In April, a study revealed that the Greenland ice sheet is sloughing off an average of 286 billion tons of ice per year. Two decades ago, the annual average was just 50 billion.
In 2012, Greenland lost more than 400 billion tons of ice.
Antarctica, meanwhile, lost an average of 252 billion tons of ice per year in the last decade. In the 1980s, by comparison, Antarctica lost 40 billion tons of ice annually.
What's more, parts of Thwaites Glacier in western Antarctica are retreating by up to 2,625 feet per year, contributing to 4% of sea-level rise worldwide. A study published in July suggested that Thwaites' melting is a time bomb that is likely approaching an irreversible point after which the entire glacier could collapse into the ocean. If that happened, global sea levels would rise by more than 1.5 feet.