Sensitivity of global climate model simulations to increased stomatal resistance and CO2 increases

Abstract

Increasing levels of atmospheric CO2 will not only modify climate, they will also likely increase the water-use efficiency of plants by decreasing stomatal openings. The effect of the imposition of "doubled stomatal resistance' on climate is investigated in off-line simulations with the Biosphere-Atmosphere Transfer Scheme (BATS) and in two sets of global climate model simulations: for present-day and doubled atmospheric CO2 concentrations. The anticipated evapotranspiration decrease is seen most clearly in the boreal forests in the summer although, for the present-day climate (but not at 2 × CO2), there are also noticeable responses in the tropical forests in South America. -from Authors