A few people have already remarked on some pretty surprising numbers in Arctic sea ice extent this year (the New York Times has also noticed). The minimum extent is usually in early to mid September, but this year, conditions by Aug 9 had already beaten all previous record minima. Given that there is at least a few more weeks of melting to go, it looks like the record set in 2005 will be unequivocally surpassed. It could be interesting to follow especially in light of model predictions discussed previously.
There are a number of places to go to get Arctic sea ice information. Cryosphere Today has good anomaly plots. The Naval Sea ice center has a few different algorithms (different ways of processing the data) that give some sense of the observational uncertainty, and the National Snow and Ice Data Center give monthly updates. All of them show pretty much the same thing.
Just to give a sense of how dramatic the changes have been over the last 28 years, the figures below show the minimum ice extent in September 1979, and the situation today (Aug 9, 2007).
The reduction is around 1.2 million square km of ice, a little bit larger than the size of California and Texas combined.
Update: As noted by Andy Revkin below, some of the discussion is about ice extent and some is about ice area. The Cryosphere Today numbers are for area. The difference is whether you count ‘leads’ (the small amounts of water between ice floes) as being ice or water – for the area calculation they are not included with the ice, for the extent calculation they are.
Update: From the comments: NSIDC will now be tracking this on a weekly basis.
I seems pretty likely the pole will be ice free (in summer) within a few decades if not sooner.
I can’t help thinking that the first satellite picture of the ice-free arctic will be truly iconic, on a par with the first images of the earth taken from space/the moon. There’s no arguing with the idea that humanity can affect the planet when faced with something as concrete as that.
This is extremely frightening and alot of the comments here regarding theories corelates well with what we are currently seeing. It is currently like 55 in Upstate new york. It felt like October today but two states to the west of us, it’s nearing 100, (and well into canada I would presume.).
I dont want to go much further into my thoughts because i dont want to upset the moderators of this blog, because I am not too too familar with the rules here as of yet. I read every blog, and most of the comments just don’t participate much because of this. I too would think maybe a forum of general climate discussion would be a great addition to this database of reliable climate discussion and information.
Although, this I believe I can add without hesitation. On the topic of a colder Northeast, I already made the point above that it is extremely cool here lately, and we seem to be espcaping most of the high heat, but If my memory serves me correctly, last year the same type of trend occured, we’d get heat, then cool for a while then intense heat back and forth. Along with it, I’ve noticed it seems that during the fall (this at least for the past couple years now) the temperatures stay much milder, giving an opprtunity this past christmas to wear a short sleeved shirt, the year before was a nice warm day as well for Christmas. I also saw a baby bird on january 5, 2007 this year, outside my window while taking down christmas decorations, in the meanwhile, the rest of the country was dealing with the cold and heavy snows, and not to mention the erratic weather. El Nino was said to be of blame, but this trend has been progressive over the past few yeras. Many locals notice the shift in seasons in the Northeast as well. We seem to get better chances for severe weather in the fall similar to the midwest (not in terms of frequency, but intesity). Albany New York had a Tornado watch out on Dec 1st 2006. Maybe one of the handful of times theres ever been the word Tornado and watch or warning in this area, and decemeber of all months.
Just my 50 cents to add to several posts above related to less artic ice effects on weather, IE the Northeast. I would only imagine from the trends and what I have read about it, that this would continue.
Re #33: [Did you ever see a lot of melting snow without a lot of mud?]
As a matter of fact, yes. It’s quite common around here (east slope of the Sierra Nevada). Porous decomposed granite soils without much organic matter, low humidity, and large day/night temperature swings means that meltwater either soaks in or evaporates almost immediately (if it doesn’t actually sublimate), so the ground just gets sort of damp.
I am curious, as we are discussing this absolutely startling rapid melt of the arctic sea ice, where the discussion of permafrost and methane enters into the equation. It would seem to me that with all the extra heat in the arctic, both atmospheric and ocean, that permafrost would also be thawing out rapidly, and we might be seeing a continuation of the rapid rise in methane that we’ve seen the last 20 years, (though it was flat to slightly lower the last 2 or 3)? Any experts here care to discuss potential permafrost/methane connections to an ice free Arctic Ocean?
Re #51 The North pole is already free of ice in the summer. In fact a Briton has been swimming there this summer to raise awareness of climate change, but he seems to have had little effect :-(
See http://news.bbc.co.uk/2/hi/uk_news/england/london/6899612.stm
In fact it was first free of ice in the summer of 2000.
