Tag Archives: global warming

Polar bears of W Hudson Bay utilizing a substantial patch of thick first year ice

There’s been no word as yet, either from tour operators or polar bear researchers, that Western Hudson Bay polar bears have come ashore for the summer/fall season. Andrew Derocher reported at the end of June that the bears tagged by his team were still on the ice and as I write this, has not yet reported them ashore.

That pattern is consistent with the presence of thick ice along the west coast of the Bay — from well north of Churchill to the south of Wapusk National Park — for the last few weeks. The weekly chart for 3 July 2017 below from the Canadian Ice Service shows that virtually all of the ice remaining is thick first year ice (>1.2m, dark green on this map):

Hudson Bay weekly ice stage of development 2017 July 3

By the 9 July, the extent of this patch of ice was somewhat reduced but still a very prominent feature over the Bay, suggesting that if adult seals are using this ice as a refuge while molting, some bears may still be attempting to hunt even though their success rate may not be very high:

Sea ice Canada 2017 July 9

Bottom line: As has been the pattern for more than a decade, 2017 will not go down in history as an especially early year for WHB polar bears coming off the ice for the summer/fall season but instead may be as late as last year, when lots of bears were reported off the ice by mid-July at Seal River (just north of Churchill), all in excellent condition.

It remains to be seen if the condition of bears will be as good this year as they were in 2016, given the late start to the season. But it does mean that the lack of trend in breakup dates since 2001 continues: breakup of the sea ice in WHB since 2001 has been about one week later than it was before 1998 (Castro de la Guardia 2017; Cherry et al. 2013; Lunn et al. 2016).

If some polar bear struggle to survive this year it will be due to the late freeze-up date last fall combined with challenging winter conditions over Hudson Bay, not because of an early breakup of the sea ice.

And while it is certainly true that the overall trend in time spent onshore by WHB polar bears since 1979 has increased by about three weeks, the lack of a continued trend since 2001 is not what was expected or predicted, especially given the marked decline in global sea ice levels that have made headlines since 2007 (Crockford 2017), and the predictions of how devastating such low levels of ice would be to polar bears in areas like Hudson Bay that have to deal with a total disappearance of sea ice in summer and early fall.

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Heavy ice off East Coast 2017 caused by winds, cold temperatures, and icebergs

Heavy sea ice off Newfoundland and southern Labrador has been an issue for months: it brought record-breaking numbers of polar bear visitors onshore in early March and April and since then has hampered the efforts of fisherman to get out to sea.

Newfoundland fishing boats stuck in ice_DFO_May 26 2017 CBC

Let’s look back in time at how the ice built up, from early January to today, using ice maps and charts I’ve downloaded from the Canadian Ice Service and news reports published over the last few months.

The tour is illuminating because it shows the development of the thick ice over time and shows how strong winds from a May storm combined with an extensive iceberg field contributed to the current situation.

Bottom line: I can only conclude that climate change researcher David Barber was grandstanding today when he told the media that global warming is to blame for Newfoundland’s record thick sea ice conditions this year.  I suspect that because Barber’s expensive research expedition was scuttled, he simply had to find a way to garner media attention for his project — and the media obliged. Read to the end and decide for yourself.

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New genetics paper is not about whether climate change causes polar bear hybrids

A new paper on the evolutionary history of bears (Bears breed across species borders: Kumar et al. 2017) has concluded that hybridization is common and natural among all species of ursids. And while some media outlets (e.g. DailyMail) have framed this as surprisingly convincing proof that experts were wrong to claim that climate change is the cause of recent polar bear X grizzly hybrids, definitive evidence against that interpretation has been available for years to anyone who bothered to look: see my recent “Five facts that challenge hybridization nonsense.”

This genetic evidence is just a cherry on top of the rest but will help get the paper the media attention the authors crave.

Polar bear X grizzly hybrids were known long before climate change and sea ice decline became an issue. See also previous posts here, here, and here. In fact, as I’ve pointed out, “most polar bear hybrids said to exist have not been confirmed by DNA testing” (including virtually all of the bears specialist Andrew Derocher claimed were hybrids, including the latest one from 2016 that prompted such gems as “Love in the time of climate change”).

pizzly_andrewderocher_300dpi_2017 paper

A polar bear X grizzly hybrid, see Kumar et al. 2017. Photo by A. Derocher.

In my opinion, the most important conclusion of this paper is that occasional but widespread hybridization among bears is why it has been so hard to say with confidence when polar bears arose (which I addressed years ago, in my Polar bear evolution series: Part 1, Part 2, and Part 3). You cannot use traditional methods of pinpointing the timing of speciation events from genetic data if one or more of the species have hybridized (traded genes). See the long, fuzzy “divergence times” for bears in the image below from the Kumar paper.

Kumar et al 2017 hybridization in bear evolution_fig 5

From Kumar et al. 2017, Fig. 5: “The scale bar shows divergence times in million years and 95% confidence intervals for divergence times [speciation events] are shown as shadings.”

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Maclean’s blames global warming for polar bear visits to Newfoundland

Without a shred of evidence, Canada’s Maclean’s magazine claims recent polar bear sightings in Newfoundland and Labrador are due to global warming — and concludes that such incidents are bound to get worse.

