By Steve Goddard and Anthony Watts
If you zoom in far enough, most anything looks scary, like this picture of a human head louse.
But when you look at it in the scale of our normal experience, not so much.
Be it lice or ice, the scale of presentation matters.
There is often criticism of cherry picking when it comes to time scales of climate data. In the case of satellite sea ice data presentation, both time scale and vertical scale are magnified. There’s only about 30 years of satellite ice data, whereas Arctic sea ice has been around for millions of years. Vertical scale is magnified to show the smallest fluctuations. Willis Eschenbach made and excellent point about scale when he comparatively demonstrated the scale of ice melt in Greenland in his essay: On Being the Wrong Size. When compared to the bulk volume of ice, the current Greenland melt is statistically insignificant.
There has been a lot of talk about commercial shipping opportunities through the “soon to be ice free” Arctic. These are normally based on highly magnified graphs published by organisations like NSIDC, similar to the one below.
A different view emerges when you take the raw data from NSIDC’s web site and plot it on graphs with a more appropriate vertical scale. Done that way, the downwards trend for April ice is 0.039 million km²/year.
The surprise of scale?
When you calculate the slope, it suggests that April sea ice extent won’t reach zero until the year 2385.
Oh, that can’t be right. How about May? May will be ice free in the year 2404, only 394 years from now. (The US is 234 years old. Copernicus was placed on the “Catholic Forbidden index” 394 years ago.)
June will be ice free in the year 2296.
July will be ice free by the year 2151.
August will be ice free by the year 2103
September will be ice free by the year 2065. (Note that September 2009 was right on the trend line.)
All of the data and plots are available here in this Google online spreadsheet.
September is the minimum and ice starts to freeze up again. No chance of an ice free Arctic in October. But something must be wrong. The experts said that the Arctic would be ice free by 2008, and that it would be ice free by 2013.
“Our projection of 2013 for the removal of ice in summer is not accounting for the last two minima, in 2005 and 2007,” the researcher from the Naval Postgraduate School, Monterey, California, explained to the BBC. “So given that fact, you can argue that may be our projection of 2013 is already too conservative.” “In the end, it will just melt away quite suddenly”
NSIDC director, Dr. Mark Serreze also says this in this 5/20/10 Globe and Mail article:
“We are going to lose the summer sea-ice cover. We can’t go back.”
Dr. Serreze is still on the ‘death spiral’. He hasn’t changed his tune.
While skeptics see cycles, by saying “we can’t go back” Dr. Serreze apparently assumes the linear trend will continue to zero.
You can see from the graphs above how ridiculous those claims are. Even if the current trends continue, there is no reason to expect an ice free Arctic anytime in the next 50 years. And even more interesting to me is the fact that September, 2007 was really not that interesting. It was only 1.5 standard deviations off the trend line, i.e. almost following the 30 year trend.
All of the the main Arctic ice experts underpredicted the 2009 minimum, except for WUWT – which predicted it correctly and early.
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Science is the belief in the ignorance of the experts
-Richard Feynman
Gail,
There are natural cycles of about 60 yrs (ocean) and 200 yrs (sun), but we only have data for about 30 yrs so there is no way in heck we have a good handle on the natural variability or what the “true average is”.
If we only have 30 years data, how can you possibly assert there are 60 or 200 year cycles?
This statement is incorrect: “When compared to the bulk volume of ice, the current Greenland melt is statistically insignificant.” This normally means the uncertainty in the measurement is larger than the measurement. That was not the case here, or at least you did not establish that in your previous post on this. You really mean that it is misleading to report the ice melt rate without mentioning the total ice mass, which is a fair point.
I disagree that the “Average Monthly Arctic Sea Ice Extent, April 1979 to 2010” graph from NSIDC is misleading. The scale is clearly given and is appropriate for the question the graph is addressing: is arctic sea ice extent declining? Yes it is. If such graph were accompanied by alarming statement like: “All Arctic sea ice is going to melt away soon!”, then they would be misleading.
Your linear projections of when Arctic sea ice might are not valid because there is no basis for assuming linearity. (You did not claim they were valid.) The concern of mainstream researchers is that positive feedbacks may accelerate the decline, while skeptics place more stock in natural cycles as you state later.
The first two news stories you cite did not claim the Arctic would be “ice free,” only that the North Pole region might be ice free in the summer. Neither story represented a consensus view; the first was from a rather obscure source.
Dr. Serreze is not claiming Arctic sea ice will be totally gone and he did not give a date. His statement – “We can’t go back” – is about positive feedback, not linear extrapolation.
You and your readers might find this article of interest. It concluded: “The projected ice-free summer Arctic Ocean may occur as early as in the late 2030s using a criterion of 80% SIA loss…”
http://www3.interscience.wiley.com/journal/123301802/abstract?CRETRY=1&SRETRY=0
This is still not a consensus view. I do not think there is a consensus assessment at this time.
