Tag: ice

Five feet high and rising!

Sea.jpg Yesterday, while dissembling, I had what I might loosely describe as a “bugger” moment. Yale’s Enviroment360 web site (which I plugged on its introduction last June) currently features an interview with Robert Bindschadler, a NASA ice expert who is working on the Pine Island and Thwaites glaciers in West Antarctica. The “bugger” moment?

e360: And in the theoretical case that Pine Island and Thwaites glaciers completely dump into the ocean – obviously it’s not going to happen in the near-future – what kind of sea level rise would they contribute to?

Bindschadler: That portion of West Antarctica, that third that flows northward primarily through those two glaciers, has the potential to raise sea level 1½ meters. That’s sort of an upper bound, a worst case. But the time scale is what really matters. Some say that we won’t see these ice shelves disappear in our lifetime – I’m not so sure. I think we might well.

e360: Are you kidding?

Bindschadler: No, no at all.

Bindschadler looks to be about my age. He reports that the ice shelf is melting from the underneath at a rate of about 50 metres per year at the grounding line. And then, a little later, just to make me spill my tea on the keyboard:

e360: I know that the IPCC was saying maybe 1 ½ feet or a half-meter of sea level rise in the 21st century. Is it your opinion that we could be looking at significantly larger sea level rise?

Bindschadler: Yeah, I think there’s sort of an unspoken consensus in my community that if you want to look at the very largest number in the IPCC report, they said 58 centimeters, so almost two feet by the end of the century. That’s way low, and it’s going to be well over a meter. We may see a meter by the middle of the century.

e360: Oh my gosh.

Bindschadler: And if this behavior that we’re seeing in Pine Island, and even Greenland continues – and we don’t see any reason why it wouldn’t continue – well, over a meter by the end of the century, I think is almost certain.

How notably prim the interviewer is. I think I might have managed something a little more Anglo Saxon. A “meter by the middle of the century” is a very long way above most people’s worst case (though not, perhaps, Hansen’s), but it makes our vulnerability to sea level rise much more of a near-term danger than a comfortable reading of AR4 might suggest. It’s a fascinating article — goes into more detail about the WA ice sheet and PIG (yes, that’s what they call it) than anything else I’ve seen in the last few years. Recommended, but not if you have beachfront property.

Meanwhile, a workshop being held at VUW in Wellington is looking at Andrill results, and finding that the WA ice sheet shows signs of repeated meltbacks over the last five million years [Stuff]:

Professor Tim Naish, director of Victoria University’s Antarctic Research Centre […] is co-science leader of the $30 million Andrill project on the ice, with Professor Ross Powell from Northern Illinois University in the United States.

“Antarctica’s ice sheets have grown and collapsed at least 40 times over the past five million years,” Prof Naish said.

“The story we are telling is around the history and behaviour of the ice sheet … as an analogue for the future,” he said.

Not good news, it seems. Expect a rush of papers covering Andrill work over the next few months.

[Johnny Cash]

Hangin’ on #2

wilkins090124.jpg

Here’s the latest imagery of the Wilkins Ice Shelf from the European Space Agency’s amazing “webcam from space” page (the ice shelf is the black structure running from top left to bottom right — sea shows as white). This image was captured on Jan 24th, and clearly shows the narrow 2km neck referred to in my recent post. Take a look at the “webcam” — the animation is regularly updated as new images are processed. In Hot Topic, I remarked how satellite views of the earth enable my senses to work overtime — this is a fantastic near real-time example.

[Hat tip to Timothy Chase in comments at RealClimate here.]

You keep me hangin’ on

wilkins26nov480.jpg According to Alister Doyle, Reuters’ man in Antarctica (now that’s a job I’d like to try…), what’s left of the Wilkins Ice Shelf is on “the brink of collapse with just a sliver of ice holding it in place“. Earlier this week, Doyle reported on a trip with the British Antarctic Survey to the remnants of the ice shelf:

“We’ve come to the Wilkins Ice Shelf to see its final death throes,” David Vaughan, a glaciologist at the British Antarctic Survey (BAS), told Reuters after the first — and probably last — plane landed near the narrowest part of the ice. […]

BAS scientists and two Reuters reporters stayed about an hour on the shelf at a point about 2 km wide.

