Earth is losing 39 cubic miles of ice per year
Oh lord, is the planet ever melting. And thanks to the GRACE satellite, we now know that the planet is shedding 150 billion tons of ice annually, like some gigantic glass of lemonade left out in the sun.
Melted down, just seven years of that lost ice would cover the entire United States in a foot and a half of water.
The good news is that the pair of satellites used to measure The Great Melt is totally badass and you should take a moment to geek out on its awesomeness:
Launched in 2002, two GRACE satellites whip around Earth in tandem 16 times a day at an altitude of about 300 miles, sensing subtle variations in Earth’s mass and gravitational pull. Separated by roughly 135 miles, the satellites measure changes in Earth’s gravity field caused by regional changes in the planet’s mass, including ice sheets, oceans and water stored in the soil and in underground aquifers.
Variations in the gravitational tug of the Earth — say, from more or less ice on the surface of Greenland — push the satellites apart or pull them together, and they can measure these changes in distance to degrees as small as 1/1000th the width of a human hair. And that is how they know that we are completely fucked.