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Temperature and concentration feedbacks in the carbon cycle
Author(s) -
Boer G. J.,
Arora V.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl036220
Subject(s) - positive feedback , carbon fibers , atmosphere (unit) , environmental science , carbon cycle , greenhouse gas , negative feedback , atmospheric sciences , carbon dioxide , flux (metallurgy) , coupled model intercomparison project , range (aeronautics) , global warming , climate change , chemistry , materials science , meteorology , climate model , physics , geology , oceanography , ecosystem , ecology , organic chemistry , quantum mechanics , voltage , composite number , electrical engineering , composite material , biology , engineering
Feedback processes in the carbon budget are investigated in a manner that parallels the treatment of feedback processes in the energy budget. The analysis is applied to simulations with the CCCma earth system model CanESM1 using a range of emission scenarios. For the atmosphere there is a positive “carbon‐temperature” feedback which acts to increase CO 2 flux to the atmosphere as temperatures warm. There is also a negative “carbon‐concentration” feedback which acts to remove CO 2 from the atmosphere via enhanced uptake of CO 2 by the land and ocean as CO 2 concentration increases. While the positive feedback associated with temperature change is reasonably linear and consistent as temperature increases, the feedback associated with CO 2 concentration is not. The negative carbon‐concentration feedback weakens with increasing CO 2 concentration thereby enhancing atmospheric CO 2 and accelerating global warming. The behaviour of the inferred carbon‐concentration feedback is different for different emission scenarios implying a dependence on state variables other than CO 2 concentration. The carbon‐concentration feedback behaviour inferred for a particular scenario may not, therefore, be used to infer system behaviour for other scenarios.