Hudson Bay sea ice loss has not accelerated since 2014: in fact, summer ice cover has improved

Susan Crockford

From Polar Bear Science

This is an early breakup year for Hudson Bay but sea ice loss has not been accelerating. While some Western Hudson Bay bears have been on land for weeks, others are still out on melting remnants of sea ice, much of it invisible to satellites. This is only the third year since 2014 that the bay has had less than usual amounts of ice, which means most years since then have had normal or nearly normal ice coverage, similar to the 1980s. Hardly the ever-worsening catastrophe of sea ice loss story being spun in the media for Western Hudson Bay polar bears.

From the tracking map above, out of the 38 visible tags or collars on bears at 11 July 2023, 16 bears (42%) were on land and 22 (58%) were still out on the sea ice. That’s virtually identical to the 40/60 percent split last week when there was even more ice.

Ice coverage this week

For the week of 10 July 2023, this ice chart from the Canadian Ice Service (below) suggests that at least four tagged bears (see chart above) are resting on ice that the satellites can’t see. It’s unlikely they are swimming because they were in similar locations last week. This is an earlier-than-usual breakup pattern, similar to what was documented for the two decades after the step-change in 1995.

Polar bears and sea ice

NASA Earth Observatory recently (12 July 2023) provided a bullhorn for activist polar bear specialists to advance their scary narrative about Hudson Bay polar bears (my bold):

In 2023, some Western Hudson Bay polar bears started to return to shore in mid-June, but others lingered on the ice well into July. “Mid-June is early to have bears on land,” said University of Alberta scientist Andrew Derocher“When I started studying polar bears in Western Hudson Bay in the 1980s, we would have bears on the ice well into August.”

Despite some of the bears swimming ashore early, Derocher noted that many bears were still out on the ice in early July, despite how little ice was left and how fragmented the last bits of ice had become.

“The bears on ice are hanging on at extraordinarily low ice levels,” Derocher said. “But better for them to be there trying to kill another seal than on land with little or nothing to eat. Bears can feed and keep putting on weight well into the summer if they have the ice. For polar bears, it truly is survival of the fattest.”

Funny that Derocher doesn’t mention that polar bears were out on the ice well into August in both 2020 and 2022: no, he leaves that part out and emphasizes that breakup is early this year.

Do polar bears in Hudson Bay kill seals in July and August

Also, despite Derocher’s statement to NASA, there is no documented evidence that western or southern Hudson Bay polar bears routinely kill seals from melting sea ice in July and August. Derocher assumes they do but he has no evidence that this actually happens because no one has ever studied this phenomenon. It’s unlikely that more than a few seals spend extented periods hauled out on sea ice in mid-summer because most of them, including adults and juveniles, will be out in open water feeding.

What’s normal breakup for Hudson Bay?

The diagram below is from a paper by Ian Stirling and colleagues (2004), and it shows what the usual or normal pattern of sea ice breakup was between 1971 and 2000. Ice conditions this year are about what was expected in late July or about two weeks early (dark grey). According to the analysis by Castro de la Guardia and colleagues (2017), breakup in 2015 was about two weeks earlier than it had been prior to 1995 or similar to this year.

Mid-July ice cover 2015-2023

However, the pattern this year is unusual compared to the last nine years. Since 2014, only 3 years out of 9 (2023, 2021 and 2017) had less than usual amounts of ice at mid-July. Four years (2016, 2019, 2020, and 2022) presented conditions that would be considered “normal” based on Stirling et al.’s long-term data (1971-2000), while 2015 and 2018 had lots of ice at mid-July but more of it than usual was in the northeast quadrant.

In other words, Hudson Bay has had normal sea ice cover at mid-July more often than it has had reduced ice cover. This means sea ice loss over the Bay has not been accelerating, rather ice coverage has been improving overall since 2014 compared to the two decades before. That’s why the claimed 27% decline in polar bear numbers for Western Hudson Bay between 2017 and 2021 could not be blamed on lack of sea ice: sea ice conditions were mostly been very good in those years.

Have a look at the ice charts below, starting with this year:


Castro de la Guardia, L.., Myers, P.G., Derocher, A.E., et al. 2017. Sea ice cycle in western Hudson Bay, Canada, from a polar bear perspective. Marine Ecology Progress Series 564: 225–233.

Stirling, I., Lunn, N.J., Iacozza, J. et al. 2004. Polar bear distribution and abundance on the southwestern Hudson Bay coast during open water season, in relation to population trends and annual ice patterns. Arctic 57(1):15-26. Open access.

For more on Polar Bears, Sea Ice, and Climate Change, go to our ClimateTV page and select Susan Crockford under speaker.

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July 15, 2023 2:12 pm

My “takeaway”: Varying Ice conditions year to year.. Normal.
Varying Weather conditions year to year.. Normal.

