Tag: Arctic

Titanic days

Awesome (defined as extremely impressive or daunting; inspiring great admiration, apprehension, or fear) time-lapse pictures of the calving face of the great glacier at Ilulisat, Greenland pouring ice into the ocean — the single biggest ice discharge of any northern hemisphere glacier. Greenlanders reckon this is where the iceberg that sank the Titanic originated. The ice face is huge — the helicopter at the beginning of the clip gives some sense of scale — but the ice is actually 1,000 metres thick at that point. This clip is only an appetiser for the Extreme Ice Survey‘s James Balog providing more detail, and showing many more truly awe-inspiring images in a recent TED talk. Well worth 20 minutes of anyone’s time — as Balog says, it’s hard to ignore the evidence of what’s happening up North.

[Hat tip to Riatsala in a comment yesterday]

More than a metre

Sea level will rise by more than a metre by 2100 according to the authors of the third chapter in the World Wide Fund for Nature’s new Arctic report, introduced by Gareth a few days ago. Eric Rignot, one of the two authors of the chapter, is principal scientist for the Radar Science and Engineering Section at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.  The other author, Anny Cazenave, is an internationally renowned research scientist from France’s national centre for space studies.

The value of the chapter is that it draws together, authoritatively and coherently, the evidence that points to considerably more sea-level rise over this century than projected in the 2007 IPCC Fourth Report (AR4). Happily politicians are taking IPCC reports much more seriously than in the past, but they should not rest on them.  Their responsibility is to be up to date with what the science is saying now. The WWF report assesses the most recent science, and finds that the impacts of warming will be more severe than indicated by the IPCC.

What follows is a summary of the main points made by the chapter.

Continue reading “More than a metre”

(Arctic) Change is now

The World Wide Fund for Nature (WWF) has just published a new report on climate change in the Arctic — Arctic Climate Feedbacks: Global Implications [PDF], and it’s a fascinating read. Over the last two years I’ve blogged regularly on the changes being seen in the Arctic — sea ice reductions, melting of the Greenland ice sheet, the danger of increased carbon release from permafrost and sea floor methane hydrates, and the possible impacts on northern hemisphere weather patterns and climate. WWF’s report — written by some of the leading names in the field (including Serreze, Stroeve, Cazenave, Rignot, Canadell, and for the methane hydrate chapter Shakhova and Semiletov) — pulls together all those strands to paint a picture of a region undergoing rapid change. The authors provide a fully-referenced review of our current understanding of the processes at work as the pole warms, with chapters covering atmospheric circulation feedbacks, ocean circulation changes, ice sheets and sea level, marine and land carbon cycle feedbacks, and sea floor methane hydrates. It’s compelling stuff, and well worth reading in full, but for this post I want to focus on the excellent overview of methane hydrate feedbacks provided by Natalia Shakhova and Igor Semiletov.

Continue reading “(Arctic) Change is now”

And now the bad news…

methaneSpits.gifActive methane plumes over the West Spitsbergen shelf discovered last summer are being driven by warming of an ocean current over the last 30 years, a new study(*) reports. The team on the British research vessel the James Clark Ross from the National Oceanography Centre Southampton (working with scientists from the University of Birmingham, Royal Holloway London and IFM-Geomar in Germany) found more than 250 plumes of bubbles of methane gas rising from the seabed of the West Spitsbergen continental margin at depths of 150 to 400 metres. From the press release:

Graham Westbrook Professor of Geophysics at the University of Birmingham, warns: “If this process becomes widespread along Arctic continental margins, tens of megatonnes of methane per year – equivalent to 5-10% of the total amount released globally by natural sources, could be released into the ocean.”

New Scientist expands the story somewhat, and looks at the total potential methane release in the region:

The methane being released from hydrate in the 600-square-kilometre area studied probably adds up to 27 kilotonnes a year, which suggests that the entire hydrate deposit around Svalbard could be releasing 20 megatonnes a year.

With global methane emissions of the order of 500 – 600 megatonnes per year, that’s a substantial potential addition to the global budget — and there’s a lot more methane hydrate on the East Siberian Shelf that is already showing signs of breaking down.

(*) Westbrook, G.K. et al. Escape of methane gas from the seabed along the West Spitsbergen continental margin. Geophysical Research Letters, 2009; DOI: 10.1029/2009GL039191 (preprint here: well worth a read)

Wouldn’t it be ice

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Pictures from my new favourite blog, Meltfactor.org, where Jason Box of the Byrd Polar Research Centre at Ohio State is posting from the Greenpeace expedition to the Petermann glacier in NW Greenland. The pictures are stunning (above shows fracturing on the end of the ice tongue) — and the insight to what’s going up there as the Arctic melts is fascinating. And, just to make every photographer jealous, they get to fly over pods of narwhals (including two young ‘uns, I reckon)…

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