When records were being set for loss of summer Arctic sea ice area (2007) and sea ice volume (2008), the deniers spent all their time talking about how quickly the ice refroze in the ensuing months. Now, they are strangely quiet on the remarkably slow refreezing we’re seeing.
Why the slow refreezing this year? I’ll post the answer from the National Snow and Ice Data Center at the end. First, some background.
“The recent sea-ice retreat is larger than in any of the (19) IPCC [climate] models,” as Tore Furevik, Vice director at Bjerknes Centre for Climate Research, pointed out in a May 2006 talk (big PPT here) on climate system feedbacks.
And that was before another staggering drop in Arctic sea-ice area in 2007 (see “Arctic Ice shrinks by an Alaska plus a Texas“).
And then we hit a record low volume in 2008 (see here), as this remarkable figure shows:
Then we saw some recovery in 2008 to the third lowest area on record, and, I expect, the second lowest volume. The Arctic ice loss is not monotonic, but reflects an overall warming trend and local weather conditions.
“What drove the dramatic retreat of arctic sea ice during summer 2007” is the title of a GRL analysis published last year. It found:
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. During summer 2007 atmospheric changes strengthened the transpolar drift of sea ice, causing more ice to move out of the Pacific sector and the central Arctic Ocean where the reduction in ice thickness due to ice advection is up to 1.5 m more than usual. Some of the ice exited Fram Strait and some piled up in part of the Canada Basin and along the coast of northern Greenland, leaving behind an unusually large area of thin ice and open water. Thin ice and open water allow more surface solar heating because of a much reduced surface albedo, leading to amplified ice melting. The Arctic Ocean lost additional 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.
And so the warming-driven thinning makes the Arctic much more vulnerable to local weather conditions.
What to make of the recent slow refreezing? I put that question to NSIDC, and Research Scientist Walt Meier replied:
I think the lesson is to not make too much from only a few data points. There is significant natural variability in the climate system, and particularly the sea ice. It is only by looking at long-term trends, after the short-term variability is averaged out, that you can make any judgments on long-term climate factors. It is particularly unjustified to draw any conclusions about sea ice from only a few days or weeks.
In the short term, winds can play an important role in the sea ice extent. If there are winds pushing the ice edge “inward”, then you either increase the seasonal decline or slow (or even temporarily reverse) the seasonal increase, depending on the season. The slow-down in the increase in October was due to winds blowing the ice northward from the Siberian coast. It looks like there is another slowdown, also likely due to winds.
What about NSIDC director’s Mark Serreze “death spiral” of Arctic ice metaphor? I noted that the NYT’s Revkin has written recently:
Meier writes:
Andy Revkin’s comment is quite apt. We don’t expect to see a continual downward trend, there will some fits and starts, but the overall trend will continue to be down.
Serreze wrote me that “I share Walt’s views.”
Finally, we have the Met Office’s recent statement, which the deniers are trumpeting:
Modelling of Arctic sea ice by the Met Office Hadley Centre climate model shows that ice invariably recovers from extreme events, and that the long-term trend of reduction is robust — with the first ice-free summer expected to occur between 2060 and 2080. It is unlikely that the Arctic will experience ice-free summers by 2020.
Analysis of the 2007 summer sea-ice minimum has subsequently shown that this was due, in part, to unusual weather patterns. Arctic weather systems are highly variable year-on-year and the prevailing winds can enhance, or oppose, the southward flow of ice into the Atlantic. Consequently, the sea ice has not declined every year, but has shown considerable variability — both in extent and thickness.
The high variability has made it difficult to attribute the observed trend to man-made emissions of greenhouse gases, although there is now enough data to detect a human signal in the 30-year trend. The trend and observed variability, including the minimum extent observed in 2007, is consistent with climate modelling from the Met Office.
