Another day, another bet on sea ice. A few days ago, a regular reader of HT emailed to ask me if I could provide some support in a long series of comments to a post at Poneke! about the showing of Swindle. So I did (my contributions start here). And now I have another bet on this northern hemisphere summer’s sea ice minimum, with a commenter calling himself “malcolm” taking the Stoat position (cold side = more ice than last year, not something out of the Kama Sutra). So here’s an update on events up North. Consider it a form guide, if you will.
Andy Revkin at Dot Earth kicks things off with a post drawing attention to a new study canvassing the views of 19 teams working on climate change in the Arctic. 14 offered numerical projections, and 11 of those expect this year’s minimum to be similar to or below last year’s record. The new Study of Environmental Arctic Change (SEARCH) programme has just produced its first monthly report. I confidently predict that these reports are going to be required reading as the melt season progresses. If you click on the “Full report” tab you can read comments from the individual submissions (which are all available for download).
So, what does this do to the odds? Five teams expect a significant new record, six are clustered around the same amount as last year (three above, three below), and three expect some rebound back towards the longer term trend. My original estimate in September last year (see first comment) was that the odds were 50/50 on a new record. I think that’s still broadly true, though the cold side odds look to be lengthening as observations come in.
This shows the same sort of curve as is available at Cryosphere Today, but usefully overlays the last six seasons information (easier to track on the full size image). What you can see here is that the extents are all very bunched together in May and June, but begin to diverge in July. 2006, for example, tracks well below the previous record year (2005) until slowing down in July enough to get back above the line, and eventually fail to reach a new record. In 2007, the July melt was (as some Arctic researchers have noted) remarkable. The next six weeks are therefore going to be very interesting. A cold July could be enough to prevent a new record. But the ice pack is “conditioned” for a big melt by the much smaller amount of multi-year ice. Two say will, two say won’t. My gut feeling? I’ll be sending my winnings to Oxfam.
For completists, here’s another view of the current sea ice extent from the State of the Canadian Cryosphere site, which uses somewhat more tasteful colours than CT.
Also link-mined from Revkin, I offer the truly amazing Extreme Ice Survey site. The pictures are wonderful, and include time lapse sequences of Greenland glaciers calving. It’s a Flash site, so I can’t link to individual bits: try clicking on “evidence” in the top nav bar, and then look at the videos. Remarkable.
Finally, what might turn out to be the first of a flurry of papers that look at the impacts of rapid Arctic sea ice loss on climate change in the Arctic [Physorg].
“Our study suggests that, if sea-ice continues to contract rapidly over the next several years, Arctic land warming and permafrost thaw are likely to accelerate,” says lead author David Lawrence of NCAR.
Remember my recent post about methane?