HELHEIM GLACIER, Greenland (AP) — This is where Earth's refrigerator door is left open, where glaciers dwindle and seas begin to rise.

New York University air and ocean scientist David Holland, who is tracking what's happening in Greenland from both above and below, calls it "the end of the planet." He is referring to geography more than the future. Yet in many ways this place is where the planet's warmer and watery future is being written.

It is so warm here, just inside the Arctic Circle, that on an August day, coats are left on the ground and Holland and colleagues work on the watery meltin...