Variability of the incoming solar irradiance and its effects on climate have received wide attention over the recent years. There is a continuous effort to reduce uncertainties in measurements of the total and spectral solar spectral irradiances, physical and empirical modelling have undergone considerable progress and novel statistical analyses have been employed. At the same time, numerical models and observations are extensively used to characterize the influence of the solar irradiance variability on climate. This session invites abstracts on measurements and models of solar spectral and total irradiance as well as abstracts on the atmospheric response to solar irradiance variability. Abstracts on comparison of atmospheric effects to different solar irradiance datasets are particularly welcome.