10/31 NEWS: See updated graphs here
UPDATED: 10/22/08 The new images below are even closer
Watching arctic sea ice rebound this year has been exciting, more so since a few predictions and expeditions predicated on a record low sea ice this past summer failed miserably. I’ve spent a lot of time this month looking at the graph of sea ice extent from the IARC-JAXA website, which plots satellite derived sea-ice extent. However, there is another website that also plots the same satellite derived data, the Nansen Environmental and Remote Sensing Center of Bergen Norway, and they have an added bonus: a standard deviation shaded area. For those that don’t know what standard deviation is, here is a brief explanation from Wiki
…standard deviation remains the most common measure of statistical dispersion, measuring how widely spread the values in a data set are. If many data points are close to the mean, then the standard deviation is small; if many data points are far from the mean, then the standard deviation is large. If all data values are equal, then the standard deviation is zero.
In a nutshell, you could say that any data point that falls within the standard deviation area would be considered “within normal variances” for the data set. That said, current sea ice extent and area data endpoints (red line) are both approaching the edge of the standard deviation (gray shading) for both data sets. Here is sea ice area:
Click for a larger image
And here is sea ice extent:
Click for a larger image
Extent has a bit further to go than area, and of course it is possible that the slope will flatten and it may not reach the SD gray area. It’s also possible it may continue on the current trend line. Only nature knows for certain. A complete presentation from Nansen is on this page which is well worth bookmarking.
What I find particularly interesting is the graph comparing the 2008, 2007, and 2006 sea ice extent. It appears 2008 extent has already bested 2006 extent:
with a hat tip to commenter Patrick Henry
I would have thought that a 31% + increase in winter max for 2008 and rising was something to shout about.
It is! (the latest number is nearer 21% but let us not quibble) It is extraordinarily welcome good news, and if the winter extent heads into normal or median territory this is also a welcome development as it means the albedo reduction feedback effect is much less. I just urge caution before celebrating this as a long term ‘recovery’ or ‘return to normal’ for the reasons mentioned, firstly there is a lot less variability in the winter extent, and secondly it is a recovery from a record shattering low point. As Dr Meier pointed out the 2007 minimum was still below the previous long term trend of -10% / decade making the new trend -11.7% / decade.
So whether this single year-on-year increase marks the reversal of the long term negative trend or is just a dead cat bounce before the the ice reduction resumes it is far too early to say.
If the warming is global and still rising as you AGWers suggest, you should have surely seen a continuing decrease of ice extent similar to the decrease of the past few years.
Not necessarily, natural variability does not disappear in the presence of a warming trend; other factors such as wind patterns continue to influence the ice extent, meaning that nobody predicts an exactly linear reduction, and that one should be cautious in drawing conclusions from short term changes.
Oooops!
As Dr Meier pointed out the 2007 minimum should of course read 2008 minimum. Apologies.
What the hayall is a “normal standard deviation”?
John Philip,
” I just urge caution before celebrating this as a long term ‘recovery’ or ‘return to normal’ for the reasons mentioned, ”
I don’t think that this is a ‘return to normal’, but rather the entire record IS normal… including 2007.
Data from the IJIS web site at http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv indicates that 2008 ice extent has now moved up into 3rd place for Oct 22nd, behind 2002 and 2003. 2008 is just barely ahead of 2004, 2005, and 2006, and way ahead of 2007. It’s a bit hard to see on the graph, because the lines for 2004/2005/2006/2008 are so close.
Note that they give preliminary numbers for us number-freaks, so the current day, and possibly the previous day, mya be subject to slight revision. But that’s it. No GISS follies going back to the beginning of the record..
PeteM: “Pumping CO2 into the air in quantities that globally changes the atmosphere is an unwise thing to do unless we really really really know the consequences.”
Let’s get some perspective here. There’s now approximately one more molecule of CO2 for every 10,000 molecules of air than there was 100 years ago.
And nobody can say for sure how much, if any, of that gain was down to man’s activities or, indeed, how much, if any, effect it’s having.
And here’s the kicker – If, as we are told, atmospheric CO2 levels remained constant to within a few tens of ppm for over a thousand years, global CO2 sinks must have tracked global CO2 sources to within a few percent over that entire period, or a few thousandths of a percent annually on average. Do you have any sort of credible explanation for this?
Re Dennis Hopkins :-
I have taken the Daily telegraph for 50 years and it saddens me that a paper that once could be relied on to deliver the facts and eschew mindless theories and speculation has in the past few years plummeted to the depths of reporting employed in the penny dreadfuls.
