interesting to note from NPR (not exactly your climate skeptic)... sea ice melt will not change sea levels, as the ice has already displaced its mass in the ocean. Glacier and sheet ice over land might...
not that I want to hash this all over again on a SAILING forum...
The devil is in the details - yes, melting "sea ice" will not change sea levels as the ice is floating and is displacing it's weight in water. However, I think some of the detail is getting lost in this translation because there is more than just "sea ice" out there. I'm betting another 10 minutes of that episode would have probably gotten around to this part of the subject.
After hearing some reports of a 30 foot sea level rise a couple of years ago, I too was skeptical so I did some research and math on my own. What I found is that even if you just consider Antarctica, where most of the ice is on a continental land mass, that a 30 foot sea level rise is incredibly EASY to hit if only a small part of Antarctica melted. This ignores Greenland, the arctic, and many other land based masses of ice. It's astonishing but true.
If Greenland were to all melt, the oceans would rise 20 feet. If Antarctica were to all melt, the oceans would rise 200 feet. We're talking about a LOT of ice out there and it's not melting "tomorrow". The main estimates on future ocean levels if the current melt rates continue is between 20 and 40 inches by 2100.
