Greenland

Two starkly contrasting views of what Greenland might do in a warming world.

First, a new paper in Nature, Eemian interglacial reconstructed from a Greenland folded ice core(NEEM Community Members, (2013)) carries the big news is that this group has managed to obtain and use the information in ice from the Eemian — the peak of the last interglacial period, about 125,000 years ago — in Greenland. Getting usable Eemian ice from Greenland has been a Holy Grail of ice core research for the better part of two decades.

The good news: the implications from this data for the Greenland ice sheet seem to indicate that it is less sensitive to climate warming than some of the higher-end estimates suggest. The NEEM ice core record suggests both that temperatures may have been warmer than once thought, and and that the ice sheet mass loss was unlikely to have been >2 m of sea level. In essence, the new data show that Greenland, while evidently contributing significantly to Eemian sea level, cannot have contributed more than half the total — despite the strong forcing.

The bad news: This once again points to Antarctica as the major source of Eemian sea level rise. There are only about 3 m of sea level rise available from West Antarctica, and it remains unclear whether all of West Antarctica may have collapsed.

Read more here: The Greenland melt

And here: Greenland defied ancient warming

Now the contrary view.

Humans have already set in motion 69 feet of sea-level rise

Jason Box is one of the premier experts on the Greenland ice sheet, having spent, in total, more than year camping on the ice over the course of  the last 2 decades. He states that we’ve already pushed atmospheric carbon dioxide 40 percent beyond Eemian levels. What’s more, levels of atmospheric methane are a dramatic 240 percent higher — both with no signs of stopping. “There is no analogue for that in the ice record,” said Box.

And that’s not all. The present mass-scale human burning of trees and vegetation for clearing land and building fires, plus our pumping of aerosols into the atmosphere from human pollution, weren’t happening during the Eemian. These human activities are darkening Greenland’s icy surface, and weakening its ability to bounce incoming sunlight back away from the planet. Instead, more light is absorbed, leading to more melting, in a classic feedback process that is hard to slow down.

“These giants are awake,” said Box of Greenland’s rumbling glaciers, “and they seem to have a bit of a hangover.”

Dr. Box is the creator of the Dark Snow Project, an ambitious attempt to Crowd-fund an arctic expedition this summer.  Over the last decade, Jason’s measurements indicate that the surface of Greenland has become darker, more absorptive of the sun’s light and heat.  There are a number of processes that could be causing it – some natural, some manmade. DarkSnowProject is designed to sample snow at various points on the ice sheet, and determine if  soot from increasing numbers of large wild fires could be one of the significant reasons for darker snow.