Reply to  sturmudgeon
July 15, 2023 4:29 pm

There also seems to be a very rough periodic shift from one side of the Arctic to the other.

The areas along the Russian coast, + Greenland Sea are all near or above the 5 year high.

Richard Page
Reply to  bnice2000
July 15, 2023 5:11 pm

But, as we saw in an earlier conversation, they did experience similar damage from the May storms. The Russian coastal areas look to have experienced a ‘refreeze’ and recovered much of their earlier sea ice extent whilst the W. Hudson bay didn’t.

Reply to  Richard Page
July 15, 2023 11:32 pm

What I really meant, was that in another few years, I suspect the Russian side will be lower, while the Hudson Bay area has higher extent.

Richard Page
Reply to  bnice2000
July 16, 2023 8:37 am

Hmm. I see your point. You think they might be weather patterns in phase with the AMO or ENSO conditions, or something unconnected?

July 15, 2023 2:13 pm

Overall, Arctic summer minimum sea ice extent has trended up since 2012 and is flat since 2007:

By contrast, Antarctic sea ice trended up from 1979 to 2014, while Arctic extent fell. Since 2014’s huge high, Antarctic extent has declined.

CO2 has increased since the near century Arctic sea ice high of 1979, so can’t explain falling Arctic and rising Antarctic ice until about a decade ago, then the polar seesaw switch.

Richard Page
Reply to  Milo
July 15, 2023 5:12 pm

Bad storm seasons are a more likely culprit for early break-up of sea ice than CO2 or temperatures.

Reply to  Richard Page
July 15, 2023 6:55 pm

All the lowest Arctic summer sea ice years involved late summer cyclones, which spread out and pile up the floes, eg 2007, 2012 and 2016 (two cyclones!).

Nicholas McGinley
Reply to  Milo
July 15, 2023 9:02 pm

You would make an absolutely awful Climate Scientismist™

Reply to  Nicholas McGinley
July 16, 2023 11:42 am

I don’t even play one on the internet.

Rud Istvan
July 15, 2023 3:13 pm

Wrote about Hudson Bay polar bears in essay Polar Bears in ebook Blowing Smoke. Remember, they are evolved from grizzlies (brown bears) and can still interbreed.
So retain some residual grizzlies traits. And that includes feeding on land in Arctic summer for up to (helicopter study estimated) 15-20% of annual caloric intake. Arctic bird nest eggs and fledglings, berries, caribou calves….
So the whole Hudson Bay summer ice thing was a scientific misfire from the alarmist beginning.

Reply to  Rud Istvan
July 15, 2023 3:25 pm

Yes. The sea ice polar bears need is landfast ice in the spring, not floes in summer. Sows emerging from their dens with cubs in early spring need ringed seal pups, ie “fat pills”, at that time. They get them by crashing through the pups’ moms’ snow lair on the shore-fast ice. The moms escape through the holes they keep open in the ice.

Ron Long
Reply to  Milo
July 15, 2023 4:07 pm

Makes you wonder if the Green Idiots think about what the actual conduct of an Apex Predator is before they make them their poster child?

Reply to  Ron Long
July 15, 2023 5:35 pm

The sensors and weapons of Ursus maritimus are uncanny. From miles away, polies can smell ringed seals in their lairs under snow. Lucky for the bears, ringed seals aren’t endangered, despite such relentless predation.

Reply to  Ron Long
July 17, 2023 2:33 pm

That requires way more intelligence and attention span than any of them can muster.

But to be fair, it’s hard to concentrate when your arm is sore and numb from being sealed in concrete to a runway.

Reply to  Milo
July 17, 2023 2:31 pm

But if there wasn’t any ice at all, even at the pole, then wouldn’t the seals have to come on land – making mealtime much easier for the bears. They might have to move further north but big deal, that’s where they evolved.

Why does the whole biosphere have to suffer to keep the bears happy?

Wouldn’t the apex predator bears be happier atop a much larger food pyramid enabled by Jurassic/Cretaceous/Eomene temps? With trees, and the animals to match, all the way to the Arctic Ocean?

Dave Burton
July 15, 2023 5:40 pm

One quibble… “summer ice cover has improved” suggests that there’s some reason to prefer more Hudson Bay ice to less, or vice-versa. The reality is that it just doesn’t matter — neither for polar bears, nor for people.

Both species have survived both warmer climates and colder climates.

In general, warmer climates are far better than colder climates. That’s why scientists call the warmest climate periods “climate optimums.” But regardless of the extent of July ice coverage, the area around Hudson Bay is still too cold to be habitable by more than a handful of people.

Do you know what else is at roughly the same latitude as Hudson Bay? Scotland.

