Warming oceans will melt glaciers quicker than expected

Jennifer Welsh in LiveScience: Ice sheets simmering in warmer ocean waters could melt much quicker than realized. New research is suggesting that as oceans heat up they could erode away the ice sheets much faster than warmer air alone, and this interaction needs to be accounted for in climate change models.

"Ocean warming is very important compared to atmospheric warming, because water has a much larger heat capacity than air," study researcher Jianjun Yin, of the University of Arizona, said in a statement. "If you put an ice cube in a warm room, it will melt in several hours. But if you put an ice cube in a cup of warm water, it will disappear in just minutes."

The researchers studied 19 state-of-the-art climate models and saw that subsurface ocean warming could accelerate ice-sheet melting over the next century, resulting in greater sea level rise that could exceed 3 feet (1 meter). Glaciers in Greenland and Antarctica will melt at different rates, though. [In Photos: Glaciers Before and After]

Given a mid-level increase in greenhouse gases, the ocean layer about 650 to 1,650 feet (200 to 500 meters) below the surface would warm, on average, about 1.8 degrees Fahrenheit (1 degree Celsius) by 2100, the researchers found.

The actual warming in different regions could differ significantly, though. They found that temperatures of subsurface oceans along the Greenland coast could increase as much as 3.6 F (2 C) by 2100, but along Antarctica would warm less, only 0.9 F (0.5 C)...

An ice shelf in Antarctica, shot by Georges Nijs, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license