Barents Sea polar bears thriving despite huge summer ice loss: spring research results are in

Reposted from Polar Bear Science

After being locked out last year, fieldwork monitoring polar bears in the Svalbard region of the Barents Sea resumed this spring. The results show that despite having to deal with the most extreme loss of summer sea ice in the entire Arctic, polar bears in this region continue to thrive. These facts show no hint of that impending catastrophic decline in population size we keep hearing is just around the corner. No tipping point here.

Svalbard polar bear territory is managed by Norway. It includes sea ice all the way to the Russian border in the east and the Svalbard archipelago: the map below is from Aars et al. 2017.

Svalbard polar bear management region. Fig 1, Aars et al. 2017.

Observations are usually collected around Svalbard by a team lead by Jon Aars and Magnus Andersen of the Norwegian Polar Institute between March and May every year and they post their results online in June. They deserve our admiration and respect for making their research results available in such a timely fashion and without fanfare. It’s something all good scientists should be able to do.

Note that Svalbard comprises only half of the ‘Barents Sea’ polar bear subpopulation: in recent years, most of the region’s polar bears have been living around Franz Josef Land in the eastern (Russian) sector (shown below) where Norwegian researchers are not permitted to work.

Spring sea ice in the Barents Sea

Shown below is sea ice extent at end May 2021 (end of the 2021 Svalbard study field season):

In general, summer sea ice decline in the Barents Sea since 1979 has been the most profound across the Arctic (with a loss of 4.11 days of ice per year from 1979-2014): that’s six times as much summer ice loss as bears in the most southern-living subpopulation (Southern Hudson Bay, which had a loss of only 0.68 days of ice per year) according to calculations by Eric Regehr and colleagues (2016).

However, last summer Svalbard sea ice extent took a nose-dive to well below average levels (shown below at 18 Sept 2020). This condition of below-average ice persisted well into the fall (not shown): sea ice levels did not come back into the purple zone shown on the graph below until mid-December 2020. The ice chart below that for 15 September 2020 shows what that looked like.

According to polar bear specialist Andrew Derocher, this situation had disaster written all over it. In early November, the ice extent was the lowest it had been since 1967.

Poor conditions at Svalbard. Arrow shows Hopen Island. If the ice arrives in early November, 20+ denning females give birth to cubs there. In recent years, sea ice has arrived far too late for pregnant females to use the Island. 2020 doesn’t look good.— Andrew Derocher (@AEDerocher) November 9, 2020

However, that’s only because he and most of his colleagues still embrace the false premise (e.g. Amstrup et al. 2007) that summer sea ice is critical for polar bear health and survival, despite compelling evidence that spring ice conditions are the crucial environmental factor (Crockford 2017, 2019), which includes the data from Svalbard. They also have neglected to take into account the much greater primary productivity (i.e. more food for all ) that areas like the Barents Sea have experienced precisely because there has been less summer ice (summarized, with references, in Crockford 2021).

2021 Svalbard spring polar bear data

First up is body condition of adult male bears (1993-2021, 2020 data missing), which is down a bit from 2019 but this amount of year-to-year variance is normal. Some male bears were in much worse condition in the late 1990s and early 2000s (note the lowest ‘tails’ on the box plots) than they have been since 2015 and the analysis of the data, which does not include 2021, concluded: There is no significant trend over time.

And how about litter sizes? Below is the graph provided for number of cubs per litter (1993-2021, 2020 missing):

Litter size 2021 = 1.75. According to the analysis of the data without 2021, “There is a statistically significant (p=0.04) weak trend of decreasing litter size over time (red line).” Note that the litter size for 2019 was the highest it’s been since 1993.

Finally, there is the proportion of females that have cubs of the year (called ‘production of cubs’), which this year was 0.54 (well above what it was in 2019):

The analysis of the data without 2021, “shows a non-significant (p=0.069) linear trend [red line] in the proportion of females with COYs over time.”

This conclusion remains (@30 June 2021) at the bottom of the MOSJ webpage:

An aerial survey to estimate the size of the shared Norwegian-Russian Barents Sea subpopulation was carried out in 2004, and the resulting estimate was 2650 bears +/- ca 30%. A new survey of the Norwegian part of the population was conducted in August 2015, and the results do not show any sign of a reduction in population size.

Bottom line: Despite extremely low summer ice and record-breaking fall ice levels in 2020, on top of this region having the highest relative decline in summer sea ice of all polar bear subpopulations, there is no signature of impending disaster in the spring 2021 polar bear monitering data: no starving bears or large numbers of females without cubs. Last summer should have been the ‘tipping point’ for this population, according to the models. But adequate winter and spring ice developed and the bears are still thriving, as they were in 2015 (Aars 2018; Aars et al. 2017).


Aars, J. 2018. Population changes in polar bears: protected, but quickly losing habitat. Fram Forum Newsletter 2018. Fram Centre, Tromso. Download pdf here (32 mb).

