Disappearance of summer sea ice

Summer sea ice will inevitably disappear in a few decades. That will make polar oceans absorb a lot more sunlight, and that in turn will speed the melting of ice on land. Even if we curb global heating in general, this will raise sea level several meters and inundate many of the world's major cities.

*"There’s nothing we can do about that now, we’ve just screwed up and let the system warm too much already,"*