Reposted from Dr. Susan Crockford’s Polar Bear Science
Posted on July 8, 2020 |
This updated blog post of mine from last year is as pertinent now as it was then: it’s a fully-referenced rebuttal to the misleading ‘facts’ so often presented this time of year to support the notion that polar bears are being harmed due to lack of summer sea ice. Polar Bears International developed ‘Arctic Sea Ice Day’ (15 July) to promote their skewed interpretation of polar bear science at the height of the Arctic melt season. This year I’ve add a ‘Polar Bears and the Arctic Food Chain‘ graphic, which readers are free to download and share. For further information, see “The Polar Bear Catastrophe That Never Happened“.
Summer sea ice loss is finally ramping up: first year is disappearing, as it has done every year since ice came to the Arctic millions of years ago. But critical misconceptions, fallacies, and disinformation abound regarding Arctic sea ice and polar bear survival. Ahead of Arctic Sea Ice Day (15 July), here are 10 fallacies that teachers and parents especially need to know about.
As always, please contact me if you would like to examine any of the references included in this post. These references are what make my efforts different from the activist organization Polar Bears International. PBI virtually never provide references within the content it provides, including material it presents as ‘educational’. Links to previous posts of mine that provide expanded explanations, images, and additional references are also provided.
Sea ice background: extent over the last year
Summer sea ice minimum 2019 (from NSIDC):
Winter sea ice maximum 2020:
Sea ice at 7 July 2019: early summer extent
Despite the fact that 2019 had the 2nd lowest extent for the month of June since 1979, by the end of June 2020 (as was also the case in 2019), there was still ice adjacent to all major polar bear denning areas across the Arctic (see chart below).
In many regions – including Western Hudson Bay, Wrangel Island, and Franz Josef Land – pregnant females that will give birth on land in December come ashore in summer and stay until their newborn cubs are old enough to return with them to the ice the following spring. See Andersen et al. 2012; Ferguson et al. 2000; Garner et al. 1994; Jonkel et al. 1978; Harington 1968; Kochnev 2018; Kolenosky and Prevett 1983; Larsen 1985; Olson et al. 2017; Richardson et al. 2005; Stirling and Andriashek 1992.
Ten fallacies and disinformation about sea ice
1. ‘Sea ice is to the Arctic as soil is to a forest‘. False: this all-or-nothing analogy is a specious comparison. In fact, Arctic sea ice is like a big wetland pond that dries up a bit every summer, where the amount of habitat available to sustain aquatic plants, amphibians and insects is reduced but does not disappear completely. Wetland species are adapted to this habitat: they are able to survive the reduced water availability in the dry season because it happens every year. Similarly, sea ice will always reform in the winter and stay until spring. During the two million or so years that ice has formed in the Arctic, there has always been ice in the winter and spring (even in warmer Interglacials than this one). Moreover, I am not aware of a single modern climate model that predicts winter ice will fail to develop over the next 80 years or so. See Amstrup et al. 2007; Durner et al. 2009; Gibbard et al. 2007; Polak et al. 2010; Stroeve et al. 2007.
2. Polar bears need summer sea ice to survive. False: polar bears that have fed adequately on young seals in the early spring can live off their fat for five months or more until the fall, whether they spend the summer on land or the Arctic pack ice. Polar bears seldom catch seals in the summer because only predator-savvy adult seals are available and holes in the pack ice allow the seals many opportunities to escape (see the BBC video below). Polar bears and Arctic seals truly require sea ice from late fall through early spring only. See Crockford 2017, 2019; Hammill and Smith 1991:132; Obbard et al. 2016; Pilfold et al. 2016; Stirling 1974; Stirling and Øritsland 1995; Whiteman et al. 2015.
3. Ice algae is the basis for all Arctic life. Only partially true because plankton also thrives in open water during the Arctic summer, which ultimately provides food for the fish species that ringed and bearded seals eat during the summer, which fattens the seals up before the long Arctic winter (as the graphic below shows).
