Arctic poised to see record low sea ice volume this year

Ice Volume PIOMAS

UPDATE:  Two commenters pointed me to the Polar Science Center. They look to have the best Arctic ice volume model around — and it’s been validated (see below).  Note:  “Anomalies for each day are calculated relative to the average over the 1979 -2009 period for that day to remove the annual cycle.”

The big Arctic news remains the staggering decline in multiyear ice “” and hence ice volume.  If we get near the Arctic’s sea ice area (or extent) seen in recent years this summer, then this may well mean record low ice volume — the fourth straight year of low volume.  And the latest extent data from the National Snow and Ice Data Center suggests we will:

NSIDC 5-10

Of course, the anti-science crowd — and much of the media — remain stuck in two-dimensional thinking.  So the headlines last month were mostly about how the Arctic ice was supposedly “recovering” to the 1979-2000 average.  Now, it was reasonable to ignore the third dimension — ice thickness — when we didn’t have good data on it.  But now we do, so it is unreasonable to continue focusing on just two dimensions in the Arctic.

Trends in multi-year ice “” ice volume “” are what matter most in terms of the long-term survivability of the Arctic ice in the summer (see New study supports finding that “the amount of [multi-year] sea ice in the northern hemisphere was the lowest on record in 2009″³).  As we’ll see, even when the ice was supposedly recovering in area 2008 and 2009, it was still rapidly shedding the thickest ice — ice older than 2 years.

I noted in March that, contrary to much misreporting, no study has yet been published undermining our understanding that human emissions are the primary cause of the long-term decline in Arctic ice volume “” a decline that shows no sign of reversal (see Study: “It is clear “¦ that the precipitous decline in September sea ice extent in recent years is mainly due to the cumulative loss of multiyear ice,” Physicist: “If temperatures change just a few tenths of a degree then this oh-so-thin ice cap is doomed.”)

I asked NSIDC Research Scientist Walt Meier, “Do you have any indication that there has been a significant recovery of multiyear ice thickness?  Do you have any indication that 2009 didn’t see a record low volume?” [see “The perennial pack ice in the southern Beaufort Sea was not as it appeared in the summer of 2009“].  He replied:

We’re doing some analysis on ice age now — we just received the latest data. So, we can’t too much now, but basically it looks like we’ve continued to lose the oldest (and thickest) ice, but we have gained some of the younger multiyear (2-3 years old) ice. There is still a whole lot of first-year ice though. As for volume, we can’t really quantify exact estimates and haven’t tried to do even rough qualitative estimates. I
don’t know if it would [be] the lowest volume, but it’s certainly far lower than it was in the 1980s and 1990s. This year and the two previous years have been the three lowest volume years, but what order they is harder to say.

So we’ve had record low ice volume for the past 3 years.  And that’s why I say, if we get near the Arctic’s sea ice area (or extent) seen in recent years this summer, then this will likely yield the fourth straight year of record low ice volume.

Here is the ice age analysis that NSIDC published last month:

NSIDC ice age 3-10

As you can see, even when the news stories were about the Arctic ice supposedly “recovering” (in area) in 2008 and 2009, it was still sharply shedding the thickest ice — ice older than 2 years.  We’ve apparently had the tiniest of recoveries in multi-year ice the last few months.  So while this may not exactly constitute a “death spiral,” the trend in ice thickness doesn’t look like a “loop the loop” either.

As a new study that “looked at the latest detailed atmospheric information, modelling and satellite measurements, including warming at different heights from the surface, for the period 1989 to 2008,” finds, “Melting ice makes the Arctic a vicious circle“:

The melting of sea ice in the Arctic has been shown by Australian scientists to be the main cause of unusually rapid warming.

The melting of sea ice in the Arctic has been shown by Australian scientists to be the main cause of unusually rapid warming.

The Nature study, “The central role of diminishing sea ice in recent Arctic temperature amplification” (subs. req’d), concludes:

Here we show that the Arctic warming is strongest at the surface during most of the year and is primarily consistent with reductions in sea ice cover. Changes in cloud cover, in contrast, have not contributed strongly to recent warming. Increases in atmospheric water vapour content, partly in response to reduced sea ice cover, may have enhanced warming in the lower part of the atmosphere during summer and early autumn. We conclude that diminishing sea ice has had a leading role in recent Arctic temperature amplification. The findings reinforce suggestions that strong positive ice-temperature feedbacks have emerged in the Arctic, increasing the chances of further rapid warming and sea ice loss, and will probably affect polar ecosystems, ice-sheet mass balance and human activities in the Arctic.

