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Arctic sea ice watch

Filed under: — group @ 10 August 2007

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).

Sep 05 1979Aug 09 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.


504 Responses to “Arctic sea ice watch”

  1. 101
    John Lang says:

    Remember the Arctic circle has 6 months of darkness starting on September 21-22. It gets very cold in the Winter at the North Pole.

    The average annual temperature at the North Pole is -24.5C (South Pole is -49.5C) ICE causing temperatures to say the least.

  2. 102

    Re #101 But it can only get down to -24.5C because the water is covered with ice! If there was only open water then the surface could not cool below -2 C. You need a solid surface nearby to provide the cold air so that deep water can freeze!

  3. 103
    NeilT says:

    I simply don’t have time to read all of these entries right now, but I will later.

    I think I have said here, a few times at least, that this was going to happen. I have been watching it very closely over the last year (daily thanks to the university of Bremen http://iup.physik.uni-bremen.de:8084/amsr/amsre.html) and the areas which showed the most warming over the winter months were pretty much the first to disappear during the summer.

    Also I watch all the cyrosphere news on a daily basis. The most interesting news to me this year was the 10m multi year ice which locked in the fishing fleet earlier this year. The icebreakers were unable to get in to reach them, yet icebreakers can sail to the pole with regularity today. That means the pole is still flushing out the thick multi year ice and replacing with new thinner ice. More melt, faster.

    It is always the summer ice lows which get the news, but it is the winter ice melt and lows which are much more dramatic, if in a smaller way, because they are the proof of much more dramatic change.

    Also after 3 winters in Sweden, spaced out over 7 years, I am personally seeing a trend. There is more cloud in the winter. As a result, temperatures are up to 10degC higher in the winter now. As a result of which the sea is not freezing as much, which means more heat from the water, etc, and the great circle goes on.

    Reports from Tara Arctic this winter were of very cloudy skies, lots of snow and, except for very severe events, much warmer temperatures than normal.

    Also a very interesting point is that the sea under the Ice cap is -1.7 degC. It is Fresh water which is freezing to -24 degC in the arctic, Sea water does not freeze until you reach -7… Remove the fresh water Ice, add clouds and you remove the ability of the pole to freeze in the winter. Then you have a Serious tipping point.

    I always find that statements like “The great oceanic conveyor stopping completely will cause another ice age” as interesting. My logic goes like this.

    The climate warms
    which warms the Arctic
    Which slows the conveyor
    Which does?
    Very little because the Arctic cannot provide the same level of cooling because it, itself, is warming. Otherwise, it would have been impossible at any time for the Arctic to have had a climate close to that of Florida. But we know for a fact that it did.

    It is like the argument that txt messaging on mobile phones will cause longer thumbs in 5,000 years. Actually not, we will all be walking around with sugar powered chips in our body in 100 years time and won’t use our thumbs for any form of messaging, just our brains. Perhaps we’ll get smarter as we use our brains more????

  4. 104
    Nick Gotts says:

    RE # [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!]

    Untrained people, let alone starving ones, do not form armies capable of invading functioning modern states. In fact, I cannot recall offhand any recorded instance of an army of the starving invading anywhere, anytime – although invading armies may starve after invading, due to “scorched earth” defence, bad weather, and/or logistic failures. Large-scale starvation in China, India or Africa may lead to state collapse, increased levels of attempted unauthorised immigration to North America and Europe, and possible wars of distraction launched against traditional and/or weak enemies by elites desperate to rally their populations, but nonsense of the sort quoted above will merely encourage racism and militarism in North America and Europe.

  5. 105
    Andrew Dodds says:

    Re: 98 (Curtis Metz)

    What are you talking about?

    The warming following the last ice age peaked around 6000 years ago, followed by a very slow temperature fall:

    http://en.wikipedia.org/wiki/Holocene_Climatic_Optimum

    And US temperatures are NOT global temperatures, or even arctic temperatures..

