Melting Antarctic glaciers that are large enough to raise worldwide sea level by more than a meter are dropping a Mount Everest's worth of ice into the sea every two years, according to a study released this week.

A second study, published Thursday in the journal Science, helps explain the accelerating ice melt: Warm ocean water is melting the floating ice shelves that hold back the glaciers.

The two new pieces of research come as officials of the World Meteorological Organization announced Wednesday that 2014 is on track to be the warmest year on record.

Scientists have long worried that the West Antarctic ice sheet is a place where climate change might tip toward catastrophe. The ice sheet holds enough