And that’s especially important since “Permafrost loss has been linked to Arctic sea ice loss.”

The news story explains:  “Dr Screen said white ice reflects a lot of sunlight, but as it melts due to man-made warming from greenhouse gas emissions, the dark water that is exposed absorbs more heat, which in turn, melts more ice, and so on.”  Actually, there are more amplifying feedbacks involved (see “What exactly is polar amplification and why does it matter?).

The story ends:

The amount of Arctic sea ice was at a record low in the summer of 2007, down about 40 per cent.

Although it has recovered slightly since, the long-term trend is down, he said. “We’re heading towards a situation where the Arctic Sea will be ice-free in summer.”

Yes, well, even the Sydney Morning Herald doesn’t quite get the story right, since “amount” would tend to suggest volume, not area.

As an aside, how hot has it been in the Arctic this spring?  Reuters reported two weeks ago:

In what looks to be another sign the Arctic is heating up quickly, British explorers in Canada’s Far North reported on Tuesday that they had been hit by a three-minute rain shower over the weekend.

The rain fell on the team’s ice base off Ellef Rignes island, about 3,900 km (2,420 miles) north of the Canadian capital, Ottawa.

“It’s definitely a shocker … the general feeling within the polar community is that rainfall in the high Canadian Arctic in April is a freak event,” said Pen Hadow, the team’s expedition director.

Anecdotes aside, the ice cap is apparently doomed “” and the overwhelming majority of CP readers will probably live to see an ice free summer Arctic.  Here is an earlier figure of mean monthly Ice Volume for the Arctic Ocean from a release by several scientific institutions:

You can compare it with the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) from the PSC at top.  The PSC notes:

PIOMAS has been extensively validated through comparisons with observations from US-Navy submarines, moorings, and satellites. The example on the left [click here]  shows a comparison of PIOMAS-derived ice volume anomalies with anomalies measured by the NASA ICEsat Satellite.

It looks like 2009 was below 2008 volume levels.  The PSC model suggests 2010 is on track for the record.  As the NSIDC reported last week:

An image from NASA’s Advanced Microwave Scanning Radiometer — Earth Observing System (AMSR-E) sensor from April 19 reveals numerous polynyas, or areas of open water in the pack ice in the Bering Sea, and broad areas of more scattered ice cover in the Sea of Okhotsk, Barents Sea, and Hudson Bay. Such conditions usually indicate that ice is about to retreat rapidly.

And guess what, that appears to be happening now, according to the NSIDC data reported in the top figure.  Stay tuned.

I still like my odds on a 90% ice free Arctic by 2020 (see “Another big climate bet “” Of Ice and Men“).


40 Responses to Arctic poised to see record low sea ice volume this year

  1. Mark Shapiro says:

    FWIW I’ll guess right here and now that we’ll see record low sea ice extent and area this September, and virtually ice-free Septembers as early as 2013. Constantly rising CO2, generally increasing temperatures, more soot from China lowering albedo, and dramatic losses in multiyear ice are all pushing us towards an ice-free arctic..

    Anyway, we can all watch ice melt daily on the NSIDC website and on the UIUC Cryosphere Today site, with its great anomaly charts (though it’s down today).

    On the subject of guesses though, I am now out of your “when will oil hit $100/barrel again” lottery. Delighted to be wrong about that one!

  2. Speedy says:

    More bad news from
    “At the same time, changing wind patterns have caused older, thicker ice to move south along Greenland’s east coast, where it will likely melt during the summer.”

  3. Wonhyo says:

    The plot shows Arctic area with at least 15% ice coverage. If thin ice sheets break up a small area of 100% ice coverage can easily expand to a much larger area of 15% coverage. I suspect this may be part of the reason 15% ice area temporarily increased (relative to the multiyear trend) in the last few months.

    It was only 2-3 years ago that 2015 was thought to be the earliest year for an ice free Arctic summer. Now the expected timeframe is 2012-2016. If previous performance in prediction accuracy is any indicator of future performance, we should consider 2012 to be the latest possible year for the start of ice free summers.

    If our society is going to deal effectively with climate change, we have to be more honest with our expectations. Otherwise, every new climate related disaster will be one we’re unprepared for.

    [JR: My big bet is for 2020. I’ll repost it.]

  4. dhogaza says:

    The plot shows Arctic area with at least 15% ice coverage. If thin ice sheets break up a small area of 100% ice coverage can easily expand to a much larger area of 15% coverage. I suspect this may be part of the reason 15% ice area temporarily increased (relative to the multiyear trend) in the last few months.

