. >> if greenman melton the water levels rose would that create another ice age? would that create another ice age? >> if those happened there would be separated by a long period. they are conserved. my sense is we are mostly concerned about in the future that we can imagine, warming and melting followed by increased water levels. later ice ages can be driven -- historically the ice ages were not driven by human behavior and we have to think about how cumin action interact with the natural world. into the future we could enter one of those periods and what would happen is that water would refreeze and water levels would come back down should that freezing occur. >> what i don't know if you have seen the movie the day after tomorrow, but that scenario of a real, very rapid shift into an ice age is in a matter of days is unrealistic. but a scenario of regional climate change like unmentioned particularly in europe, that might happen possibly. the science is not settled but it is possible that the happen because of shifting ocean currents. the gulf stream warmers the