Guest Post by Willis Eschenbach
Inspired by this thread over at Bishop Hill’s excellent blog, I thought I’d write about sea ice. Among the many catastrophic things claimed to be the result of “global warming”, declining sea ice is one of the most popular. We see scary graphics of this all the time, things that look like this:
FIgure 1. Terrifying computer projections showing that we may not have any Arctic sea ice before the end of this century. Clearly, the implication is that we should be very concerned … SOURCE
Now, what’s wrong with this picture?
The problem with the picture is that the earth has two poles. And for reasons which are not well understood, when one pole warms, the other pole cools.
Looking at just the Arctic sea ice is like looking at someone who is pouring water from one glass to another and back again. If we want to see how much water there is, it is useless to observe just one of the person’s hands. We need to look at both hands to see what is happening with the water.
Similarly, to see what is happening in the frozen parts of the ocean, we need to look at global sea ice. There are several records of the area of sea ice. One is the Reynolds Optimally Interpolated dataset (Reynolds OI V2). A second is the National Snow and Ice Data Center (NSIDC) record. Finally, we have the Hadcrut Ice and Sea Surface Temperature dataset (HadISST1). All of them are available from that most marvellous resource, the KNMI data portal .
It turns out that the NSIDC and the HadISST1 records are nearly identical. The correlation between the two in the Arctic is 0.995 (1.0 is perfect agreement), and in the Antarctic it is 0.999. So in Fig. 2, I have not shown the NSIDC dataset, but you can imagine that there is a third record almost identical to the HadISST1 dataset. Here is what has happened to the global sea ice area from 1982 to the present:
FIgure 2. Global Sea Ice Area 1982-present. Data from satellite observations.
As you can see, while it is certainly true that the Arctic has been losing ice, the Antarctic has been gaining ice. And the total global sea ice has barely changed at all over the period of the record. It goes up a little, it goes down a little, it goes nowhere …
Why should the Antarctic warm when the Arctic cools? The short answer is that we don’t know, although it happens at both short and long time scales. A recent article in Science Magazine Online (subscription required) says:
Eddies and the Seesaw
A series of warm episodes, each lasting several thousand years, occurred in Antarctica between 90,000 and 30,000 years ago. These events correlated with rapid climate oscillations in the Arctic, with Antarctica warming while the Arctic was cooling or already cold. This bipolar seesaw is thought to have been driven by changes in the strength of the deep overturning circulation in the North Atlantic Ocean, but some have questioned how completely that process can account for the fine details of Antarctic warming events.
Keeling and Visbeck offer an explanation that builds upon earlier suggestions that include the effects of shallow-water processes as well as deep ones. They suggest that changes in the surface salinity gradient across the Antarctic Circumpolar Current were caused by the melting of icebergs discharged from the Arctic, which allowed increased heat transport to Antarctica by ocean eddies. This mechanism produces Antarctic warming of the magnitude observed in ice core records.
However, not everyone agrees that this is the full explanation. Henrik Svensmark adds another factor to what may be happening:
The cosmic-ray and cloud-forcing hypothesis therefore predicts that temperature changes in Antarctica should be opposite in sign to changes in temperature in the rest of the world. This is exactly what is observed, in a well-known phenomenon that some geophysicists have called the polar see-saw, but for which “the Antarctic climate anomaly” seems a better name (Svensmark 2007).
To account for evidence spanning many thousands of years from drilling sites in Antarctica and Greenland, which show many episodes of climate change going in opposite directions, ad hoc hypotheses on offer involve major reorganization of ocean currents. While they might be possible explanations for low-resolution climate records, with error-bars of centuries, they cannot begin to explain the rapid operation of the Antarctic climate anomaly from decade to decade as seen in the 20th century (figure 6). Cloud forcing is by far the most economical explanation of the anomaly on all timescales.
Regardless of why the polar see-saw is happening, it is a real phenomenon. Ignoring it by looking just at the Arctic leads to unwarranted conclusions about what is happening to sea ice on our most amazing planet. We have to look at both hands, we have to include the other side of the ice, to see the full situation. The real answer to what is happening to global sea ice is …
Nothing.
Willis – Right you mostly are.
To be perfectly clear, the catch is that their models of declining polar bear populations begin with the IPCC predictions of climate change. So the results are rather predictable.
