Computer simulations of the impact on climate of solar variability generally fall into four categories[ First\ there are lower atmosphere GCM experiments\ in which enhanced solar activity is represented by changes in spectrally integrated solar constant[ Secondly\ there are GCM studies of the dynamical response of the middle atmosphere to changes in solar ultraviolet\ mainly concentrating on the northern hemisphere winter\ and how these impact the troposphere[ These studies have been instructive in providing an understanding of some of the mechanisms involved but\ because of the very di}erent nature of the assumptions made\ give rather di}erent suggestions as to potential patterns of change[ In particular predicted zonal mean temperature changes in the lower stratosphere are usually of opposite sign in these two types of experiment[ None of these GCM studies include interactive photochemistry and the third category of modelling work is concerned with the photochemical response of the middle atmosphere to enhanced solar ultraviolet[ These generally employ 1D models to predict changes in ozone and other gaseous species[ Recently it has been realised that the responses "to a variety of external forcings# of the lower and middle atmospheres are linked through both radiative and dynamical mechanisms and should not be viewed in isolation from each other[ Thus the fourth type of modelling study\ which is still in its infancy\ attempts to represent solar variability by realistic changes in both irradiance and ozone concentrations[ In this paper these various modelling studies are reviewed and some new results presented which con_rm previous theoretical suggestions that\ in the northern hemisphere winter\ the atmosphere may respond to solar changes in a similar way as to the injection of volcanic aerosol[ The implications of the results of the model studies for the detection of solar!induced climate change are discussed[ Γ 0888 Elsevier Science Ltd[ All rights reserved[