The planetary wave response to global warming with single forcing of greenhouse gases (GHGs) is investigated in this study by using a total of 11 model results that anticipated CMIP3 4×CO2 experiments. It is shown that the amplitudes of the planetary wave fluxes over Siberia, the Eastern North Pacific, and the North Atlantic decrease by approximately –10% to –30% in the warming context. In particular, the vertical wave flux over the Eastern North Pacific significantly decreases by –28.6%. The weakening of the planetary waves is partly associated with the decreased land-sea thermal contrast, which may be caused by the radiation effect of CO2 and the different surface heat capacities of land and sea. The present work provides a clear understanding of the responses of plane-tary waves to GHGs forcing.