See http://news.bbc.co.uk/2/hi/americas/888235.stm
But the ‘powers that be’ forced the New York Herald to withdraw that story. Things are a lot worse than you are allowed to know.
Re 48. Different people have different modes of neural processing, well described in the literature on neural linguistic processing. To many people, showing a graph is a waste of time. They don’t know how to interpret graphs; they haven’t had the training, and so it is not a surprise. Showing a picture however can be very powerful, especially if two pictures are shown as before and now. That leaves the person to whom the pictures are shown with the problem (or opportunity) of thinking about what the picture for the ‘after’ condition might look like.
The real problem, though, is how to get over the problem of the failure of climate scientists to deliver absolutely clear messages to the world about the potential for sea level rises of the order of metres over the coming decades. The IPCC has demonstrated failure in that regard, and has run away for 6 years. Perhaps it should be re-convened on a 12-monthly basis specifically for the emergency topic of sea level rise.
The world is probably justified in thinking that the potential sea level rise over the next century is a few inches or, for those who don’t do inches, a few centimetres. Climate scientists, or those who give themselves that description, will mumble to each other. What might they say? Perhaps a discrete conversation over coffee might go along the lines:
Climate Scientist A: “we know it’s not a few centimetres”
Climate Scientist B: “we are reticent, we can’t go public”
Climate Scientist A: “oh, leave it to Hansen, he’ll do the going public bit”
Climate Scientist B: “but will we still get funding and will we still be able to publish our work in peer-reviewed journals?”
Climate Scientist A: “oh yes, we can tell them that the rise will be a few centimetres but then add a bit on the end to cover our arse”
Climate Scientist B: “what bit will that be?”
Climate Scientist A: “we’ll add the phrase … but it could be more”
Climate Scientist B: “oh … that means we are covered when the ice sheets do start to disintegrate”
Climate Scientist A: “you got it!”
The time for reticence is over. The world needs a clear message.
For example, where can the public find the results of a Delphi study of the world’s top 100-500 climate scientists’ estimate of what sea level rise might be up to 2100?
Yes indeed, what is going on in the Arctic sea ?!?
Have a look at:
http://www.servumpecus.canalblog.com/archives/2007/08/05/
With my best regards,
Servumpecus
Meanwhile, sea ice coverage at the south pole is above average. Does RC have any posts discussing expected trends in southern hemisphere sea ice ?
re 56
“The time for reticence is over. The world needs a clear message.”
Michael, have you seen the report of the joint study by Sigma XI and the United Nations Foundation? Entitled “Confronting Climate Change: Avoiding the Unmanageable and Managing the Unavoidable”, it strikes me being as along the lines of what you are asking for.
http://www.sigmaxi.org/about/news/UNSEGReport.shtml
I think the real problem is that unless you read American Scientist magazine, or follow the proceedings of the UNF, John Q. Public is not going to know it exists. Which, IMHO, is the real problem. I think the climate scientists have been rather clear in their message.
It’s the media. On one hand, they muddle the issue by allowing themselves to be manuevered into suppounding the “It’s a debate” promoted the denialists (Dodo-ists?), most likely because conflict sells more papers than conclusions. Second, again related to selling papers in an era where readership is declining, they are more interested in letting us know what and who Brittney, Lindsey and Paris are running their automobiles into, detailing the latest tragic family slaying, repeating teh latest al Qeada warning. Something like the oncoming climate disaster, supposed to happen far in the future and with no Katrina to make it current and “sexy” just isn’t selling papers.
So John Q. Public (re Joe Six-Pack & Matilda Make-up) haven’t heard the news and likely wouldn’t pay attention if they did.
Now if only some poor, starving Polar Bear ate Paris Hilton, maybe the issue would get some press…
*sigh*
Question (one of those wake-up-in-the-middle-of-the-night kind).
In 2005 and, I think, 2006, the ocean currents off Northern and Central California were much warmer than expected. Combined with weak upwelling, the zooplankton production dropped precipitously, in some areas to 14% of normal, if I’m remembering correctly, which led me to wonder:
Has anyone done any projections of biomass levels for the Arctic seas over the next year based on what’s happening? (I’m assuming they have, given 2005’s ice retreat).
Also, of course, is there some sort of correlation between what California currents from the north experienced in 2005 (and 2006) and the decline of sea ice in the Arctic?
