Sunday, December 27, 2009
A physicist purports to prove that there has been no statistically significant warming since 1995, the earliest date that I have seen asserted for this claim among the skeptics. Anybody out there with a good refutation?
Like many things our fine friends in Washington do...simply lowering one's standards and having media cooperation will work miracles.
In this case the "standards" are the confidence levels generated by statistical analysis of the data.
If one lowers the confidence level below 90% - miraculous things can be done with data...virtually anything that you want!
The EPA has has done this before with the infamous 1993 dictum on
Passive Smoke and lung cancer.
There is truly no end to what one can do with data if one is willing to torture the statistics enouhg to make one's point...and then release them to a population with no training in data analysis.
This we have the "dangers" of Passive Cigarette Smoke, Global Warming, Post Menopausal Estrogen use, Peanut allergy...etc, etc, etc ,etc ....ad infinitem.
Quite hilarious, actually.
The problem I have with this is that a 15-year trend line is meaningless. To discuss global warming, it's necessary to look at actual trends, not short bursts of noise. Take an ordinary AM radio frequency, for instance, say WLS out of Chicago, located at 890 kHz (in case you were curious). Such a signal, being amplitude modulation of a sine wave, resembles the chart presented in the article. Were I to do a trend line of a couple of seconds out of an hour's broadcast show, I could find you any trend line you wanted. Were I to look at a trend line over the entire hour, though, the slope would be zero--the data are, after all, centered on 890 kHz, and the basic frequency does not change.
Now let's look at the Earth's global temperature. Looking at the chart containing a mere 30 years of data, as presented, I can find any linear slope you'd care for me to find. Were I to look at a chart of 4B years of data from the Earth's history, I'd find a noisily rising temperature line, driven by a number of factors: the accretion of an atmosphere, the ebb and flow of methane and water vapor and free hydrogen, the steadily increasing heat output of the sun, the precession of the earth's orbit around the sun (which, among other things, on a roughly 26 kyr cycle places the sun's most direct angle of incidence at the Earth's closest point of approach to the sun and then at the Earth's farthest point), the ebb and flow of life on the planet, and so on. Is the Earth warming, then? You bet. The sun is going to continue to increase its heat output until it expands into a red giant whose diameter includes Earth's orbit. So that's the baseline against which we must assess anthropogenic warming--the only warming trend we should worry about at our current, and projected near-term, technology capabilities.
So over what period is it useful to look at trend lines? One (still baseline, for any deviations from the long-term baseline) would be from the beginning of Cro Magnon's presence to now. Another (baseline) would be from when we started growing grass on purpose and building cities to present. Another baseline would be from the beginning of the Industrial Age to present. But even these only provide baselines; they do not imply causes--or even correlations. But given these baselines, it then--and only then--becomes useful to explore causes. And 15-year trend lines are useless for this. Even a 30-year trend line, derivable from the presented chart, which would appear to show a slight increase, but with more complete analysis probably would be indistinguishable from flat, would be useless.
And in the end, it's insufficient to identify reliably a trend. We need to know causes, or at least strong correlates, else we still know nothing about needed (if any) responses. It's been posited, for instance that atmospheric CO2 is hugely on the rise. Yet we still have less CO2 in the air than in earlier, prehistoric times. It's been posited that temperatures currently are rising. Yet we're still cooler than we were 1,000 years ago.
And so on. The dishonesty and atrocity perpetrated by the ghouls of UEA and GHCN simply have sent honest research back to the starting point of collecting original, raw data for honest, dispassionate analysis. Even the analysis that began this missive, while one of the few honest attempts actually to look at the data, is useless, as it discusses a period of time that is too brief have value.
realclimate.org -- the alarmist site cited immediately above -- has a two-fold response to explain away the recent "warming pause." 1) it's just a statistical quirk, and 2) it's based on the East Anglia Hadley dataset -- the NASA GISS dataset doesn't show a pause.
If it's #1, if a ten-year pause is a quirk, why can't you also conclude that a slight warming trend in the decade before is also just a statistical quirk.
If it's #2, that's actually proof that you can get different results because of how you pick your datasets. I've got a lot on this in posts below.
ps. "NASA GISS" only has a weak affiliation to the rocketeers and is actually run out of space above the Seinfeld Diner at 112th and Broadway.
Well, the analys is true as far as it goes, but read through the comments to find why this is a bad use of statistics. It's the assumptions that go into using a technique that kill you.
You really need to start your confidence analysis with how reliable each sensor is and wrap it all the way up to the trend.
