Summary
Study of four glaciers dotting the high Andes in Colombia, Peru and Bolivia shows that, at least in the tropics, the retreat is unprecedented. The glaciers are smaller than they have been in more than 11,700 years, the beginning of a warm interglacial period geologists refer to as the Holocene.
The new findings are a sign that more of the world’s glaciers are likely retreating far faster than predicted, possibly decades ahead of earlier predictions. ‘This is the first large region of the planet where we have strong evidence that glaciers have crossed this important benchmark – it is a ‘canary in the coal mine’ for glaciers everywhere’
Surprisingly, they found no “sunburn.” “We found essentially no beryllium-10 or radiocarbon-14 in any of the 18 bedrock samples we measured in front of four tropical glaciers,” Gorin said. “That tells us there was never any prior exposure to cosmic radiation since these glaciers formed during the last Ice Age”
