model spread in this rapid response. A substantial amount is linked to how the land surface partitions a change in latent versus sensible heat flux in response to the CO2-induced radiative perturbation; a larger increase in sensible heat results in a larger decrease in global precipitation. Model differences in the land surface response appear to be strongly related to the vegetation response to increased CO2, specifically, the closure of leaf stomata. Future research should thus focus on evaluation of the vegetation physiological response, including stomatal conductance parameterizations, for the purpose of constraining the fast response of Earth’s hydrologic cycle to CO2 forcing.

DOI: 10.1002/2016GL071392
Citation:
DeAngelis, AM, X Qu, and A Hall.  2016.  "Importance of Vegetation Processes for Model Spread in the Fast Precipitation Response to CO2 Forcing."  Geophysical Research Letters 43: 12550-12559.  https://doi.org/10.1002/2016GL071392.