Memo to media, non-cryosphere scientists: The peer-reviewed literature does not provide support for the view that the Arctic “recovered” in 2008 — and even what happened in 2009 has now been called into question (see below). Don’t fall into the mindset of the anti-science disinformers, who all seem to think two dimensionally.
In July, leading cryoscientists at JPL, the Polar Science Center at the University of Washington, and NASA published a major peer-reviewed article, “Thinning and volume loss of the Arctic Ocean sea ice cover: 2003-2008″ (discussed here) and posted this figure of Arctic ice volume:
Not bloody much “recovery” or “reversal” from 2007 to 2008.
Now Andy Revkin has just posted a typical Goldilocks piece on Dot Earth — it’s not too hot, it’s not too cold. I don’t want to rehash all of my problems with this approach, but I will say that since the observational evidence shows that warming of the climate system is “unequivocal” — and essentially the entire scientific community and every member government of the IPCC agrees with that analysis — it is clearly reasonable for the media to discuss certain very unique, extreme weather events predicted by climate science in the context of that warming — as Revkin himself once did in discussing the remarkable extremes in Australia last year [see CNN, ABC, WashPost, AP, blow Australian wildfire, drought, heatwave "Hell (and High Water) on Earth" story "” never mention climate change]. Since we’re not in a cooling trend, of course, it would be illogical for a competent reporter to use a cold snap as evidence of such a non-existent trend.
I want to focus on a quote he got from Richard Betts, the head of the climate impacts division at Britain’s Met Office, which shows that even the most knowledgeable climate experts don’t follow the literature as closely as they should:
One classic example is the dramatic decline in Arctic sea ice in 2007, which was then partly reversed in 2008 and 2009. Although there is still definitely a declining trend in Arctic sea ice (2009 and 2008 were still the second and third lowest sea ice extents, after 2007) there was a lot of hype surrounding the 2007 minimum even though that was partly just natural variability in the Arctic climate.
Well, we’ve already seen that Betts was wrong abut the reversal in 2008. He was focused on the two-dimensional Arctic ice coverage, and apparently missed the sharp drop in volume, which I dare say is “dramatic” and much more important.
The scientific literature has also weighed in on the cause of the 2007 decline (see “What drove the dramatic retreat of arctic sea ice during summer 2007?“). Let me quote from the Geophysical Research Letters (subs. req’d) analysis by four scientists from the Polar Science Center, Applied Physics Laboratory, College of Ocean and Fishery Sciences, University of Washington, Seattle:
A model study has been conducted of the unprecedented retreat of arctic sea ice in the summer of 2007. It is found that preconditioning, anomalous winds, and ice-albedo feedback are mainly responsible for the retreat. Arctic sea ice in 2007 was preconditioned to radical changes after years of shrinking and thinning in a warm climate.“¦ The Arctic Ocean lost additional (sic) 10% of its total ice mass in which 70% is due directly to the amplified melting and 30% to the unusual ice advection, causing the unprecedented ice retreat. Arctic sea ice has entered a state of being particularly vulnerable to anomalous atmospheric forcing.
So, yes, that minimum was partly due to natural variability, but in fact it was mostly due to warming. Arguably, absent the warming trend, there’d have been exceedingly little chance of anything like the 2007 decline.
Final question: Did the ice recover from 2008 to 2009? To answer, that you must read the new study, “Perennial pack ice in the southern Beaufort Sea was not as it appeared in the summer of 2009” (subs. req’d), which I discussed at length here: “Where on Earth is it unusually warm? Greenland and the Arctic Ocean, which is full of rotten ice.”
That study concluded:
Our results are consistent with ice age estimates (Fowler and Maslanik, http://nsidc.org/news/press/20091005_minimumpr.html) that show the amount of MY sea ice in the northern hemisphere was the lowest on record in 2009 suggesting that MY sea ice continues to diminish rapidly in the Canada Basin even though 2009 areal extent increased over that of 2007 and 2008.
If it’s true that the amount of multiyear sea ice in the northern hemisphere was the lowest on record in 2009, then it is hard to say that there was any genuine recovery.
Second, the satellite and other measurements that suggested two-dimensional recovery of sea ice extent have been called into question. It appears an unfortunate trick of Nature helped hide the decline of Arctic ice:
In September 2009 we observed a much different sea icescape in the Southern Beaufort Sea than anticipated, based on remotely sensed products. Radarsat derived ice charts predicted 7 to 9 tenths multi-year (MY) or thick first-year (FY) sea ice throughout most of the Southern Beaufort Sea in the deep water of the Canada Basin. In situ observations found heavily decayed, very small remnant MY and FY floes interspersed with new ice between floes, in melt ponds, thaw holes and growing over negative freeboard older ice. This icescape contained approximately 25% open water, predominantly distributed in between floes or in thaw holes connected to the ocean below. Although this rotten ice regime was quite different that the expected MY regime in terms of ice volume and strength, their near-surface physical properties were found to be sufficiently alike that their radiometric and scattering characteristics were almost identical.
