Reporting on the behavior of ice sheets is difficult, even for science journalists, because the terrain is so difficult, and so much is still unknown about Antarctica. But a couple of weeks ago in Rolling Stone, Ben Wallace-Wells published the single best story about this subject I have ever seen. It's long, but great.
Here's the nut graph, from well into the story:
In the past few years, scientists have begun to worry that the world's glaciers have entered what they call a "runaway feedback mode," in which the dramatic changes to the water and wind and ice caused by global warming have not only accelerated but have themselves begun to alter the climate, creating a dynamic that could be irreversible. Both Antarctica and Greenland are now losing ice at twice the rate they were in 2002 — as much as 400 billion tons each year. In July, after the planet's six warmest months on record, a giant crack opened up overnight in the Jakobshavn Glacier; for the first time ever, scientists monitoring satellite data were able to observe in real time as an iceberg covering 2.7 square miles broke off and floated into the sea. Three weeks later, an even larger iceberg — four times the size of Manhattan — cleaved away from another glacier to the north of Jakobshavn, stunning scientists who study the ice sheets. "What is going on in the Arctic now," says Richard Alley, the geoscientist at Penn State, "is the biggest and fastest thing that nature has ever done."
The story covers not only the scientific questions, but the ingenuity the scientists displayed in finding answers to questions that appeared insolvable, and it touches on their emotions as well. Remarkable.
[to see a NASA/GISS short film of the Pine Island Glacier calving mentioned in the story, go here]