Guest post by Steven Goddard
Several people keep asking why am I focused on winter snow extent. This seems fairly obvious, but I will review here:
- Snow falls in the winter, in places where it is cold. Snow does not generally fall in the summer, because it is too warm.
- Winter snow extent is a good proxy for winter snowfall. Snow has to fall before it can cover the ground.
So what about summer snow cover? Summer snow cover declined significantly (from the 1970s ice age scare) during the 1980s, but minimums have not changed much since then. As you can see in the graph below, the overall annual trend since 1989 has been slightly upwards.
Data from Rutgers University Global Snow Lab
Note in the image above that there has been almost no change in the summer minimum snow extent since 1989, and that the winter maximums have increased significantly as seen below.
Summer snow cover is affected by many factors, but probably the most important one is soot, as Dr. Hansen has stated.
The effects of soot in changing the climate are more than most scientists acknowledge, two US researchers say. In the Proceedings of the National Academy of Sciences, they say reducing atmospheric soot levels could help to slow global warming relatively simply. They believe soot is twice as potent as carbon dioxide, a main greenhouse gas, in raising surface air temperatures. … The researchers are Dr James Hansen and Larissa Nazarenko, both of the Goddard Institute for Space Studies, part of the US space agency Nasa, and Columbia University Earth Institute.
http://news.bbc.co.uk/2/hi/science/nature/3333493.stm
The global warming debate has until now focused almost entirely on carbon dioxide and other greenhouse gas emissions, but scientists at the University of California – Irvine, suggest that a lesser-known problem – dirty snow – could explain the Arctic warming attributed to greenhouse gases….The effect is more conspicuous in Arctic areas, where Zender believes that more than 90 percent of the warming could be attributed to dirty snow.
http://www.scienceagogo.com/news/20070506202633data_trunc_sys.shtml
In summary, winter snowfall is increasing and currently at record levels, and summer snow extent is not changing much. Earlier changes in summer snow extent were likely due primarily to soot – not CO2.
Why Is Winter Snow Extent Interesting?
Several people keep asking why am I focused on winter snow extent. This seems fairly obvious, but I will review here:
1. Snow falls in the winter, in places where it is cold. Snow does not generally fall in the summer, because it is too warm.
2. Winter snow extent is a good proxy for winter snowfall. Snow has to fall before it can cover the ground.
So what about summer snow cover? Summer snow cover declined significantly (from the 1970s ice age scare) during the 1980s, but minimums have not changed much since then. As you can see in the graph below, the overall annual trend since 1989 has been slightly upwards.
Data from Rutgers University Global Snow Lab
Note in the image above that there has been almost no change in the summer minimum snow extent since 1989, and that the winter maximums have increased significantly as seen below.
Summer snow cover is affected by many factors, but probably the most important one is soot, as Dr. Hansen has stated.
The effects of soot in changing the climate are more than most scientists acknowledge, two US researchers say. In the Proceedings of the National Academy of Sciences, they say reducing atmospheric soot levels could help to slow global warming relatively simply. They believe soot is twice as potent as carbon dioxide, a main greenhouse gas, in raising surface air temperatures. … The researchers are Dr James Hansen and Larissa Nazarenko, both of the Goddard Institute for Space Studies, part of the US space agency Nasa, and Columbia University Earth Institute.
http://news.bbc.co.uk/2/hi/science/nature/3333493.stm
The global warming debate has until now focused almost entirely on carbon dioxide and other greenhouse gas emissions, but scientists at the University of California – Irvine, suggest that a lesser-known problem – dirty snow – could explain the Arctic warming attributed to greenhouse gases….The effect is more conspicuous in Arctic areas, where Zender believes that more than 90 percent of the warming could be attributed to dirty snow.
http://www.scienceagogo.com/news/20070506202633data_trunc_sys.shtml
In summary, winter snowfall is increasing and currently at record levels, and summer snow extent is not changing much. Earlier changes in summer snow extent were likely due primarily to soot – not CO2.
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Hi Steve,
Thanks for getting back to me. It wasn’t clear in your article that was what you were trying to show. (I hadn’t read read your previous article I’m afraid and you didn’t point to it here.)
I had a few other questions too, which I think are still relevant.
I wondered if the trend in the Northern Hemisphere Annual Snow Cover Plot was sufficient to give you confidence that there was a trend – only it looks very slight, to tell the truth, and you don’t say what the error margin is.
And I also wondered why you thought it might be useful to begin your plot from a minimum in the data. By picking unusual data don’t you think you might get unusual results?
