New research suggests that Greenland’s vast ice sheet isn’t as fragile as some climate scientists feared.
The work, published in Nature this week (see abstract), indicates the majority of ice on Greenland could remain intact for hundreds of years even if the planet warms considerably.
The study used ice cores to study conditions during a period of natural global warming that occurred between 115,000 and 130,000 years ago, when temperatures were about 14.5 Fahrenheit degrees higher than they are today. This was known as the Eemian period.
During this inter-glacial time about 75 percent of Greenland’s ice sheet remained intact. Accordingly, the study also indicates that Antarctica, which has much more ice, must have contributed significantly more to a sea levels that were 25 feet above what they are today.
Nevertheless this paper will likely muddy the already very muddy waters of the interface scientists have with the public and their perception of this issue.
As usual, Andy Revkin zeroes in on this point, noting the widespread attention the spectacular visuals of melting ice that have appeared in climate change films and other productions. It has been a useful tool in rousing public concern about climate.
The concerns about recent trends on Greenland’s giant ice mass have been warranted, given signs of extensive surface melting and the possibility, explored here, that meltwater gushing to the ice sheet’s base through natural “drain pipes” called moulins could accelerate the flow of ice to the sea. The stunning documentary “Chasing Ice” conveys the drama and mystery in all that melting, and the impact of warmer sea water on the areas where Greenland’s glaciers meet the sea.
I saw these dynamics up close in 2004, and it’s a thrilling, chilling experience (video).
But the new work puts all of this in the context of long stretches of time, which is vital if one’s goal is to avoid overreaction and to focus attention where real risks lie.
The real risks may lie in Antarctica, Revkin says, which may be more unstable than scientists have thought.
It’s interesting that Revkin’s go-to scientist on ice issues, Richard Alley of Penn State University, says this paper makes him more concerned about future sea level rise rather than less, because it suggests Antarctica is more vulnerable.
That’s a defensible scientific reaction, but it’s not one that’s easy to sell with a public divided over climate science. The fact is, the major conclusion of this paper is that Greenland’s ice appears to be more robust than scientists have been telling us.
That is a message that will play into those who like to cast doubt on scientific conclusions about climate change.