NASA scientists have been observing ice masses in Greenland and Antarctica since 2002. They conclude these are melting into the ocean causing sea levels to rise. Greenland and Antarctica are currently losing ice mass at a rate of 285, and 145 gigatonnes respectively annually. Those numbers confused us. We wanted to know how to comprehend a gigatonne of ice in terms we understand.
How to Comprehend a Gigatonne of Ice by Volume
Greenland and Antarctica shed approximately 5,640 gigatonnes of ice between 2002 and 2007. NASA obtained this data during the Grace satellite mission that determined the distribution of mass around the planet. Those gigatonnes would cover Texas with an ice sheet 26 feet high.
One gigatonne is one billion metric tonnes. A typical auto weighs around two metric tonnes. Central Park in Manhattan, New York City is a half-mile wide by two-and-a-half-miles long, or 843 acres. One gigatonne of ice on it would be just over 1,000 feet tall.
Greenland and Antarctica Lost 49,000 Gigatonnes Since 1901
Knowing how to comprehend a gigatonne of ice helps us understand that number, which would otherwise be meaningless. It’s the size of the ice loss since the start of the 20th century according to NASA’s best estimate. Those 49,000 gigatonnes of ice could cover mainland United States in an ice sheet 22 feet high. Or alternatively stack the entire Moon surface 5 five feet tall.
Sea levels would rise by 20 feet if all the Greenland ice melted according to National Snow and Ice Data Center. If we lost the entire ice sheet of Antarctica too, then this would raise sea levels by an additional 200 feet. The water would flow inland up valleys, rivers and canals. The results would be devastating. Lower lying parts of many cities including New York, Miami, and Hialeah Florida would disappear beneath the waves.
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Preview Image: Grace Satellite Mission