And the only in Alaska, thanks to the EPA. That’s when I first noticed Sarah Palin. She called them bluff when she was governor and the state has taken the EPA to court to challenge that bogus ‘science.’
On the other hand, in Canada they were brave enough to stick closer to the evidence and did not raise their listed threat level when they reviewed them last year. Some Canadian scientists are True Believers but overall they are far more scientific than the EPA missionaries.
And yes they do invite the Inuit to the meetings in Canada, and they do pay attention to what they say.
So, they are officially doomed in Alaska but not in Canada.
Things are a little more complicated than you describe about denning and summers.
Its not ‘hibernation’ exactly but close enough.
Depending where they are, summers are their starvation season, and when they are least active. That’s the story in southern Hudson Bay.
Only the females MUST den, to have cubs or to shelter young ones. In some areas the male bears don’t. Depends on where they are/food availability.
As for ‘are they declining’? Well, we do know more than some would suggest. For one thing, which population? But overall, here’s the bottom line. In the 1960s the global population was estimated at only 5-10 thousand. That was an admitedly rough estimate but… then they severely restricted and regulated hunting. Now the population estimates are in the range you suggest. And simple common sense tells us that when you reduce hunting mortality the population will grow unless there is some other limiting factors – which, if there are any, are not significant.
These are not just recent population highs but historic and almost certainly prehistoric highs because the Inuit traditionally killed every polar bear they could – they were a direct threat, a threat to their stored food, and a source of meat, fat and furs – and so did the Euros who arrived later. Same story in Eurasia.
Those who imagine that early Inuit or any other of the similar people in Eurasia couldn’t readily kill them – the ‘pristine wilderness fairy tale’ – just don’t understand those people or their abilities, and of course they ignore their helpful dogs. And bears are easiest to kill in their dens.
You correctly noted that they survived prior warming periods. They weren’t optimum for them but they did survive. But for as long as humans have been in the Arctic, human predation on them has been the factor that mattered most. With their low reproductive rate they – like grizzly/brown bears (their close relatives) – just can’t withstand much hunting pressure. And in warmer periods, or when they had less food, their reproduction rates would be lower, as would their populations, and they could survive hunting pressure still less.
For a real shock read the historical journals of the Arctic and you will discover that they were very, very, very rare with local or regional (and explainable) exceptions.
blackswhitewash.com (03:44:32) :
Anu (23:19:11) :
Ahh, we are back to the “its rotten ice” nonsense again.
——————
The argument last year seemed to be that only Dr. Barber seemed to use that phrase, “rotten ice”.
It seems like the term is now acknowledged by more organizations, for instance NASA’s JPL and UCAR:
http://media.thestar.topscms.com/acrobat/cc/e5/a80893c24759919867add7104bbe.pdf
Two structurally different ice formations that give the same readings to the Geoscience Laser Altimeter System (GLAS) sounds plausible to me – it only measures the height of the ice. A diode pumped Q-switched Nd:YAG laser operating in the near infrared (1064 nanometers) is used for the measurement of surface topgraphy – if rotten ice and solid multiyear ice can give the same returns, so be it.
http://icesat.gsfc.nasa.gov/glasinstrument.php
Perhaps one of the 309 comments to this thread:
http://wattsupwiththat.com/2009/12/14/a-look-at-sea-ice-compared-to-this-date-in-2007/
show the “rotten ice” concept to be nonsense. I haven’t read them all yet.
The article itself does not do it – rotten ice says nothing about sea ice extent, it is a 3D ice volume problem. Other organizations now do use the phrase, but the argument should have been, not that only Dr. Barber uses that phrase, or that it “dupes” the satellites as to 2D extent, but that as a groundtruth check on the data, it was done only in the southern Beaufort Sea.
Absent more such “expeditions” to investigate the state of multiyear ice, the most they can say is that a very small percentage of multiyear ice seems to be “rotten”. The result is merely suggestive, frosting on the cake of evidence pointing to a march to ice free summers in the Arctic.
It’s the cake itself that is the main evidence – thick multiyear ice is disappearing, whether rotten or solid.
Of course, with the caveat that Willis pointed out – where is the data in the circle 86°N to 90°N coming from ? I haven’t looked into it enough yet.
