- 16 Jun 06, 09:39 AM
As Julian has already told you, I’m here with him in Greenland, studying the signs of Arctic meltback. We’ve seen some of the evidence that the glaciers are retreating, and also we’ve been up close and personal with several floes of sea ice. It can be very tranquil out here in the fjord, surrounded by the beautiful multiyear floes, which are so beaten up by their years of crashing into one another that they look like whipped up meringue. But once in a while you hear a sudden crack like a pistol shot, and watch a large block of ice tumble into the sea. And all around there are the uneven dripping sounds of the Arctic melting.
Melting sea ice is a perfectly natural thing. It happens here every summer, and even now—which is quite early for Greenland—some of the floes have blue-green ponds of meltwater on their surface. (Incidentally, even though sea ice is just frozen seawater, the older ice spends its first few years letting all the salt trickle out of wiggly channels below the surface, and the topmost part is now more or less salt free. That means the pools of meltwater taste fresh and sweet—I know, I drank some! Apparently whalers used to use these pools to replenish their water sources, and sometimes to take a chilly dip.)
However, we have also heard worrying evidence that the sea ice is melting more rapidly than before, and that the northernmost ice cap is shrinking. Satellite data show that the summer sea ice has receded by 8 % per year over the past three decades. And some models predict that by the end of the century, the white polar ice cap in summer will be replaced completely by a deep blue ocean.
I’ve just written about Arctic climate change in an article published this week in Nature called “the tipping point of the iceberg”. Those of you who have a subscription can check it out here:
For the rest, I’ll give a quick summary.
Basically, I talk about “tipping points” in the Arctic. I look especially at three vulnerable areas, the Greenland ice sheet, the Arctic sea ice, and the ocean circulation. All three of these have some kind of “tipping point” beyond which they will change more or less irreversibly. The good news is that at the moment, scientists believe that we are still some way off the danger point for completely melting the Greenland ice sheet, or from tipping ocean circulation over the edge.
The bad news is that it looks as if the Arctic sea ice is already on its way. Also with us in Greenland is Jacqui McGlade, director of the European Environment Agency. When I was chatting to her yesterday, she told me that this would make a radical, but perhaps very interesting, difference to the ecosystem hereabouts. She thinks, as do I, that the Earth isn’t particularly afraid of change. It’s a restless planet, and change is part of its nature. But those of us that are living on its surface right now might well start to be alarmed when we realise the scale of the change, when we see the white ice receding, and some of our favourite animals—polar bears, seals and walruses—start to die off. I personally wonder if the Arctic sea ice is such an icon of our planet that losing it might nudge public opinion over its own tipping point with regard to climate change. As one of the scientists I spoke to for my Nature article said: “Tipping points are part of the problem, but they could also be part of the solution.”
Today I will talk a bit more to Jacqui about the different possible futures that Europe faces, and also about what sort of choices we have. She’s the first person I’ve met in a long time who has specific suggestions for what we can do to change our future for the better. I’ll let you know what she comes up with.