    It was cold north of alaska and the persistence of that ice later than we’ve seen in recent years is real. It’s been counterbalanced by ice melting more rapidly on the other side of the arctic.

    However, that persistent ice that’s hanging on longer than typical will all melt, and quite soon, and has been doing so fairly rapidly the last couple of weeks, which is why I think the extent has been somewhat rapidly plunging recently.

    JAXA shows the pace slowing a bit the last couple of days … I think the story will be boring for several weeks, because it’s mid-summer when the race gets hot. As speedy pointed out with his snippet from the NSIDC site, things aren’t looking good regarding old ice and therefore volume.

    My own WAG is that extent will be lower than 2009 this year, but not as low as 2007. But at this point, all you can do is guess. Wind, temps, etc in mid-June through mid-September will settle things.

  5. MarkB says:

    The denier focus on sea ice extent isn’t a good political strategy in the long-run, although they’ll be on to their next short-term trend by then (there’s always cold weather somewhere). Astute observers might already note that the extent is retreating rapidly at present – now near the 2007 path. It seems unlikely that any natural variation can stop (for very long) the combination of anthropogenic-driven factors in the Arctic – being GHGs (even more influence in higher latitutes), black carbon, and further feedback from melting sea ice.

  6. Wit's End says:

    The stamina and dedication of scientists conducting research in the arctic is humbling! video:

  7. Wonhyo says:

    Dhogaza #4: After taking a closer look at the ice volume graph, I do see that the downward trend leveled off in the last two years, which means summer ice will likely remain beyond 2012, barring a sudden downturn. Is there any known reason for increased ice in the Alaskan Arctic with decereases on the other side? Is this leveling off part of a short term cyclic trend? If so, how long will it be before we should expect the next downturn?

    JR: Do you still stand by your 2020 prediction? I think that’s optimistic but not unreasonable. I’ll revise my expectation back to 2012-2020 for seasonally ice free Arctic.

    Off topic: I heard a report on my local NPR station the the Gulf oil gush rate estimate has been revised upward to 70,000 barrels/day, based on analysis of undersea video. Note that this is the video that BP withheld from the public until recent days, and that BP gave an upper limit estimate of 60,000 bpd in their closed door testimony to Congress. Does anybody get the feeling BP has been lowballing their leak rate estimate all along? BTW mainstream media hasn’t picked up the 70,000 bpd revision, yet.

  8. Doug Bostrom says:

    I believe I mentioned it here before, but it’s fun (for some of us, anyway) to run numbers on increased Arctic energy absorption strictly thanks to loss of albedo. An almost unbelievable number of extra terawatts are sinking into the Arctic Ocean on a sunny August or September day, many times our total electrical generation capacity.

    How rapidly can winter add ice cubes to our giant experimental tea kettle? Not fast enough, apparently.

  9. Dan R says:

    Is it worth showing a graph of Arctic sea-ive volume anomaly?

  10. Michael says:

    The ice volume graph posted above only goes through 2004; more recent estimates are now available here (NSIDC mentions it at the end). They say that ice volume for March 2010 was the lowest on record – and also for September 2009. Plus a semi-regularly updated graph, current through April 30.

    Incidentally, I was wondering when it would be mentioned (I was just looking at this old post).

    Also, this is my first post here, but I am a regular reader.

  11. PeterW says:

    Hi Joe,

    By the look of the first year ice it seems we could have 50% of the Arctic Ocean open this year on the Siberian side. Does it really matter that the whole ocean isn’t open yet. Isn’t this enough to really kick start the positive feedback in the North?

    Reading this I’m reminded of your post about the “Vast East Siberian methane stores destabilizing and venting”. Isn’t this guaranteed with a open Arctic Ocean? And therefore we are guaranteed a catastrophic release of CO2 and methane that pretty well ends the game?

    How on earth can you put this genie back in the bottle? Shouldn’t we be scared to death that this is about to happen?

  12. Aaron Lewis says:

    Some of that “multi-year ice” is really multi-year slush without much strength.

  13. Jeff Huggins says:

    NOTE (please)

    ExxonMobil just announced that its Annual Meeting of Shareholders will be held on Wednesday, May 26, in Dallas.

    In “honor” of the occasion, and in preparation for it, I’d like to offer to do a guest post (this weekend or very early next week) to help people here, and perhaps even some ExxonMobil shareholders, and perhaps even some ExxonMobil Board Members, face and come to grips with some of the “stories” that key ExxonMobil stats and quotes can tell us, if we care to pay attention to them. In other words, let’s look at a few stats and quotes that can help us “understand” ExxonMobil in important ways.

