The greatest masses of ice on Earth, in Antarctica and Greenland, aren’t just melting — this melt is accelerating.
How much ice are these critical polar regions losing into the oceans? NASA uses satellites to diligently measure the conditions of these colossal ice sheets. Between 2002 to 2017, the GRACE satellite observed 5,641 gigatonnes of ice loss. (For reference, a single gigatonne is equivalent to 1 billion metric tons — and there are about 2,200 pounds in a single metric ton.)
“This is enough to cover Texas in a sheet of ice 26 feet high,” said NASA.
To help visualize a single gigatonne, NASA made a new video, shown below in its shorter form (via Instagram) and longer form, which is only 24 seconds and definitely worth your time. As NASA notes, a gigatonne of ice in 843-acre Central Park would reach 1,119 feet high.
That’s taller than Manhattan’s iconic Chrysler Building, once the tallest building in the world.
Antarctica is losing six times more ice than it was in the 1980s. And Greenland’s rate of melt has accelerated by seven times since the 1990s.
Both of these historically unprecedented events are ultimately driven by a relentlessly heating planet, as atmospheric carbon dioxide concentrations continue to skyrocket.
In Greenland — home to an ice sheet two and a half times the size of Texas — a warming atmosphere is driving much of this melt. Meanwhile, in Antarctica, warmer ocean waters are eating away at the ends of glaciers that float over the ocean, known as ice shelves. This poses a giant problem.
The mighty Thwaites glacier, one of the largest glaciers on Earth, lies in Antarctica. Warmer ocean waters are melting away the ice shelf at a “tremendous rate,” and in the coming decades the glacier may pass the point of no return — meaning unstoppable amounts of Thwaites’ ice on the Antarctic continent will pour into the sea.
“Thwaites is the one spot in Antarctica that has the potential to dump an enormous amount of water into the ocean over the next decades,” Sridhar Anandakrishnan, a professor of glaciology at Penn State University, told Mashable.
Thwaites alone could trigger over two feet of sea level rise this century.
Already, though, many gigatons of ice are pouring in the sea. Under extremely optimistic (if not nearly impossible) scenarios wherein global society curbs Earth’s warming at an ambitious 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-Industrial Revolution temperatures, the relatively conservative UN Intergovernmental Panel on Climate Change (IPCC) expects around two feet of sea level rise this century.
But it could be more, much more. This depends on how much society curbs its carbon emissions in the coming decade and beyond, and potentially stabilizes the warming climate.