Edinburgh, in southern Scotland, is at 56°N latitude. Scapa Flow is at 59°N latitude.

comment image

The largest community on Hudson Bay had fewer than 1000 people. The greater metropolitan Glasgow area has a population of more than 1.8 million.

The reason Scotland is a nice place, albeit a bit chilly, and Hudson Bay is brutally cold, is that the Gulf Stream carries enough warmth to Northern Europe to make it habitable, despite its high latitude.

comment image

If the UK were colder (more like Hudson Bay), then by any objective measure it would be WORSE.

If Hudson Bay were warmer (more like the UK), then by any objective measure it would be BETTER.

How is it possible that that is that not obvious to everyone?

Nicholas McGinley
Reply to  Dave Burton
July 15, 2023 8:05 pm

It is not obvious because people do not think critically.
They just repeat what they have been told is true, and never even begin to go through the process of forming their own ideas based on the sum of all their accumulated knowledge.

Dave Fair
Reply to  Dave Burton
July 15, 2023 9:52 pm

Poverty kills, including by cold. Decreasing energy availability and increasing its cost increases poverty and deaths. CliSciFi kills.

Reply to  Dave Burton
July 17, 2023 2:35 pm

Exactly 😍

Nicholas McGinley
July 15, 2023 8:01 pm

How exactly is more ice an improvement?

Reply to  Nicholas McGinley
July 15, 2023 11:35 pm

I have often wondered that.

PBs hunt on the edge of the receding ice edge, so there is a larger area if there is somewhat less ice. A lot of sea ice means they have to travel much further from land.

Then you have the marine species.. If there is too much sea ice, they go elsewhere.

There are some species only now making a return to the Arctic, which were last seen before the LIA.

Geoffrey Williams
July 16, 2023 1:56 am

Thanks Susan for your really informative post.
However I do have a question; why are there any bears at all in Hudson Bay in summer when there is so much ice further north . .

Richard Page
Reply to  Geoffrey Williams
July 16, 2023 4:38 am

Follow the seals. They’ll be near the edges of the sea ice.

Reply to  Richard Page
July 17, 2023 2:37 pm

Rhetorical question – he’s implying that the bears prefer the warmer temperatures down south and that researchers have ice on the brain.

Bill Halcott
July 16, 2023 3:11 am

I just finished a Fake News report that said exactly the opposite.

Tom Abbott
Reply to  Bill Halcott
July 16, 2023 6:37 am

That happens every year. The climate change alarmists claim it is worse than ever in the Arctic and the Polar Bears are hanging on by a thread, and then Susan comes in and puts everything into perspective by showing us the Polar Bears are doing very good.

I miss ole Griff’s sputtering and complaining about the good news coming from Susan about the arctic. An article by Susan would certainly bring him out. Unfortunately, he tended towards personal attacks against Susan for some reason known only to him.

I guess that era is over with, though. His excuse for leaving was that WUWT would give out his personal information if he was forced to register under his real identify.

Hey, Griff. We all knew what your full name was, for years. You’ve always been in danger of having your personal information made public, but we never did do that, did we.

You just couldn’t stand the heat, so you got out of the kitchen.

Reply to  Tom Abbott
July 17, 2023 2:46 pm

I’m under PCman999 – and no, it doesn’t say that on my driver’s license – Griff and Stokes were/are just annoying, didn’t add anything except propaganda to the discussion. It’s fine if they have a scientific point to discuss but bickering about some trivial point just gave headaches and polluted the scientific discourse.

There people here that believe co2 has no effect, little, medium and even large, that ‘greenhouse effect ‘ is just a property of the whole atmosphere (the average temperature of the atmosphere is basically just the black body temperature – which gets concentrated at the surface and is compensated by frigid temps higher up), all kinds of things, but keep coming here to discuss the science or even just the logic of it all, and not regurgitated propaganda.

July 16, 2023 9:34 am

Dr. Susan Crockford . . . what a beautiful scientific mind and excellent author/communicator! Telling it like it is, backed up with spot-on graphics and numerous valid references.

IMHO, she exemplifies the standards to which all scientists, amateur or professional, should strive.

Thank you, Dr. Crockford.

July 17, 2023 2:20 pm

“in fact, summer ice cover has improved”

That’s a subjective statement based on what? Did you ask the polar bears what percentage of ice they prefer? What about the seals? How about the plants and fish under the ice, don’t they get a vote?

The world would be better off with no ice caps at all, with all that wasted moisture in circulation, back to the paradise conditions of the Cretaceous period.

Prove me wrong.

Pat from Kerbob
Reply to  PCman999
July 17, 2023 5:07 pm

Clearly she is addressing the climate/insane for whom less ice is a catastrophe.
It’s soothing sounds so they don’t have to freak out, she is humoring the children.
Don’t spoil the joke

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