R Gates,
Why are you posting two year old links as evidence against increase since 2007?
I would love to see an article up on WUWT about the importance of correcting alpha levels for multiple tests of statistical significance as well.
The following Q&A from the FAQ section of NSIDC answers my question about whether the Arctic sea ice extent measures the the thickness of the ice as well as it’s surface area. It does not.
“What is sea ice extent, and why do you monitor that particular aspect of sea ice?
Sea ice extent is a measurement of the area of ocean where there is at least some sea ice. Usually, scientists define a threshold of minimum concentration to mark where the ice ends; the most common cutoff is at 15 percent. Scientists use the 15 percent cutoff because it provides the most consistent agreement between satellite and ground observations.
Scientists tend to focus on Arctic sea ice extent more closely than other aspects of sea ice because satellites measure extent more accurately than they do other measurements, such as thickness.”
http://nsidc.org/news/press/2007_seaiceminimum/20070810_faq.html
stevengoddard says:
May 24, 2010 at 7:59 am
barry
You must have missed this post from yesterday.
No, I read it. No mention of whether the sea ice is recovered or not. I see that the four sea ice products I know of show current sea ice extent below average and near the 2007 line for this time of year. Three of four show sea ice extent below 2007.
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
http://www.iup.uni-bremen.de:8084/amsr/ice_ext_n.png
http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_ext.png
Last month you posted that Arctic sea ice extent had recovered. Do you hold to that view at this time?
Steven Goddard, be careful you don’t dig too deep a hole for yourself. You’re reaching levels of arrogance I only see climate scientists being accused of.
If this summer’s circumstances in cloudiness and wind etc. are anywhere near those of summer 2007 the minimum sea ice extent record will be shattered.
As you (or anybody else) cannot be certain this won’t happen, I really don’t see why you are being so incredibly cocky. You’re recklessly gambling with your and WUWT’s credibility, or what’s left of it.
REPLY: Oh Neven, puhleeze. I read what you say elsewhere about me, WUWT, and its contributors. Your “concern” is bullcaca. – Anthony
@barry: “Can we get an update on whether it has recovered or not?”
No it has not. “In April, the centre published data showing that sea ice had almost recovered to the 20-year average. That ignited a flurry of interest on climate change skeptic blogs. [Who could they be talking about?] But much of that ice was thin and new. The warmest April on record in the Arctic made short work of it. Ice cover has already fallen back to where it was in 2007 at this time of year and is disappearing at a faster pace than it did then.”
http://www.theglobeandmail.com/news/national/arctic-sea-ice-heading-for-new-record-low/article1575212/
When an alarmist blog calling itself ‘skeptical science’ tells you what to think, it’s always a good idea to check it out first.
Here’s a good starting point regarding sea level changes. Also, see here.
Chris1958, this might address your question:
http://www.newscientist.com/article/dn12872-shrinking-ice-means-greenland-is-rising-fast.html
Most of the current Arctic sea ice “loss” is in the eastern Arctic. How much of that “loss” is due to the wind blowing ice out of the catchment area?
My thoughts are that air temperature has little effect on changes in the amount of Arctic ice, and it is mainly sea temperatures and the strength of currents which cause the oscillations to the quantity of sea ice. Wind direction/strength also play a major role in determining the outcome of this deterministically chaotic system.
Linear trends have no meaning and it is easy to ‘cherry pick’ a period showing sea ice reduction or growth. The biggest nits are the scientists who promote the idea of Arctic ice being in a ‘death spiral’. They clearly don’t have a clue about the complexity of our polar systems!
OK, so if a linear trend is not to be expected, why so much stress on it in the post?
And if it’s not going to be linear, then what will it be? Logic would seem to suggest that the loss of sea ice will accelerate, for several reasons, but particularly increased water vapor (#1 GHG) with increased open water in the Arctic (water vapor feedback), and increased absorption of shortwave radiation by that open water (albedo feedback.)
Who are you gonna believe? [blink gif, takes a few seconds to load]
R. Gates says:
May 24, 2010 at 8:06 am
Very interesting, but the assumption is the trend will be linear, rather than look something like this: (very unsophisticated graph, but gets the point across)
http://www2.norwalk-city.k12.oh.us/wordpressmu/precalc/files/2008/12/math.bmp
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I just want to comment on the above quoted first paragraph of your post, rather than your entire post.
The linked graph implies a rapid disappearance of Arctic sea ice , as measured by its extent, once it becomes thin. That makes sense because the difference between, for example, 10 and 1 is greater than the difference between 1 and 0.
Since extent measures only the ice’s surface area, what do we know about changes in its thickness or volume that might suggest when it will become thin enough to disappear for part of the year?
