Constraints on the temperature sensitivity of global soil respiration from the observed interannual variability in atmospheric CO2

Carbon cycle feedbacks have been shown to be very important in predicting climate change over the next century. The response of the terrestrial carbon cycle to climate change depends on the competition between increased respiration due to warmer temperatures and increased uptake due to elevated CO2levels. Whether the terrestrial carbon cycle remains a sink for anthropogenic carbon, or switches to become a source, depends particularly on the response of soil respiration to temperature. Here we use observed global atmospheric CO2concentration to constrain the behaviour of soil respiration in a coupled climate–carbon cycle GCM.