The glaciers that make up the Patagonian Icefield of South America have been on the decline for the past four decades, with the rate of melting increasing 50% over the past decade, according to new research.
Combined, the Northern and Southern Patagonia Icefield are the largest areas of ice in the Southern Hemisphere outside of Antarctica. From the 1970s to 2000 they were melting at a rate that contributed 0.042mm to sea level rise each year, but from 2000 to now they have been melting such that they add 0.067mm to sea level rise. Since 1998 they've contributed about 2% of total observed sea level rise. (Science Daily)Put another way, just the melting of these icefields has contributed enough water to the world's oceans since 2000 that it would cover the entire US to a depth of 3.3cm.
Though there are some glaciers that have been stagnant over this time period, and some have advanced (as is the case with glaciers worldwide), on the whole these glaciers are in retreat. The Southern Patagonian Icefield has on average lost 1.8m of ice and snow each year since 2000.
The retreat has been most noticeable at high elevations, driven in large part by warming temperatures contributing directly to melting and indirectly to more precipitation falling as rain rather than snow, in turn increasing the rate at which the glaciers move and increasing the size of glacial lakes, both decreasing ice cover.