    Re: 100, 102 (Alistair)

    20K warming in Greenland in 3 years? Certainly the removal of permanant arctic ice would be bad, but I wasn’t aware of any research that said it was *that* bad..

  6. 106
    Dan says:

    re: 98. “I remember some climatologists back in the late 1970’s predicting that the Earth was heading for the next Ice Age.”

    You may want to read about that myth at http://www.realclimate.org/index.php/archives/2005/01/the-global-cooling-myth/

  7. 107

    [[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.]]

    Curtis — The world has NOT been warming “since the last ice age.” If you calculate the effects from the assorted Milankovic cycles (it involves a lot of matrix math), you find that we passed the peak of the interglacial 6,000 years ago and the world should now be COOLING. The present warming is not natural. “We’re just coming out of an ice age” doesn’t correspond to reality.

  8. 108
    J.S. McIntyre says:

    re 104

    “Large-scale starvation in China, India or Africa may lead to state collapse, increased levels of attempted unauthorised immigration to North America and Europe, and possible wars of distraction launched against traditional and/or weak enemies by elites desperate to rally their populations, but nonsense of the sort quoted above will merely encourage racism and militarism in North America and Europe.”

    Agreed … to a point. As someone once said, no country is more than a couple of meals from revolution. And from revolution is born chaos.

    This is a new age, a nuclear age, and that changes the equation dramatically. Put another way, the worst type of enemy is one that is convinced they’ve nothing to lose.

  9. 109
    Nick Gotts says:

    Re #108 [As someone once said, no country is more than a couple of meals from revolution. And from revolution is born chaos.]

    Well, “someone” was wrong! Food shortages may cause riots, but revolution requires a loss of the ruling elite’s control over a significant segment of its armed forces (and while there’s any available food at all, the armed forces and their dependants will be first in line), or the successful formation of rival forces in an area uncontrolled or very poorly controlled by the ruling elite.

    [This is a new age, a nuclear age, and that changes the equation dramatically. Put another way, the worst type of enemy is one that is convinced they’ve nothing to lose.]

    Agreed – but the enemy we have to fear is a ruling elite on the edge of losing control, not a starving horde. Even then, such an elite is much more likely to attack a neighbour perceived as weaker than a core power – but there are cases where this could lead to a nuclear war big enough to cause global breakdown.

  10. 110
    CobblyWorlds says:

    I note the NSIDC Arctic Ice News Page http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html
    Particularly figure 5 http://nsidc.org/news/press/2007_seaiceminimum/images/20070814_rate.jpg (and comments).
    It seems that this unusually early melt is due to specific conditions: “Taken together, the rapid sea ice losses that we’ve seen in June and July can partly be explained from the effects of this “triple whammy”: it was warm; atmospheric circulation pushed ice away from the coast; and skies have been fairly clear.” (and yes; I have noted the paragraph that follows the above quote)

    So before people start incorporating this into considerations of long term melt trend, future years might not quite reach it for a bit. i.e. don’t go expecting this to happen next year. The trend is still worrying enough without possibly unwise extrapolation from one years data.

    What particularly interests me with regards the Arctic ice-melt is the effect on Northern Hemisphere climates by impact on jet stream tracks. Obviously there’d be a further impact on permafrost and glacier melt, but this warming with regards sea level rise is a longer term issue. So as with the vagueries of Arctic geo-politics it’s something we’ll find out as we go.

    I’m less and less convinced about the utility of equating changes in the Thermohaline Circulation with events such as the Younger Dryas and coming up with “freezes”. Changes in atmosphere and ocean circulation implied seem to me to be far more important for us, due to food impacts. We’ve had odd summer weather this year in the UK (as far as I can see, largely down to the El Nino), a summer that just goes to show how a change in Pole/Equator weather systems can have substantial impacts.

