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Changes in interannual climate sensitivities of terrestrial carbon fluxes during the 21st century predicted by CMIP5 Earth System Models
Author(s) -
Liu Yongwen,
Wang Tao,
Huang Mengtian,
Yao Yitong,
Ciais Philippe,
Piao Shilong
Publication year - 2016
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
eISSN - 2169-8961
pISSN - 2169-8953
DOI - 10.1002/2015jg003124
Subject(s) - primary production , biome , environmental science , representative concentration pathways , carbon cycle , atmospheric sciences , carbon flux , climatology , precipitation , climate change , coupled model intercomparison project , temperate climate , global warming , global change , atmosphere (unit) , climate model , ecosystem , meteorology , ecology , oceanography , geology , biology , physics
Terrestrial carbon fluxes are sensitive to climate change, but the interannual climate sensitivity of the land carbon cycle can also change with time. We analyzed the changes in responses of net biome production (NBP), net primary production (NPP), and heterotrophic respiration (Rh) to interannual climate variations over the 21st century in the Earth System Models (ESMs) from the Coupled Model Intercomparison Project 5. Under Representative Concentration Pathway (RCP) 4.5, interannual temperature sensitivities of NBP ( γ Temp NBP ), NPP ( γ Temp NPP ), and Rh ( γ Temp Rh ) remain relatively stable at global scale, yet with large differences among ESMs and spatial heterogeneity. Modeled γ Temp NPP and γ Temp Rh appear to increase in parallel in boreal regions, resulting in unchanged γ Temp NBP . Tropical γ Temp NBP decreases in most models, due to decreasing γ Temp NPP and relatively stable γ Temp Rh . Across models, the changes in γ Temp NBP can be mainly explained by changes in γ Temp NPP rather than changes in γ Temp Rh , at both global and regional scales. Interannual precipitation sensitivities of global NBP ( γ Prec NBP ), NPP ( γ Prec NPP ), and Rh ( γ Prec Rh ) are predicted not to change significantly, with large differences among ESMs. Across models, the changes in γ Prec NBP can be mainly explained by changes in γ Prec NPP rather than changes in γ Prec Rh in temperate regions, but not in other regions. Changes in the interannual climate sensitivities of carbon fluxes are consistent across RCPs 4.5, 6.0, and 8.5 but larger in more intensive scenarios. More effort should be considered to improve terrestrial carbon flux responses to interannual climate variability, e.g., incorporating biogeochemical processes of nutrient limitation, permafrost dynamics, and microbial decomposition.