Ref – Leif Svalgaard (10:06:20) :
Pascvaks (09:45:54) :
P. – “One of the first laws of Human Nature has the acronym KISS (Keep It Simple Stupid!). Einstein was brilliant at it;..”
L.S. – Einstein once said: “keep it as simple as possible, but no simpler“.
_________________________
My guess he was talking to a PhD; warning him not to underestimate “people”.
P – “Don’t assume IQ tests have anything to do with wisdom or intelligence.”
L.S. – “Science has nothing to do with IQ-test, nor with wisdom, nor with intelligence.”
___________________
I’m sorry, what planet did you say you were from?
PS: Ref your ref to WP article to Kadaka – 🙂
PPS: Exchanges like this are a waste of brain cells. I don’t have any I can afford to spare and you would be better occupied discovering something new for the rest of the tribe. God bless!:-)
Leif Svalgaard (10:31:11) :
Wow. I question the MSM presentation, and you rebut with an MSM article. Is this like when we “climate skeptics” question what the IPCC does with the research, and we get rebutted by references to the IPCC?
Beginning analysis of spin…
Science was co-opted to promote atheism with the insistence that accepting science meant rejecting a belief in God, and believers pushed back against said “science.” Is that supposed to be surprising?
As polls go, it helps in understanding the results to know who asked the questions, what groups were polled, and it is especially important to know the exact wording of the questions.
As it stands, 10 thousand years is about the length of “recorded human history” thus is solid evidence of humans existing “in their present form.” If you take Genesis as metaphor, accept evolution and the actual science, with the caveat that God “tweaked” an existing pre-human primate to bring about humans, then yes, you could very well agree on a poll that “God created humans in their present form 10,000 years ago (or less)” and still not be a Young Earth Creationist.
To recap, you are trying to affirm “…half of Americans believe the Earth is 6000 years old.” What have you provided? 10,000 years ago, not 6000, humans were created in their present form, not that the Earth is only that old.
Plus, evolution as presented has changed over the years. My mother well remembers in school being explicity taught that man descended from the apes. A common ancestor for the seperate lines of humans and other large primates was a change in theory that came later. Thus, as originally taught, one may say that “man shares no common ancestor with the ape,” not be a Creationist, and only be faulted for considering a straight line yielded “no common ancestor.”
One of the first things that science teaches us, is that the “reality” we experience with our senses isn’t even half of what really exists. Factor in current theory involving dark matter and energy, we don’t even realize a tenth of what is out there. Science needs to acknowledge its own limitations. At best it can state “we have found no evidence that a ‘higher power’ was involved at this time” and leave it at that.
Instead we have “scientists” insisting science says there is no God, and that science and religion cannot coexist. We have this article, which takes poll results showing one thing, juxtaposes it with Young Earth Creationism, that ends up being cited as affirming that half of Americans believe the Earth is only 6000 years old, thus half of Americans are permanently scientifically illiterate.
Let’s pull another fact from the article.
How is that unscientific? We haven’t even identified all the life on this planet, we are still discovering new life forms in extreme environments, and even ones overlooked where we had searched before. To say that all life must have evolved from the same microrganism ages ago is actually the unscientific position, as the same conditions that the one came from could have yielded others, and all life has yet to be identified thus we cannot draw such a conclusion about all life.
And another…
So what is wrong with that? Open debate, presenting alternate theories, letting the research stand on its own… Isn’t that what we “climate skeptics” argue for in the presenting of climate science? If the scientific robustness is so obvious, then let it be obvious, toss it all out there and let people make up their own minds.
Instead we get loud insistence that the science says this and only this, dissent is squashed as unscientific, demands that even the most basic of claims be backed with research, that should very well be peer-reviewed to count…
Which brings us to Leif Svalgaard (10:43:13)…
>> Leif Svalgaard (10:31:11) :
kadaka (09:58:37) :
Half of Americans believing the Earth is 6000 years old? Not credible
http://www.washingtonpost.com/wp-dyn/content/article/2005/09/24/AR2005092401262.html <<
Are you referring to this statement?
"Polls taken last year showed that 45 percent of Americans believe that God created humans in their present form 10,000 years ago (or less) and that man shares no common ancestor with the ape."
Besides being 45% and not 50%, the question referred to how long humans have been around, and not the Earth itself. I have met people who stated they believed the Earth was only ~6000 years old (including a particle physicist, amazingly enough), but nowhere near 45%. My sample includes numerous co-workers at a can factory (summer job) who were happy to talk about the big bang when they found out I was an astronomy major, so I don't think it's just a selection effect.
