Interactions between vegetation and climate: Radiative and physiological effects of doubled atmospheric CO2

Abstract

The radiative and physiological effects of doubled atmospheric carbon dioxide on climate are investigated using a coupled biosphere-atmosphere model. Five 30-year climate simulations, designed to assess the radiative and physiological effects of doubled CO2, are compared to a 30-year control run. The response of the terrestrial biosphere to radiative force alone (conventional greenhouse warming effect) reveals important interactions between the climate and the vegetation. Although the global mean photosynthesis exhibits no change, a slight simulation is observed in the tropical regions, whereas in the northern latitudes photosynthesis and canopy conductance decrease as a result of high temperature stress during the growing season.