New Scientist has an interesting article that puts a new twist on the dangers of global warming. A group of researchers from Bowling Green working in Siberia have evidence that flu viruses can survive a freezing winter locked in ice and then infect local wildlife when they thaw again. In fact, they also believe that these freezing and melting cycles serve as "melting pots" for flu viruses from year to year to mix and form new strains. It seems as though each freeze-thaw cycle kills about 90% of each virus, but that still leaves enough alive to make a comeback the next year.

Of course, this brings up the possibility that viruses that have been frozen away from mankind for much longer could be released by global warming and could make a comeback as glaciers and other frozen areas melt in the future.