Steve Goddard – Thanks. That is one exceptionally large bear, predictably from the Bering Strait where they grow largest.
It must have had an exceptionally rich food source and been weighed at its seasonal peak. And it would be interesting to know the background on that bear and how they weighed it. I shall look into that.
Because a) its from wiki, and b) it only says “reportedly weighed.”
But in any case it is the equivalent of 8 foot tall human. Most polar bears in the Bering Strait area not remotely close to that size, and in the rest of the Arctic they are smaller.
However, with almost no hunting in Alaska now, there may be more getting huge there now… unless they are all starving because of The Warming of course (sarcasm).
DeNihilist (15:20:46) :
Willis, have you heard about this? They are reprocessing old Nimbus data from the 60’s. Hoping to extend their artic/anyartic snow/ice knowledge by about 50%.
http://nsidc.org/monthlyhighlights/january2010.html
———–
Interesting.
They saw a disappearing window of opportunity to recover these data. Only one tape drive remained in the world that could read the Ampex two-inch media. Plus, the original Nimbus researchers were now in their late 70s and 80s, and contact with them would be critical to answering some of the necessary instrumentation questions.
Sounds like they got to it just in time.
Hope it yields some useful data.
Stacey (01:58:19) :
With regard to sea ice volume,my recollection is that when it became obvious that the sea ice in the Arctic was back to ‘normal’, and it was observable, the alarmists had to come uo with something that was not so observable, the thickness of the ice.
———————–
I don’t think the timelines would support that hunch.
The Arctic sea ice extent was lowest in summer 2007, so by “back to normal” you probably mean 2008, 2009, and so far this year (all years more than 1 std dev below the 1979-2000 average, but still, more than 2007 most days).
ICESat was launched Jan 12, 2003. It was probably conceived, designed, built and tested starting in the early to mid 1990s.
Cryosat was a similar ESA satellite launched on Oct 8, 2005. There was a launch failure (it was launched in Russia using a modified ICBM), so it never attained orbit. Cryosat-2 is scheduled to launch next month – but the fact remains, Cryosat was conceived back in 1998.
http://en.wikipedia.org/wiki/ICESat
http://en.wikipedia.org/wiki/CryoSat
NASA also uses airplanes to gather some data on ice thickness, as well as other satellites:
Scientists have been interested in ice thickness for many years before the “recovery” of 2D ice extent in the Arctic starting in 2008. If they found the ice getting thicker every year, they would publish that. Publish or perish.
Willis, would that human garbage include those in the “Explorer Team” on the Catlin Arctic Survey. Those bears must be getting hungry with those rising temperatures and all that swimming practice.
Steve Goddard (14:30:17)
“Polar Bears eat seals because there isn’t much else for them to eat.”
Logically then, pandas eat bamboo “because there isn’t much else for them to eat.”
Iana($expert anything). I suspect pandas took to eating bamboo because there
was lots of it around. That’s a law of nature: where a large food supply exists,
something will arise to exploit it.
Seals need land (to mate, give birth, nurse, sleep). If the mainland is quiet, they’ll
live there (eg. sea lions in Patagonia). If there’re predators on the mainland, they’ll
move to the islands. If predators swim out to the islands, they’ll move to the ice…
Steve Goddard (14:30:17) :
Vincent (14:03:06) :
“Polar Bears eat seals because there isn’t much else for them to eat. What do you suggest that a 3,000 pound mammal eat in a place where there are no trees and the growing season is only a few weeks long? Ladybugs?”
I can say, first-hand, that when we ran low on food during our canoe trip up the Labrador coast in 2001 we had to rely on ladybugs—boiled or split and dried over willow smoke fires. They are HUGE there and fortunately for the polar bears, the cool weather makes them slow fliers and thus are easy to catch. When we headed inland, however, we were able to sustain ourselves on Culex giganticus, the famed 15 lb. mosquitoes of the Ungava plateau. 🙂
Steve Goddard (14:40:40) :
Anu,
Disappearance of multi-year ice is mostly a 2D phenomenon. It is due to wind blowing the ice horizontally more than ice melting vertically.
—————————–
That’s certainly one factor.
I also read about 2007 being unusual in that an ice “arch” (dam) did not form in the narrow Nares Strait, west of Greenland, the only time on record. This allowed ice to flow unobstructed through winter and spring.
