General Discussion
In reply to the discussion: 'Horrible' Sea Level Rise Of More Than 3 Feet Plausible By 2100, Experts Say - NBC [View all]HooptieWagon
(17,064 posts)My assumpions for the calculations:
1) a 2degC rise in temp (from 20deg to 22deg) resulting in a decrease in density from . 998203 to .997770. Those numbers are for fresh water, salinity of ocean water varies widely.
2) Ocean volume of 1.3 billion km^3, and an average depth of 3,682 m...which gives an area of about 353,068,984 km^2. These figures do not include Seas and Gulfs, which are but a fraction of the total volume. Volume and average depth from Wiki, I calculated area from that.
3) the calculated rise due to the 2deg temp increase is 1m, assuming the area doesn't increase as the Ocean rises. Of course it will, but I had no way of estimating how much.
The 1m increase is a great deal more than I would have guessed, how ever the volume was far greater than I would have supposed, average depth being 3 or 4 times greater than I would have thought. The figures you cited probably are fairly accurate, after doing this rough calculation.
What I haven't yet seen from any estimates is an allowance made for increased evaporation due to increased area and higher temp. That will be a substantial amount, and will reduce the amount of ocean rise. It is possible that the increased cloud cover from greater evaporation would cause a cooling, depending on how much moisture remained in the air, and how much precipitated (and where).