About half of the climate models involved in the Intergovernmental Panel on Climate Change fourth assessment report, show that ice declines in steps — failing to recover from extreme years. The observed temporary recovery from the 2007 minimum in 2008 and 2009 indicates that the Arctic ice has not yet reached a tipping point, if such exists. We expect Arctic ice to continue to decline in line with increasing global temperatures. If the rate of global temperature rise increases then so will the rate of Arctic sea-ice decline.
First, how disappointing that the Met Office appears unaware of the analysis showing that the Arctic did not experience a “recovery” from 2007 to 2008, unless losing 2000 cubic kilometers of sea ice is a recovery.
Serreze responds:
I agree with the Met Office that going seasonally ice free by 2020 is unlikely. I still think were looking at somewhere around 2030.
He makes one final point:
One thing we need to come to some agreement on is what we call “ice free.” Do we mean no ice at all in mid September or something like less than 1 million square km? “Ice free” is one of these terms like “tipping point” that tends to get tossed around without being all that well defined. I’m guilty of this myself.
I’m also moving towards the view that the bigger issue is not the when we go ice free, for we seem destined to do so, but the ecological and climatic implications of losing the ice.
I’d certainly second that last point, especially since the major climatic implication is accelerated warming of the carbon-rich permafrost (see here).
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The link to the presentation showing Arctic sea ice extent declining faster than IPCC model predictions appears to be broken. It’s missing a “t” in the extension.
http://www.arcus.org/ annual_meetings/ 2006/ downloads/ presentations/ af_thursday/ panel1/ 4_0215pm-Tore_Furevik.ppt
[JR: Yes, thanks, I've fixed it.]
Walt Meier has the appropriate perspective on short-term data points. This post helps observers note how so-called “skeptics” selectively cherry-pick short-term data to support pre-determined views and ignore inconvenient data and of course long-term trends. They argue like lawyers.
What I like about this post is that Joe isn’t making some naive knee-jerk reaction based on this data, as we see in global warming denial circles. Instead, he’s seeking expert advice on what the data implies.
The longer the we have before an ice free Summer Arctic the better…however I think the Met’s 2060-2080 estimate seems way too optimistic…I’d love it if it took that long, but I don’t think we’ll have nearly that long.
Joe you still thinking an ice free Arctic happening by 2020? Just wondering what your opinion was at this point.
This slow regrowth has been striking. The lack of sea ice in the Eastern Barents andin Kara Sea is remarkable. Novaya Zemyla is still mostly ice free. http://arctic.atmos.uiuc.edu/ cryosphere/ NEWIMAGES/ arctic.seaice.color.000.png
SST in the Kara Sea are also very warm as yet, suggesting sea ice will remain slow to form here.
http://www.osdpd.noaa.gov/ data/ sst/ anomaly/ 2009/ anomnight.10.22.2009.gif
Granted that one shouldn’t make too much of short-term data points. However, if the short-term trend of ice coverage does go below the record lows of the 2007 data in the next few weeks or months, it’s certainly worth noting and something that the popular media – maybe even Fox? – will probably report.
El Nino
How does El Nino affect sea ice? I thought there was a lag of a couple years between ENSO and Arctic temps?
The El Nino-Arctic Sea ice connection has not been identified as a strong one
“Finally, and perhaps, most importantly, NPO/WP is strongly linked to marginal ice zone variability of the
Arctic seas with an influence that surpasses that of other Pacific modes. Although NPO/WP variability and
impacts have not been as extensively analyzed as its Pacific cousins (PNA, ENSO), it is shown to be more
consequential for Arctic sea ice and North American winter hydroclimate.”
from: http://www.atmos.umd.edu/ ~nigam/ Linkin-Nigam.JCLIM.May.2008.pdf
In most Arctic Sea Ice papers ENSO is not raised.
This NSIDC graph should be updated to yesterday’s situation soon. Will it be yesterday or today that the previous record low for this date’s re-formation of the Arctic ice extent is matched or exceeded. The role wind is perceived to play is good to know. Even so, the extent line in the Bering Seas closely aligns with were that water is yet in twilight for part of the day. In the last week it has both qualified as re-formed ice extent and lost that rating.
