Re: I have to say that 200-300 years doesnt overly concern me
Water vapour is vastly different from the carbon dioxide problem. The distribution of water amongst its states is related to the temperature of the planet + atmosphere. If the planet is cooler, there will be less gas, much more liquid, a bit more solid.
The original poster, although suffering from head way too far up his backside, is essentially correct. If you can get your hands on loads of cheap clean energy, you can convert CO2 into something that doesn’t trap heat so efficiently, and roll back the gains in thermal efficiency we have given the planet. You can’t really repair the damage, what is lost is lost.
How far the water rises is really besides the point in terms of the looming disaster. The large blocks of ice on the planet serve to moderate the climate. As these moderators disappear, we will experience extremes and shorter transitions between the extremes. Some say we are already experiencing that, but given how much ice is still around, I think that might be calling the game a bit early.
Secondarily, if there is less ice, then there is more water and more water vapour. However the distribution function works, more water vapour means more precipitation. More precipitation means that streams, rivers, lakes, etc.. will also expand, so Chicago may have more to worry about than Miami.