The ice lost through Nares Strait was some of the thickest and oldest in the Arctic Ocean.
http://www.sciencedaily.com/releases/2010/02/100219164337.htm
It also looks like the multiyear ice recovered about 11% in March 2009 over March 2008, a figure I hadn’t seen before:
http://www.arctic.noaa.gov/reportcard/seaice.html
The same page also shows that the 2D extent in March is only vaguely correlated with minimum 2D extent in September:
http://www.arctic.noaa.gov/reportcard/figures/seaice2009fig2-sml.jpg
As I said before, this decade’s data will be crucial to how many people see climate change in the 21st century. If Arctic ice thickness and 2D extent grow back to 1979-2000 averages, if global temperatures go down 0.2 deg C, even with the sun cycle picking up, climate science will certainly look like they got it wrong. On the other hand, if the trends continue, and Arctic ice thickness continues to be measured thinning, if 2D extent gets less and less (with the expected annual variability), and global temperatures go up another 0.2 deg C or so, it will look like things are unfolding as predicted.
I expect the latter, but I’m hoping the data shows otherwise.
Anu,
Arctic ice is thickening over the last two years, not thinning – and is now above normal in extent as well.
http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_area.png
Sleepalot (21:13:10) :
Sounds like you should volunteer for next year’s Catlin expedition.
Willis,
You said some polar bears “live where there is no ice for most of the year.”
There aren’t any regions in the Arctic that are normally ice free for more than four months.
http://arctic.atmos.uiuc.edu/cryosphere/
Note the temperature profile at 80N. Less than 90 days above freezing per year.
http://ocean.dmi.dk/arctic/meant80n.uk.php
Unintentionally, I’m sure, this probably ranks as one of the funniest things I’ve read here, certainly in a while.
I wonder if someone thinks “winter wheat” is like certain plants that require forest fires to crack open their seeds? Maybe this “winter wheat” grows pre-frosted, making it easier to create breakfast cereal?
I will say, however, that living in Calgary completely surrounded by wheat fields and cattle ranches, the very concept of cold weather being beneficial to ANY food crop is not just laughable, it’s mockable.
I get the logic behind warmer weather creating drier conditions, especially far away from the ocean like here… that makes perfect sense… however, the alleged “need” for cold for a crop? Not on this planet.
Steve Goddard,
“Polar Bears eat seals because there isn’t much else for them to eat. What do you suggest that a 3,000 pound mammal eat in a place where there are no trees and the growing season is only a few weeks long? Ladybugs?”
Ok Steve, you it’s clear that you didn’t read my reply at all Or you started reading and stopped halfway through.
I’ll make it simple and just quote my concluding sentence: “Therefore, when the ice disappears, the seals will hunt fish from the shores and that’s where the bears will be found.”
Is that clear enough for you Steve? Seals will fish from the shores; bears will hunt the seals feeding from the shores.
Steve Goddard (23:10:38) : edit
Yeah, “much of the year” would likely be more accurate for most populations.
You’re right about the Arctic … but not all polar bears live above 80N. In fact, not all of them even live above the Arctic Circle. Some live as far south as Southern Greenland (60°N), and South Hudson Bay and the southern end of the Davis Strait (52°N).
See the population map above. The white circle is the Arctic Circle (66.5°N)
Take a look at the Cryosphere Today map for today, we’re at the time of maximum ice for the entire year. Look at Southwestern Greenland … no ice today, at maximum ice time. But polar bears live there, the Davis Strait population. Hudson Bay is ice-free for 4-5 months every year, but polar bears live there.
Regarding SW Greenland, there’s a detailed study here of polar bears and ringed seals. Inter alia it says:
Life is amazingly tenacious and adaptable … the article is worth a read, the situation is much more complex than ice vs. no ice.
To
Steve Goddard (22:59:43)-
Although I agree that the graphs show thickening
and more extensive arctic ice this year-
and I believe that
based upon my observations of certain temperature data that
there is a high probability that Ice is increasing in the arctic-
I still consider it highly probable
that some of the ice increases this year are in fact
due to previous years data winnowing and suppression and graph
manipulations by hottie fellow travelers with agendas and expectations
that the ice would in future decrease to match their graphs
(and to promote AGW) – and who were
deliberately underestimating and spuriously graphing their spurious
ice measurements–(years of lying)
and who now are under the microscope and are
reluctant to continue their statistical
farces(s).
