I seem to be fully engaged in the “Earth Day” meme today… Or maybe it’s just that lots of people are posting on a topic that I really care about.
Either way, it looks like it’s going to be a busy day here on the blog.
So here’s an article posted about the increasing melt-rate of the ice sheet covering Greenland.
“‘2007 was a shocking year,’ Scott Luthcke, who works with GRACE at NASA’s Goddard Space Flight Center in Maryland, told me later.
One record melt season does not spell the end of Greenland, of course, and journalists must always be wary about sounding too alarmist based on short-term records. But overall, the outlook for Greenland is simply not good: Changes in speeds of the island’s outlet glaciers show that, no matter whether they are advancing or retreating, they are far faster at changing their behavior than anyone had thought before.
As the article was going to press, we learned that another pair of key Greenland papers would appear the next day online in Science. Such is the peril of scheduling features far in advance while knowing your competitor journal has interesting papers under review.
The basic point of the two new papers — that vast quantities of meltwater can form and then drain away atop the ice sheet each summer – made it into my feature anyway. But if you want more details, check out the original papers at the Science Express website. One paper, with lead author Sarah Das of the Woods Hole Oceanographic Institution, reports on a 4-kilometre-long melt lake that vanished into the ice sheet within the space of two hours. The other, with lead author Ian Joughin of the University of Washington’s Applied Physics Laboratory, describes seasonal speed-up in ice flow along Greenland’s western flank – though not so much in the outlet glaciers. Together, the papers confirm how meltwater likely helps lubricate the slippage of the ice sheet towards the ocean.”
Read the rest here.
While this is worrisome in and of itself, keep in mind that there’s reason to believe that a big slug of cold fresh water is going to disrupt the North Atlantic conveyor currents that cause northern Europe’s climate to be much more temperate than it ought to be.
If this melting trend continues, we’re going to find out pretty quickly whether or not the currents will get switched off. And if they do, it’s going to be a tough transition for the palm trees in Dublin. (Amongst others…)