Melting ice in Greenland has triggered a positive feedback, releasing
dust that darkens the surface so that it absorbs more light and heats
up to melt more ice.
A different positive feedback loop is speeding melting of Antarctic ice.
This leads me to think that that forecast sea-level rise is an
underestimate. I am not surprised, since the forecasts are based on
known phenomena only, and that makes them conservative.
A mere 10 meters of rise would inundate many cities around the world.
Can we dam the Mediterranean Sea? It would be a megaproject and a
great challenge, but might be cheaper than protecting, or losing, the
heart of every city on its coasts.
It might be necessary to transfer lots of water and/or salt across the
dam, but that would be better than letting the Mediterranean flood so
many cites.