Here’s a link to an excellent powerpoint that gives a nice overview of why the Arctic Sea Ice loss is tending to become NON-linear. Highly recommended for the “warmist” and skeptic alike:
http://lpvs.gsfc.nasa.gov/LPV_meetings/Beijing09/Stroeve.pdf
Steve, for you to believe the sea ice decline is going to be linear makes me wonder what else you don’t understand about how climate works. And you also seem to conflate ice free summers with ice free Arctic. No one expects the Arctic Ocean to be ice free in winters. It is the summer ice cover that is going to disappear, resulting in a sea ice climate more like Antarctica.
I would love to see you address your recovery statements you made earlier in the sea ice posts. Seems you were wrong, yet you don’t want to admit it. Sea ice is not behaving as you had hoped, making your previous posts on assumptions about this summer incorrect. Makes me wonder more and more what else you are wrong about…
Kevin McKinney says:
May 24, 2010 at 8:37 am
Kevin, indeed the ice loss has accelerated. Doing a trend analysis on the September ice extent (in the Arctic Basin, which excludes the East Greenland Sea and the Canadian Archipelago) from 1979-1998 gives a trend line of -0.032+/- 0.017 million sq-km/yr. Compare this with a trend line of -0.165 +/- 0.044 million sq-km/yr from 1999-2009. These slopes are statistically different from each other at a 95% confidence level.
Steve doesn’t seem to want anyone to know this…
jcrabb says:
May 24, 2010 at 5:12 am
So the IPCC is correct expecting the Arctic to be Summer ice free some time after 2050.
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NO, Climate runs in cycles. We just went through a time with all the cycles set to positive (warm). We are now due for thirty years of COLD. That means 2040’s could be like the 1970’s. It all depends on what other cycles kick in and when. If the sun continues in a funk (the source of all energy) then we could be looking at a little ice age especially if the volcanoes like Katla kick in too.
Climate science is a very new science and the subject is complicated. What we are currently seeing is the political Spinmiesters taking advantage of this to pass laws that funnel money out of your pocket and into theirs. The fact is that most funding is for papers that have the global warming catch phrase.
<i”….A 12-year low in solar “irradiance”: Careful measurements by several NASA spacecraft show that the sun’s brightness has dropped by 0.02% at visible wavelengths and 6% at extreme UV wavelengths since the solar minimum of 1996. The changes so far are not enough to reverse the course of global warming,…” NASA
“….At least 10 to 30 percent of global warming measured during the past two decades may be due to increased solar output rather than factors such as increased heat-absorbing carbon dioxide gas released by various human activities, two Duke University physicists report…. However, they emphasized that their findings do not argue against the basic theory that significant global warming is occurring because of carbon dioxide and other greenhouse gases ….” Duke Physicists Report
Here is a study where the false finding reported make me very angry.
“….Americans are likely to suffer from kidney stones in the coming years as a result of global warming, according to researchers at the University of Texas.
Kidney stones, which are formed from dissolved minerals in the urine and can be extremely painful, are often caused by caused by dehydration, either by not drinking enough liquid or losing too much due to high heat conditions.
If global warming trends continue as projected by the UN Intergovernmental Panel on Climate Change in 2007, the United States can expect as much as a 30 percent growth in kidney stone disease in some of its driest areas, said the findings published in Monday’s Proceedings of the National Academy of Sciences. …” Global warming may increase kidney stones
This is very misleading. The real cause especially in the ” “kidney stone belt” of the southeastern states of Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee. “ is ICED TEA and other caffeine laden beverages. Drinking lots of WATER, not soda and ice tea is the correct method of prevention and this minor detail is completely missing from the article. GRRRrrrrr
There are plenty of other examples. Pamela Grey mentioned at the beginning of the year how the “global warming” phrase was the necessary “get out of jail free card” needed to get her papers published and she hoped climategate would mean it would be no longer necessary.
She meant to say, “satellite data” on arctic ice extent. We have other data on the PDO.
R. Gates
Great link thanks. It shows exactly why scientists shouldn’t jump to conclusions about non-linearity based on a one-year blip. I’ll bet the authors regret having written it now.
Kevin McKinney
The point is that the predictions of very early ice disappearance are not supported by the data.
Wren,
I didn’t realize that plotting NSIDC data was arrogant. Perhaps it would be more reasonable to forecast an ice-free Arctic by 2013?
The reason that Serreze forecast an ice free pole in 2008 was because it started out with first year ice that summer. The lesson to be learned is perhaps that even first year ice won’t disappear that far north.
I hereby post the predictor of predictors for any required prediction, forecast, or seer:
Multiply the average PDO year times the mean square root square of ENSO moment plus the 2nd derivative of the AMO temperature minus natural log of the distance between any two planets at midnight zulu divided by three Solar Flare units plus the standard deviation regression rate of Greenland’s Ice pack squared plus last weeks sun spot number (choose wisely) times todays solar flux minus the first deviation of Antarctica ice pack times the low cloud on a clear day times the datum curve derivative of the first integration of the specific gravity of Guinness Stout plus linear motion of the total volcanic output times the time it took to post all the above remarks.