A mechanism exists whereby global greenhouse warming could, by inxensifymg the alongshore wind stress on the Ocean surface, lead to acceleration of coastal upwelling. Evidence from several Werent regions suggests that the major coastal upwelling systems of the world have been growing in upwelling intensity as greenhouse gases have accumulated in the earth's atmosphere. Thus the cool foggy summer conditions that typlfy the coastlands of northern California and other similar upwelling regions might, under global warming, become even more pronounced. Effects of enhanced upwelling on the marine ecosystem are uncertain but potentially dramatic.