    Thanks to William Chapman and all at Cryosphere Today (an all year regular site for me) and Mark Serreze and all at NSIDC for their seasonal roundups. Greatly appreciated by this British amateur climate science enthusiast. :)

  11. 111

    #102, Alastair must have lived in the Arctic, that is correct, the coldest place for ice is just North of Ellesmere and Northwest Greenland in February when a local High spreads Northwards often generating -50 C conditions at sea level, this creates multy year ice. The open Arctic ocean sea water scenario during winter is a little more complex, the biggest component has something to do with winds, which actually keep Polyneas open at -40 C. Clouds come next, so with say -24.5 C conditions, you can have open water provided it is always windy, or very cloudy with a little less wind. Weather underground Dr Masters, called it right when he said that further South winter will be delayed as well, but the biggest thing is the dynamics now of a cold and warmer zone at the Pole, surely affecting current weather everywhere in the Northern henmisphere. Not so long ago the Pole had a more even distribution of ice and that was the summer/fall weather we were use to.

  12. 112
    Dave Nicosia says:

    I have noticed that each year the main variability and recent ice decline has been in the shallower part of the Arctic Basin. The deepest part of the basin seems to keep its ice coverage each year. I wonder if the recent minimums are the lowest that the ice extent can get given the present state of the arctic climate and it won’t get any worse unless there is more significant arctic warming. One other item of interest is that the reanalysis data from NCEP shows that much of the region of the arctic basin where there is open water was slightly BELOW average in temperature from June through August10th in the height of the melt season. Could it be the warmer waters of the north atlantic ocean(warm phase AMO) that are flowing up into the arctic basin part of the reason for the shallow water melt-off in recent years? The decline really kicks in after the mid 1990s when the AMO flipped to the warm phase. From the late 70s to mid 90s, there was some small decline but the AMO was in the cold phase much of this time and slowly phasing back to the warmer phase. Could this decline be
    relayed to the AMO phase at least partly??

  13. 113
    Aaron Lewis says:

    Re 53
    The Salinas River is dead. That mud in the lettuce farmer’s fields is made with water from Sierra snow melt.

    Re 81, 82
    My point was that as much as 80 meters of relatively fresh water floats on the surface of the Arctic, and on which, most of the sea ice floats. This layer of fresh water has a dramatic effect on the formation of Arctic sea ice. Fresh water freezes at higher temperature than sea water.

    Frozen bulk sea water sinks. The ice that forms on the surface of the ocean is crystals of fresh water ice that exclude most of the impurities as they freeze. It must be significantly colder for ice crystals to form from sea water than from fresh water. This fresh water ice floats. The impurities rejected from the crystals form cold brine that sinks.

    If, and when, the fresh water ice melts, it often leaves a layer of low salinity water which may protect other sea ice from the warmer, saltier water that is below the surface in the Arctic. Thus, sea ice protects the surface layer of fresh water from storm mixing, and, the layer of fresh water protects the sea ice from the warmer saltier water below.

    Lose the Arctic sea ice, and storms mix the surface fresh water into the warmer, saltier mid-waters making the reformation of sea ice much more difficult. This is in addition to the loss of albedo as the ice melts.

  14. 114
    Hank Roberts says:

    Curtis Metz, do you mind my asking, where do you get your beliefs? I’m always curious what sources people have relied on for what they believe to be true, when they come here and post those beliefs.

    I went looking for what you posted and found the same thing a few places, but nowhere that looks like a primary source, just people stating the same belief:
    http://www.google.com/search?num=100&hl=en&newwindow=1&safe=off&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&hs=lCB&q=%22been+warming+since+the+last+Ice+Age%22+%22will+continue+to+warm%22+&btnG=Search

    If these aren’t you, or even if they are, can you say a bit about your source, who you trusted for what you believe? What source you relied on?

  15. 115
    Timothy Chase says:

    Barton Paul Levenson (#107) wrote:

    Curtis — The world has NOT been warming “since the last ice age.” If you calculate the effects from the assorted Milankovic cycles (it involves a lot of matrix math), you find that we passed the peak of the interglacial 6,000 years ago and the world should now be COOLING. The present warming is not natural. “We’re just coming out of an ice age” doesn’t correspond to reality.