Thanks in advance.
re 50 (and #45 & OT)
I’d be delighted to see a Friday Roundup …
=========================
Agreed. That said, regardless of your feelings for the author, you should read it. The problems associated with ethanol are fairly straightforward, and laid out well. And switchgrass is not a solution, particularly once you factor in land use, transportation and processing costs. And this isn’t even factoring in the energy efficiency figures versus the cost of bringing home the bacon.
The real problem, IMHO: it’s a panacea, a short-term, likely unsustainable effort that does little more than give the appearance of “doing something” when, in fact, it’s actual positive effect is negligible, while the negative is large (You’ve heard of the “tortilla crisis”, right?) in terms of higher corn prices and lost land better used for food production.
That said, I’ll shut up and worry about something more in line with the subject, like how the warming Arctic will affect the ocean’s ability to produce food.
re 58:
Meanwhile, sea ice coverage at the south pole is above average. Does RC have any posts discussing expected trends in southern hemisphere sea ice ?
========================
Could you provide a link to this? I’m personally curious as my wife is journeying to the Ross Sea in February…
That said, I believe Timothy Chase said something contrary to what you are saying in #34. Hopefully this will get sorted out.
David in 58 remarked:
“Meanwhile, sea ice coverage at the south pole is above average.”
Yeah, and there is no Sun in the South pole at the moment.
Besides, there is neither obvious trend nor alltime record maximas/minimas in Southern Sea Ice Area data. See:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.south.jpg
Its too bad we can’t compare the last equivalent weather situation, 1934 for instance. But, satellite technology being what it is takes getting satellite date from that period a little difficult. My grasp of the obvious.
Re 54- R. Gates raised the question about methane release and permafrost melting because of the extra heat in the Arctic. I have been watching with concern the temperature anomaly off the NE Siberian coast, which has persisted for weeks, seen here:
http://weather.unisys.com/surface/sst_anom.html
Surely this portends more rapid disintigration of the Siberian permafrost coastal shelves, with the attendant release of methane. Am I correct in recalling that there are substantial methane hydrates included in these structures?
JS McIntyre (#62) wrote:
Nope.
He was speaking strictly of sea ice. (#58) I was speaking of glaciers and some parts of the interior of the Antarctic, but made no mention of sea ice. (#34)
As I have pointed out previously, if Antarctica were to experience a sudden loss of glaciers, you would expect an increase in sea ice, not a decrease.
However, Petro is right (#63) – no obvious trend in sea ice.
I am curious, though: how were you able to know the number of my post? I assume you looked it up, but this doesn’t make any sense given the fact that the two posts were clearly speaking of different things, and both posts were short enough I presume the difference would have been obvious.
Alastair McDonald (#55) wrote:
Now that is a dramatic detail!
Something which bears repeating – particularly in essays.
It should be obvious how bad things are to anyone reading the headlines who has a wit of common sense – given the power struggle that is beginning to be waged by Russia, Canada, US, Sweden and the Netherlands over the Arctic Ocean oil reserves. Fighting over oil under these circumstances! Someone must have a perverse sense of humor.
re: #61 OT
“Agreed. That said, regardless of your feelings for the author, you should read it. The problems associated with ethanol are fairly straightforward, and laid out well.”
?? Peace: you seem to be reading something other than what I posted.
I have previously recommended Jeff Goodell’s “Big Coal” several times (hence, if anything, I’m favorably disposed), but I didn’t think his RS piece (which I’d read before I commented) was up to that standard. Robert Rapier’s blog is way more informed and balanced, with well-nuanced discussions (including some agreement/disagreements with Khosla) but that doesn’t come through very well in JG’s RS piece.
For example, RR says: “I firmly believe we should be aggressively researching the potential of cellulosic ethanol…But I think the hype has gotten way out of touch with reality at this time.” *That* is good, albeit a tiny sample of fairly complex discussions there.
Anyway, back to Arctic ice, please; let’s take this ethanol stuff to i-r-squared.blogspot.com or some other more relevant place.
Freeman Dyson cast some interesting doubts (as heresies) about the climate modeling in GW on the Edge website here:
http://www.edge.org/3rd_culture/dysonf07/dysonf07_index.html
He isn’t claiming GW is untrue, just possibly too reliant on poor models.
Any comment about this?
Re 66,62,63 – The cryosphere today website has a graph of current sea ice coverage over the last year in both the Arctic and the Antarctic, together with the current difference from the 1979-2000 mean value. The difference from the mean is obviously corrected for the time of year. In the Antarctic it currently shows about 0.6million square kilometres more ice that the mean.