Aars, J., Marques,T.A, Lone, K., Anderson, M., Wiig, Ø., Fløystad, I.M.B., Hagen, S.B. and Buckland, S.T. 2017. The number and distribution of polar bears in the western Barents Sea. Polar Research 36:1. 1374125. doi:10.1080/17518369.2017.1374125

Amstrup, S.C., Marcot, B.G. & Douglas, D.C. 2007. Forecasting the rangewide status of polar bears at selected times in the 21st century. US Geological Survey. Reston, VA. Pdf here

Crockford, S.J. 2017. 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 19 January 2017. Doi: 10.7287/peerj.preprints.2737v1 Open access.

Crockford, S.J. 2019The Polar Bear Catastrophe That Never Happened. Global Warming Policy Foundation, London. Available in paperback and ebook formats.

Crockford, S.J. 2021. The State of the Polar Bear Report 2020. Global Warming Policy Foundation Report 48, London. pdf here.

Regehr, E.V., Laidre, K.L, Akçakaya, H.R., Amstrup, S.C., Atwood, T.C., Lunn, N.J., Obbard, M., Stern, H., Thiemann, G.W., & Wiig, Ø. 2016. Conservation status of polar bears (Ursus maritimus) in relation to projected sea-ice declines. Biology Letters 12: 20160556.

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Sweet Old Bob
July 1, 2021 6:41 pm

The suspense is getting to be un bear able !

Reply to  Sweet Old Bob
July 1, 2021 6:57 pm

Bearly funny

Rory Forbes
Reply to  Sweet Old Bob
July 1, 2021 7:06 pm

The alarmists should be embearassed.

Reply to  Sweet Old Bob
July 1, 2021 8:25 pm

Can we get a paws on the bad puns?

Reply to  MarkW
July 1, 2021 8:53 pm

How many more of these bad puns can a polar bear?

July 1, 2021 7:04 pm

Hmm, plump. Fat, even. This is the time to donate to World Walrus Foundation. A joint project of walruses and seals. Think of the pups!

Rory Forbes
Reply to  n.n
July 1, 2021 8:09 pm

Your blubbering isn’t fooling me one bit.

Reply to  n.n
July 1, 2021 8:26 pm

This site is positively awash in humor today.

July 1, 2021 9:28 pm

There has been a lot less Polar Bears are doomed messages in recent years, it seems they are realizing their doom and gloom for the Bears are a dead end issue.

I started a Polar Bear thread at a forum that ran to many pages, but most of the baloney were in just the first 6-8 pages then intermittent after that as the accumulating evidence being posted over the next few months became overwhelming, they mostly stay away from it now.

The same with this forum where the thread is still growing with the addition of this very post today.

Polar Bears Are Thriving | – Forum for US and Intl Politics

Jay Willis
Reply to  Sunsettommy
July 2, 2021 1:28 am

That’s mainly a result of the high quality and persistent work of Susan crockford in my opinion.

Reply to  Sunsettommy
July 2, 2021 3:10 am

WWF are currently running an ad on UK TV begging for donations so that WWF can can save the Polar Bear. It is highly emotive and utterly dishonest but I don’t doubt many are fooled by it.

Reply to  Simonfromashby
July 2, 2021 3:03 pm

Is it another one of those ‘only 19 cents a day’ things we so often see?

July 2, 2021 12:09 am

54% of females having an average of 1.75 cubs EVERY YEAR. That sounds like a recipe for rapid exponential growth.

Humans in the West get told we’re having too many children if females average 1.75 children in their entire lifetime !!

Last edited 1 year ago by Greg
July 2, 2021 12:25 am

In general, summer sea ice decline in the Barents Sea since 1979 has been the most profound across the Arctic (with a loss of 4.11 days of ice per year from 1979-2014): that’s six times as much summer ice loss as bears in the most southern-living subpopulation

And bear in mind that ice loss has been worse in recent years and there have been several where the ice did not refreeze to around Svalbard to late December, or the connection to the main pack melted out early in spring.

the ice is not recovering, it is declining, and this will have an impact on the bears.

Reply to  griff
July 2, 2021 1:49 am

It’s already harmed them so severely that their population has increased and they’ve all gotten fat.

Reply to  griff
July 2, 2021 4:36 am

Can you tell us at what temperature ice refreezes?

Richard Page
Reply to  griff
July 2, 2021 5:22 am

Griffy – Derocher spent 20 years plus developing his failed theories on alarmist polar bear decline and you’re trying to convince us all that you know as much with one post? Take another look at the charts of arctic ice – the extent of ice in the spring (the critical period for polar bears) has been fairly consistent and with good coverage. It doesn’t matter a damn if the ice breaks up in the summer and refreezes later in the year to polar bears. The population stats on polar bears supports this – increasing healthy populations with more cubs surviving into adulthood; the exact opposite of what you’d have us believe. Stop your foolish whining and celebrate what has been a superb conservation story – polar bears are doing great, they have thriving, healthy populations all over the arctic and will continue to thrive despite your silliness.

Last edited 1 year ago by Richard Page
Reply to  Richard Page
July 2, 2021 5:39 am

Given a system as dynamic as polar sea ice, there will always be some locations that are lower than average, and some locations that are higher than average.

griff’s gimmick is to claim that whatever area is lower than average this year, is proof that arctic sea ice is in permanent decline.

