A hierarchy of numerical models will be used to investigate the interactions between radiation, dynamics and chemistry of the atmosphere, especially in regard to climatic effects of increases in atmospheric trace gases. The three year project will utilize 2-D models of the stratosphere and the troposphere to study effects of trace gas increases on global and regional ozone production, as well as the combined effects of changes in ozone and other radiatively active trace gases on the tropospheric climate. There are significant differences in initial radiative forcing between increases in CO2 versus other radiatively- active trace gases. General circulation model simulations using the Community Climate Model of the National Center for Atmospheric Research will be carried out to investigate any differences in subsequent climatic feedbacks caused by increased CO2 and other trace gases. This project should enhance our capability to model important physical and chemical processes that affect the climate system and may lead to improved understanding of the extent to which C02 greenhouse warming will be augmented by other atmospheric trace gases.