    Solar forcing has been diminishing at least since 1960 and as such, we are experiencing solar cooling. The only problem is that the temperature is still going up.

    When it is said that solar variability may have been the dominant forcing in the early twentieth century, our best estimates are that this is true only if you break up the forcing of the greenhouse gases, e.g., carbon dioxide or methane. Relative to a base year of 1880, it would appear that the forcing due to anthropogenic greenhouse gases have had a greater forcing than that of solar variability – continuously – since 1880.

  16. 116
    Aaron Lewis says:

    Re 113
    Is this bit of physics in either the ice model or the ocean model or did this interface between ice and ocean get left out?

  17. 117
    John Locke says:

    An interesting forum.My question is why are the temperatures last year , but even more dramatically this year , so high in the area of the Canadian Archipelago? I have noticed that this summer of 2007 they are consistently 4 – 6C higher than the norms , eg Resolute and even Alert.

  18. 118
    Walt Meier says:

    Re: #72 hoosiernorm:

    You’re looking at the seasonal cycle of the total extent. There is strong seasonal variability, so the interannual change during specific time of year isn’t easy to see in the images you’re referring to. That’s why anomaly images are produced.

    walt

  19. 119

    #117, Mainly because the Earth is warmer, more energy in its system, and that it takes time for the excess heat to escape to space, especially when its replaced by a continuous cause for more heat (greenhouse gases. including especially new sources of water vapour a powerful feedback). Monthly warming anomalies in the Canadian Archipelago went almost continuously, with a few breaks for several recent years. I have observed not only extensive clouds (during long lasting Polar “heat waves” ), but also warmer temperatures during clear dark skies which are quite amazing. A warmer heat threshold has been surpassed and maintained which means that the entire Polar region is changing along with it.

  20. 120

    Re #117 I suspect the main reason why the summer temperature around the ARctic are much higher is that there is more water vapour which is the main greenhouse gas. Water vapour produces a positive feedback because it causes warming and warming means more water vapour. Provided clouds do not form, then then water vapour can cause a runaway warming. While there is ice on the ground, there is very little water vapour in the air. However once the ice/permafrost has melted the ground can get very warm, and so does the air and water vapour. Sea ice melting will have a similar effect, but the sea surface cannot warm as much as the land.

  21. 121
    Steve Bloom says:

    Re #97: I just noticed that I quoted a figure of 18C for early 20th century Arctic temperature rise. That was a typo from the paper; obviously it should be 1.8C. Hopefully that didn’t give anyone the wrong idea.

    Re #s 100/5: Big temperature rises in NH high latitudes are known to accompany the end of ice ages. Even if the 20C number Alastair quoted is high (I haven’t checked), and given that the worst we could expect now would be a smaller number than the ice age terminations since we’re starting off with higher temps and lower ice mass, bear in mind that even a few degrees additional warming in Greenland would seal the fate of the ice sheet. Then it would just be a question of how fast the melt/collapse will come. Of course this is the big fear being expressed by Hansen just now.

    Re #118: Thanks for sticking with the thread, Walt!

  22. 122
  23. 123
    John Locke says:

    I thank those who have attempted an explanation for the consistently high temperatures in such places as Resolute , Alert and I might add Eureka ( the last mentioned environmental Canada explained was due to bare rock and an inland location)Personally I suspect unusual wind circulation patterns.But even with northeasterlies lately produced temperatures still consistently 4C above what you would expect .I am not a physicist so plain common sense explanations please.I use ” Arctic Theme Page ” for my data.
    I have incidentally noticed some discrepancy between ice coverage given by “Cryosphere today ” and “Environmental Canada ice coverage with explanation ”

    ta

  24. 124
    NeilT says:

    Re:112

    So why is the current years melt (unprecedented or not), reaching right into the heart of the deep arctic basin?

    Watching the daily IR maps for the last 6 months has been very revealing in terms of melt freeze patterns.