In my original post I was merely asking for intelligent comment on the future of antarctic sea ice.
I imagine nobody else noticed but the NOAA and the NCDC changed the historic sea ice extent data in January of this year. The changes were very, very substantial.
If you want a BEFORE and AFTER, here is link to gif image.
http://img401.imageshack.us/img401/2918/anomalykm3.gif
As well the best place to look at sea ice extent is using the VISIBLE satellite picture from AQUA/MODIS/TERRA satellites. These VISIBLE real-time images show there is more arctic sea ice than shown by the NCDC and the Cryosphere Today.
http://rapidfire.sci.gsfc.nasa.gov/realtime/
In the data collected by National Snow and Ice Data Center, University of Colorado, Boulder, CO.
http://nsidc.org/seaice/characteristics/difference.html
The melt and recovery show that the total Arctic Ice in manner of Millions of sq. miles. It lists it’s data as being about the same. How is the pack getting smaller if the recovery level and the melt level are consistently the same? Can anyone help me here?
John Wegner (#71) and hoosiemorm (#72),
I believe it might help everyone to check out a chart showing Northern Hemisphere Sea Ice Extent which has not been updated to include 2006. (Unless you are suggesting they went back and edited this image as well, John – but this would seem to imply intent.) This is done seasonally…
Northern Sea Ice Extent
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.updated.2005.jpg
For John, here is another image from 2005, albeit based on annual trends..
28 September 2005
Sea Ice Decline Intensifies
Figure 1: September extent trend, 1978-2005
http://nsidc.org/news/press/20050928_trends_fig1.html
John, somehow I don’t think the images of the Arabian Peninsula will be very helpful.
Re: Post #65
I have only recently become more interested in the methane part of the equation, and certainly the great unknown (isn’t it all though really?) is how quickly the permafrost will respond to the temperatures associated with a summertime ice free arctic.
Does anyone know where we can get reliable and near real-time atmospheric methane concentrations for various parts of the planet? I think the reponse of permafrost and perhaps even methane caltrates in the deeper (and warmer ocean) would be of keen interest considering how potent a GH gas it is.
ftp://sidads.colorado.edu/pub/DATASETS/PASSIVE_MICROWAVE/POLAR_STEREO/ANCILLARY/ICE_EXTENT/SMMR-SSMI_BOOTSTRAP/BROWSE/gsfc.bootstrap.extent.Total-Arctic.1978-2004.n.gif
So is the Colorodo Chart Wrong?
[[Freeman Dyson cast some interesting doubts (as heresies) about the climate modeling in GW on the Edge website here:
http://www.edge.org/3rd_culture/dysonf07/dysonf07_index.html
He isn’t claiming GW is untrue, just possibly too reliant on poor models.
Any comment about this?]]
Yes. Freeman Dyson is given to making extravagant claims in fields he isn’t really familiar with.
On 10 August 2007, NOAA data showed the direct Northwest Passage through the McClure Strait north of Banks Island to be completely open. I’ve scanned the recent data and cannot find a precident (though 1998 and 1999 go very close).
The historic plot is here: http://polar.ncep.noaa.gov/seaice/analysis/nh/nh12.20070810.gif
[The previous direct NWP minimum appears to have been ~20 Sept 1998: http://polar.ncep.noaa.gov/seaice/analysis/nh/nh.19980920.gif ]
#73 – Timothy Chase – the MODIS/TERRA/AQUA satellites are in a polar orbit and take pictures every 5 to 10 minutes. Click on one of the images and you can use the Prev and Next buttons on the side to move back and forth in the orbit to see the North Pole or just about anywhere on the planet in real-time or in the last 24 hours at least.
The images also allow you to use different wavelengths and Zoom into 4km, 2 km, 1 km, 500M or 250M resolutions.
Here is the 4 km Visible image of the Siberian side of the Arctic ocean including the North Pole from about 10 hours ago (remember 24 hours of sunlight in the Arctic circle this time of year.)
