Guest post by William M. Briggs professional statistician
It is statistically appropriate to point to this year’s frigidity as evidence that the theory of man-made global warming is suspect.
Sure is cold out there, unusually so. By “unusual,” I mean the temperature is on the low end of the observed temperatures from previous winters.
Of course, we don’t have any more than about 100 years of reliable measurements, so it’s possible that the freeze we’re experiencing now isn’t as unusual as we suspect. But, anyway, it still sure is cold.
If you recall, a lot of global warming models predicted it would be hot and not cold, and to risk redundancy, it sure is cold. Does this dissonance between the models’ predictions and what is actually happening mean that those models are wrong?
No. But it sure as ice doesn’t mean that they are right.
Here’s the thing: No matter how cold the winter is, no matter how much snow falls, the global warming models will not be disproved. In technical language, they cannot be falsified by the observations.
Another way to say this is that the winter we’re seeing is consistent with what the models have been predicting. Again — does this consistency mean that the models are right and that the theories of man-made warming are true?
No.
Consistency is such a weak criterion that almost any imaginable theory of climate will produce predictions that are consistent with observations. The term is probabilistic: It means that what actually happens had to have some chance of occurring according to a model. If global warming climate models said, “It is impossible that this winter will see temperatures below X,” and temperatures did, in fact, drop below this threshold, then the models would be inconsistent with the observations. The model would be falsified.
But global warming climate models never make statements like that. They say that any temperature is possible, even if this possibility is low. Certain temperatures have probabilities as low as you like, but they are never precisely zero. (To anticipate an objection: “that number was practically zero” is logically equivalent to “she was practically a virgin.”)
Man-made global warming is just one of many possible theories of climate. Another is the Business-as-Usual Theory (BUT), which states that whatever happened last year will more or less happen this year, and so on into the future.
The winter we’re seeing is consistent with the BUT, which like the man-made global warming theory, never says any temperature is impossible. Further, BUT is corroborated more strongly by this winter than is the man-made warming theory. BUT’s predictions are closer to what we actually see.
“Stop right there, Briggs! You’re making the classical mistake of confusing weather with climate. The global warming models make predictions of climate and not weather. This winter doesn’t mean anything!”
I am not making that mistake, and it is you who are confused. Weather is climate. More specifically, aggregations of weather are climate. Means, averages, and distributions of daily weather comprise climate. That is, climate is a statistical phenomenon and depends for its existence on defining a reference time frame.
For instance, if “climate” is defined as the yearly mean temperature, then this year’s cold winter will produce a yearly mean temperature that is colder than average (as long as the coming summer isn’t abnormally hot: winter, of course, overlaps two calendar years and a hot summer can balance out a cold winter in the yearly mean).
So it is appropriate to point to this year’s frigidity as evidence that the theory of man-made global warming is suspect. If “climate” is defined as the decadal mean temperature, then this year’s cold winter will push the decadal mean lower. And it is still acceptable to point to this year’s winter as evidence against the man-made global warming theory.
Just as it was appropriate when the media trumpeted each and every “record setting high!” as evidence for that theory.
The difference is that one day’s temperature has little influence on a yearly mean — it is just one out of 365 other numbers that make up the average. One day’s temperature is thus weak evidence for or against any theory of climate.
But a slew of months with higher- or lower-than-average temperatures will push that yearly mean higher or lower. A season’s mean temperature is stronger evidence for or against any climate theory than is a day’s.
Back in the 1990s, when the yearly mean temperatures were increasing, this was touted as evidence for the man-made global warming — but those years’ temperatures also corroborated the Business-as-Usual theory. Which theory was better?
For the past decade, we have had a string of years with mostly decreasing temperatures. This is strong evidence against the man-made global warming theory, but pretty good testimony for the BUT. So far, the BUT theory is winning on points (there are other climate theories the BUT doesn’t beat). This doesn’t mean that BUT is true and that the man-made global warming theory is false, but it does suggest that this is so.
You can’t have it both ways. It is a mistake to extol evidence that supports the man-made global warming theory and to cry foul when presented with evidence which weakens that theory.
That so many do this says more about their desires than it does about any theory of climate.
Reposted from: http://pajamasmedia.com/blog/actually-weather-is-climate/
with permission from the author. Visit his website: http://wmbriggs.com/blog/
EARTH”S INTERNAL FURNACE
The real answer is within.
Temperatures inside the Earth are close to those on the surface of the Sun, somewhere around 10,000 Degrees Fahrenheit.
This internal Earth heat slowly dissipates through the Earth’s crust.
This heat must logically play some role in surface temperatures, certainly keeping our orb from freezing. Temperatures only 1 Kilometer below most land masses are too hot to survive in without mechanical cooling.