    I suppose time will tell as the sea gains more and more heat each year, whether or not the main central cap will melt. But it doesn’t look good.

    My feeling is that the 2006 cooling was unprecedented and 2007 is more representative of the general trend.

    Generally I wonder why, once science has defined events such as tipping points, science tries to deny cumulative events and tipping and tries to pass them off as aberations??

  25. 125
    Timothy says:

    91 – I don’t think you can create a useful view of the risk by asking for the best-guess estimates from a large number of scientists in this case. The simple, plain fact is that we simply don’t know how quickly Greenland will melt so this necessarily introduces a large amount of uncertainty.

    The best course of action to take is simply to restrict emissions so that the warming is not sufficient to melt Greenland. This will be easier to achieve the earlier we start seriously to attempt to do so. We have wasted enough time already and there remains considerable uncertainty about how much time we have left (it might not be much).

  26. 126
    Larry says:

    Even the NSIDC is within 40,000 Km of the minimun as of August 13, which is about 1 or 2 days melt at this time of year, so I imagine the NSIDC will announce the official mimimun in their weekly update.

    I find that Environment Canada 50% ice coverage chart is always out to lunch for the far north. I find that huge sections of ice suddenly disappear overnight, suggesting that they don’t update for weeks at a time.

    Also I have not seen anything on the North Pole webcam camera 3 or 4 deployment, and the Polarstern is now heading south again after getting to 85 north. The last photos showed the ice to broken up to deploy the new cameras at 85 north. Does anybody know if they aborted that mission for the two new north pole web cams?

  27. 127
    Timothy Chase says:

    Timothy (the other Timothy) stated in #125:

    91 – I don’t think you can create a useful view of the risk by asking for the best-guess estimates from a large number of scientists in this case. The simple, plain fact is that we simply don’t know how quickly Greenland will melt so this necessarily introduces a large amount of uncertainty.

    There are a few things we do know and rather well.

    First, the arctic will be free of sea ice during the summers – and sooner rather than later. Second, a rise in temperatures in the northern hemisphere is usually accompanied by a drop in temperatures in the southern hemisphere. Third, ice loss in Greenland has been (for lack of a better word) accelerating during the past years with ice quakes increasing in frequency and intensity. The same is happening in the Western Antarctic Peninsula with over a hundred glaciers picking up speed as they head towards the coast. Fourth, both Greenland and Antarctica are experience net mass loss. Fifth, rising water will raise glaciers which are partly emersed by ocean.

    Positive feedback. Between Greenland and the Western Antarctic Peninsula. Things could start moving very, very quickly. And it would seem they already are with regard to the arctic sea ice. A lower albedo in the arctic due to the loss of sea ice is a large part of what is raising the temperatures in Greenland. More sunlight being absorbed.

    This certainly isn’t a time to panic.

    Never is. But I believe it is time to start acting more wisely.

    PS

    Nice to meet my namesake.

  28. 128
    Steve Bloom says:

    Re #127: I think that second peninsula reference should be to the West Antarctic Ice Sheet.

  29. 129
  30. 130
    Sphere says:

    Anyone bother to look at http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg as a step function graph rather than thinking either in terms of long-term average trends or very short-run events? Last time the area anomaly was positive was in early 2003, but running back as far as 1997 the usual anomaly was about 1/2 million — with only brief excursions far from that range. Starting in early 2005 it took a step down to about a million. Given how long its been at nearly 2 million now compared to the generally brief diversions usually seen, it seems likely that another step down has happened — although it would be too soon to project a usual value for the anomaly (the transition may not be complete).

  31. 131
    seo yaismasi says:

    Each year the Arctic sea ice meltback appears more dramatic and prompts the obvious discussions on causes.

  32. 132
    Matti Meikäläinen says:

    I live in southern Finland which is still quite far from north pole, 2000 miles or something. But I have noticed that the winter here corresponds quite well the ice coverage in arctic sea. Last time we had a cold winter here was 2002/2003. It was the last time when you could safely drive with car on top of the sea ice. And that was also the last time when arctic ice anomaly was positive.