According to the Cryosphere Today software-produced image in this thread, there is supposed to be very little sea ice here whereas obviously there is (Note clouds are sometimes in the way but if you go back and forth and look at other images you can directly see with your own eyes whether there is sea ice or not.)
http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007223/crefl2_143.A2007223234001-2007223234500.4km.jpg
Rapid Sea Level Rise of 500mm per decade is possible, its not a question of if but when. We can all see the process starting now in which the melting will facilitate the cascade of the land based ice into the sea, giving the general public a bit of a shock. I think we will see the start of the cascade in a decade or two, I hope not. What I think needs to be discussed is the preparation for such an event, being early is not a problem, more than anything it will help society move into the next stage of civilisation. Their are a lot of things to do, but I would just like to mention one. Nuclear power stations on the coast line do pose a bit of a problem, especially the ones being planned now. Decommissioning will not be possible when the cascading takes effect as the sea level rise will be rapid and unforgiving. Renewable energy can work, especially the CETO technology being developed in Perth Western Australia. A lot of things can be done about climate change, I just wonder what path we will all take.
Re 79. In addition to potential burial-at-sea of nuclear reactors there is also the potential for wash-out of thousands of toxic dumps. Potential dislocations spreading through global supply chains during this process may have a high impact on decommission and rebuild capacity. The situation requires urgent international attention.
Re # 19 Aaron Lewis
“normal sea water sinks as it cools,”
No argument there.
“thus normal ocean water freezes from the bottom up.”
Not normally, it doesn’t. As the upper layer of water cools and approaches its freezing point (in contrast to fresh water, in seawater the freezing temp equals the temperature of maximum density), the sinking (downwelling) slows – the layer of water at the surface is in contact with the colder atmosphere and starts to freeze first, with ice crystal formation causing it to expand. Hence, ice freezes at the surface, just as it does in fresh water. Brine rejection by the ice will add salt to the underlying water and cause downwelling under the ice, but that is a gradual process. If you were thinking of anchor ice formation, that occurs only in very specific situations (http://en.wikipedia.org/wiki/Anchor_Ice; http://amsglossary.allenpress.com/glossary/search?id=anchor-ice1)
At least is how I understand it.
# 81 I should have said ice forms at the surface, just as it does in fresh water.
[Response: That is overwhelmingly the case, but curiously you do sometimes get ice forming at depth when supercooled water from underneath ice sheets moves into the open ocean. I think it’s sometimes called ‘marine ice’ . – gavin]
re 66
That said, I believe Timothy Chase said something contrary to what you are saying in #34. Hopefully this will get sorted out.
Nope.
He was speaking strictly of sea ice. (#58) I was speaking of glaciers and some parts of the interior of the Antarctic, but made no mention of sea ice. (#34)
==============
I note you didn’t seem to have a problem with David’s remark “Meanwhile, sea ice coverage at the south pole is above average” when, in fact, there is no sea ice at the south pole, or any within hundreds of miles.
I bring this up not to be contentious, but to underscore that you did mention the West Antarctic Pennisula in #34 (“The West Antarctic Peninsula is going”), where a great number of glaciers are emptying into the sea, which was where I made the association, as I tend to think of the sea surrounding the territory as part of the area. I didn’t think I needed to be clearer, but in retrospect, I should have.
My apologies.
J.S. McIntyre (#83) wrote:
Not a problem.
I myself keep reading over what I am about to post, but maybe a little too quickly. It is only after I go back that I will notice that some sentence is garbled, usually either near the very beginning or end of the post. The beginning is worse as this is what people are likely to read first. But it is usually at that point that the mind is still in the process of tuning up, sorting out your thoughts, trying to put everything into context. It is only later that you know exactly what it is that you want to say.
Then of course there are the misinterpretations of what other people have said, of their intent, responding to what you think they have said or what you think was the intent behind their words. I enjoy participating, trying to take into account everything I can, but I probably don’t measure up to what I would like most of the time.
Sometimes I will respond to what someone else has responded to, but typically in more detail because I am still trying to get everything straight in my own head. Different responses will probably speak to different people, longer responses to some, shorter and more direct responses to others. As such I don’t see a problem with different people responding to the same post.
But sometimes I wonder whether this too might be misinterpreted – as if I think that I am in some sort of a contest with others. But it most certainly isn’t a contest, at least as I see it. I just think that everyone should do the best that they can and not worry too much about the rest.
Anyway, this is probably more personal detail than most will care to hear. But I figure some will find some value in it simply in terms of being able to see what others are probably going through. There is a great deal at stake, and I am sure the emotions often run high for others as well as myself.
The remarkable point in Arctic sea ice extent is not that it is lower by the year in summer (and in yearly average), it is that winter sea ice cover hardly declined from the long-term average.
See the seasonal trends here.
