Here's what Wadhams had to say in an interview
on Real News
"A few years ago, I predicted that the summer sea ice--that's the September minimum--would go to zero by about 2015. And at that stage, it was only really one model that agreed with me. My prediction was based on observations from satellites and from measurements from submarines of ice thickness, which I've been doing from British subs, and Americans have been doing the same from American subs. And the trend was so clear and so definite that it would go to zero by 2015 that I felt it was safe to make that prediction, and I still think it is, because next year, although this year we don't expect things to retreat much further than last, next year will be an El Niño year, which is a warmer year, and I think it will go to zero.
And once it goes to zero in the summer, it is sort of irreversible, because it means that the next summer there'll be a longer ice-free period. Instead of just one month, there might be two or three months, because the water warms up during the summer months. If there is no ice there, it's absorbing solar radiation, the water's warming up.
As we've heard, one of the things that would happen from that is that the water on the continental shelves warms very much. We've seen seven degree temperatures from satellites. And that means that the seabed permafrost near the coast then melts, and that releases methane. And the methane effect, I think, is the biggest of all the threats from the retreat of sea ice. We've got other effects as well. The retreat is causing warmer air over Greenland, which is causing the Greenland ice cap to melt faster and sea level rise to accelerate.
But the biggest immediate threat, I think, is that the warming of the water in summer is causing methane to be released from the seabed because of the melt of offshore permafrost. And this is something that's being documented by a Russian-American group, and for several years. And we're joining them with some European funding, which we're putting in to help fund their work and going out with them.
So I think that the documentation of this and the fact that the extra methane we see each summer--that's the big, increasing amounts of methane plumes in the Arctic reaching the surface, releasing methane into the atmosphere--and that's reflected in NASA's measurements from satellites of methane levels in the atmosphere in the northern hemisphere, which have started to go up again quite fast after having been flat for a decade or so. I think that that is a big threat.
But the loss of the sea ice is something that's, I think, irreversible, because all the trends are towards decreased sea ice extent, and there's no countervailing trend that will bring the ice back. The biggest effect is an albedo feedback effect, for instance, the fact that as the ice disappears, you're replacing highly reflective ice and snow with poorly reflective water. And that has an effect of increasing the rate of warming of the Arctic, and that increases the rate of retreat of the ice. So all the feedbacks are positive. There's no negative feedbacks that will tend to bring the ice back. Once it's gone in summer, it's gone, and I think the summer ice-free season, having started very soon, maybe next year, will then extend itself so that we might have a number of months of ice-free conditions. We'll have plenty of ice in the winter, of course.
But that ice-free summer will have all these knock-on effects of increasing methane release, maybe producing a catastrophic pulse of methane, which has been predicted based on how much methane is sitting in the form of methane hydrates. And that pulse would be very catastrophic. We examined this with climate modeling and economic modeling and found that a pulse of the size that's predicted based on how much methane is there could cause a temperature rise of 0.6 of a degree within 20 years. Now, that's a big addition to the amount of warming that is already going on. It's pretty much doubling the rate of global warming.
And so--plus it's costing some astronomical amount of money as well to the planet. This is using a model, an economic model. So the cost to the planet of having this happening far exceeds any of the benefits we might get from Arctic oil or shipping through the Northwest passage. We're really stuck with a massive economic cost and, of course, a catastrophic cost to the planet.
So all these things are bound to happen, sadly. And the only way in which they wouldn't happen would be if for some surprising reason the methane hydrates on the seabeds stopped emitting methane. But then we wouldn't get off scot-free, because the other source of increased methane is permafrost on land, and that's also melting as the climate warms. And it's a slower process, but in the end there's more methane going to be released from that over many decades than would be released from a pulse in the Arctic Ocean. So in the end we'll have the methane impact on global warming, which hasn't been taking account of IPCC [models]. It's going to come in and it's either going to hit us fast or it's going to get us slowly, but it's going to hit us."