    Last winter here was very short. We only had sea ice one month. That was February. Both December and January were warmest in the recorded history.

  33. 133
    Larry says:

    Its now official. The more conservative NSIDC has now indicated that we have broke an all time minimun ice extent as of August 16.

    So we now have new records, for area as of August 9 and extent for Aug 16 from NSIDC. And we have at least another month to go.

    Link

  34. 134
    Chris S says:

    Reply to 133: Well, that should sum it up well. We can expect to hear the nay-sayers attribute this to a “unusual cloud free melting season allowing more of the suns engergy to make it the lowest it’s ever been recorded. And many people will buy it as the “supporters” as I call them try to “nail” the science down and then argue with someone who knows much more about Atmospheric Science and AGW theories then themselves. Then they get mad when you correct them, destroying their “theory”.

    My personal favorite is when naysayers confuse the Artic and the Antartic with each other, claiming the “south pole is all ice, no land. You think Antartica is a continent because its such a huge piece of ice? It’s entertaining but severly fustrating at the same time. I also had to argue why AGW doesn’t tend to “increase” the ammount of hurricanes, just their intensity.

  35. 135
    Sphere says:

    Reply to 134. Well now you’ve got the other end to contend with. Recently someone from Greenpeace tried to involve me in “global warming”. My reaction, and response, was: Too late.

    We can jawbone all we want to, but the storyline is set — and there’s not a whole lot we’ll be able to do about it. Not saying that I really know what’s coming down the pike, but it’s too late to make any sort of societal change that will have a real effect. (My best guess is that I’ve got valuable ocean-front property in about two decades — currently at about 100 feet overlooking Boston.)

  36. 136
    Hank Roberts says:

    Hey, greed and selfishness are forms of spiritual poverty, and will always be with us.
    “Too late” is just another excuse not to learn enough about the science to realize you may very well be wrong.

    That’s what science is for.

  37. 137
    Sphere says:

    Reply to 136. I see you don’t get it.

  38. 138
    Hank Roberts says:

    I got it —- a 10-year window of opportunity to take decisive action. Lucky me it happens when I’m available to help.
    James Hansen et al, 2007. Climate Change and Trace Gases. Philiosophical Transactions of the Royal Society – A. Vol 365, pp 1925-1954. doi: 10.1098/rsta.2007.2052. http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_2.pdf

  39. 139
    Jim Steele says:

    Chris S. wrote: “My personal favorite is when naysayers confuse the Artic and the Antartic with each other, claiming the “south pole is all ice, no land. You think Antartica is a continent because its such a huge piece of ice? ”

    It sounds like you must be arguing with 3rd graders to find naysayers who confuse the Arctic and Antarctic in such a way.

    Perhaps you can instruct the slightly more educated naysayers like myself. I do not questions the extent of melting Arctic ice. I do question why the cause would be pinned on CO2- a well mixed greenhouse gas that should warm both poles somewhat equally.

    Why is the sea ice in the Antarctic not melting?

    Why has Antarctica not warmed or even cooled in the last 20 years when we are at near record global temperatures?

    And why was the Antarctic peninsula warming from 1940 to 1970 when the atmospheric temeratures were globally cooling?

    And why with all the melting in the Arctic, has sea level dropped over the past 20 years?

    Perhaps these are more sophisticated questions than you are prepared to answer? But the CO2 connection does not readily explain any of these differences to a naysayer [edit]

  40. 140

    All of the AR4 models were already getting ice extent wrong, yet still fit the historical data, so the models have other errors that compensate for missing this increased melting climate behavior. The models may well go wild in their projections while the climate continues its rather unalarming pace.

  41. 141

    Re #138 where Hank wrote ‘I got it —- a 10-year window of opportunity to take decisive action.’

    Sorry Hank, but you are wrong. There is no 10 year window of opportunity. That may have existed when the Kyoto treaty was negotiated ten years ago, but it has gone now.

