Circum-Pacific marine and terrestrial records indicate a series of temperature-inferred oscillations during the late glacial. While many previous studies have probed the role of the North Atlantic in these oscillations, we test the sensitivity of the northern hemisphere air temperatures to North Pacific sea surface temperature (SST) oscillation in the Goddard Institute for Space Studies general circulation model. The effect of a colder North Pacific is to cool air temperatures over North America, as well as parts of Europe and Asia. The colder SSTs result in a large hemispheric response due to the loss of water vapor as a greenhouse gas. The large sensitivity of the northern hemisphere to a North Pacific SST change has implications for the ice age climate as well as the late glacial interval. The results of this experiment provide a rapid mechanism for widespread cooling which has not been previously addressed. ¿ 1997 American Geophysical Union