Does anyone know when was the last time Arctic ice levels were within the ‘normal’ range?
Most of the time the earth is in an ice age, so normal would be Chicago buried under a mile of ice.
Great article, and a perfect illustration for my next installment on “How the Warmists Scheme”. It’s not quite “As The World Turns” but interesting nonetheless.
So did you think it was just a random thing when the Warmists started using the term “Climate Change” interchangeably with Global Warming? Climate by nature changes. The patterns change, the timing of marked events change. You see Climate Change IS happening, because it always does, in fact the word “change” is not needed as change is implied by use of the word Climate. And this is the trap.
Yes the Arctic has gotten warmer, and the Antarctic cooler, the midwest states have had warmer weather, while parts of the Soviet Union have had cooler ones. Weather changes. It warms in one place or time, and it cools, in another, and it is the net sum of what you get that ends up being the climate. BUT IT IS NOT FIXED. If January is warmer this year than last, that in and of itself means nothing. That is unless you REQUIRE that january be cold. However historically, no such requirement existed. That is until the Warmists decided that Global Warming was not selling, and came up with the Climate Change song and dance, which imposed this requirement. So now, if we have no hurricanes in October but many in November, then it’s Climate Change, because OCTOBER is supposed to be when we have the most hurricanes. Or, if in the case of Anthony’s graphs, Arctic Sea Ice begins melting quicker in August, then we are surely doomed to see “catastrophic” ice losses, given that September is when the greatest ice loss is “supposed” to happen.
That is exactly what happened this year. We lost ice rapidly in August, and the Warmists couldn’t hold their tongues, proclaiming this year a total tragedy, the year of the Northwest Passage, etc etc. And it was all based on the totally false logic of a fixed climate. The fact is when we have more hurricanes in November, all it means is that we have more hurricanes in November. Less ice in August means less ice in August, nothing more. The Warmists are constantly doing these extrapolations from some baseline that doesn’t exist. And they are totally baseless. This fact is made clear by Anthony’s illustration of the quick recovery of Arctic Ice late summer, which flies fully in the face of the propagandist doomsday predictions the Warmists were making as recently as 8 weeks ago.
Climate is not and never has been fixed, and thus Climate Change is a junk term. Around this meaningless term, the warmists build false assumptions and arguments based on faulty premise. Then they knowingly and deceptively bait and switch it with “Global Warming” in hopes of making you buy the bigger fish. Of course once you do, then you are an easy markfor them to tax your guilt away, along with your freedom and standards of living.
Some Aprils are colder than others. Some Decembers are snowier than others. We all know that, accept that, and view it as normal. That such normal events have been extrapolated out (with the help of models and statistics) to be some end of the world scenario that we all caused by driving cars is utterly ridiculous. I have to applaud the careful and clever manipulation, but only amidst the tears that come with believing that human beings could conceive or believe such a scam…
Flanagan,
“What is usually reported as the standard value for ice extent is the 79-2000 average where the ice extent decreased only quite slowly. Why take the 79-2007 average instead?
Oh, yes, I see! So you can include the 2000-2007 years which are way below the 79-2000 average to make it look like it’s “going to normal again”, while actually it’s going back to the 2000-2007 average.”
What deity declared the period 1979 – 2000 to be what is “normal”?
Whoever wrote,
“having a baby is the most polluting act most individuals can do”
…is one who dwells in the deepest, darkest crevices of some lunar body. In other words, a lunatic.
I think using needles to pierce a skull and kill the developing brain of an innocent unborn is far more polluting to that life, don’t you think?
Darn those environMENTAList wackos. They care more about trees than humans. Don’t believe me? I cannot CUT a tree in my own yard due to environmental regulations. Got that? However I can CUT the life of an innocent unborn… no problem.
Planet in peril. Climate catastrophy. Save the earth. You are all nut jobs.
God help us.
@ur momisugly John Philip
“So whether this single year-on-year increase marks the reversal of the long term negative trend or is just a dead cat bounce before the the ice reduction resumes it is far too early to say”.
You mean …. the science is NOT settled !!!
Heresy ! You flat-earther you.
Arthur Glass (07:07:09) :
I don’t want to be a neutrino but I do want to be a butterfly. That way I can flap my wings and cause a Hurricane to form. I just need to learn how to focus so my hurricanes form exactly where I want them.
Rich,
You miss the point. If GHGs are really a crisis then reproducing is an unforgivable act of pollution and baby permits will be the inevitable consequence of carbon permits.
