barakn writes "Scientists have savaged the new movie The Day After Tomorrow, which depicts global warming causing a new ice age and freezing New York solid. The movie follows on the heels of a report to the Department of Defense in February, written by two guys who are not climatologists, about the implications of global warming triggering the growth of ice sheets in the northern hemisphere. There is a plausible theory which suggests that melting ice may release enough fresh water to halt circulation of warm water from the Gulf Stream, thus significantly cooling Europe and the east coast of North America. Note that this theory depends on melting ice, not growing ice, which may be one reason scientists find the ice age scenario so hard to swallow. New satellite evidence suggests a part of this circulation may already be slowing down. Those on the North American west coast will not have to worry about ice sheets, but changes in Arctic ice could mean the western drought will be permanent. For those of you who would rather do something before it's too late, iron seems to work, but the long-term ecological implications are still unknown."