Until the community of cryosphere scientists resolves this apparent overestimation of ice recovery by their standard measurement techniques, claims that the Arctic ice recovered even in 2009 are premature. The stunning decline in Arctic ice volume in recent years remains very strong evidence of human-caused warming and something the media has every reason to continue to write about in the context of overall global warming stories.
Previous in TP Climate Progress
regarding the “recovery” in 2008/9 I’m guessing he got his information from here
http://nsidc.org/news/press/20091005_minimumpr.html
“At the end of the Arctic summer, more ice cover remained this year than during the previous record-setting low years of 2007 and 2008. However, sea ice has not recovered to previous levels. September sea ice extent was the third lowest since the start of satellite records in 1979, and the past five years have seen the five lowest ice extents in the satellite record.”
Which is also what David Rose in the Mail on Sunday (as per your previous post) used as the basis for his claim that arctic sea ice is increasing rapidly.
Back in 2007, the decline in minimum summer sea ice coverage was heavily promoted as visible evidence of accelerating arctic ice melt. Now that it has reverted to the mean trend line, you tell us that looking at those 2-D images that were heavily hyped back in 2007 really isn’t all that informative, and we need to look at other metrics (volume). From a PR perspective, this has a sneaky feel to it, like you are mainly interested in spinning the facts to promote a political agenda. If your goal is to preach to the choir (and generate traffic from that audience) then this approach probably works. I wonder about its effectiveness for persuading others.
[JR: My goal is to explain the science and its implications. Obviously 2D is easier to measure -- or at least we thought so until this new paper came out. Anyway, if you'd like to refute the volume research, go ahead, otherwise I have a sneaky feeling that you are mainly interested in spinning non-facts to promote your agenda. After all, I have multiple links to the actual scientific literature. And you have, what? Your feelings?]
Fine again, Joe! The point is multiyear. Perhaps people understand the multiyear point in the Baltic Sea conditions. Five months some ice near the coast, seven without any ice. No multiyear ice, of course. Earlier whole the sea ice covered, but never any multiyear ice.
Looks like the Arctic is going after the same fashion. And then, of course, there is no sense to speak so much of the area of the ice, only the volume of the summer ice.
Roger thinks that once something is identified as flawed it can never be used again. Just because a metric is inferior doesn’t mean it’s not useful. Ice area measurements showed a recent increase of what we can also identify through other means as young, thin ice. Now it seems that, despite the flaws in considering ice area alone, this metric is once again in line with others. This is called supporting evidence.
Two quotes from the NSIDC press release Andrew Adams usefully references:
“Only 19 percent of the ice cover was over 2 years old, the least in the satellite record and far below the 1981-2000 average of 52 percent.”
“A lot of people are going to look at that graph of ice extent and think that we’ve turned the corner on climate change. But the underlying conditions are still very worrisome.”
This chart from the same press release, showing a 11% per decade declining trend in Arctic sea ice is rather conclusive even without ice volume information: http://nsidc.org/images/arcticseaicenews/20091005_Figure3.png
Perhaps the fact that ice area is much easier to measure than ice volume is a big reason for it’s widespread use.
Roger wrote: “… this has a sneaky feel to it …”
Why don’t you try paying less attention to your “feelings” and more attention to the facts?
A few points to note here, based on ongoing exchanges with about 15 “cryosphere scientists,” some of which took place standing on the shifting floes around the North Pole (I vote for Joe to make a field trip):
1) There is still pretty wide agreement that the big melt of 2007 betrays as much about gaps in understanding and modeling skill as it does about the Arctic’s fate in a warming world.(Joe may recall my description of the much-touted “death spiral” as more a series of loop-the-loops.. long-term trend clear, path murky.) Bottom line: the great ice loss of summer 2007 was substantially set up by the export of huge amounts of thick old ice many years earlier, as described here:
“… The striking Arctic change was as much a result of ice moving as melting, many say. A new study, led by Son Nghiem at NASA’s Jet Propulsion Laboratory and appearing this week in Geophysical Research Letters, used satellites and buoys to show that winds since 2000 had pushed huge amounts of thick old ice out of the Arctic basin past Greenland. The thin floes that formed on the resulting open water melted quicker or could be shuffled together by winds and similarly expelled, the authors said.”
http://www.nytimes.com/2007/10/02/science/earth/02arct.html
2) Joe’s focus on volume versus extent (or area) is a bit funky given the still-conflicting research on how much thin ice matters to the ability of the Arctic to avoid entering a new normal state of “no ice” summers. Note this excerpt from a piece of mine on various putative tipping points in the climate system:
“For example, the idea that recent sharp retreat of summer sea ice around the North Pole has now taken on its own momentum has been challenged recently in papers by the earth scientists John S. Wettlaufer of Yale and Ian Eisenman of the California Institute of Technology. They contend that thin ice floes have the capacity to regrow quickly as summer ends, balancing out the melting that occurs as sunlight hits and heats dark open water.”
