Check, Check, Check . . .

James Hansen is retiring from NASA.

He is one of the leading climate scientists in the world, and has been for decades.  He's been more right longer than anyone else.

In 1981 (!) he and his team did a study entitled, "Climate impact of increasing atmospheric carbon dioxide" in which some predictions were made about what we would face in the (then) future.  These have begun, far ahead of schedule, and are accelerating.  From the abstract:

Potential effects on climate in the 21st century include the creation of drought-prone regions in North America [check] and central Asia [check] as part of a shifting of climatic zones [check], erosion of the West Antarctic ice sheet [check] with a consequent worldwide rise in sea level [check], and opening of the fabled Northwest Passage [check].

Sea level is in fact rising because of melting ice sheets, about a third to a half of the 3.2 mm/yr happening now.  Ice sheet contribution is doubling about every 7 years, but it's pretty early in the process to see exactly how that is going to go.  It will be either fast or really fast: kids alive today will see the loss of cities like Miami either near the ends of their lives or in the middle.  We should have a better sense of timing in 5 or 10 years.

The short version of sea level rise is that the ocean has been taking in enormous amounts of heat, so ice sheets (like West Antarctica) that are grounded below sea level cannot survive.  In other words, something on the order of 70 ft of sea level rise now is unavoidable.