Ok, this has devolved into a science vs. religion discussion with Evolution and Creationism mixed in. This includes you Leif.
Other moderators–why are you letting this through?
This stops now.
I mean it.
Don’t make me go back and go through dozens of comments with with a scythe.
Frequency Components of Rutgers University Global Snow Lab
I removed an annual signal by working with the winter months of weeks 49 through 9, averageing the snow cover data. I subtracted the average value to work with the difference. The difference function initially declined and then inclined. A fit of a line through the data gave an R^2 of .000428 (very noisy data). Matching the difference function with a cosine curve with a period of 60 years and a 7.2 year shift gaive an R^2 of .0809, about 326 times higher than a straight line. I believe the NAO time period is on the order of 60 years.
Re: charles the moderator (13:55:00)
Charles,
I am no fan of Creationism, especially Young Earth Creationism. I am not arguing science vs religion, from my perspective.
I am complaining about science being used for an agenda, as we do with climate science specifically. I am upset by what I saw as half of my countrymen being declared as unable to understand science solely because of their religious views.
That is all.
Thank you ctm!
Like in Germany?
Jay,
If you were measuring the height of a mountain, would you start the measurement at the bottom and end it at the top? Hopefully. You started the measurement at the bottom because that is the sensible place to do it.
What if someone told you that you should have started your measurement on a neighboring peak of identical height, and that statistically speaking the topography is flat? Would you take them seriously?
Disregarding your obviously keen perception and acumen, I will continue to visit here; additionally, I may even see some valid science discussed.
Perhaps, though, few would mind if you follow your own advice.
Hi Steve,
That’s an interesting response. If I wanted to measure the height of a mountain, then yes, I suppose I would start at the bottom and end at the top. What I wouldn’t do though, is suppose that I had discovered a meaningful trend and expect the mountain to keep on getting higher beyond the top. If you see what I mean.
Roger Knights (16:55:55) :
“willful distortion of the scientific process for monetary and political ends.
Such distortion would not be successful if the citizenry were scientific literate.”
Like in Germany?
I didn’t know that Germans were distorting the scientific process any more than the US immigration rules against the feeble-minded…
Phil M. (05:44:51) :
actually i think the internet has done a pretty good job exposing the limitations and assumptions of the post. In short order. Now if the article had been in a journal, it would hang around as long as mann’s bogus de centering
Charles the moderator
Of course anti-religious intolerance and on the other hand religious bigotry should be excluded. However the creationism issue has been pushed into the political mainstream actively by a part of the Church. So it is fair game, surely?
And using “religion” as a metaphor for (for instance) a political agenda and a new morality behind AGW, with historic parallels, need not be censored I would have thought.
Reply: I didn’t want to go into specifics. This is not a site to debate religion vs. science. It is also not appropriate to lump religion as anti-science as I would concur this is bigotry. I personally know very religious medical researchers. ~ ctm.
Phil M.
An alternative to cherry-picking your start date, e.g. 1989 start for snow data, is the much more ambitious approach taken by the AGW movement – to change the historic record Stalin-air-brush style, to edit flat with a virtual iron the temperature record before the 1970s – much reduced 1930-40s warmth, no more MWP etc. Do you think this is preferable?
Is it permissable to look at the evolution of any parameter with time? If so, then it is arguable that any start point after the beginning of the universe 13 odd billion years ago is “cherry-picking”. The accusation becomes meaningless.
Since 1989 snow extent has increased. (Contrary to climate model predictions.) In its own terms a simple and valid statement. Live with it.
DirkH (08:15:05) :
Thank you very much for answering my questions. Of course I immediately have ten more questions.
When I wondered:
“Are Oxygen and Nitrogen warmed at all, when sunlight passes through them?”
You responded:
“No interaction between visible light and O2 or N2, otherwise air wouldn’t be transparent for visible light. So visible light that is reflected e.g. by snow will go outwards. There might be refraction by water droplets, so clouds will diffuse visible light. In the absence of clouds, the light reflected by snow (or white roofs, or any part of the surface) will just radiate into space without warming anything significantly.”
However then I read, at the start of Roy Spencer’s UAH site:
“Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere.”
I assume the oxygen must be able to hold heat, for them to be able to measure the heat it emits. This suggests that, while oxygen may not absorb heat directly from visible light, it does absorb heat through an indirect process, involving several steps.
