Ala Khazendar, the leader of this NASA study, explains that two thirds of Larsen B collpased in 2002 in less than 6 weeks. The remnants of this ice shelf are now melting and fragmenting very quickly and should break apart by 2020.
Ice shelves are thick platforms of ice that form where ice flows from land into cold ocean waters. They act like barriers so that the glacial ice does not enter the ocean at a fast pace, preventing a rise in sea levels.
Ice shelves themselves are already in the ocean and their disintegration does not directly increase sea-level rise, but the concern comes from the ice that will soon be dumped directly into the ocean by the then-unprotected glaciers.
To make matters worse, the study also found that Leppard and Flask glaciers (two of the three main glaciers feeding into Larsen B) have thinned by 65-72 feet (20-22 meters) and their decline has accelerated significantly since the 2002 collapse.
Needless to explain that what is happening in the Antarctic Peninsula goes hand in hand with the extremely high levels of atmospheric emissions of greenhouse gases from the burning of fossil fuels and the inevitable rise of the global temperature.
According to Greenpeace, “with a fossil fuel intensive future, a global average sea level rise of 26-59cm (10-23 inches) is expected over the next hundred years […] This will be around two thirds due to thermal expansion of the oceans (water expands as it heats up) and one third due to melting.”