According to the NSIDC report: “[i]n June, ice extent declined by 88,000 kilometres per day, more than 50% greater than the average rate of 53,000 kilometers (20,000 square miles) per day. This rate of decline is the fastest measured for June.”
WWF US Climate Change Communications Director, Nicholas Sundt, wrote on the WWF US climate blog that the average sea ice extent was the lowest for any June in the satellite record, which extends back to 1979. As he explained, the NSIDC has reported that the “linear rate of monthly decline for June over the 1979 to 2010 period is now 3.5% per decade”.
To put the situation in perspective:
- The average arctic sea ice extent was 1.29 million square kilometres (498,000 square miles) below the 1979 to 2000 average. That departure from average is equivalent to the areas of California, Texas and Florida combined.
- The daily decline in sea ice extent (averaging 88,000 kilometers or 34,000 square miles per day) was a daily decline greater than the area of South Carolina.
WWF is currently following a number of bears in the Arctic region on the WWF-Canon Polar Bear Tracker, including bears in Svalbard in Norway, the Hudson Bay and Southern Beaufort Sea in Canada. These bears rely on sea ice for many aspects of their survival.
According to WWF Canada’s director of species conservation, Pete Ewins, extremely high temperatures in southern Canada this week are paralleled by relatively high temperatures in Churchill in the West Hudson Bay, with 17C daily temperatures recorded this week, compared with a July monthly mean of 12C.
This spells problems for all polar bears in the region, including the bears that WWF is currently following in the Hudson Bay area, Dr Ewins said.
“Our three bears here are still clinging to the remaining patch [of sea ice] north of Churchill – where they may well be catching some inexperienced young seals resting at the edge of chunks of sea-ice. But 3 other satellite collared females in this subpopulation are already ashore (this is a good 3 weeks ahead of the July average date ashore – July 25th, reflecting the rapid early retreat of the sea-ice this year), and now trying hard to conserve as much energy as possible in these sweltering conditions. This all means more polar bear stored fat burned up, and increasing mortality/declining body condition if the ice continues to be later to re-form in November.
“Given the weather forecast for the next few days, we are expecting our three females and their cubs to be heading for shore within the next week.”
Dr Andrew Derocher of the University of Alberta, who works with WWF to monitor the Hudson Bay bears, said:
“We have 3 collared bears ashore in Western Hudson Bay. The average date since 2005 [for the bears we are studying to come ashore is July 25 so if we translate the 18 extra days, it means the bears will use up about 14 kg extra fat this year IF they get back on a normal date.
“If freeze up is delayed like last year, some bears will experience a fasting period of over 160 days. [Research] suggests this sort of period will result in a major jump in mortality. I guess we have to hope for an early freeze-up or that the bears managed to get lots of seals before they were forced ashore.”