PRECIPITATION SENSITIVITY TO GLOBAL WARMING - COMPARISON OF OBSERVATIONS WITH HADCM2 SIMULATIONS

Recent century-long experiments performed with global climate models h ave simulated observed trends in global-mean temperature quite success fully when both greenhouse gas and aerosol forcing has been included. The performance of these same experiments in simulating observed globa l-scale changes in precipitation has not previously been examined. Her e we use a gridded terrestrial precipitation dataset for the period 19 00 to 1996 to examine the extent to which observed global and zonal-me an precipitation sensitivities to global warming have been captured by a series of model simulations recently completed by the UK Hadley Cen tre. There are signs that the model has been able to reproduce at leas t some of the observed zonal-mean variations in the precipitation sens itivity to warming. Questions remain both about the quality of the obs erved precipitation data and about the spatial scale at which anthropo genically-forced global climate models can be expected to reproduce ob served variations in precipitation.