Estimates of climatic influence on the carbon cycle

Abstract

Abstract. The influence of climatic change on the carbon cycle is important as part of a CO2-climate feedback loop. However the magnitude of the coupling depends on the timescales involved. We expand on previous analyses of the ice-core CO2 data from the pre-industrial period 1000–1750, extending the analysis into the 20th century. Our results emphasise the limitations of characterising the climate-to-CO2 influence by a single number γ. Even once a time-scale dependence is incorporated, the coldest part of the Little Ice Age seems to reflect different behaviour to that in earlier or later centuries. Different temperature reconstructions appear to capture distinct aspects of pre-industrial cl..