http://www.nytimes.com/2009/03/29/weekinreview/29revkin.html
Finally, when the study of Beaufort Sea “rotten” ice came out, I queried my sea-ice posse (names provided on request) and they pointed to many issues with those conclusions. Hajo Eicken at the University of Alaska, Fairbanks, said satellite tracking has more problems when ice is, overall, thinner (this is just a tiny taste of the issues raised):
“I wonder whether overall the trend towards thinner younger ice may have resulted in a net underestimation rather than overestimation of the area of multiyear ice. What we observed at SHEBA (and see in Barrow on a regular basis) is that for thinner (<2 m) multiyear ice and first-year ice, melt ponds can fill with seawater by the end of the melt season (due to higher permeabilities of such thinner, more porous ice), resulting in the overlaying of desalinated old ice by newly frozen saline ice in the fall and winter. As a consequence, a significant fraction of the multiyear ice has surface emissivity signatures of first-year ice."
Yet more evidence of the hazards of putting too much emphasis on a particular paper, perhaps (in other words, supporting Dr. Betts' point).
[JR: I would have said it is transparently obvious that ice volume is a better measure than ice area, if you want to understand long-term trend and the mpact of human emissions — though it’s great to have both measures. Again, I’d love you to ask your leading cryosphere scientists whether the dramatic melting we’ve seen in recent years would have occurred absent the long-term warming trend. If you’re not refuting the volume analysis than I can’t see how you can say focusing on ice volume is “a bit funky” — it’s clearly a more important measure of the system’s ability to recover, which is the central point of this post.]
Betts seems to lack perspective. There are strong trends (such as Arctic sea ice) where variability is not all that important while there are weaker trends where variability has a stronger effect. People will die in heat waves with or without warming so we can only say what the excess deaths are to some extent, not which individual deaths are owing to warming. He does not distinguish these cases all that well. Really, it is all about how distinguishable the trend is. Also, he seems puzzled that reporters check multiple sources. His word ought to be good enough for them. This suggests that he has a perspective problem here as well. Perhaps the problem will clear up eventually.
JR, please stop this abomination! http://www.adn.com/news/politics/fbi/murkowski/story/1088929.html EPA may be the last resort to save our planet and somebody has to prevent this corrupt politician (top recipient of energy/natural resources money for 2010 – $368,946 according to open secrets.org) from impeding their ability to regulate.
Is that the sound of melting ice – or goalposts being moved?
Guess I’ll just watch to see if this amazingly thin ice continues to extend further south again this year.
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
A little “pie in the face” information about the state of Arctic Sea Ice.
The Jan 2010 issue of Cruising World had an article by the first Americans to complete a west to east run of the Northwest Passage in a single season. They said they were one of 11 attempts at the passage in 2009 and that all 11 completed it. These are not ice breakers, but cruisers. In fact, one was a stock production fiberglass sailboat. A direct quote from the article:
“For the most part, we’re sailors, not scientists, but we understand that cruising boats are running the exalted Northwest Passage in record numbers. We also know of so many excellent sailors who tried in the past (pre 2007) on numerous occasions to make this voyage but were turned back by thick, multi-year ice that now is simply no longer there.”
In my view the current CO2 problem is more about “energy imbalance” than the minimal ~0.5 C world average temperature increase and easier to visualize as such.
The current Energy imbalance is measured at ~ 0.5 W/m2 average. Attempts by some of the CP commentators have attempted to grasp that number and we produced numbers with wide “error bars” but not without merit as it is understanding rather than numerical accuracy we are looking for. (More peer review, we like that around here, will no doubt change the numbers but it is clear that we are talking a LOT of energy here.) How much? Our numbers reveal about 35,000 to 60,000+ standard US type W87 NUCLEAR warheads a DAY popping off without radioactive waste to muck the works! or, melting ~ 11 Nimitz class aircraft carriers per second. Every single second of every day. Just as it takes a lot of energy to heat a large pot of water one degree F, it takes a LOT of energy to raise the worlds oceans the measured amount noted by science. And clearly we have a lot at our disposal. Think of the oceans as a large battery that we are “charging.” Just as a charged battery can provide an impressive spark, the stored energy in the oceans can give added energy to storms, or hurricanes. Evaporate more water to fall as rain, floods, even SNOW in the winter. Bend or intensify jet streams to bring “arctic outflow” a bit further south, (Florida, I am talking to you). Shift established weather patterns. And since most of the warming is happening at the poles, Andy, we have perhaps the energy of ~20,000 nukes a day to intensify a seasonal wind to break up long established multi-year ice! And 20,001 tomorrow, 20,002 the next…
Think Global Climatic Disruption!
