The changes in ground-level UV radiation that accompany changing cloud cover and stratospheric ozone levels may have serious consequence for numerous biological and geochemical cycles that are critically important to the well-being of the biosphere. Moreover, because carbon dioxide, nitrous oxide, methane, halocarbons, carbon monoxide and carbonyl sulfide all have natural sources and sinks in the biosphere, alterations of the biogeochemical cycles could introduce significant positive or negative feedbacks to the atmospheric concentrations of these important trace gases. To better assess the possible ramifications of changing UV levels on biogeochemical dynamics, this workship assembled a diverse group of experts, including atmospheric chemists and physicists and aquatic chemists, biochemists and biologists. Participants were asked to help identify and more clearly define: i) the potential effects of climate change on ground level solar UV (and visible) radiation, ii) the impacts of solar UV radiation on geochemical processes in aquatic systems, iii) the effects of solar UV radiation on biological processes, with emphasis on the possible effects of enhanced UV-B (280-320 nm) radiation. Participants were asked to discuss experimental and theoretical approaches to better characterize and model these processes on both regional and global scales. Questions that were addressed at the workshop included. Keywords: Remote detectors; Radiative transfer; Atmospheric chemistry. (kt).