Recent research has shown that less ice in summer has improved ringed and bearded seal health and survival over conditions that existed in the 1980s (when there was a shorter ice-free season and fewer fish to eat): as a consequence, abundant seal populations have been a boon for the polar bears that depend on them for food in early spring. For example, despite living with the most profound decline of summer sea ice in the Arctic polar bears in the Barents Sea around Svalbard are thriving, as are Chukchi Sea polar bears – both contrary to predictions made in 2007 that resulted in polar bears being declared ‘threatened’ with extinction under the Endangered Species Act. See Aars 2018; Aars et al. 2017; Amstrup et al. 2007; Arrigo and van Dijken 2015; Crawford and Quakenbush 2013; Crawford et al. 2015; Crockford 2017, 2019; Frey et al. 2018; Kovacs et al. 2016; Lippold et al. 2019; Lowry 2016; Regehr et al. 2018; Rode and Regehr 2010; Rode et al. 2013, 2014, 2015, 2018.
4. Open water in early spring as well as summer ice melt since 1979 are unnatural and detrimental to polar bear survival. False: melting ice is a normal part of the seasonal changes in the Arctic. In the winter and spring, a number of areas of open water appear because wind and currents rearrange the pack ice – this is not melt, but rather normal polynya formation and expansion. Polynyas and widening shore leads provide a beneficial mix of ice resting platform and nutrient-laden open water that attracts Arctic seals and provides excellent hunting opportunities for polar bears. The map below shows Canadian polynyas and shore leads known in the 1970s: similar patches of open water routinely develop in spring off eastern Greenland and along the Russian coast of the Arctic Ocean. See Dunbar 1981; Grenfell and Maykut 1977; Hare and Montgomery 1949; Smith and Rigby 1981; Stirling and Cleator 1981; Stirling et al. 1981, 1993.
Recurring polynyas and shore leads in Canada known in the 1970s. From Smith and Rigby 1981
5. Climate models do a good job of predicting future polar bear habitat. False: My recent book, The Polar Bear Catastrophe That Never Happened, explains that the almost 50% decline in summer sea ice that was not expected until 2050 actually arrived in 2007, where it has been ever since (yet polar bears are thriving). That is an extraordinarily bad track record of sea ice prediction. Also, contrary to predictions made by climate modelers, first year ice has already replaced much of the multi-year ice in the southern and eastern portion of the Canadian Arctic Archipelago, to the benefit of polar bears. See also ACIA 2005; Crockford 2017, 2019; Durner et al. 2009; Hamilton et al. 2014; Heide-Jorgensen et al. 2012; Perovich et al. 2018; Stern and Laidre 2016; Stroeve et al. 2007; SWG 2016; Wang and Overland 2012.
Simplified predictions vs. observations up to 2007 provided by Stroeve et al. 2007 (courtesy Wikimedia). Sea ice hit an even lower extent in 2012 and all years since then have been below predicted levels.
6. Sea ice is getting thinner and that’s a problem for polar bears. False: First year ice (less than about 2 metres thick) is the best habit for polar bears because it is also the best habitat for Arctic seals. Very thick multi-year ice that has been replaced by first year ice that melts completely every summer creates more good habitat for seals and bears in the spring, when they need it the most. This has happened especially in the southern and eastern portions of the Canadian Arctic Archipelago (see ice chart below from Sept 2016). Because of such changes in ice thickness, the population of polar bears in Kane Basin (off NW Greenland) has more than doubled since the late 1990s and numbers of bears in M’Clintock Channel (in the SE Archipelago) have reportedly also increased. See Atwood et al. 2016; Durner et al. 2009; Lang et al. 2017; Stirling et al. 1993; SWG 2016.
