Ringed seal biologist Steven Ferguson, in a statement to a reporter from the Winnipeg Free Press, made one of the boldest predictions I’ve ever heard:
“Hudson Bay could experience its first free winter within 5-10 years.”
You heard it here, folks. It appears Ferguson thinks Hudson Bay was never ice-free in winter even during the Eemian Interglacial, when the Bering Sea was ice-free in winter – something that has not come close happening in recent years (Polyak et al. 2010:1769).
Sounds like a bit of ill-advised grandstanding to me.
Here’s the ground-truth follow-up to my suggestion of what polar bear habitat would likely look like 6 weeks after the minimum extent was reached this year – which was looking then like it would mirror 2009.
You’ll find my discussion, posted on September 22, here. At that point (September 13), ice extent was 5.1 million square kilometers; now it is 9.1 million square kilometers (Fig.1).
Have a look at the maps below: Fig. 2 to see how ice extent at October 31st compares to ice extent at the end of October 2009, and Fig. 3 to see what ice concentrations looked like in the Canadian Arctic.
Posted in Life History, Sea ice habitat
Tagged Beaufort, Canadian Ice Service, Chukchi, Eastern Beaufort, Ferguson, grey-white ice, Hudson Bay, polar bear, sea ice extent, summer ice minimum, young ice
On Aug. 27, 2012 sea ice extent dipped below the yearly minimum extent reached in 2007.
The sea ice at this point, a five-day average, was 4.1 million km squared and the lowest point reached since satellite records began in 1979. The National Snow and Ice Data Center (NSIDC) thought it was important enough to issue a press release.
There are sure to be more than a few media-hungry folks who will be moaning about the fate of the poor polar bears because of this report. Before people get too hysterical, a bit of rational perspective might be helpful.
Keep in mind that 4.1 m sq. km (Fig. 5) is about the size of Greenland (2.166 m km2) plus Mexico (1.972 m km2), or about the size of India (3.287 m km2) plus Pakistan (0.809 m km2), figures from Wikipedia.
It may be a ‘record’ low, but it’s still a lot of ice: 4.1 m km2 is not anywhere close to an ‘ice-free’ Arctic!
Arctic sea ice melts – or gets pushed out of the Arctic and then melts – every year, leaving various amounts behind. The ice lingering at mid-September adds to next year’s ‘multiyear’ ice.
The maximum extent is usually reached mid-to-late March. Have a look at how this ‘low extent’ developed from the March maximum this year. Even if you’ve looked at some of these maps, you may not have looked at them one after the other. I’ll compare these to the fall maps for 2007, after the Sept. minimum and discuss these in relation to polar bear habitat. Contineu reading
Posted in Life History, Population, Sea ice habitat
Tagged Amstrup, Durner, Ferguson, ice thickness, Mauritzen, Messier, Ovsyanikov, polar bear evolution, sea ice extent, summer ice minimum
This review was originally posted June 30, 2012 at my evolution blog here
It was picked up as a guest post at Hilary Ostrov’s blog “The View from Here” July 1, 2012 under the title Of polar bears, polemics and climate warming
THE ORIGINAL REVIEW, RE-POSTED BELOW WITH MY EMPHASIS, HAS AN UPDATE ADDED JULY 26 2012, FOUND BELOW THE REFERENCE LIST
I recently came across a review of Ian Stirling’s latest book Polar Bears: The Natural History of a Threatened Species (2011, Fitzhenry & Whiteside) in the March 2012 issue of the journal Arctic, written by Arctic biologist Steven Ferguson. What is remarkable about Ferguson’s review is not what he says about the book but what he does not: lavish praise for Stirling’s polar bear stories but barely a mention of the book’s dismal predictions for the future. To be fair, all of the photographs in this book are outstanding (some are truly stunning) and the polar bear stories and life history information make for a fascinating read.
However, in reality this is not just a book about polar bears but a polemic discussion about the future of Arctic sea ice. Readers of Ferguson’s review might be surprised to find that there is an entire chapter dedicated to “climate warming” (“the game changer in polar bear conservation” according to Stirling). The climate warming chapter is as eye-catching in its own way as the rest of the book: who could miss the enormous, scary-looking graph predicting summer sea ice declining to zero within the next 90 years (described as a “NSIDC & NASA sea ice decay projection,” taken from Stroeve et al. 2007)? Or the two large photos, from different angles, of a bear that died in 1989 when its winter den collapsed? Oddly, such in-your-face photos and graphics seem not to have impressed Ferguson enough to warrant more than a few words in a list of topics covered (“models of future Arctic change”).
In contrast to Ferguson’s benign and somewhat fawning overview, my impression of the book was quite different.