In the last few years we moved past sea ice extent to sea ice volume. Now, Barber and others tell us that some of that ice is “rotten.” It is time to move forward to “ice mass.”
Now, we take that lesson and apply in to ice sheets that are rotting before our very eyes. This fall, moulins and their associated drainage networks have been marching up the flanks of Greenland. The ice on Greenland is also rotting.
Some stuff to point out:
“…return to the mean trend line,…” – which trends downward more steeply than the concensus of IPCC ice models and certainly shows that global warming is causing severe losses to the perennial ice-covered Artic Ocean.
Large losses of perennial ice cover didn’t occur during periods of strongly positive Arctic Occillations where ice was pumped out of the system by winds. Something big has changed recently.
Old versus new ice does matter. Seals and other ice-dependent wildlife need thick, stable ice; not ice that comes and goes each summer. Much habitat for artic wildlife has already been lost. The arguments here are kind of like the black knight in Monty Python’s Holy Grail sketch (“It’s just a flesh wound!”)
The loss of perennial ice cover is threatening to expose sea surface that sediment studies now show has been covered by ice for well over one million years. Long enough for polar bears and other arctic wildlife to evolve and become dependent upon perennial sea ice. The Arctic ecosystem has already been irretrievably changed and much is being lost.
As a recent study points out: once the Artic Ocean is exposed enough, wave action will churn the waters down to hundreds of feet and bring much more salty and slightly warmer water to the surface meaning much less perennial sea ice.
I disagree with loop the loops. Death spiral is a more apt metaphor due to the wave mixing and other difficult to model physical processes. A positive feedback.
Is the statement from Betts really worth getting upset about? He clearly puts the statement in context, in that the trend is downward. Why is it out-of-bounds to simply note that 2007 was an outlier, when using a commonly used (if somewhat imperfect) measure?
Perhaps area extent isn’t the best metric, and perhaps other metrics don’t show 2007 to be such an outlier. But I’d continue looking at extent, as a part of the big picture.
#8: I understand your concern, but lobbyists, think tank representatives and lawyers assisting in writing bills really isn’t big news. I’d also say that Murkowski has every right to put forward a bill; the big question is whether it will pass. Rejoice, that’s democracy in action!
ps. You really shouldn’t be hijacking threads. ;)
Andy Revkin:
> Joe’s focus on volume versus extent (or area) is a bit funky…
Even a simple, ignorant (not an insult!) and intuitive view of this is puzzling. Exaggeration to demonstrate a point: is a 1cm layer of ice more likely to vanish than a 100m layer of ice?
It seems ludicrous to suggest that a focus on volume is “a bit funky” (whatever that means). The thinner the ice cover, the more susceptible it is to complete melt. How could that not be obvious to anyone?
Also, why put ‘cryosphere scientists’ in quotes? That smacks of Denier-speak – as though they’re not real scientists.
Not impressive.
#15, I apologize, I wasn’t intending to *hijack* a thread! (srsly?) I was just hoping JR would do something along these lines: http://climateprogress.org/2010/01/12/polluters-lisa-murkowski-amendment-to-thwart-epa-endangerment-finding-alaska-warming/
Thank you JR! I will be linking that post in comments to all the Alaska bloggers so you can expect many visits from anti-Palinistas from there as well as all over the world…and there are many.
Bravo. It’s critical to make the connection between the science and politics of climate chaos and what is actually happening in the quotidienne, as it is being felt in places like Alaska, and Australia, and Kenya. If we are to have a prayer that human civilization won’t be destroyed altogether, we must motivate people with the real impacts in order to effect a conversion to clean energy on a monumentally rapid scale.
Oh sorry for the interruption, now let’s get back to rotten ice…
Lief, I LOVE your thinking: “Think of the oceans as a large battery that we are “charging.”” I think you’re scientifically astute!
As a member of Andy Revkin’s “sea ice posse,” I would like to add that we have known for decades that ice volume is a more meaningful measure than extent to assess the health of Arctic (or any) sea ice. Until recently, however, satellites have only been able to provide observations of ice extent and area on a large scale. It is now possible to estimate ice volume from data provided by new satellite sensors, declassified submarine upward-looking sonars, and new methods that estimate ice age, which is related to ice thickness. The emphasis has been on ice extent because for three decades that’s all we had. The new information information tells us that the health of Arctic sea ice is even worse than we thought.
Ice extent is still a highly relevant variable for understanding energy exchange between the ocean and atmosphere, which is the path to understanding mechanisms of change in the ice cover, and how the atmosphere and global climate system will respond to that change.
Good information here. I enjoyed reading this and can’t wait for more. Keep up the good work.