So some of the gains could be simply because
this year’s graphs are slightly more accurate than previous years’.
But to me, this slight gain in ice in no way
validates any of these graphs.
Vincent (01:11:52) :
Read how polar bears actually hunt. Your belief system doesn’t change reality any more than Michael Mann’s does.
http://en.wikipedia.org/wiki/Polar_bear
If there was little ice, seals would have to birth/rest somewhere solid. They can’t birth or rest in the water. So obviously, they’d have to do so on shorelines. Polar bears would do what they always have — follow the seals.
Wow! Don’t look now but it appears that the maximum Acrtic Sea Ice Extent thusfar recorded by JAXA http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent.png is about to surpass 2003 hitting an all time HIGH over the prior 8 years.
Coming soon to an AP headline near you in three, two, one…: “Polar bears facing starvation. ‘Climate change’ blamed for dwindling access to open water to hunt seals.”
FWIW – yesterday’s figures from IARC-JAXA show Arctic ice extent at 14.363m km², just below the 14.375m km² peak reached March 8. Ice area is also holding steady. Come September it should be intersting to see how well this slow recovery has progressed, keeping in mind that between now and then there are sure to be fluctuations in extent that prove nothing.
Meanwhile, back up in the Arctic, a resupply plane (DC3) is grounded by bad weather; waiting to resupply the Ice Base where the thin ice crust (their words) has to be more than 3 feet thick in order to support the plane’s weight. Further north, the explorers continue their trek to the pole and are also getting ready to get resupplied. They’ll probably make it to the pole, with an appropriate message that (of course) “it’s worse than we thought!”
Willis,
The Hudson Bay is normally ice free for only three months a year. August through October.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.13.html
Anu (22:06:33) :
Steve Goddard (14:40:40) :
Anu,
Disappearance of multi-year ice is mostly a 2D phenomenon. It is due to wind blowing the ice horizontally more than ice melting vertically.
—————————–
That’s certainly one factor.
I also read about 2007 being unusual in that an ice “arch” (dam) did not form in the narrow Nares Strait, west of Greenland, the only time on record. This allowed ice to flow unobstructed through winter and spring.
The ice lost through Nares Strait was some of the thickest and oldest in the Arctic Ocean.
http://www.sciencedaily.com/releases/2010/02/100219164337.htm
And as I’ve pointed out before it’s open again this year:
http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2010088/crefl1_143.A2010088190000-2010088190500.500m.jpg
If anything it’s more open than this time in 2007
It also looks like the multiyear ice recovered about 11% in March 2009 over March 2008, a figure I hadn’t seen before:
http://www.arctic.noaa.gov/reportcard/seaice.html
That’s showing non-seasonal ice, i.e. includes 2nd yr ice.
The same page also shows that the 2D extent in March is only vaguely correlated with minimum 2D extent in September:
http://www.arctic.noaa.gov/reportcard/figures/seaice2009fig2-sml.jpg
Indeed, the recent ‘lack of decline from max’ appears to be associated with a strong flow of fragmented ice out of the Fram and east of Svalbard, which doesn’t bode well for ice extent later in the year.
Willis Eschenbach (21:15:59) :
Phil. (20:55:24)
Kazinksi (18:50:18) :
“”I woinder why they picked 2007 to end the data series? I think we all know.”
Yes we do, the graph is dated 23 Sept 2007!”
Well played, that’s exactly why I try not to speculate on motives.
Very wise, the first time I saw that figure was in Stroeve et al, 2007 and derivatives of it in a presentation by Maslowski from June 2008.
Anu,
you write:
“I imagine if the Arctic Ocean waters are getting a bit warmer in the summers, those weak cyclones could get stronger”.
Could you tell me what supplies energy to those extra-tropical cyclones?
Latent heat or something else?
When you find the answer, will you report to us all?
Thank you.
Phil.
A negative AO is typified by high pressure or clockwise circulation. The older ice is located north of Canada and Greenland and is circulating away from the Fram Strait.
http://iabp.apl.washington.edu/maps_daily_track-map.html
Summer extent will very likely increase again this year.
Something seems to be up in the Arctic:
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
Or perhaps there is a problem with their algorithms …