Reply to  MarkW
July 2, 2021 7:01 am

Always starting with the peak in 1979, of course.

I can’t figure out why he thinks that 100% sea ice year is in anyway desirable for existence of life. !

Reply to  griff
July 2, 2021 5:37 am

This “declining” ice still hasn’t breached the lows set in 2012.
As usual, griff see’s what his handlers tell him to see, and nothing else.

Reply to  MarkW
July 2, 2021 6:40 am

One and a half times as much Barents Sea ice this year as there was in 2006 !

Over three times as much as in 2013, and over four times as much as in 2016

Richard Page
Reply to  MarkW
July 2, 2021 6:43 am

To credit Griff with having handlers is to credit him with more importance than is clearly warranted. Griff is simply an irrelevant, unimportant person with delusions of adequacy. In short, he’s a nobody that desperately wants to be seen as a somebody so is merely repeating bits and pieces of alarmist drivel he’s read elsewhere in the hopes he’ll be seen to be making a name as an informed ‘expert’. I’ve tried to convince him that he needs professional, psychological help with his delusions but, so far, to no avail.

Reply to  griff
July 2, 2021 6:36 am

According to MASIE, current levels of sea ice in Barents Sea are above those of ……

2006, 2009, 2010, 2012, 2013, 2016, 2018 and is above the 15 year average

Sea ice didn’t freeze around Svalbard even in mid winter in 1922

1979 was a time of extreme high levels of sea ice, similar to the levels of the Little Ice Age

That is not good for any sea life. !

Guess what griff, the Polar bears are doing well because of the drop in sea ice

You are talking arrant nonsense as always, griff.

Tom Abbott
Reply to  clarence.t
July 2, 2021 7:32 am

“1979 was a time of extreme high levels of sea ice, similar to the levels of the Little Ice Age”

The late 1970’s were the coldest period since the 1910’s.

comment image

So it would be logical to assume that there would be less arctic ice as the temperatures warmed from the 1970’s until now. There was also less arctic ice when the temperatures warmed from the 1910’s to the 1940’s. Then the ice increased as the temperatures cooled from the 1940’s to the 1970’s. And round and round, and up and down, we go.

Griff thinks the temperatures will continue to warm because of CO2, but the temperatures may cool back down to the levels of the 1970’s and the 1910’s, too. My guess is that is the way it will go.

And the globe has currently cooled by about 0.6C since the high point of 2016. The temperatures are not continuing to warm, Griff, even though more CO2 is going into the air.

Alarmist climate scientists seem to think that a trend will continue forever. At least, they operate on that assumption. History is not their friend.

Last edited 1 year ago by Tom Abbott
Reply to  griff
July 2, 2021 6:46 am

MASIE Barents Sea ice extent since 2006

comment image

Red is 2021

Last edited 1 year ago by clarence.t
Reply to  griff
July 2, 2021 6:52 am

Russian Ice chart 29th June….. plenty of sea ice around Svalbard

comment image

Reply to  griff
July 2, 2021 8:33 am

Declining polar bear numbers is like fusion-power — always 40 yrs in the future.

PS Grifter, why is it you never reply on the science-posts, but only on these types?

Reply to  griff
July 2, 2021 8:53 am

“the ice is not recovering, it is declining, and this will have an impact on the bears.”
Okay, let’s take the first bit as being correct, whether it is or not. How do you explain the fact that there has been no impact on the polar bears during all the years that this ice ‘is not recovering’? If there has been no impact during that time, why should there be an impact in the future?

Reply to  griff
July 2, 2021 12:46 pm

so sorry Grif- you aren’t responding to the polar bear message but to old propaganda. They are a bit discouraging in that the predictions then were that polar bears were losing population. As a note about animal populations- only ones that are artificially limited, rather than having too few young, are liable to long population declines. Species such as polar bears still can start increased population growth and migration to better areas immediately.

They don’t wait around to die.

Reply to  griff
July 2, 2021 2:17 pm

the ice is not recovering, it is declining, and this will have an impact on the bears.

Tell us more about the impacts, any idea what impacts that will be ?

July 2, 2021 7:58 am

Need side by side (“before & after”) photos of the fat subject photo bear (after), and that bony, emaciated dying bear (before) with the caption/story:

“The warming of the arctic may be disputed, but the positive impact on the polar bear population is obvious. Please help us continue help these beautiful creatures. Donate now so we may continue our efforts ….”

July 2, 2021 8:30 am

Please buy the caw fart stopper, because if it will save at least one polar bear, it will be worth it. Works on people, too!

cow fart stopper.jpg
Reply to  Spock
July 2, 2021 4:03 pm

If you put any of those fart stoppers in a cow’s rear end..

…. you would increase the amount of BS coming out !

Richard Page
Reply to  clarence.t
July 2, 2021 6:45 pm

See, that’s the problem right there. It’s a cow stopper – what you really need is a bull stopper!

July 3, 2021 2:26 pm

And this despite not only low sea ice, but the total absence of tour group delivery for convenient snacking…

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