Macleans 7 April 2017 polar bear headline with photo_sized

But since it’s likely that polar bear populations in Davis Strait are still increasing (as they were in 2007), Maclean’s might be correct in their prophesy that bear visitations are bound to get worse — just not for the reason they think.

Without any justification or even a quote from an expert, the author of this piece (Meagan Campbell)  blames man-made global warming for recent polar bear visits to Labrador and Newfoundland:

“Since bear sightings in the early winter have been linked to climate change, some parents are more concerned for their future grandchildren.” 

That’s just bad logic. Actually, the fact that global warming has not killed off polar bears as predicted means there are lots of bears to come ashore causing problems in late winter (while they wait for Arctic seal pups to be born, so they can eat them).
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Science behind the video Polar Bear Scare Unmasked – updated paper now available

Announcing the publication today of Version 3 2 of my paper that tests the hypothesis that polar bear population declines result from rapid declines in summer sea ice, updated with recently available data. Version 2 provides the scientific support for the information presented in the GWPF video published yesterday, “Polar Bear Scare Unmasked: The Sage of a Toppled Global Warming Icon” (copied below).

Crockford 2017 V3 title page graphic 3

[The graphic above was created by me from the title page and two figures from the paper]

Updated 1 March 2017: I added an important reference to the paper below that got overlooked in previous versions (the work of Armstrong et al. 2008, see this post), making Version 3 the latest and most up-to-date.

Crockford, S.J. 2017 V3. Testing the hypothesis that routine sea ice coverage of 3-5 mkm2 results in a greater than 30% decline in population size of polar bears (Ursus maritimus). PeerJ Preprints 2 March 2017. Doi: 10.7287/peerj.preprints.2737v3 Open access. https://doi.org/10.7287/peerj.preprints.2737v3

Version 3, published 2 March 2017, adds an important reference; Version 2, published 28 February, incorporates additional reviewer comments and suggestions received on Version 1, as well as the updates noted above.

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Polar Bear Scare Unmasked: The Saga of a Toppled Global Warming Icon [video]

For more than ten years, we’ve endured the shrill media headlines, the hyperbole from conservation organizations, and the simplistic platitudes from scientists as summer sea ice declined dramatically while polar bear numbers rose.

Now, just in time for International Polar Bear Day, there’s a video that deconstructs the scare. It runs about 8 minutes, written and narrated by me, produced by the Global Warming Policy Foundation.

Polar Bear Scare Unmasked: The Saga of a Toppled Global Warming Icon

Update 28 February 2017 See my follow-up post for the science behind the video, featuring a new version of my sea ice/polar bear hypothesis paper, just published (and updated with new data).

Crockford, S.J. 2017 V3. Testing the hypothesis that routine sea ice coverage of 3-5 mkm2 results in a greater than 30% decline in population size of polar bears (Ursus maritimus). PeerJ Preprints 2 March 2017. Doi: 10.7287/peerj.preprints.2737v3 Open access. https://doi.org/10.7287/peerj.preprints.2737v3

Thriving numbers – & two great books – are ample reason to rejoice on Polar Bear Day

Ten years of summer sea ice levels expected to kill 2/3 of the world’s polar bears by 2050 instead saw polar bear numbers grow. And this year, there are also two fabulous books about polar bears and their outstanding success story to celebrate on International Polar Bear Day (Monday 27 February 2017).

os-and-fm-cover-drafts-14-dec-2016

One is suitable for kids (Polar Bear Facts & Myths) and another for adults and teens who want the details (Polar Bears: Outstanding Survivors of Climate Change) – see the right sidebar to buy on Amazon or my author website for details on all additional formats. A couple of excerpts from them are below.

So forget turning down your thermostat in a pointless gesture to “reduce your carbon emissions and help polar bears” — as Polar Bears International advocates for Polar Bear Day. Instead, treat yourself or a friend and order a book with a rational approach to species survival.

Speaking of species survival, think about the inconsistency in how some species are treated according to the US Endangered Species Act (ESA). Humpback whale numbers recovered after decades of protection; in 2016, after the state of Alaska filed a petition to delist, most populations were officially removed from the ESA list of ‘threatened’ species.

humpback-whale-and-calf-012016-noaa

Humpback whale and calf, NOAA image.

In contrast, by 2015, polar bear numbers had also recovered despite years of low sea ice loss not predicted until 2050, yet remain officially ‘threatened’ with extinction.

polar_bear_family_at_bone_pile-kaktovik-20-april-2016

Fat bear family at Kaktovik, Alaska (Southern Beaufort), April 2016. USGS photo.

US National Marine Fisheries Service defended the delisting of humpback whales against activists who insisted human-caused global warming threatened the species, but the US Fish and Wildlife Service defends flawed polar bear prophesies.

My books lay out the polar bear success story: in simple form for younger readers and in detail for others. See the excerpts below.

crockford-pb-outstanding-survivors-2017_end-of-pg-30

Polar bears have not been driven to the brink of extinction by global warming. In fact, they are thriving (see my final conclusions on pg. 30 of Polar Bears: Outstanding Survivors of Climate Change, above and pg. 32 of Polar Bear Facts & Myths below.

crockford-pb-facts-and-myths-2017-pg-32

If you’d like to support my efforts to bring this to everyone’s attention, please consider buying a copy or two of my books. If you’ve already done so, keep in mind that your local library might be glad to have copies donated. They also make great gifts.

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