The heating process probably has cycles over time of hotter and cooler periods, or some kind of heat pulsing. Some change is happening inside our planet if our magnetic poles keep alternating from time to time, and super-volcanoes periodically explode.
What if climate change is really related to variations in the heat being transmitted and released through the crust in pulses of decades or centuries or longer periods of normal fluxuations ?
Has this been mentioned as a factor to be taken into consideration before we completely condemn carbon dioxide by humans as an alleged cause of irreversible warming destined to destroy the planet and our way of life as we know it ?
There must be some deep mine temperature statistics somewhere to reveal this detectable component.
I submit that Earth’s Internal Heat must play some role, even if minor, in climate variability.
“Look more closely grasshopper, the real answer is within.”
I’m confused?? What did he say?????
A very good article, and I’m beginning to wonder whether the distinction between climate and weather isn’t just a hangover from the days everyone thought the climate long-term weather was static.
An area that really needs to be extended is the frequency analysis of the variability of the global warming signal. Evern the UK Met Office know that variation increases the longer the period you are considering, so that the noise signal INCREASES over longer periods and so it is HARDER to predict the long term rather than short term. So, how ironic it was for us in the UK to hear the Met Office exuse for their prediction of a mild winter when we had one of the coldest winters in 30 years: “its far more difficult to predict season to season than century to century” HAVEN’T THEY READ THEIR OWN PUBLICATIONS ON NOISE PROFILE OF GLOBAL TEMPERATURE.
Any for anyone who wants to see a natural reproduction of the global temperature signal from purely natural noise have a look at this link: http://www.tursiops.cc/fm/pink.gif
And the final noise, is that there is going to be a UK parliamentary investigation into climategate: http://www.parliament.uk/parliamentary_committees/science_technology/s_t_pn14_100122.cfm
AND IF THERE IS ANY NEED TO HELP CO-ORDINATE SUBMISSIONS I AM WILLING TO GIVE MY TIME TO THIS!
Bravo! Some more cogent analysis with a bit of wit from Mr. Briggs. We skeptics/denialists are usually quite good at qualifying our comments about cold as “weather not climate” but maybe its not necessary.
Very good and very clear.
Pielke Sr., I believe, said it this way: Climate is experienced as weather.
Part of the dumbing down due to AGW theory is that many people implicitly believe that there is something called ‘climate’ that is seperate from weather.
It’s ok, honest someone from the Met office is going to explaine why we had extreme snow
http://www.channel4.com/programmes/snowstorm-britains-big-freeze
what do you think their explination is likely to be?
We in the UK are in the middle of the fifth or sixth Iraq inquiry into WMD – an issue that is notorious for the “sexed up data”, the “dodgy dossier”, with “real and imminent threats of WMD”.
Change Weapons of Mass Destruction to “Weather of Mass Destruction”, and the sexed up claims in the dodgy IPCC dossier of real and imminent threats of hurricanes snow, heat, rain, drought, and politicians in pink leatards pretending to be cats (google Galloway, big brother).
The only concern I have about the analogy is that “weather isn’t climate” – but since the WMD – hurrucanes, droughts, etc. that constantly gets in the news isn’t climate but weather …
It always a good ice breaker to talk about the weather…
K Bray says “Temperatures inside the Earth are close to those on the surface of the Sun, somewhere around 10,000 Degrees Fahrenheit.”
No…no…..you haven’t been listening. Al Gore says the temperature of the interior of the earth is “millions of degrees.” And they have special drill bits that can drill into that. Now go into the corner and repeat that over and over until it is true.
This was exactly the point that I was trying to make on the story http://wattsupwiththat.com/2010/01/14/spencer-a-demonstration-that-global-warming-predictions-are-based-more-on-faith-than-on-science/#comments.
Of course, it comes out so much better when the person explaining it knows what they are talking about 🙂
Thank you Mr. Briggs
Briggs,
Surely we can find some means of “updating” our belief one way or the other vis a vis AGW on the basis of seasonal outcomes. That is, an update on Bayesian grounds. If this is not possible then AGW is not a testable hypothesis. I haven’t given much thought to how to go about this, though.
A consistent “experiment” should make more distinct the difference between a hypothesis and its alternative(s) with more data. I don’t see this as occuring with respect to AGW–if anything doubt is now growing and that is more like a “pathological” hypothesis–i.e. per Irving Langmuir.
