America under President Trump might not own Greenland (yet), but decisions made by his administration will help determine the ice-covered island’s long-term fate and ours.

US emissions of greenhouse gases, as well as emissions from other countries, have tipped the balance to make Greenland a major contributor to global sea-level rise.

It’s no secret that the Greenland ice sheet is in trouble. This melt season, which is wrapping up, has brought the most significant ice loss, and related sea-level increase, since the record melt year of 2012.

Much of the ice melted in a one-week period when the island was in the throes of a heat wave that had moved in from Europe.

According to Ted Scambos, a senior research scientist at the University of Colorado, this year Greenland…