This research program constitutes a continuation of previous NSF Grant ATM-8515310. This program concerns the coupling of atmospheric radiation models with climate models in order to estimate terrestrial climatic change. Specific areas of research concerning the present and proposed programs are: (1) improving infrared radiative transfer models; (2) understanding the impact of anthropogenic aerosols upon Arctic climate; (3) understanding the dependence of planetary albedo upon solar zenith angle for deserts and vegetated surfaces; (4) exploring the role of clouds upon climate and climate change; (5) understanding diurnal variability of the solar radiation budget for deserts. This work may lead to fundamental improvements in numerical modeling of the climate system.