    In the paper you cite, Hansen et al. wrote:

    Palaeoclimate data show that the Earth’s climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states. One feedback, the ‘albedo flip’ property of ice/water, provides a powerful trigger mechanism. A climate forcing that ‘flips’ the albedo of a sufficient portion of an ice sheet can spark a cataclysm. Inertia of ice sheet and ocean provides only moderate delay to ice sheet disintegration and a burst of added global warming. Recent greenhouse gas (GHG) emissions place the Earth perilously close to dramatic climate change that could run out of our control, with great dangers for humans and other creatures.

    Where he wrote “Inertia of ice sheet and ocean provides only moderate delay to ice sheet disintegration” I think he was referring to the Greenland and Antarctic ice sheets. The Arctic sea ice sheet does not have that inertia, and with its demise there will be a major release of the main greenhouse gas – water vapour. Hansen’s cataclysm is only about ten months away, not years.

    You can see that with the recent melts the recovery of the winter ice has begun later in the year. After this record melt the regrowrh will start later yet and the near total recovery we have seen in the past will not be possible this winter due to lack of time. Next summer the smaller ice pack will melt even faster and alsmost certainly disappear altogether.

    We have already seen this year that the areas of the world with Mediterranean type climates are suffering record temperatures which cause destructive wild fires. They reached the outskirts of Athens this week. With no Arctic sea ice these regions will become deserts within a year, and the disrption to world agriculture will result in global famine.

    Think about it :-(

  42. 142
    dhogaza says:

    I do question why the cause would be pinned on CO2- a well mixed greenhouse gas that should warm both poles somewhat equally.

    Why should it warm both poles somewhat equally?

  43. 143
    Chris S says:

    Reply to post 139:

    Well, yes they are far more sophisticated for me to answer considering I am a 23 year old who changed majors from teaching Earth Science, to doing something a bit more challenging and getting a M.S. in atmospheric science, which I’d later in life would like to each those same classes I’d be taking. I speak of “Naysayers” I’m not talking about Atmospheric Scientists and Climatologists like your selves. I’m talking about 30 – 50 year old men and women who confuse the artic ice cap and anatartica. You can’t pass 3thd grade if you don’t know the difference. Sad but true. It could be the cause of why so many people are swindeled.

    But as someone who has always thought “Scientifically” and “theorized” everything I’ve ever read on any science matter, I often wonder about alot of things that are said not only here, but everywhere about Climate.

    But I’ll give it a shot…

    Perhaps you can instruct the slightly more educated naysayers like myself. I do not questions the extent of melting Arctic ice. I do question why the cause would be pinned on CO2- a well mixed greenhouse gas that should warm both poles somewhat equally.

    Isn’t there a large carbon sink in the southern hemisphere that was recently studied and deemed “completely saturated of Co2″? Maybe that’s the reason. I’m still studying Calculus so that would be more on the level of your expertise to study, but it would make sense that if the ocean has been obsorbing most of the Co2, and what is it, half of the world population is located in the northern hemisphere, as are most of the industrial countries which would lead me to believe that they are somehow correlated.

    Why is the sea ice in the Antarctic not melting?

    This is the first I’m hearing of this. Last time I checked, it was melting, much quicker then expected. Didn’t the Laresn B Ice shelf colopase some decades ealier then expected?

    Why has Antarctica not warmed or even cooled in the last 20 years when we are at near record global temperatures?

    Possibly for the same reasons mentioned above about the Northern Hemisphere influencing the artic more rapidly then the antartic, considering most of the Co2 pollution comes from the Northern Hemisphere. If there’s a general “lage” in Co2 concentrations, like mentioned in another blog on this site, then that would lead me to believe that there’s a lag of the Co2 mixing from the nothern hemisphere into the sourthern hemisphere. How many data collectors are there in the Antartic anyways? Isn’t it almost impossible to reasearch there due to the conditions?

    And why was the Antarctic peninsula warming from 1940 to 1970 when the atmospheric temeratures were globally cooling?

