So there's no check points, no pause button and no way to tell if your stalling. So far I'm on the first mission and I've been killed by all three. I don't think I'll play until it has those things.
Metema's right... If Greenland melted, the extra water would mess up the currents in the Atlantic ocean. Then, no hot water flowing into the Atlantic, so Europe would go into an ice age. I'm not sure about the rest of the world though...