    The Annual Meeting will occur in less than two weeks from today. Media organizations are supposed to contact ExxonMobil (see their website), in the next several days, to reserve a place. CAP, can you send someone?

    Anyhow, I think people need to “get smart” about this company, and now would seem to be a good time.

    Be Well,


  14. jyyh says:

    If there’s someone wondering how “a slight recovery in multiyear ice” can speed up the loss, it’s in scattered shatters (ref to Caitlin survey) and thereby exposes the flanks of the individual floes to atmosphere and sun.

  15. Andy says:

    RE: Wonhyo: The 70,000 barrel/day estimate was discussed on NPR (which broke the story) and was also discussed on the evening news. The question is how much of that volume was gas and how much oil? I think the researchers involved in these estimates didn’t have that information and therefore simply gave total volume estimates. I think this coverage will finally get BP to share additional information or perhaps try a little harder to come up with their own estimate. They’ve been insisting along with the Coast Guard that it was impossible to measure. Why the Coasties would take this tack is impossible for me to fathom. At any rate, it brings up the possibility that a lot of this oil isn’t reaching the surface….yet. I predict the Gulf will be burping up tar balls for many years to come from all of this.

  16. Mark Shapiro says:

    Looking at the PSC ice volume anomaly graph above, we’ve melted about 5,000 km3 over the last 4 years alone (plus about 1,000 km3 from the Greenland and Antarctic ice sheets in that time).

    Is that enough latent heat to account for some of the missing heat that Kevin Trenberth had been looking for recently?

  17. Andy says:

    The low spots in the ice volume graph are mostly end of summer measurements when melt has reached its greatest point. This year has already almost equaled the lowest volumes recorded in 2007, 2008 and 2009 and will surely drop much below them as the majority of the melt season lies ahead yet. I see nothing to indicate this won’t be a record low year for ice aerial extent as well as volume. “Death Spiral” it is then.

  18. Andy says:

    Sorry to remain OT but this is cut from a just published (on-line) NY Times story on the 70,000 barrel/day estimate “….Dr. Lubchenco, the NOAA administrator. “Having greater precision about the flow rate would not really help in any way.”

    This is extremely troubling. Either Dr. Lubchenco doesn’t understand how her agency makes damage assessments to bill oil companies for spills, or something fishy is going on here. Damage assessment models that determine harm to the plankton and other pelagic communities requires a spill volume estimate. These can end up as the largest portion of the total damage estimate (lots of $$$).

  19. jyyh says:

    Mark, I haven’t done calculation. Add to that, some of the heat might enter the cores of the ice sheets through the crevasses and ice caves/pores formed during the previous melting season in the spring-early summer. And the reference was Catlin Arctic Survey (not Caitlin). (How long it takes to read correctly?)

  20. Andy says:

    RE: my comment at #18 – oops, I see the graph from the Polar Science Center is anomoly; not total volume. Still, this year is exceptional and if the winds continue to pump the ice out as now, then it looks to reach a record low volume in September.

  21. Richard Brenne says:

    Great post, great data, great graphs, great comments. . .

    Joe, you’re right (and commenters are right as well) to focus on 90% loss of sea ice, because that’s obviously the vast majority and the lack of ice albedo is the huge positive feedback we’re all most concerned about.

    It’s the same with glaciers melting – the last 10% is typically the hardest to melt as mountain glacier retreat up to the highest altitudes where addition snowfall can be accumulating (on the summit of Mt. Shasta for instance) as temperatures warm closer toward freezing when snowfall can be much heavier than at colder temperatures.

    Also the headwalls are often shading glaciers on north facing slopes making complete melting take a lot longer than up to 90% of melting.

    As with sea ice disappearing, what matters most is volume – in glacier melt this is the key, not so much the terminus or area – because that will lower the baseline of melting and stream and river flows throughout the driest months.

    So I’d recommend we all use the 90% figure as a benchmark rather than complete disappearance, which is less easily achieved and really not as important as losing the vast majority of ice. And doing so by 2020 seems quite realistic.

    As always, good analysis and communication, Joe. You must be a physicist or something. . .

  22. GFW says:

    Mark, jyyh,

    Let’s see, 5000 km3 of ice is about … 4.5 x 10^18 grams of ice. So that’s about 1.5 x 10^21 joules (over 4 years). According to SkepticalScience, Trenberth is already counting sea ice for 1 x 10^20 J/y, so our figure is only 4 times his.