My question remains, is the atmosphere heated at all by visible light passing through it, and does the albedo-effect heat it twice, by bouncing descending long wave radiation back through it a second time?
The place to test this would be just north of the Arctic Circle during the winter solstice. Although the sunlight never strikes the ground, just north of the Arctic Circle during the winter solstice, it passes very close to earth. In fact, (in theory,) if you stepped one step north of the Arctic Circle, an ant by your feet might be in shadow all day, but your face, an altitude of six feet, would briefly be bathed in sunshine at noon.
Such sunshine passes through the atmosphere without ever touching the ground. It therefore would not be turned into infrared radiation by striking a physical surface. Would that air show any warming, during the period of time the sunshine passed through it?
If it did, then the albedo-effect could be expected to doubly-warm the troposphere, for as long as the expanded snow-cover lasted. It then would create a sort of false-warming, for the atmosphere would appear to warm even as a great deal of heat was lost to outer space.
To me, this is one answer to this post’s title, “Why Is Winter Snow Extent Interesting?” I don’t care so much about trend lines, as I care about the immediate effect of the snow cover.
Another interesting thing to contemplate is how much heat will be sucked up (becoming latent heat) just melting all the snow.
In the 1st half of the 20th century Germany was the most scientifically literate country around, but it distorted the scientific process in, for instance, rejecting relativity, stacking scientific positions in universities with stooges, and indulging itself in some fairly crackpot anthropology, archaeology, etc.
I think that “scientific literacy” has had the effect, in the modern Western world, of making its educated and informed elites more gullible than the scientifically benighted about the pronunciomentos of consensus science on things like catastrophic global warming (and certain other eviro-alarms like all in-place asbestos being a threat).
“Man is so necessarily mad that not to be mad is but another form or madness.” (Pascal)
“Man is a reasoning, not a reasonable, animal.” (Alexander Hamilton)
What’s needed to avoid catastrophe (such as enviro-alarmism and hyper-precautionism would entail) is reasonableness, not mere reasoning (science). What’s needed also is an awareness of the basic madness of individuals and groups, including scientific consensuses.
What’s dangerous is the scientistic insinuation of people like Bill Nye the Science Guy that the modern world has discovered, in the scientific method, a reliable (self-correcting-in-the-long-run) truth detector. The global warming episode shows that it takes outsiders to perform that correction — ironically including flat-earthers and creationists. Such persons, who aren’t intimidated by the parvenu authority of science, find it easier to razz the emperor. This is why the benighted, backward US (personified in Senator Inhofe), and not enlightened Europe, has resisted warmist doctrine and legislation, and thereby saved the world from a catastrophe greater than any inflicted to date by unscientific forces.
Science is the institution that has risen to the top of the heap as social arbiter of reality and trustworthiness. That has provided “Satan” with a wonderful disguise to pull another fast one on humanity. “It’s always the one you least suspect” that is Satan’s Slave. Science has become too full of itself, too prideful, too powerful, too inbred, too narrow and unreflective. This has provided its practitioners and acolytes, perverse and base as they are — being human and wanting to make a name for themselves and throw their weight around — with a temptation to do “Satan’s work”: inflicting madness and suffering on humanity.
But that attempt was a minor stain on science in comparison with the explicit endorsement of Hansenism by official science. Therefore, sweeping changes are needed in science’s funding, institutional set-up, procedures, and incentives — including second-thinking about the commonplace that scientifically absurd ideas can have only a malign social effect. That’s too superficially plausible to actually be true. We seem to need such absurdities as a safety valve for our basic nuttiness; lacking them, we’re in danger of becoming stark staring sane and going on a “scientific” rampage.
Leif Svalgaard (07:59:30) :
(…) As has been said so often, half of Americans believe the Earth is 6000 years old. Right there, one loses that segment of the population.(…)
Reply: I didn’t want to go into specifics. This is not a site to debate religion vs. science. – ctm
Nowhere did I mention religion. I simply referred to the fact (and WP seems credible enough on this point – surely the builders of the museum referred to would not contest that number or would rather see it increase) that half of all Americans believe the Earth is only 6000 years old. In this connection it is irrelevant if the actual percentage is 45% or 50% or 44.6783% or if the 6000 is 10,000 or whatever. On the other side of the coin, there are more people in India than the above number of Americans who believe the Universe is 311 trillion years old. Both numbers are indications of science illiteracy, and that is my point and has nothing to do with religion as such.
Jay,
Nowhere in the article did I make any predictions of future trends. All I did was locate the mountain and measure it’s average slope. Tamino tried to use creative statistics to make the mountain disappear. Which one of us is being more honest?