7. Polar bears in Western and Southern Hudson Bay are most at risk of extinction due to global warming. False: Ice decline in Hudson Bay has been among the lowest across the Arctic. Sea ice decline in Hudson Bay (see graphs below) has been less than one day per year since 1979 compared to more than 4 days per year in the Barents Sea. Hudson Bay ice decline also uniquely happened as a sudden step-change in 1998: there has not been a slow and steady decline. Since 1998, the ice-free season in Western Hudson Bay has been about 3 weeks longer overall than it was in the 1980s but has not become any longer over the last 22 years despite declines in total Arctic sea ice extent or increased carbon dioxide emissions. Ice coverage over Hudson Bay at the end of June in 2020 was as high as last year, providing good sea ice conditions for WH and SH polar bears for the last five years at least. See Castro de la Guardia et al. 2017; Regehr et al. 2016.
Loss of summer sea ice per year, 1979-2014. From Regehr et al. 2016.
8. Breakup of sea ice in Western Hudson Bay now occurs three weeks earlier than it did in the 1980s. False: Breakup now occurs about 2 weeks earlier in summer than it did in the 1980s. The total length of the ice-free season is now about 3 weeks longer (with lots of year-to-year variation). WH polar bears tagged last year were still on the ice at the end of June 2020. See Castro de la Guardia et al. 2017; Cherry et al. 2013; Lunn et al. 2016; and video below, showing the first bear spotted off the ice at Cape Churchill, Western Hudson Bay, on 5 July 2019 – fat and healthy after eating well during the spring:
9. Winter sea ice has been declining since 1979, putting polar bear survival at risk. Only partially true: while sea ice in winter (i.e. March) has been declining gradually since 1979 (see graph below from NOAA), there is no evidence to suggest this has negatively impacted polar bear health or survival, as the decline has been quite minimal. The sea ice chart at the beginning of this post shows that in 2020 there was plenty of ice remaining in March to meet the needs of polar bears and their primary prey (ringed and bearded seals), despite 2019 being the 11th lowest since 1979 (and the highest since 2013).
10. Experts say that with 19 different polar bear subpopulations across the Arctic, there are “19 sea ice scenarios playing out“ (see also here), implying this is what they predicted all along. False: In order to predict the future survival of polar bears, biologists at the US Geological Survey in 2007 grouped polar bear subpopulations with similar sea ice types (which they called ‘polar bear ecoregions,’ see map below). Their predictions of polar bear survival were based on assumptions of how the ice in these four sea ice regions would change over time (with areas in green and purple being similarly extremely vulnerable to effects of climate change). However, it turns out that there is much more variation within and between regions than they expected and more differences in responses to summer sea ice loss than predicted: contrary to predictions, the Barents Sea has had a far greater decline in summer ice extent than any other region, and both Western and Southern Hudson Bay have had relatively little (see #7). See Amstrup et al. 2007; Atwood et al. 2016; Crockford 2017, 2019, 2020; Durner et al. 2009; Lippold et al. 2019; Regehr et al. 2016. My latest book, The Polar Bear Catastrophe That Never Happened, explains why this prediction based on sea ice ecoregions failed so miserably.
References
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More of the ice than ever is first year ice: older and thicker ice has substantially melted.
and we have currently the lowest extent on record for this date.
And yet the bears are still there, who would have thought it. Look on the bright side we gave the great renewable revolution another year to materialize and emissions will be down this year thanks to a virus 🙂
1) The “official” record only goes back a couple of decades.
2) Unofficial records show that ice levels have been much lower in the past.
3) So what?
Griff
If you ever go to the library and archives at the Scott Polar Institute in Cambridge you will find many books and papers-many by Russian scientists-that showed that back in the 20’s and 30’s there was a lot of first year ice during those 2 warm decades. Don’t forget it was the melting Jacobsen glacier that did for the Titanic
Modern records only go back to the late 70’s
tonyb
You won’t find Griff in a library, too many inconvenient facts for him. Only The Guardian approved “facts” for him. If he did go to a library he’d find many MANY books that disproves the atmospheric warming driven by 0.04ppm/v CO2.