    But the “missing” heat is between 3 x 10^21 J/y and 1 x 10^22 J/y. Assuming the low end of the missing heat, this greater estimate of sea ice melt still only accounts for 1/10 of the missing heat.

    So, it might be part of an answer, but not a big part. OTOH, if the higher estimate of arctic sea ice melt is correct, it implies a mechanism (warmer water melting the ice) and there aren’t a lot of ARGO buoys in the arctic. So some of the the missing heat could be at various depths in the arctic ocean. In other words, if he underestimated the amount of ice melt he *may* have underestimated the increase in ocean heat content in the arctic, which is less sampled than most of the oceans.

    If that is the case, he’s probably on top of getting better estimates.

  23. _Flin_ says:

    Very Interesting. Does anybody know when there will be data from Cryosat-2? Commissioning phase of 6 months, so we can expect data around October and the first papers in the middle of next year?

  24. FredT34 says:

    The russian maps are worth watching regularly, too.

    Also, this figure from Ignatius Rigor’s site is useful to remember how the ice extent and thickness looked like in 1987: We’re far away from any “recovery” !

  25. Here is an excellent paper regarding predicting sea ice extent:

    It shows that decreasing ice thickness is making it harder to forecast the next season’s extent.

    I found this statement most revealing:

    …these results suggest that regardless of the sea ice regime, prognostic potential predictability is generally significant for the first and second winters, ice area during the spring transition season shows less predictability, and summer ice area has potential predictability with a 9-month lead time.

    Scott A. Mandia, Professor of Physical Sciences
    Selden, NY
    My Global Warming Blog

  26. Bob Wallace says:

    Another site giving daily extent updates. Includes lines for the previous three years, 1979-2006 average plus the one standard deviation band.

  27. Lewis Cleverdon says:

    Given that we seem near certain to have near ice-free conditions on the arctic sea in summer this decade,
    and given the multiple other feedbacks with which this will interact more strongly than at present (for all any public awareness of this is pretty hazy)
    it seems vital to transpose the ice-loss phenomena into a measure that is accessible to the layman if its importance is to be understood by politicians, industrialists, journalists and the public.

    Additional forcing in terms of watts-per-square-metre is the scientific measure of course, but it’s not used or comprehended much outside the scientific community.

    So I’m hoping that it may be possible to present the impacts of the loss of ice cover as a matter of GTCO2e/yr (gigatonnes-of-CO2-equivalent-per-year), which measure could be readily understood by all and sundry. It would provide a simple measure for assessing just how far this feedback alone has advanced toward the critical threshold of exceeding the natural carbon sinks, after which our options for mitigation seem tenuous at best.

    The sole benefit of the evident acceleration of this albido-loss feedback is that its scale is plain enough to nail the delusion that we can resolve the global warming issue solely by ending GHG emissions and by geo-engineering in the form of carbon recovery via native afforestation.

    From this perspective, it would seem that the critical advance is now the discussion of:
    just what is the requisite global governance for any field trials of albido enhancement techniques to be justifiable,
    and how its operation should be integrated with the global treaty to end GHG emissions ?



  28. Mark Shapiro says:


    Thanks for the data and calculations. As you note, in addition to the latent heat, the rising temperature of the remaining ice and the water could mean heat content that hasn’t been measured yet.

  29. John McCormick says:

    I do not think Ray Welch would object to my copying his March 22 comment on an earlier Arctic ice melt piece. He definitely raises the central question: are we going to soon experience an abarupt climate change?

    Ray Welch says:
    March 23, 2010 at 11:25 pm
    What will happen to the weather when the ice cap collapses, and the Arctic inverts from heat reflector to heat sink? What will happen to the seasonal highs and lows that are driven by seasonal temperature gradients? What will happen to the jet stream? What will happen to the methane-laden tundra that surrounds the Arctic Ocean? No one knows, but here’s my guess: we won’t like it.

    Is not the disappearance of the ice cap the trigger of abrupt climate change to fear most? Is this not a cause for great urgency?

  30. prokaryote says:

    Science stunner: Vast East Siberian Arctic Shelf methane stores destabilizing and venting
    NSF issues world a wake-up call: “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.”

    No climate model currently incorporates the amplifying feedback from methane released by a defrosting tundra.

    The new Science study, led by University of Alaska’s International Arctic Research Centre and the Russian Academy of Sciences, is “Extensive Methane Venting to the Atmosphere from Sediments of the East Siberian Arctic Shelf” (subs. req’d). The must-read National Science Foundation press release (click here), warns “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.” The NSF is normally a very staid organization. If they are worried, everybody should be.