In engineering we run “factorial” experiments. Once our “table of contrasts” is filled and sufficiently replicated, we ought to be able to say what factors and interactions are significant and which are not. No one has tried this yet with regard to AGW, although I think it may be possible to look at instances of past climate change and do such a thing. However, as the outcome of temperature increase/decrease seems to not have a clear connection with historical changes in CO2, analysis of my hypothetical table of contrasts would probably throw it away as a factor.
a breath of fresh air from a statistician!
You are a credit to your discipline. Only someone with a deep grasp of his field could so succinctly expose such a widespread abuse, especially by warmers and their coterie.
You’ve explained it so well that even I understand it.
Common-sense, the bedrock of wisdom.
@bucko36
He said if it’s cold, it suggests it’s not getting warmer.
IsoTherm (13:56:14) : The link gives me an access violation.
Is there any statistical test for a random walk? Could ‘average temperature’, what ever that is, be following a random walk? The lags that are evident in the auto-correlation statistics make me wonder.
K. Bray, I’m confused. Al Gore assured me it was millions of degrees just under the surface. 😉
‘(To anticipate an objection: “that number was practically zero” is logically equivalent to “she was practically a virgin.”)’
OK, now I’m reminded of a certain scene from the film “Chasing Amy.” Who knew Kevin Smith was a climatologist? 🙂
IsoTherm (13:56:14) : ‘[quoting the Met Office] “its far more difficult to predict season to season than century to century” HAVEN’T THEY READ THEIR OWN PUBLICATIONS ON NOISE PROFILE OF GLOBAL TEMPERATURE.’
Just out of curiosity: back in 1909, what did they predict for the winter of 2009-2010?
My take from this article: 21st Century temperature records are “consistent with” global warming, global cooling, neither, “…UFOs, astral projections, mental telepathy, ESP, clairvoyance, spirit photography, telekinetic movement, full trance mediums, the Loch Ness monster and the theory of Atlantis.” (with apologies to “Ghost Busters”)
There is a way of looking at the weather-climate distinction that should be easy for everyone to understand. When a student goes to class, in most school systems there is an overall course grade based on the average of the grades of a series of tests (and other graded activities). The weather is like the test grade for a single test, one of many in the course, and the climate — based as it is on “average” weather — is like the overall grade for the course. Hence it makes sense to say that unusually cold weather is like a failing test grade for global warming, and unusually hot weather is like a passing test grade for global warming. Just as one failed test does not necessarily mean a student fails the course, so one cold winter does not necessarily disprove global warming — but failing a test makes failing the course that much more likely, and a cold winter makes it more likely that global warming is false.
The problem is, tell it to a warmer, point outside to the snow, and he says “So what?” The MSM have told him that the planet is warming and he trusts the MSM more than his own lying eyes. People really do, they are proud that their educated upbringing made them so good at abstracting away their own sensory experiences and suspend their disbelief and understand that it must be pretty hot EVERYWHERE ELSE.
To shake up the belief system of warmers, i made good inroads telling them about the logarithmic nature of CO2 forcing (they usually don’t know that!), the tiny amount of the forcing compared to the sun’s radiative flux, and the fact that temperatures started rising BEFORE 1950 when CO2 started rising. It’s exhausting but i keep hacking away at the foundations of the believes of the ones that are still able to listen. Some are lost cases, though. They won’t find out of the believe in AGW even when they freeze to death in midsummer.
Probability is just so damn “uncertain”.
Thankyou Dr Briggs for your very logical comments. Of course weather is climate and vice versa. The whole “weather is not climate” meme is very frustrating to me. After all climate is composed of statistical measures of weather, as Dr Briggs has clearly enunciated. Thankyou!
Briggs…said:
Man-made global warming is just one of many possible theories of climate. Another is the Business-as-Usual Theory (BUT), which states that whatever happened last year will more or less happen this year, and so on into the future.
Right: 0.5 ºC in 150 years should be this
Nice article, using statistics always gets them just look at Steve Mc, do any of ‘the team’ have maths qualifications or is enough to have a good imagination when deciding the latest temps.
I know this is off topic but the first comment is of some interest to me. I, too, thought the internal heat of the earth’s core was bound to have SOME effect on global surface temperature. Just think what it’s like hugging a hotwater bottle (I’ve been doing a lot of that this last month). But then I thought, well, the effect is obviously not enough to prevent a snowball earth and all the extensive glaciations over the last 2 million years. But maybe there is a teensie bit of an effect to add to all the others – solar radiation, sunspots, cosmic rays, UHI etc. I really find it hard to totally discount all those undersea hydrothermal vents.
Does anyone else have a view?
p.s. I enjoyed the Briggs article, BTW, and am really cheered the UK Parliament Science and Technology Committee is shaking its feathers at last re CRU.
Marcel Leroux had convincingly demonstrated it a while ago…