“It’s very unlikely that our presence here is enough to initiate any cracks,” Vaughan said. “But it is likely to happen fairly soon, weeks to months, and I don’t want to be here when it does.”

The Dominion Post‘s Paul Easton picked up the report, and managed to turn it into a story about sea level rise. Rather odd, because Doyle explicity notes:

Loss of ice shelves does not raise sea levels significantly because the ice is floating and already mostly submerged by the ocean. But the big worry is that their loss will allow ice sheets on land to move faster, adding extra water to the seas. Wilkins has almost no pent-up glaciers behind it. But ice shelves further south hold back vast volumes of ice. “When those are removed the glaciers will flow faster,” Vaughan said.

Unfortunately for us all, the most recent research suggests that the West Antarctic is warming significantly, as this image from the cover of this week’s Nature demonstrates rather well:

West-Antarctic-in-red.jpg
(E Steig/NASA)

See also: Guardian (UK) on Steig et al, Reuters on summer rain on the Antarctic Peninsula and the clear air down there, and a Danish researcher finds yet another reason to project that sea level rise this century will exceed IPCC estimates. More on land ice and the Arctic next week.

[The Supremes]

Tear-stained letter #2

pottypeer.jpg Some summer reading for NZ prime minister John Key: Christopher, Viscount Monckton of Brenchley (“I’m no potty peer”) has penned another of his dippy epistles — an “open letter” in the next issue of Free Radical, an NZ libertarian publication. His last, to John McCain, was a triumph of hilariously overblown climate crank nonsense. This looks to be no more succinct, but has the publishers of FR chortling with excitement. From Not PC:

This is pure gold; the world’s leading climate ‘skeptic’ explains to NZ’s new Prime Minister that the apocalyptic vision of catastrophic anthropogenic climate change is a lurid and fanciful account of imagined future events that was always baseless, was briefly exciting among the less thoughtful species of news commentators and politicians, and is now thoroughly and scientifically discredited.

Thoroughly and scientifically? How exciting. Let’s take a look.

Continue reading “Tear-stained letter #2”

Cold moments

arcticmethane.jpgMore data on the state of the methane hydrates on the Siberian shelf emerged during the American Geophysical Union’s Fall meeting in San Francisco this week. At a press conference covering recent work in the Arctic, Igor Semiletov, the leader of the team working on the Yakov Smirnitsky last (Arctic) summer, told reporters:

“The concentrations of the methane were the highest ever measured in the summertime in the Arctic Ocean,” Semiletov said. “We have found methane bubble clouds above the gas-charged sediment and above the chimneys going through the sediment.” [Science Daily, e! Science News]

A reporter at the press conference, who blogs at A Change In The Wind, asked Semiletov if the increase in methane release his team had discovered constituted “a global emergency”. In his blog entry he writes:

[…] his struggle with the question was evident. I tracked him down later, and asked if he felt he was the wrong person to be answering such a huge question. He admitted his discomfort, but said he thought it was the best question he was asked, and insisted:

“I am the person responsible for this research, and I think we have to tell people that something is happening now with the subsea permafrost.”

Why? A Change In The Wind explains:

Semiletov thinks that if just 1% of the ESAS methane is released, it will push total atmospheric methane up to 6 parts per million, and cites researchers such as David Archer in arguing that this would push us past the point of no return, towards runaway global warming.

Six ppm methane is a little over three times the current level, and with a global warming potential of 25, is equivalent to 150 ppm CO2, or 50 years worth of current annual CO2 emissions. There’s no reference to any time scale for this release, but the possibility should be enough to ring alarm bells — and loudly.

[There’s plenty of other Arctic/climate related material to blog from the Fall AGU meeting, and I’ll get to some of it soon, but for the time being Christmas shopping looms…]

[Title reference]