    It is increasingly clear that if the world strays significantly above 450 ppm atmospheric concentrations of carbon dioxide for any length of time, we will find it unimaginably difficult to stop short of 800 to 1000 ppm.

  31. Lewis Cleverdon says:

    Prokaryote –

    “It is increasingly clear that if the world strays significantly above 450 ppm atmospheric concentrations of carbon dioxide for any length of time, we will find it unimaginably difficult to stop short of 800 to 1000 ppm.”

    I wonder if it is correct to give the threshold figure as 450 ppmv. Given the fact that, due to the ~35-yr timelag on GHGs’ warming impacts, the acceleration of the interactive feedbacks that we now observe is driven by warming off 330 ppmv of CO2 in 1975, I rather doubt that 450 ppmv would be a viable peak.

    Even staying at 400 ppmv for any length of time is looking pretty dodgy. Consider a scenario of 400 ppmv reached in 2015, and then 15 years of plateau while a global forestry program takes hold, i.e. by 2030, followed by the 35 years of time lag. This scenario implies anthro-warming rising for 5+35 years, i.e. until 2050, and then holding steady until 2065.

    The prospect of the feedbacks taking anything like as long as that to exceed the remaining carbon sinks, especially with 55 years of additional anthro-warming, looks to me pretty remote.

    Seems like “It’s later than we think . . .”



  32. Greg Robie says:

    Thrice this year on Twitter I miss-called the start of the melt season in the Arctic. But I was only somewhat wrong. The extended ice formation this year happened in the Bering Sea and the Sea of Okhotsk. To the degree the winds at 300 MB indicate surface winds, sea ice was blown on shore through March and early April. From what I observed, the ice extent pretty much stopped growing mid-February in the Arctic Ocean. The extreme Arctic Oscillation’s effect withstanding, it was the Gulf Stream (i.e. the lack of its traditional influence on the Jet Stream) that riveted my attention this winter. The Polar Jet circulated unimpeded around the globe—across Mexico, Florida, on to Morocco and then to India in a pattern I have never seen before. The Ferrel Cell was basically subsumed by the Polar Cell. This made the US south really cold while it rained in Greenland.

    The referenced polynyas have since filled in, but their existence—and when they turned up—along with the experiences of the Catlin Survey trekkers suggest that the thinner ice can move around more (as speculated by Wonhyo in #3). I assume having the ice necessary to land a plane on and take them off the north pole was a consideration for their final all nighter. Last year’s expedition was cut short, in part, due to concerns regarding safe ice issues for the extracting plane. The Arctic has changed and is changing.

    The current slope of the curve of the melt approximates what occurs in June. This is not unprecedented but it could indicate that the freezing season ended for the Arctic Ocean as much as 4-6 weeks “early.” While the current steep decline in the extent is the loss of March and April’s ice from the Bering Sea and Sea of Okhotsk, the ice cap is rapidly thinning out over the eastern reaches of the Siberian continental shelf heralding another record melt year. As noted, there were some cold temperatures in the Arctic this winter, I do not think that will translate into such having caused the usual volume of ice to be created. From watching the melt for a couple of seasons now, I expect to see the extent to easily break the 4 million sqKM mark this year . . . and flirt with the 3 million sqKM level.

  33. mike roddy says:

    To Peter W, and to Joe and the excellent commenters who followed up:

    Has anyone developed equations to calculate the relationship between Arctic sea ice loss, albedo, and effects on Arctic shelf methane releases, or are these ratios unknown?

  34. Greg Robie says:

    Mike #34,

    What I’ve read indicates that the relationship among ice loss, albedo and the warming of the clathrate permafrost cap on the ESAS are among the know unknowns. An initial unknown is are the releases studied in 2008 a ‘normal’ event. While such a question is a good one to ask, I’ve read that the temperature of the continental shelf permafrost is between -1 and -1.5 degrees C. I do not remember how dated this temperature assessment is (BTW, and for comparison, the permafrost on land is -12 degrees C.) Anyway, I believe it was a Scientific American article I read that reported on heat transfer dynamics in the ocean (other than through macro currents) is accomplished through 10M thick thermosyphoning micro-currents. I do not remember the rate of heat transfer these provided, but it wasn’t too fast. To the degree these thermosypnones are at work in the Arctic, heat from solar incidence is working its way down. The amount of heat being transfered is increasing with longer and greater losses of summer ice. This dynamic means that there will be a time delay between the tipping point being effected due to heat gain and the observed destabilization of the methane hydrates under the permafrost/former permafrost cap.