For polarbears, the bigger problem is thick ice in spring, not thin ice.
But that doesn’t inerest you, as I assume 😀
And yes, ther German Polarstern expedition had problems with thick ice, you remember ? 😀
Griff, polar ice melting is known since about 170 years, said NPI
https://rp-online.de/panorama/wissen/wwf-rekonstruiert-klimawandel-in-der-arktis_aid-8597387
Find the old ice charts here
Well, that may not go far enough back to the interesting ship logs. The north pole was completely ice free from about 1665-1685 when Dutch sailors went to 88 N and one sailed past the pole to report no ice visible at all.
There is no situation even similar to that level of melting these days.
Taking my £100 bet that Arctic ice will bottom out above four million square kilometres in mid September as usual? Less I pay.
Great, more fish more seals more bears. Seals (like penguins) don’t like thick ice.
I’d love to know what Griff’s definition of ”ever” is.
Remember when you made a bet about ice and bears in the Arctic and you said you would not return to WUWT if you lost. IIRC, you lost and now you’re back being critical about the work of an actual expert on the subject. What gives?
As always a great read by Sr. Susan. Although I like the idea of a polar bear population in harmony (maybe balance is a better word!) with the seals, I have a confession to make. After I returned from Vietnam I never had nightmares, but after I returned from a season in a grizzly bear zone in the Alaska range, which included face-to-face encounters with enraged large bears, I had nightmares. Sure I had a Dirty Harry Special with me, but you cannot imagine the attack capability of a large bear until you are up close to one. Stay sane and safe (I’m sure Dr. Susan has this figured out).
Ron, I never had a bear attack nightmare until I wrote my polar bear attack thriller, EATEN (links on my polar bear and personal websites). I read a lot of stories about all kinds of bear attacks. Once I had to imagine polar bear attacks for my book, I started having nightmares.
My sister, who helped me edit early versions of the novel (and so knew what was going to happen) argued the picture of a threatening polar bear on the cover was unnecessary. But when she read the final printed version before going to bed one night, she said she woke up at 3 am sitting bolt upright watching that bear walking through the doorway.
I am of the opinion that fear of bear attacks are a primal fear for humans after a long history of co-existence throughout the northern hemisphere (another primal fear, from the southern hemisphere, is the fear of snakes). Bears, especially predatory black bears, will eat you alive. Good to avoid.
Speaking of black bears, I was looking at a home for sale on line in central Ontario and it said, about its good sized acreage, “Lots of wildlife”, accompanied by a photo of a black near in the yard.
Maybe that’s why they are selling…
Ron, I, too worked two summers in mining exploration in the Dawson Range in the Yukon of Canada, in 1969-70 that was reputed to have one of the largest populations of grizzlies in North America. The Dawson range is a comparatively small area that wasn’t glaciated during the glacial max. It therefore had a good soil profile and abundant wildlife.
I was dropped off by helicopter by myself each morning with my gear and an old Lee Enfield .303 rifle. I was one of few that didnt have a fairly close-up experience, but I did see them everyday from the air and from mountain slope vantage points. Yeah, they added piquancy to the daily grind.
Ron
Years ago, I knew a geologist who was in the field out of Whitehorse.
And survived an attack by a grizzly.
Severe scars.
On further trips into the bush he carried a .357 Magnum.
If you get in touch with me, I’ll send an amusing story about an encounter with a black bear.
bobhoye@shaw.ca
New to Alaska, a coworker invited me on a moose hunting trip. When he learned I would carry a .357 Magnum for bear defense, he suggested I file off the weapon’s front sights. He said it would hurt less when a bear shoved it up my a$$. A .44 Magnum is the minimum power carry in Grizzly/Brown bear country. My wife bought me a .454 Casull.