But most greens don’t make an issue of this because they know they would lose whatever public support they have despite the logical inconsistency.
John Phillip, you are exactly right about not paying too much attention to short term trends. Natural variability does skew the interpretation.
A perfect example of this is looking at the last millennium. You see an upward trend leading up to the climate optimum in the Medieval Warm Period, where temperatures were 3-5F higher. Accordingly you can easily observe an overall downward trend since. Significantly clearer than the conclusions Warmists try to draw from the multiple <1F up and down trends of the last decade. Looking at things from your viewpoint, Global Warming ceases to exist.
Funny. That’s what most of us have believed all along.
Hi Raven,
I was being slightly sarcastic. I didn’t miss the point. In fact, I mentioned population control in my previous post on this thread.
But I agree with you. Atlreast for now the public support won’t be there. But won’t it… eventually?
Alan B. and Anthony,
Thanks for the info.,
John D.
There appears to be a HUGE discrepancy (3 million KM2) between this:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg
and this:
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
both mesauring the same thing. Knowing the former’s bias.. now should we be doubting its measuring method.
Peter (14:31:25) :
” … If, as we are told, atmospheric CO2 levels remained constant to within a few tens of ppm for over a thousand years, global CO2 sinks must have tracked global CO2 sources to within a few percent over that entire period, or a few thousandths of a percent annually on average. Do you have any sort of credible explanation for this? ”
At a high level – the idea of a dynamic equilibrium . Chaotic systems can support stable zones (it even sometimes happens in the financial world :-))
When humans burn fossil fuels in industrial quantities they become a new source of CO2 . This changes the balance between source and sinks which would lead to an increase in the levels of CO2.
Conceptually this can be checked by running an experiment where we significantly reduce the burning of fossil fuels and see if the annual increase slows or reverses. Maybe with the current down turn we may be able to able to informally check this – assuming all other CO2 sinks/sources behave in a stable or predictable manner.
No deity ever declared some time period to be the absolute reference. But in a decreasing time series, comparing with the moving average is not a measure of the decrease rate but rather of the decrease acceleration. Which is obviously not the same.
Derek D (17:17:02)
“You see an upward trend leading up to the climate optimum in the Medieval Warm Period, where temperatures were 3-5F higher”
As discussed in previous threads the MWP was in all probability not a global event but regional anomolies occuring asynchronously around the globe. Increasing evidence shows there was a prolonged cold period in the southern hemisphere at the time the Vikings were starting colonization of a small coastal portion of Grennland. There was also a prolonged warm spell in the southern hemisphere during the northern hemispheres LIA.
Mary Hinge
“As discussed in previous threads the MWP was in all probability not a global event”
Well, it was apparently about as global as the current warming, i. e. the northern hemisphere and at least part of the southern tropics, but apparently not Antarctica.
“a small coastal portion of Grennland”
It was a small part of Greenland, but not really a small area. If you want an idea of the scale, think of Connecticut and the coastal plain of North Carolina, plus part of New Jersey (the so called “middle settlement” which is not mentioned in historical sources, but only known archaeologically)
Peter stated “When humans burn fossil fuels in industrial quantities they become a new source of CO2 . This changes the balance between source and sinks which would lead to an increase in the levels of CO2.
Conceptually this can be checked by running an experiment where we significantly reduce the burning of fossil fuels and see if the annual increase slows or reverses. Maybe with the current down turn we may be able to able to informally check this – assuming all other CO2 sinks/sources behave in a stable or predictable manner”
The last sentance is the key. With the oceans neither (last three years) rising or warming, and plant life increasing, then things are not staying the same. I hope the CAGW crowd does not try to claim the world economic crisis and reduced global consumtion as the cause of the recent cooling, when they eventually admit to that cooling.
PeterM: “At a high level – the idea of a dynamic equilibrium . Chaotic systems can support stable zones”
That much I can just about swallow.
But you have several chaotic and semi-chaotic systems, some independent, some semi-independent, some nett sources, some nett sinks.
The concept of all of those reaching dynamic equilibrium corresponding to the same level of CO2, over hundreds or thousands of years, stretches credulity past breaking point, I’m afraid.
Peter (04:52:12) :
I think you mean to say it stretches ‘your’ credulity .
If some sort of (temporary ) equilibrium was never possible despite all of those varying complex systems then it stretchs ‘my’ credulity as to how long term life (which requires some limits to system variability) could have survived the instabilities given we are taking hundreds of millions of years.
And this still misses the point that we know significant quantities of CO2 is being introduced into the atmosphere by burning fossil fuels .