Geophysical Research Letters, 24 January 2022
A patch of unusually cold water in the North Atlantic Ocean – nicknamed the “Blue Blob” – has temporarily slowed the melting of Iceland’s glaciers since 2011. This regional cooling was caused by meltwater pouring off the Greenland ice sheet and Arctic glaciers, as well as the slowing of Atlantic overturning currents. The water in the “Blue Blob” is so cold that it decreases the temperature of the air flowing over it, which then affects the atmosphere surrounding Iceland. This cooling effect appears to have slowed the rate of ice loss from Iceland’s glaciers during the past decade. From 1995 to 2010 (before the emergence of the “Blue Blob”), Iceland lost on average about 11 gigatons of ice every year due to glacier melting. Coinciding with the emergence of this cold-water region in 2011, the rate of Iceland’s ice loss has almost halved. The “Blue Blob” does not appear however to have slowed ice loss from nearby glaciers in Greenland and Svalbard, because these glaciers are less exposed to the ocean than those of Iceland. Rising global temperatures will likely overcome the cooling effect caused by the “Blue Blob” within the next thirty years; by 2050, ice loss from Iceland is anticipated to again accelerate to rates even higher than those observed between 1995-2010. Under a high emissions scenario, Iceland’s glaciers could lose one third of their current volume by 2100, and completely disappear by 2300. Conversely, a low emissions scenario consistent with the Paris Agreement’s 1.5°C goal could preserve much more of Iceland’s glaciers and important water resources.