Open AccessRecent Amplified Global Gross Primary Productivity Due to Temperature Increase Is Offset by Reduced Productivity Due to Water Constraints
Author(s) -
Madani Nima,
Parazoo Nicholas C.,
Kimball John S.,
Ballantyne Ashley P.,
Reichle Rolf H.,
Maneta Marco,
Saatchi Sassan,
Palmer Paul I.,
Liu Zhihua,
Tagesson Torbern
Publication year - 2020
Publication title -
agu advances
Language(s) - English
Resource type - Journals
ISSN - 2576-604X
DOI - 10.1029/2020av000180
Subject(s) - environmental science , productivity , latitude , atmospheric sciences , climatology , primary production , offset (computer science) , vapour pressure deficit , climate change , global warming , satellite , vegetation (pathology) , ecosystem , geography , ecology , computer science , biology , photosynthesis , botany , geodesy , transpiration , economics , macroeconomics , programming language , geology , medicine , pathology , aerospace engineering , engineering
Satellite remote sensing observations show an increased greenness trend over land in recent decades. While greenness observations can indicate increased productivity, estimation of total annual productivity is highly dependent on vegetation response to climate and environmental conditions. Models have been struggling to determine how much carbon is taken up by plants as a result of increased atmospheric CO 2 fertilization. Current remote sensing light use efficiency (LUE) models contain considerable uncertainty due to the lack of spatial and temporal variability in maximum LUE parameter and climate sensitivity defined for global plant functional types (PFTs). We used the optimum LUE (LUE opt ) previously derived from the global FLUXNET network to improve estimation of global gross primary productivity (GPP) for the period 1982–2016. Our results indicate increasing GPP in northern latitudes owing to reduced cold temperature constraints on plant growth, thereby suggesting increasing negative carbon‐climate feedback in high latitudes. In the tropics, by contrast, our results indicate an emerging positive climate feedback, mainly due to increasing atmospheric vapor pressure deficit (VPD). Further pervasive VPD increase is likely to continue to reduce global GPP and amplify carbon emissions.