    Both the weather and the types of clouds are changing in the Arctic, so while the albedo values are being determined primarily by the sea ice loss, they are also effected by these factors. Expansion of the boreal forest fauna into the Arctic tundra—primarily following fires—is also effecting albedo. Also, atmospheric methane concentrations fluctuate seasonally by about 50 ppb (being higher in winter and slowing heat loss). According to a study published in January by the School of GeoSciences at the University of Edinburgh, 30% of the renewed increase in atmospheric methane is originating in the high northern latitudes; within the Polar Cell. As the atmospheric methane level has been rising, it seems reasonable to conclude that the winter cooling has been slowing and, consequently, everything warming. Perhaps CH4 will come to be understood as a key force driving the warming trend in the Arctic.

    With methane—among other feedbacks—left out of the calculations, five years ago an ice free Arctic was being modeled to occur 80-100 years from then. Detonation of the methane time bomb was a future event that was at least 200 years distant. Making ratios out of these predictions relative to current observations is something that can be done. While such does little to lessen the known unknowns, it does point out how big the unknown unknowns are.

    Today I revisited Real Climate’s March discussion of the ESAS methane releases asserting CO2 was the GHG to focus on. The EPA’s contracted paper on methane and nitrous oxide emissions from natural sources, published in April, does not cover the ESAS releases. According to the science it compiles, methane hydrates are expected to destabilize slowly and over long time spans with the methane being absorbed in the water column. It seems the reason the question about whether the releases are normal occurs quickly to knowledgeable people because due to what is known what is being observed cannot be happening . . . yet. I have to wonder if what is unknown is proportional to the trust affords to what one knows.

  35. Greg Robie says:

    AM reading of previous post catches two obvious errors: fauna should be flora; affords should be afforded.

    If anyone is interested in links to what I have referenced in my comments, please ask. I can be reached through contact links at my linked website, and will check back here to the comment section of this blog post for a few days.

  36. prokaryote says:

    32, ” I wonder if it is correct to give the threshold figure as 450 ppmv. Given the fact that, due to the ~35-yr timelag on GHGs’ warming impacts, the acceleration of the interactive feedbacks that we now observe is driven by warming off 330 ppmv of CO2 in 1975, I rather doubt that 450 ppmv would be a viable peak. ”

    This remark it the mainstream opinion – if you ask me we need 280 ppm.
    If you want a major wake up call, see ( This is the single most importent finding! ) And every branch of society should adopt or the planet will become our enemy.

    – You would have to go back at least 15 million years to find carbon dioxide levels on Earth as high as they are today, a UCLA scientist and colleagues report Oct. 8 in the online edition of the journal Science.

    “The last time carbon dioxide levels were apparently as high as they are today — and were sustained at those levels — global temperatures were 5 to 10 degrees Fahrenheit higher than they are today, the sea level was approximately 75 to 120 feet higher than today, there was no permanent sea ice cap in the Arctic and very little ice on Antarctica and Greenland

    “Carbon dioxide is a potent greenhouse gas, and geological observations that we now have for the last 20 million years lend strong support to the idea that carbon dioxide is an important agent for driving climate change throughout Earth’s history,”

    Levels of carbon dioxide have varied only between 180 and 300 parts per million over the last 800,000 years — until recent decades, said Tripati, who is also a member of UCLA’s Institute of Geophysics and Planetary Physics. It has been known that modern-day levels of carbon dioxide are unprecedented over the last 800,000 years, but the finding that modern levels have not been reached in the last 15 million years is new.

    Prior to the Industrial Revolution of the late 19th and early 20th centuries, the carbon dioxide level was about 280 parts per million, Tripati said. That figure had changed very little over the previous 1,000 years. But since the Industrial Revolution, the carbon dioxide level has been rising and is likely to soar unless action is taken to reverse the trend, Tripati said.

    “During the Middle Miocene (the time period approximately 14 to 20 million years ago), carbon dioxide levels were sustained at about 400 parts per million, which is about where we are today,” Tripati said. “Globally, temperatures were 5 to 10 degrees Fahrenheit warmer, a huge amount.”

    Tripati’s new chemical technique has an average uncertainty rate of only 14 parts per million.

    “We can now have confidence in making statements about how carbon dioxide has varied throughout history,” Tripati said.

    In the last 20 million years, key features of the climate record include the sudden appearance of ice on Antarctica about 14 million years ago and a rise in sea level of approximately 75 to 120 feet.