Thus in winter, most of the summer melt refreezes. Why is that? In summer there are more clouds than in the past. This reduces the influence of the sun (or the melting would be larger). In winter the reverse happened: less clouds than usual, thus with more open skies during polar night, more heat radiation escapes to space and water freezes more rapidly.
See Science”
Something that climate models didn’t expect…
Ferdinand said:
“The remarkable point in Arctic sea ice extent is not that it is lower by the year in summer (and in yearly average), it is that winter sea ice cover hardly declined from the long-term average.”
Contrary to your claim, there is a shrinking trend in winter sea ice cover starting around 1972. Dramatic drop has occured during last four winter. See: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg
Re # 19 Aaron Lewis
“Think about how much more lake effect snow is now being produced down-wind of Lake Erie, now that Lake Erie has a shorter freeze season”
I don’t know about recent changes in lake effect snow due to warming to date, but lake effect snow on Lake Erie’s Southern shore (and that of the other Great Lakes) is predicted to decrease by the end of the century due to global warming:
The Future of Lake-Effect Snow: A SAD Story
From Acclimations, January-February 2000
Newsletter of the US National Assessment of
the Potential Consequences of Climate Variability and Change
By Peter J. Sousounis, The University of Michigan
[Excerpt]
“Recent simulations from the Canadian Model (CGCM1) and the United Kingdom Hadley Model (HadCM2) suggest that the climate in the Great Lakes region by the end of the 21st century will be warmer and wetter — with the CGCM1 being warmer and drier than the HadCM2 (4 vs 2°C and 25% increase vs 50% increase). While understanding the mean temperature and precipitation changes predicted by the models is important, day-to-day weather will be affected by corresponding changes to cyclone tracks, arctic outbreaks, and lake-effect snow patterns. In predicting these crucial day-to-day local aspects of the weather, even the current suite of GCMs is inadequate. However, some conclusions about the local weather patterns can be made with confidence by understanding the connection between the large scale flow patterns and local weather. In this respect, both models are more similar and suggest that by the end of next century, the typical winter may be comparable to what we experience now during a moderate-to-strong El Nino. The coldest winters may be comparable to what we experience now in a normal winter. Snowfall totals may therefore be half the current normal totals with lake effect snow being significantly reduced, especially over the southern portions of the region where average temperatures barely support snow now. Both the CGCM1 and the HadCM2 suggest a more zonal flow pattern, meaning more Pacific systems, fewer Gulf of Mexico systems, and fewer Alberta Clippers. Alberta Clippers are a primary source for reinforcing the cold air over the Great Lakes in winter. Fewer outbreaks likely means less lake-effect snow.
Impacts on recreation
Less lake-effect snow could potentially have a considerable impact on the winter recreational activities of the region — particularly in the southern portions, where significant reductions in snowfall totals coincide with populous urban centers like Chicago, Detroit, Cleveland, and Buffalo. …”
http://www.usgcrp.gov/usgcrp/Library/nationalassessment/newsletter/2000.02/Lakefx.html
Re 69. Freeman Dyson writes at that link “The most alarming possible cause of sea-level rise is a rapid disintegration of the West Antarctic ice-sheet, which is the part of Antarctica where the bottom of the ice is far below sea level. Warming seas around the edge of Antarctica might erode the ice-cap from below and cause it to collapse into the ocean. If the whole of West Antarctica disintegrated rapidly, sea-level would rise by five meters, with disastrous effects on billions of people.”
Freeman Dyson suggests that we are relying too much on models.
Where are the models of ice sheet disintegration that the world is relying on?
Where are the models of ice sheet disintegration that contain the physics of ice streams, effects of surface melt descending through crevasses and lubricating basal flow, or realistic interactions with the ocean?
Where are the models predicting the sizes of mini-Meltwater pulses that may be expected through the next few decades as the WA and Greenland ice sheets begin to disintegrate?
It is only when such models do become available that more realistic assessments of the potential impacts on other systems (eg industrial dynamics, economic circuitry, life-support systems) can be made.
On the matter of ice sheet disintegration and huge sea level rises, Freeman Dyson should reconsider his position. The world is not overly relying on models. There is plenty that is being observed and plenty to be observed, but there is a dirth of models on matters which are of critical importance that may give us better insight into the unnecessary emergencies we are allowing to happen.
