Over 12 trillion tons of Earth’s polar ice has melted, as scientists warn about sea-level rise

Since 1979, approximately 12.5 trillion tons of ice from Greenland and Antarctica have melted, enough to cover the continental United States in a layer of ice 5 feet deep. The study, published in Scientific Data, reveals that this alarming ice loss is primarily due to warmer ocean waters eroding the ice sheets from below and melting them from the sides.

Study co-author Eric Rignot, an ice scientist at the University of California, Irvine, declares, "The ice sheets are melting away fast." The melting has caused global sea levels to rise by about an inch since 1979, and for every third of an inch of sea level rise, an additional 2 to 3 million people are flooded annually. The Jakobshavn glacier in Greenland is receding at a rate of up to 164 feet per day.

The researchers found that ice sheet mass loss has been increasing over the decades, with the most significant changes occurring in the 2010s. This acceleration suggests that even if global warming were halted, the trend would continue for decades. The study combines data from 45 independent surveys and 27 different satellites, leading researchers to express confidence in the upward trend.

While short-term stability in Antarctica has been observed due to record snowfall, this temporary respite is likely just a "bump in the record." New York University ice scientist David Holland warns that dynamic processes, which are more abrupt and can trigger runaway "tipping points," pose the greatest concern.