    “We have shown that this dramatic rise in sea level is associated with an increase in carbon dioxide levels of about 100 parts per million, a huge change,” Tripati said. “This record is the first evidence that carbon dioxide may be linked with environmental changes, such as changes in the terrestrial ecosystem, distribution of ice, sea level and monsoon intensity.”

  37. Lewis Cleverdon says:

    Prokaryote – Agreed. 280 ppmv is the rational goal. At issue is the means used to achieve that end, given the realities of:

    – the current worldwide aspirations to maintaining or raising energy supply;
    – the minor and unreliable effect of the carbon sinks in recovering airborne carbon;
    – the many decades needed for a global native afforestation program to achieve over 120 ppmv CO2 of carbon recovery;
    – and the action of the interactive feedbacks in the interim as time-lagged warming takes effect.

    I wonder how many here may agree that the first two “Windows of Opportunity for Precaution”, being the rapid ending of anthro-GHG outputs [WOP1] and the gigahectare of native afforestation optimized for carbon recovery [WOP2] are no longer remotely sufficient to control the feedback outputs and restore 280 ppmv, for all they are utterly necessary components in fulfilling the task ?

    Where that logic is accepted, the additional deployment of the most sustainable means of albido enhancement [WOP3], to reduce the warming in the interim and thereby decelerate the feedbacks, becomes rational as the sufficient complement for the task’s achievement.

    If anyone can propose a viable alternative strategy, I’d very much like to hear of it.



  38. Jim Simpson says:

    As a non scientist but one who’s keen to gain a better understanding of the pros & cons of the Global Warming/Climate Change debate, I found the above exchanges regarding future loss of Artic ice most interesting & informative. Thank you.

    However, I seem to recall when I was at school in Australia (more than 50 years ago now I’m sad to admit) that there were times in the not too distant past (the late 1800’s, early 1900’s I recall which seems only yesterday in the overall geological scheme of things relative to this particular subject) when there were past instances of significantly less Artic ice such that even the much sought after North West Passage was said to have been navigatable by ocean going vessels. True or not ?

    If true, could some one please help me understand why the repeat of such an event either now, or in the future should be considered exceptional? Infrequent perhaps, but I would not have thought exceptional.

    Presumably levels of greenhouse gasses (eg CO2) were markedly lower then (true?).

    If so, and in the absence on those occasions of (I assume) higher levels of CO2 V’s today, what then triggered the reduction in Artic ice coverage & might it not be also be related to your current Artic ice observations?

  39. prokaryote says:

    ” -I wonder how many here may agree that the first two “Windows of Opportunity for Precaution”, being the rapid ending of anthro-GHG outputs [WOP1] and the gigahectare of native afforestation optimized for carbon recovery [WOP2] are no longer remotely sufficient to control the feedback outputs and restore 280 ppmv, for all they are utterly necessary components in fulfilling the task ?”

    A question about how fast measures can be scaled. It seems we will see the worst case scenarios ( ) unfold, because people decide not to listen to the warning.

    How sensitive is the human organism to climate change?

    A change in climate causes rapid evolution of multiple life-history traits and their interactions in an annual plant.

    Climate change is likely to spur rapid evolution, potentially altering integrated suites of life-history traits. We examined evolutionary change in multiple life-history traits of the annual plant Brassica rapa collected before and after a recent 5-year drought in southern California. We used a direct approach to examining evolutionary change by comparing ancestors and descendants. Collections were made from two populations varying in average soil moisture levels, and lines propagated from the collected seeds were grown in a greenhouse and experimentally subjected to conditions simulating either drought (short growing season) or high precipitation (long growing season) years. Comparing ancestors and descendants, we found that the drought caused many changes in life-history traits, including a shift to earlier flowering, longer duration of flowering, reduced peak flowering and greater skew of the flowering schedule. Descendants had thinner stems and fewer leaf nodes at the time of flowering than ancestors, indicating that the drought selected for plants that flowered at a smaller size and earlier ontogenetic stage rather than selecting for plants to develop more rapidly. Thus, there was not evidence for absolute developmental constraints to flowering time evolution. Common principal component analyses showed substantial differences in the matrix of trait covariances both between short and long growing season treatments and between populations. Although the covariances matrices were generally similar between ancestors and descendants, there was evidence for complex evolutionary changes in the relationships among the traits, and these changes depended on the population and treatment. These results show that a full appreciation of the impacts of global change on phenotypic evolution will entail an understanding of how changes in climatic conditions affect trait values and the structure of relationships among traits.