Global Warming

Melting Greenland ice now source of 25% of sea level rise

Ocean levels rose 50 percent faster in 2014 than in 1993, with meltwater from the Greenland ice sheet now supplying 25 percent of total sea level increase compared with just 5 percent 20 years earlier, researchers reported Monday.

The findings add to growing concern among scientists that the global watermark is climbing more rapidly than forecast only a few years ago, with potentially devastating consequences.

Hundreds of millions of people around the world live in low-lying deltas that are vulnerable, especially when rising seas are combined with land sinking due to depleted water tables, or a lack of ground-forming silt held back by dams.

Major coastal cities are also threatened, while some small island states are already laying plans for the day their drowning nations will no longer be livable.

Greenland alone contains enough frozen water to lift oceans by about 7 meters (23 feet), though experts disagree on the global warming threshold for irreversible melting, and how long that would take once set in motion.

Overall, the pace of global average sea level rise went up from about 2.2 mm a year in 1993, to 3.3 mm a year two decades later.