That there is any observable correlation between solar incidence and ice extent re-formation would have me looking for other factors. I would be looking at the quantity of CH4 in the Arctic’s atmosphere in these regions (if good data was available), cloud cover dynamics, and anomalies in water temperatures to see what else may be feeding into our leaving the beloved* paradigm of Kansas behind.
Dorothy posted a link in a comment here to data from the UK Met Office Hadley Centre that models this winter being a relative heat blast for the Arctic. I’ve played with the Met’s modeling and, while asking what creates it, note that the quote included in this post makes no reference to it.
To the degree I am an educated layperson relative to the science, what I have yet to see, and would assuage my fears that the professionals are lost to their version of motivated reasoning in there current assessments, is a reasoned explanation of why current observations, relative to the relatively recent past predictions, seem to be catching them flatfooted. When the ice free Arctic arrives (and Mark makes a good point that such is a poorly defined/used term) is of less relevance than that of being able to vet policy (and relative costs of policy choices) from an understanding that includes why the goal post an ice free Arctic Ocean represents is rushing into the present.
CH4 levels seem to me to be the most important candidate for developing hypotheses around for doing so. The slow motion methane time bomb is one of these that I feel needs to be dusted off, stripped of its IPCC “wild card” status, and considered to be a reasonable candidate. I recognize that doing such is to cry fire in a crowed theater. Given the probability that the theater is on fire, how responsible is not crying fire—or at least (to the degree the absence of data allows) honestly evaluating methane’s climatic “pyrogenic” footprint within the current dynamics.
I think we are in a situation where achems razor does not serve homo sapiens well (i.e. its the wind) when what defines “simple” within the science community (i.e. what has been focused on, funded, and studied) may have been too simple; too comforting; too grounded in the false hope of motivated reasoning.
* beloved—though not enough for us/US 1st Worlder’s to conceive, to say nothing of embrace, the suffering and sacrifice needed to keep such from becoming an historical epoch.
A correction to #8 above: I meant Beauford not Bering Sea. Dyslexia has a lot of iterations and I get to live with several! =)
Story in Reuters today…
Arctic multiyear sea ice is effectively gone…
http://www.reuters.com/ article/ latestCrisis/ idUSN29351585
A recent article based upon NASA’s data from GRACE reviews recent ice mass loss from Greenland and Antarctica:
http://thingsbreak.files.wordpress.com/ 2009/ 10/ increasing-rates-of-ice-mass-loss-from-the-greenland-and-antarctic-ice-sheets-revealed-by-grace.pdf
I know that ice scientists are very reluctant to try to model and forecast ice loss, because of lack of understanding of exactly what’s going on yet. But that’s how we ended up having no quantitative estimate of ice mass loss in the last IPCC report. So, could the trends shown in Figures 1 and 2 of this article be input into a projection of future sea level rise through 2100 as an interim estimate, based on current trends, until we have more sophisticated ice loss models?
Does anyone now seriously doubt the need to geoengineer the Arctic as a last-ditch effort to save the Arctic Sea Ice? It’s clear that emissions reductions alone will not be enough. Even if we can get a socio-political agreement to reduce emissions in the next year or two, it will be so watered down as to be effectively useless on the short time scales relevant to Arctic sea ice.
Unfortunately, when the Arctic Sea Ice melts away completely, it’s “game over” as far as emissions reductions are concerned. The surrounding Arctic permafrost holds 1,600 GtC (see 2009 PNAS paper by Candell et al). When that rapidly melts and turns to methane, we’re looking at the equivalent release of more than 100 times the historical total of human CO2 emissions. The amplifying GHG feedbacks associated with this are staggering.
Almost certainly, the only option to prevent the arctic sea ice cover from collapsing is some kind of albedo enhancement technique, such as marine cloud seeding or stratospheric aerosols. Once the sea ice is gone, it will never come back, no matter how much geoengineering is applied. So we had better get started researching how to geoengineer effectively and safely, eh?