    This is news to me, and is interesting. Where there less volcanic activity during this period? Are there El Nino’s, or La Nino’s that form in the southern pacific? Alot of questions to ask. Seems like not enough research has been done in the Southern Hemisphere. Well, I remember reading that research in the southern hemisphere is less extensive then that of the northern hemisphere as well.

    And why with all the melting in the Arctic, has sea level dropped over the past 20 years?

    Where is that coming from? You mean the “Artic sea level?” or worldwide sea level. That question isn’t very clear. Aren’t islands in the pacific being slowly depopulated because they are sinking? I’m assuming you mean the artic sea level? Wouldn’t geological features of the ocean basin under the ice cap reflect how the added water spread out? I know we’re still mapping the entire Earth’s ocean floor features, so I konw that there can’t be much information of what the land looks likes under the cap and artic ocean. That must have some sort of influence.

    My biggest question is, if there is a natural cycle, then why are we warming up when the cycle says we should be cooling?
    Theres obviously a lot of unknowns in this field and along with many other scientific fields. Thats the point of science. What I never understood, (and im not pointing you out specifically because I dont even know you or your field of expertise) is all these “scientists” like Linzden, who ask these sorts of questions. Why not do studies on them to figure them out? Isn’t that the point of a scientific question? is to obtain an answer? I’ve been hearing these sorts of questions for a couple years now, yet theres seems to be nobody studying why.

  44. 144
    Sphere says:

    Re #141. “Hansen’s cataclysm is only about ten months away, not years”. I think I’ll wait for the end of this summer’s ice melt before deciding whether to mark the date as next summer — or this one.

    “With no Arctic sea ice these regions will become deserts within a year, and the disrption to world agriculture will result in global famine.” You’re being a bit too definitive for my tastes here. While you may be correct, I don’t see where we can tell where the rains will fall. Desert perhaps, or jungle. (I also don’t know enough about hydrology. Can the water table deplete so fast as to create a desert in one year?)

  45. 145
    Sphere says:

    Re #139. “Why has Antarctica not warmed or even cooled in the last 20 years when we are at near record global temperatures?”

    Um, what about http://www.cdc.noaa.gov/map/images/fnl/sfctmpmer_365b.fnl.html ?

  46. 146

    [[Not saying that I really know what’s coming down the pike, but it’s too late to make any sort of societal change that will have a real effect. ]]

    I have to agree with you. To me it seems quite clear that 1) global warming is real, 2) human technology causes it, and 3) it’s a major problem. But I don’t think we’ll do anything about it in time to prevent a crisis. The human pattern is to let the disaster happen, then react. We don’t prevent crises.

  47. 147

    [[Why is the sea ice in the Antarctic not melting? ]]

    Who says it’s not melting?

    If you mean the extent of sea ice isn’t decreasing, that’s probably because there’s more calving at the edges, yes? You can’t be talking about the main body of ice, because since the disintegration of the Ross Ice Shelf a few years ago, that number is very definitely down.

  48. 148
    Sphere says:

    Re 147″ “disintegration of the Ross Ice Shelf ”

    That would be Larsen B. http://nsidc.org/iceshelves/larsenb2002/

    If the Ross goes then most likely the West Antarctic would quickly follow.

  49. 149
    David Price says:

    re.141 the jet Stream is not moving northwards this side of the Atlantic. It is flowing streight across England, causing floods etc. This is further south than normal. the hot weather in the Mediterrainian must have some other cause. Something similer happened 20 years ago,when Southern Europe had record temperatures Northern Europe had persistant rain and cold temperatures.

  50. 150
    Sphere says:

    Re #146: “But I don’t think we’ll do anything about it in time to prevent a crisis.”

    I was born in 1952, and I think it was already too late when I was born. Perhaps we could have done something to make the transition come later, or less suddenly, but I think the great coal burning of the 1800s had already sealed our fate.

    All we’re doing now is digging the hole deeper, and our only hope is for a few very big volcanic explosions.


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