Re #78:
Yes, but not sure why you would say that the MODIS images differ significantly from Cryosphere Today. Here is the MODIS Aqua of the Northwest Passage on Saturday, with the direct McClure Strait route all but open for perhaps the first time in recorded history:
http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007223/crefl2_721.A2007223184001-2007223184500.2km.jpg
Roald Amundsen could have motored through in under 10 days. (He actually took 3 years, and a much less direct route).
How is the record low sea ice impacting greenland? Someone knowing current developments in ice quake frequency or outlet flows?
BTW the lack of media coverage of this current event baffles me… It should be front pages news!
Re 59. Thank you for the link. From page 93 of that document: “A complete collapse of the Greenland Ice Sheet, projected to take roughly 1,000 years once local warming reaches about 3°C (which is expected by late this century), would increase global mean sea level by about 7 m. The collapse of the West Antarctic Ice Sheet (WAIS), which would likely take a comparable amount of time, would add another 4 to 6 m. While the IPCC’s 2001 estimates do not anticipate significant loss of ice mass from either ice sheet during the 21st century, accelerated retreat of some ice streams has recently begun in Greenland, and some parts of the WAIS also seem to be nearing destabilization (Vaughan and Spouge, 2002; Schiermeier, 2004; Dowdeswell, 2006.)”
I am not sure that addresses the matter of a clear reference point of the liklihood of a sea level rise of several metres by 2100 for business-as-usual.
There is a state of confusion amongst risk managers.
There needs to be a Delphi study in which the top 100-500 climate scientists input their estimate of what they expect the sea level rise to be by 2100 if we carry on business-as-usual. Delphi studies which accumulate the experts’ opinions / estimates into one summary histogram are standard practice for futures studies in science, technology, engineering, etc. There doesn’t have to be named attribution to each data point.
The world needs a reference point that says … this is the expectation profile of a very large number of the world’s climate scientists of sea level rise through the next 9 decades.
Once the world has that reference point, others can then do their jobs with the world’s best estimate. The IPCC SLR numbers were not that. There is too much at stake for climate scientists to allow risk managers in corporations and elsewhere to continue assuming that the IPCC SLR estimates of a few centimetres are the ones that should be used.
The world needs its best estimate. The matter is urgent.
I’ve looked at the MODIS satellite images a little closer (and with some places having less cloud cover.)
There still isn’t a way through the NorthWest Passage without an icebreaker. Maybe in another week or two.
But that is just the problem with the Passage. There is only a few weeks from mid-late-August to mid-September when the Passage is open for non-ice-breaking ships. In some years, there is no opening at all.
As well, there are two or three distinct paths to take. In any one year, only Path3 is open while 1 and 2 are closed off. It would make no sense to station a ship off Baffin Island in early August wating for the satellites to tell you which one of 3 Paths is open for the next few weeks.
In addition, the winds can quickly close off any opening so the risk-return trade-off is just not there (unless global warming extends the Opening to two or three months, rather than a few weeks.)
Re #83:
J.S., there is a lot of sea ice in the Antarctic winter, which makes it very difficult to impossible to reach any coastal station. See: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.south.jpg
Summer sea ice is around 2 million km2, winter around 15 million km2.
The overall trend seems to be slightly positive, between 0.5-1 million km2.
Re #86
Petro, indeed, there is a winter shrinking, with the past few years some extra. But since 1970, the winter trend is about -0.5 million km2 over 35+ years, while the summer trend is about -2 million km2 in the same period. That means that summer-winter refreezing increased with about 1.5 million km2. Which is remarkable, as one may expect that winter and summer decrease would be similar.
Re #90
Up to 2004, the retreat of the largest Greenland glacier (near Ilullisat) can be seen at Wiki, but one need to compare the period 1953-2003/4 to the previous period of strong retreat of the breakup point (1929-1953) at the same page. Moreover, the summer (melt) temperatures around Greenland don’t/hardly reach the 1930-1945 temperatures.
re 93:
“…there is a lot of sea ice in the Antarctic winter, which makes it very difficult to impossible to reach any coastal station…”
Yes, I understand this about winter conditions; it’s rather common knowledge. For McMurdo Station, if I recall orientation correctly, this affects flights from New Zealand and other (relatively) nearby points, as well. It is not unusual for planes to be turned back mid-flight due to changing weather. Which is why the coastal stations have intermitant arrivals, and the interior stations, like the South Pole station, are completely cut off during Antarctic winter.
Of course, my original question regarded sea ice extent in February, which is Antarctic summer.
The link you provided was originally posted by Petro in 63, where I first saw it. But thank you all the same.