Joe, if you have a better, alternate solution to save the sea ice without geoengineering, please make my day and share it. I’m a *highly* reluctant proponent for it. I wish we didn’t need it, but the alternatives are far worse.
Cynodont
New paper published today in Nature Geoscience (Nov 2009) suggests that current climate models are missing some critical amplifying feedbacks that increase the warming response of the Arctic to CO2 forcing:
“Warm and wet conditions in the Arctic region during Eocene Thermal Maximum”
A. Sluijs et al
from the conclusion:
“Specifically, our results imply that some mechanism, probably through cloud feedbacks not incorporated in the models29,30, substantially reduced Arctic winter cooling under high-CO2 conditions. Depending on the climatic and greenhouse- gas concentration threshold at which such mechanisms become significant, they might comprise unforeseen positive feedbacks for future Arctic warming.”
I expect that the warming of the Arctic will continue to accelerate beyond the already frightening accelerations just discussed. Not much time left to save the arctic sea ice.
Cynodont
Cynodont:
you must slash, almost eliminate, the BLACK CARBON, OZONE and NITROUS OXIDE emissions. They cause half of Arctic warming and their lifetime is of weeks, not centuries like CO2.
The effect will be evidwent within months. Reduce CO2, and the effect will be noted in the longer term(i.e some decades)as some fraction of degree less warming(3,5°C warming instead of 4°C warming, a great victory eh!)
JR: Are you seeing the ANTARCTIC sea ice, now at record low in the AMSR-E data?(at the site http://www.iup.uni-bremen.de:8084/amsr/ice_ext_s.png
?
Anonymous: Are you seeing the ANTARCTIC sea ice, now at record low in the AMSR-E data?
Anonymous – the data produced by the folks as NSIDC would appear to indicate:
a) Antarctic sea ice is not a record low
b) You can cherry pick with the best of them
http://nsidc.org/ data/ seaice_index/ images/ daily_images/ S_timeseries.png
Another correction to comment #8—and this time it is the wind’s fault!
Neither the day before yesterday nor yesterday placed the re-formation of the ice extent in record territory for the date. Watching this animated 31 day graphic representation of the Arctice ice extent shows how the re-formation does shit around. Given the warmth of parts of the Arctic Ocean represented in this link offered by Mauri Pelto (comment #3), the wind may huff and puff but the old record will be challenged not to soon be blown away. =)
BTW Cynodont (#12), wouldn’t it be important to know how much of a role CO2 and CH4 are, respectively, playing in the ice loss unfolding in the Arctic if one is thinking geo-engineering is realistic. If so, I believe this is not known. While methane’s study has been an AGW stepchild when it comes to funding and perceived importance relative to a science career I know that the permafrost on the continental shelf that is/was keeping the clathrates solid/froze is about -1° C. The report recently published of last summer’s study of methane release over the continental shelf suggest the warming seen in Mauri’s link (and water having its greatest density at 40° F when fresh water—I don’t know what it is for salt water), means that the heat necessary to raise the ocean floor temperature to above freezing is in the system, or will be before geo-engineering could restore the Arctic to its former condition (but, regardless, permafrost cannot be created in an interglacial period.
It also is instructive to look at the website of the Select Committee on Energy Security and Climate change chaired by Congress Markey, ACES is framed around an assertion that atmospheric methane is stabilized (see the last paragraph of the ”Science Basics“ page. If the political wisdom in DC is ignoring the renewed increase in CH4 in the atmosphere, thinks the tabling of methane over the past decade is due to policies to, do you think they will believe this success masked an increase in the release of CH4 in the Arctic?
The last two links in #14 seem to be corrupted.
For the report try: http://www.noc.soton.ac.uk/ nocs/ news.php?action=display_news&idx=628
For Markey’s science try: http://globalwarming.house.gov/issues/globalwarming?id=0002