A brief historical perspective on the failed predictions that have plagued scientific understanding of Arctic sea ice changes – predictions embraced wholeheartedly by polar bear specialists and conservation experts. It’s worth a watch.
Transcript here from the Global Warming Policy Foundation.
Posted in Advocacy, Sea ice habitat, Summary
Tagged death spiral, decline, extinction, facts, history, polar bear, predictions, sea ice, September ice minimum, threatened
Arctic sea ice tied 2007 for extent at the September minimum less than 3 weeks ago but with the refreeze proceeding much faster than 2007, seals will soon be returning to the ice edge and polar bears will be back to feeding like they did in 2010.
Sea ice extent less than 5.0 mkm2 lasted less than 6 weeks (23 August – 28 September), according to NSIDC.
Posted in Conservation Status
Tagged Barents Sea, Chukchi Sea, extent, feeding, freeze-up, habitat, Hudson Bay freeze-up, hunting, ice-free, polar bear, sea ice, seals, September ice minimum
Average polar bear habitat for November 2014 was well within two standard deviations1 and higher than 2003, according to the November report from the National Snow and Ice Data Center (line and labels added, below).
Notice that the lowest average November level occurred in 2006 — not 2007 (after the second lowest September extent since 1978) and not 2012 (after the lowest September extent since 1978). Take note that the scale on the graph above does not go to zero but to a whopping ~9.5 million square km!
Quotes from the NSIDC monthy report and sea ice maps for November 2014 and 2 December 2014 below.
UPDATE 3 December 2014: CIS has issued a new ice map corrected for ice level on Hudson Bay – new map below.
Posted in Sea ice habitat
Tagged arctic sea ice, Chukchi Sea, CIS, Davis Strait, Hudson Bay, NSIDC, polar bear, polar bear habit, sea ice extent, September ice minimum, standard deviation
Freeze-up of Hudson Bay sea ice is well underway now, virtually the same time as it was the last three years, and in 2008. Bears in the north will be able to move out, while near Churchill and in Southern Hudson Bay, some bears will be able to successfully hunt for seals on the newly-formed ice close to shore.
Over the next week or so, all the bears onshore will gradually move out onto the ice as freeze-up progresses. By the time there is ~10% ice coverage on the bay, most bears will have moved onto the ice (except pregnant females that have made dens onshore).
The Arctic outbreak underway in over North America may hasten this process along (see 7-day and 14-day weather forecasts for Churchill). Ice maps below courtesy Canadian Ice Service.
It seems pretty clear now that time of freeze-up on Hudson Bay is not correlated with the extent of sea ice at the September minimum. Have a look at the maps and graphs below. UPDATE: more recent maps added below (ice concentration 15 November; ice development 14 November).
Satellites images might be able to replace aerial counts of polar bears in some places — if there are no clouds. But it seldom distinguishes cubs and can’t tell males from females, found a 2012 study of Foxe Basin bears that’s just been published.
Note: This is my 200th post since July 26, 2012!
Posted in Population
Tagged aerial survey, cubs, Foxe Basin, helicopter survey, polar bear, population estimates, Rowley Island, satellite images, sea ice, September ice minimum, Seth Stapleton, USGS
University of Alaska Fairbanks (UAF) is offering a new interactive sea ice map (which they call an atlas), that looks interesting and potentially useful, announced at Alaska Dispatch over the weekend (January 25, 2014: “New sea ice map offers a long-term look at climate change”).
At the moment, the years and months available include January 1953 to December 2012. Oddly, 2013 data is not included. The sea ice atlas charts polar bear habitat for the Southern Beaufort and Chukchi Sea subpopulations (including the Bering Sea), as well as the western portion of the Northern Beaufort Sea subpopulation region.
Posted in Sea ice habitat
Tagged Alaska, atlas, Beaufort Sea, Chukchi Sea, John Walsh, polar bear, sea ice, sea ice atlas, sea ice concentration, sea ice extent, September ice minimum, University of Alaska Fairbanks, Walsh
“Although there have been jumps and dips, average atmospheric temperatures have risen little since 1998, in seeming defiance of projections of climate models and the ever-increasing emissions of greenhouse gases.” Jeff Tollefson, January 15, 2014, Nature. [open access]
The eminent science journal Nature has finally acknowledged that global average temperatures have not behaved as predicted by climate models over the last 16 years. [h/t A. Watts]
Note that predictions of future sea ice declines and associated predictions of future polar bear declines are totally dependent on these climate models.
Here’s my question: if global temperatures have basically flat-lined since 1998, why has Arctic sea ice continued to decline?
If average global temperatures govern Arctic sea ice behavior, why was 1998 (or the year after) not the lowest September sea ice extent reached over the last 30 years? Oddly, 2012 was the lowest September extent (see graphs below, from NSIDC).
Paradoxically, not only has sea ice continued to decline since 1998 – despite the hiatus in global warming – but since 1998, all but one polar bear populations have either increased in size, not declined, or are doing very well by other measures (see previous summary post, “Polar bears have not been harmed by sea ice declines“).
Sea ice extent graphs for September (which all the hysteria is about) compared to selected months from March, June and November. Ranges given are approximate; note the differences in scale for each graph. NSIDC graphs, colored labels added.
The polar bear biologists and professional activists of the IUCN Polar Bear Specialist Group (PBSG) continue to insist that since 1979 increasingly smaller amounts of Arctic sea ice left at the end of summer (the September ice minimum) have already caused harm to polar bears. They contend that global warming due to CO2 from fossil fuels (“climate warming” in their lexicon) is the cause of this decline in summer ice.
In a recent (2012) paper published in the journal Global Change Biology (“Effects of climate warming on polar bears: a review of the evidence”), long-time Canadian PBSG members Ian Stirling and Andrew Derocher (both of University of Alberta) summarized their position this way:
“Climate warming is causing unidirectional changes to annual patterns of sea ice distribution, structure, and freeze-up. We summarize evidence that documents how loss of sea ice, the primary habitat of polar bears (Ursus maritimus), negatively affects their long-term survival”
I’ve spent the last year examining their evidence of on-going harm, but in addition, I’ve looked at the evidence (much of it not mentioned in the Stirling and Derocher paper1) that polar bears have either not been harmed by less sea ice in summer or have thrived in spite of it.
This is a summary of my findings. I’ve provided links to my original essays on individual topics, which are fully referenced and illustrated. You are encouraged to consult them for complete details. This synopsis (pdf with links preserved, updated; pdf with links as footnotes, updated) complements and updates a previous summary, “Ten good reasons not to worry about polar bears” (pdf with links preserved; pdf with a foreword by Dr. Matt Ridley, with links as footnotes).
Update 8 September 2013: to include links to my post on the recently published Chukchi population report; updated pdfs have been added above.
Update 22 January 2014: added figure comparing March vs. September sea ice extent using the same scale, from NOAA’s “2014 Arctic Report Card,” discussed here.
Posted in Conservation Status, Population, Sea ice habitat, Summary
Tagged Arctic, Barents Sea, Beaufort Sea, body condition, breakup dates, cannibalism, Chukchi, climate change, climate warming, Davis Strait, death spiral, Derocher, global warming, harm to polar bears, heavy sea ice, Hudson Bay, hybridization, ice-free, negative effects, polar bear, polar bear numbers increasing, Polar Bear Specialist Group, Polar Bears International, prolonged ice-free season, ringed seals, sea ice, sea ice decline, September ice minimum, Stirling, summary, summer ice minimum, victim of climate change