Timothy Chase (#67) said: It should be obvious how bad things are to anyone reading the headlines who has a wit of common sense – given the power struggle that is beginning to be waged by Russia, Canada, US, Sweden and the Netherlands over the Arctic Ocean oil reserves. Fighting over oil under these circumstances! Someone must have a perverse sense of humor.
I know this is off topic, but I think that the powers-that-be are probably even more afraid of peak oil than they are of global warming…..
re 94, 93 et al
Answered my question re Sea Ice in February.
It’s a pretty informative, interactive link:
http://nsidc.org/data/atlas/
Just click on your favorite hemisphere. It doesn’t address record amounts, though I will note everything I looked at regarding SHELF ice and glaciers point to a decline, not an increase.
Re #93: “That means that summer-winter refreezing increased with about 1.5 million km2. Which is remarkable, as one may expect that winter and summer decrease would be similar.”
And after the summer ice goes completely, the difference will be even larger! The key point is that what refreezes is quite thin, and thus is prone to quick melting the next year. Ironically the refreezing allows the retention of much of the heat gained by open water during the summer.
Regarding Greenland temps, this paper discussing trends for the entire Arctic is useful. From the conclusions:
“In the Arctic in the mid-1990s an abrupt rise in SAT was noted (by about 18C in comparison with the 1951–90
mean); this then stabilized and has remained at this level up to now. The greatest warming occurred in autumn and spring, and the lowest in summer and winter. In the period 1995–2005, the warming was greatest in the
Pacific (by 1.458C) and Canadian (by 1.268C) regions,
and lowest in the Siberian region (by 0.828C).”
That said, the exact pattern of warming is not the same as predicted by the models, and there is no published detection and attribution study for the Arctic.
Another thing to bear in mind about Greenland is that inferring temperatures up on the ice sheet from the surface stations around the edges has its limitations.
1978 and 1979 were the coldest years in the US since 1929. There was a general cooling trend in the US since the Dust Bowl days of the mid 1930’s down to 1979. I remember some climatologists back in the late 1970’s predicting that the Earth was heading for the next Ice Age. Strange that you would use 1979 as your comparison photo. It would be nice to have one from the mid 1930’s or mid 1950’s when it was just as hot as it is now but there were no satellites to take the pictures back then.
By the way everyone is missing the point. The Earth is warming. It has been warming since the last Ice Age and will continue to warm until the break over point to the next Ice Age is reached no matter what Humanity does. We only have the choice to get to the break over point earlier or later by the actions that we take.
Re #67 [given the power struggle that is beginning to be waged by Russia, Canada, US, Sweden and the Netherlands over the Arctic Ocean oil reserves.]
I’ve not heard that Sweden or the Netherlands have any territorial claims in the Arctic. Norway and Denmark (which has sovereignty over Greenland) do. There’s a map here:
http://news.bbc.co.uk/2/hi/americas/6941426.stm
Re #93: “That means that summer-winter refreezing increased with about 1.5 million km2. Which is remarkable, as one may expect that winter and summer decrease would be similar.”
If one was to think that the winter and summer decrease would be similar then they would not be facing up to reality.
The winter ice grows out from the perennial ice cap due to the cold air forming over the ice and freezing the water at the ice edge. This growth can continue until the surrounding water is at a low enough latitude that the water is too warm to freeze. Since ocean sea surface temperatures change little on an annual basis the maximum ice edge does no vary either. On the other hand, the minimum ice edge is determined by the thickness of the ice. As the perennial ice thins then since the sun can melt a fixed thickness, a larger area will be completely melted and expose the ocean beneath.
If the sea ice system was linear, then winter and summer decrease would be similar, but there are positive and negative feedbacks. The positive feedbacks dominate the melting and that will lead to a sudden collapse of the ice.
Not only will the sea ice disappear suddenly, but with its demise the main air conditioning unit for the Northern Hemisphere will be gone. This will lead to an abrupt warming with temperatures in Greenland rising by 20C within three years, just as they did 10,000 years ago at the start of the Holocene.
Timothy Chase (#67) said: It should be obvious how bad things are to anyone reading the headlines who has a wit of common sense – given the power struggle that is beginning to be waged by Russia, Canada, US, Sweden and the Netherlands over the Arctic Ocean oil reserves.
That fight over oil reserves will be nothing compared to the wars that will ensue when the starving Chinese, Indians, and Africans invade North America, Russia, and Europe in search for food!