9. Winter sea ice has been declining since 1979, putting polar bear survival at risk.
Why pick 1979 as a starting point? Here’s the series of graphics
from the first five IPCC reports on “sea ice extent”. Is that the same as “winter sea ice”? Well anyway sea ice extent has been known for several years before 1979 and it’s fairly obvious that the historical data has been omitted and or re-written by the IPCC.
On the issue of polar bear population, a short search shows that most web pages acknowledge an increase over the last several decades, but most offer unsubstantiated excuses why that doesn’t mean anything.
Is Vladimir Putin throwing money overboard or he knows otherwise
Russia is building the first nuclear icebreaker of the new generation
The Russian state company Rosatom announced earlier this week that it has started the construction of the icebreaker “Russia”, the first in the new series code-named “Leader”, which is being built in the “Zvijezda”(Star) shipyard , in the Russian far east.
The Leader-class icebreaker, also referred to as LK-120Ya, will be twice as powerful as the country’s current nuclear icebreakers. The vessel will use two RITM-400 type nuclear reactors to power four propellers with 30 MW capacity each. With a total displacement of 69,700 tons it will also be more than twice as heavy as Russia’s newest and currently largest icebreaker, Arktika.
The vessel is designed to break channels as wide as possible through the sea ice for oil and gas tankers to follow in its wake. To this end the Leader-class is nearly 48 meters wide, 13 meters more than current icebreakers. With massive amounts of power and its large weight the vessel will be able to break through up to four meters of ice, compared to 2.3 meters for the current Arktika-class.
You have to hand it to the Russians; they just love building things bigger than anyone else, and they are good at it too.
If they ever get a decent government, they could be a real economic powerhouse. Instead, they mostly just sell gas to western Europe.
Oh, good for the Russians – and for the idiots to be that will try to sail the Northwest Passage to prove the ice is disappearing. The Russians can rescue them, and hold them as collateral until some climate science sponsor pays the rescue operations costs.
Oh, I forgot. The climate science sponsor will pay for helicopter rescue. The Russians can then do salvage ops with their ice breakers.
Correction: it’s the Canadian Coast Guard that’s doing the rescuing in the NWP.
Evidently it’s a great time to be a polar bear! They are so cute and cuddly.
I’m not sure what is in store for us in the short future ice wise. It looks like 2020 will be a good year for Greenland. It had a late start to the the melt season and with late snows, its albedo is still above normal. Snow is forecast the next few days over the high ice sheet. Western Hudson Bay is still covered and the open water season there will be short this year. Late melting means colder water to start the freeze season. The US Rockies have had late snows and Glacier National Park’s “Going to the Sun” road is still being cleared.
The Southern Hemisphere is getting a great start to winter. Snow is falling in quite a few places. Argentina is forecast to be quite cold well into July and after that it may continue on. Antarctica is doing just fine freezing. The Earth’s magnetic field is still falling, so with the Solar Min allowing more cosmic rays in and reduced protection we really don’t know how this will all end up. Quite a few studies indicate upper atmospheric ionization matters on tropospheric storms. Plus O3 generation is effected.
Since 2020 is the year of the Devil, all we need is one or two big volcanoes to go off and time to buy 5 years of freeze dried food and head for the hills. The big ones almost all go off during the Sun’s quiet time, so it isn’t outside of possibility. Hopefully they stay quiet.
“Summer sea ice loss is finally ramping up: first year is disappearing, as it has done every year since ice came to the Arctic millions of years ago.” I wouldn’t say “millions of years” since there have been ice ages (permanent ice caps) and warm periods (partial or complete melts?) in between during the last million years. It’s certainly true during an interglacial like we now have. The alarmists will jump on any mistake to say “the whole paper is full of errors”.
Eric, I’d argue that during Glacial periods there was still first year ice but there was less of it and it developed much further south than during Interglacials, and would still have melted during the summer.