Gotta say the climate change reports I've seen are even worse though. I wouldn't allow the use of any of this in my day job as a DoD test engineer.
"http://www.skepticalscience.com/. By best, I mean they appear to take a rational approach to rebuttal"
Having taken a look at this site, I assume you're joking.
The post about how the MWP wasn't really that warm, citing a study by (I am not making this up) Michael Mann, gave me a chuckle, but after they cited the UIC study as proof of "consensus" about AGW, I was laughing too hard to read any more.
thye sources of information on world temperatures are:
a) Hadley-East Aanglia CRU -- source of the Crutape emails. these people gamed the "peer review" system and cooked their data sets (we have the evidence for both the Russian data set which was cherry-picked to have only the urban areas and the French data set, where French climatologists went back to the raw data [because East Anglia would not provide it to them] and concluded there was no warming for decades) Nothing from them can be believed.
B) the Argos ocean buoys--originally they showed a temperature decline, but the guy in charge went back and "corrected" the data to correspond to CRU and GISS. Ever hear of "confirmation bias?
C) GISS the Godard Institute that is James Hansen's bailiwick. They have been caught in some embarrassing "failures" such as not knowing the 1930s were3 the hott4est decade3 of the 20th century, but, more importantly, their data does not come from "SPACE" but from the US Historic Climate Research Network, a series of ground sites all around the country. 70% if the sites produce garbage. They are misplaced-- mostly because the places (environments) have changed radically since they were established. Cities have grown, airports are right next door, etc. Go to Watts's surface stations site for the exhaustive study with documentary photographs and temperature graphs proving their data set is useless. And even their inflated numbers show a decadal cooling.
D) RSS Systems and University of Alabama Huntsville, separate organizations both use satellites and radiosondes (balloons) They show no warming for 30+ years.
At the same time atmospheric CO2 has gone up steadily. The ony reason for believing in global warming is a priori-- increase in CO2 leads to uncreased temperatures. Something that has never been proven.
To invoke Richard Feynman, if your experiment fails, your theory is no good. If the data proving your theory has to be cooked, you need another theory.
I suggest people google Nir Shaviv and Hans Svensmark.
1. "D) RSS Systems and University of Alabama Huntsville, separate organizations both use satellites and radiosondes (balloons) They show no warming for 30+ years."
That's not true - RSS and UAH both show warming. Here for more info:
2. The global warming "pause" - there is no pause, the 2000s are the warmest decade in the instrumental record, and 2009 is the fifth warmest year on record.
3. TH's link actually says "it is 'somewhat more likely than not' that the underlying trend in 1995-2009 was a warming trend". I believe he means a 72% chance. Given that the calcs are done by a known denialist (Lubos Motl) using the most favorable dataset he can find (UAH), it's all very unimpressive.
Eric Hines wrote the most useful comment so far, beginning ..." a 15-year trend line is meaningless".
A recent little essay by Jim Hansen offers a short, readable introduction to how the global temperature data is assembled, what care is taken to try to keep the data honest, and the consequences when there are screwups in the data pipeline. The original PDF is on Hansen's site. The link above is to a post by Australian climate scientist Barry Brook (Adelaide University) on his blog BraveNewClimate.com — which I recommend to anyone interested in policy options that will actually work (in contrast to feel-good but useless policies like Kyoto, cap-and-trade, etc.)
"That's not true - RSS and UAH both show warming. Here for more info:
To quote another commenter, "that's not true". But don't take my word for it - let's look at the Wikipedia article you linked:
"For some time the only available satellite record was the UAH version, which showed cooling globally. A longer data series and several corrections to the UAH method leaves the UAH series showing warming, though less than RSS version"
If the UAH data showed cooling, and the RSS data showed, um, less warming than the UAH data, it sounds a lot like those sources don't show any warming.
Granted, it's a travesty when the data conflict with settled science like AGW, but that's not a problem when you can just "adjust" the data to something more to your liking, then claim the data supports your reli..., er, theory.
Anon says "the RSS data showed, um, less warming than the UAH data"
That's not true. Read the quote that you just cited a second time. It says that UAH showed warming, but less warming than RSS.
The quote about cooling was prior to corrections. Now even UAH acknowledges warming.
You've got to laugh...any climate change oops global warming post and up pops Brian and Brian Schmidt (are they the same person) to defend the faith. Lets looks at the wikipedia reference he sites.
Check the History Tab and what do we see, one infamous William M Connolley with about 10 re-edits and even one from Brian Schmidt. Very amusing siting wikipedia as an authoritative source, especially one edited by Connolley. Heres a link to his work