Roger Knights (05:30:37) :
In the 1st half of the 20th century Germany was the most scientifically literate country around, but it distorted the scientific process in, for instance, rejecting relativity, stacking scientific positions in universities with stooges, and indulging itself in some fairly crackpot anthropology, archaeology, etc.
Relativity was not universally accepted back then. Einstein didn’t get his Nobel Prize for relativity. And, BTW most Americans reject the consequences of GR even now.
What’s needed also is an awareness of the basic madness of individuals and groups, including scientific consensuses.
I think it is politicians that claim there is a scientific consensus. It is only in a situation where a people is illiterate that their leaders can lead them down the garden path. Your notion that it is the absurd crackpots that are now saving the world is in itself absurd.
In this thread climate (as described by time series) is awash with quotes of RSquared (R^2, R2) computed in virtually every case by performing a simple (linear) regression of supposedly homogeneous observations on date or time. It also seems to me that some posters may not be familiar with the background to RSquared and its relationship to “the real world”. It’s worth remembering that although RSquared is a genuine and useful statistical measure of “goodness of fit” of a model (any model) to the data, it is not at all informative about the value of the model, simply because in order to convert it to /useful/ inferential statistics you must also provide further information, to wit the quantity of information on which it is based. Statistical tables exist for this purpose, but there are various methods in the maths of regression analysis to do the same thing. If there’s not very much – say a few tens of observations – there’s a further complication because the data are a time series, with almost inevitably considerable serial correlation, so there has to be an adjustment to the quantity that describes the amount of information by methods that have been extensively discussed in Climate Audit. For large data sets, these adjustments, which affect the probability statements that can be made about the data, are I think unlikely to affect the outcome seriously. However, this does not, in my opinion, throw much further light on the scene.
What would be more informative for most readers, I venture, is a simple statement of the estimated coefficient of interest (typically the increase/decrease of some parameter over a given time interval) together with its confidence intervals at a specified probability level, say 90% or 95%. This information provides an instant, simple and unmistakable message about the analysis. If the confidence interval includes zero, the estimated slope cannot be significant at levels greater than the one on which the interval is based.
Something else that I always hope to see is a graphic that shows the the fitted (usually least squares) line together with the two hyperbolae that describe the confidence interval for the line, and the other hyperbolae that describe the interval within which a future observation from the same population can be expected to fall at the chosen confidence level. The software I use does this, and I remain surprised that nobody else presents such information. I don’t know how to post graphics to this thread, so can’t illustrate what I mean. For those of you who like to think of fitting higher order model to data, such plots can be most enlightening. The confidence intervals for extrapolations of a cubic fit can really be quite alarming.
Now you can legitimately choose whatever confidence level you fancy. There’s absolutely nothing sacrosanct about 95% or 90%. These merely express the betting odds at which you are prepared to make a quantitative statement about the outcome of the analysis. You might well decide that 30% was adequate, because it provides narrow confidence bands and would apparently support your hypothesis despite rather nonedescript data. In the days when I was an industrial scientist involved with trying to persuade engineers, chemists and physicists to adopt statistical design of experiments to improve their productivity, I reached the conclusion that in their scouting experiments they instinctively tended to use an approximate 70% level on which to base their further actions. Who can blame them, if these actions were not potentially very expensive if they finally proved to be misguided. However, the roughly 2:1 chance of being right was sufficient to persuade them that they were “doing the right thing”.
In earth-shaking climate science the choice of confidence levels in assessing the import of noisy data is something that I feel should be carefully and pro-actively contemplated by all those involved, included those influential non-scientist and non-statistician outsiders who take world-affecting decisions based on data that are not always what they seem.
I hope that this makes sense to everyone!
Robin Edwards,
I used a stock market program which backfitted stock data with extremely precise fits using multiple order polynomials. Unfortunately, the equations were completely worthless at predicting future behaviour of the stocks.
“with four parameters I can fit an elephant and with five I can make him wiggle his trunk”
Johnny Von Neumann
Steve Goddard.
Of course, Steve! Did the software also produce the confidence interval plot? This is almost always a nasty surprise to aficionados of polynomials.
I’d guess that with five parameters even Von Neumann would have had some problems with elephants, but it’s certainly a quote worth remembering.
Robin
Tom_R (09:38:24) :
>> Phil. (08:48:21) :
No the photon is absorbed it does not emerge from the collision at all. <<
Then why is the sky blue?
Rayleigh scattering.