Also, there was still a melt season during the height of the warmest interglacials, just much reduced compared to recent times. There is data, for example, showing no ice in the Bering Sea *in winter* during the height of the Eemian (last Interglacial) but there was still winter ice in the Chukchi Sea (one of the so-called ‘peripheral seas’ of the Arctic Ocean) to melt over the summer. It is likely there was still ice over the winter in Hudson Bay, for example, that melted earlier in summer than it does today.
See this post on sea ice extent during the LGM http://polarbearscience.com/2015/04/21/polar-bears-barely-survived-the-sea-ice-habitat-changes-of-the-last-ice-age-evidence-suggests/
Based on my experience here in Northern Indiana, some years lots of cold/ice, some years not so much cold, less ice. Why would the polar regions be any different and why would the critters that make them home not have evolved to go with the flow?
So during glacial periods you would find your polar bears and seals further south where summer sea ice loss of first year ice would be normal. Both species don’t like thick ice. And don’t forget sea level was much lower so many places we now find sea ice would be land = no fish = no seals = no bears.
Great post.
Especially appreciate Dr Crockford’s note in Comments section “Bears, especially predatory black bears, will eat eat you alive.”
Here in WA state, the prevailing myth is black bears are harmless vegetarians. I’ve been stalked by black bears on the trail in Montana, been attacked in an outhouse by a black bear in Alaska. Dr. Crockford is right.
Dr. Crockford,
Thank you for another very informative and world-class article rebutting polar bear- ice – seal – global warming claims and predictions.
Free speech is good and your book, The Polar Bear Catastrophe That Never Happened is excellent.
In October of 1990 when I was in the Beaufort Sea of the Arctic Ocean, I did not see a polar bear but the captain of the ship did receive satellite radio calls on two occasions for use of the helicopter to rescue native whale hunters who were in peril after their skin boat was damaged by the targeted whale resulting in the whalers stranded and freezing on a chunk of ice. In both cases, the helicopter was sent to the rescue at our cost and risk. The dirty little secret is that some of the whales had been appended with radio transmitters by researchers, the native hunters had radio receivers, but the whales resisted.
97% of Polar Bears are born in December and are Sagittarius / Union of Concerned Astrologists
I am just a dumb, retired water resources injuneer, and am not qualified to talk about the science.
But when people talk to me about sea ice and polar bears, I always ask if polar bears evolved in the last 1,000 years; if not, they must have survived through the 400 years or so when Leif Erikson and his buddies were farming in Greenland. If it was warm enough to farm in Greenland, then there must have been much, much less ice in the Arctic than today.
Polar bear populations are doing better because of the increased ease of access to bottles of coke, which they are addicted to. These cute and cuddly creatures sit around their campfires and tell children stories all night while chugging coke – This is actually a coke epidemic according to the ATF.
Can anyone explain from a Darwinian point of view the very conspicuous black nose of a polar bear? Stalking seals with a white one would be easier ?
The whole skin of a polar bear is actually black. The white hair isn’t camouflage so much as it’s a light pipe that absorbs IR light, shunts it to the skin, and helps keep the bear warm.
Arctic sea ice coverage as shown by satellite data is often used as a proxy for temperature starting in 1979.
On that basis it is reasonable to assume that the ice coverage now is comparable with ice coverage back in the 1930’s when the atmospheric CO2 concentration was ~300ppm and human CO2 emissions were relatively insignificant.
http://www.climate4you.com/images/70-90N%20MonthlyAnomaly%20Since1920.gif
That doesn’t imply that CO2 is not a climate factor.
Susan,
Very thorough and interesting Q&A. I like how you addressed each point with arguments and references. This may serve as a good template for the Deniers of the world Unite post.
I have an older book ”Ice Island” (Tim Weeks and Ramona Maher, 1965) describing research stations established temporarily on unusually thick arctic ice floes. Each seemed to gradually break up. Are such floes still there, or did they eventually disappear (no climate warming comment intended)?
Re: the foodchain graph
Susan,
copepods and amphipods are not krill. Krill is euphausids.