Dr. Roy Spencer proves what we have been saying for years, the USHCN (U.S. Historical Climatology Network) is a mess compounded by a bigger mess of adjustments.
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USHCN Surface Temperatures, 1973-2012: Dramatic Warming Adjustments, Noisy Trends
Guest post by Dr. Roy Spencer PhD.
Since NOAA encourages the use the USHCN station network as the official U.S. climate record, I have analyzed the average [(Tmax+Tmin)/2] USHCN version 2 dataset in the same way I analyzed the CRUTem3 and International Surface Hourly (ISH) data.
The main conclusions are:
1) The linear warming trend during 1973-2012 is greatest in USHCN (+0.245 C/decade), followed by CRUTem3 (+0.198 C/decade), then my ISH population density adjusted temperatures (PDAT) as a distant third (+0.013 C/decade)
2) Virtually all of the USHCN warming since 1973 appears to be the result of adjustments NOAA has made to the data, mainly in the 1995-97 timeframe.
3) While there seems to be some residual Urban Heat Island (UHI) effect in the U.S. Midwest, and even some spurious cooling with population density in the Southwest, for all of the 1,200 USHCN stations together there is little correlation between station temperature trends and population density.
4) Despite homogeneity adjustments in the USHCN record to increase agreement between neighboring stations, USHCN trends are actually noisier than what I get using 4x per day ISH temperatures and a simple UHI correction.
The following plot shows 12-month trailing average anomalies for the three different datasets (USHCN, CRUTem3, and ISH PDAT)…note the large differences in computed linear warming trends (click on plots for high res versions):
The next plot shows the differences between my ISH PDAT dataset and the other 2 datasets. I would be interested to hear opinions from others who have analyzed these data which of the adjustments NOAA performs could have caused the large relative warming in the USHCN data during 1995-97:
From reading the USHCN Version 2 description here, it appears there are really only 2 adjustments made in the USHCN Version 2 data which can substantially impact temperature trends: 1) time of observation (TOB) adjustments, and 2) station change point adjustments based upon rather elaborate statistical intercomparisons between neighboring stations. The 2nd of these is supposed to identify and adjust for changes in instrumentation type, instrument relocation, and UHI effects in the data.
We also see in the above plot that the adjustments made in the CRUTem3 and USHCN datasets are quite different after about 1996, although they converge to about the same answer toward the end of the record.
UHI Effects in the USHCN Station Trends
Just as I did for the ISH PDAT data, I correlated USHCN station temperature trends with station location population density. For all ~1,200 stations together, we see little evidence of residual UHI effects:
The results change somewhat, though, when the U.S. is divided into 6 subregions:
Of the 6 subregions, the 2 with the strongest residual effects are 1) the North-Central U.S., with a tendency for higher population stations to warm the most, and 2) the Southwest U.S., with a rather strong cooling effect with increasing population density. As I have previously noted, this could be the effect of people planting vegetation in a region which is naturally arid. One would think this effect would have been picked up by the USHCN homogenization procedure, but apparently not.
Trend Agreement Between Station Pairs
This is where I got quite a surprise. Since the USHCN data have gone through homogeneity adjustments with comparisons to neighboring stations, I fully expected the USHCN trends from neighboring stations to agree better than station trends from my population-adjusted ISH data.
I compared all station pairs within 200 km of each other to get an estimate of their level of agreement in temperature trends. The following 2 plots show the geographic distribution of the ~280 stations in my ISH dataset, and the ~1200 stations in the USHCN dataset:
I took all station pairs within 200 km of each other in each of these datasets, and computed the average absolute difference in temperature trends for the 1973-2012 period across all pairs. The average station separation in the USHCN and ISH PDAT datasets were nearly identical: 133.2 km for the ISH dataset (643 pairs), and 132.4 km for the USHCN dataset (12,453 pairs).
But the ISH trend pairs had about 15% better agreement (avg. absolute trend difference of 0.143 C/decade) than did the USHCN trend pairs (avg. absolute trend difference of 0.167 C/decade).
Given the amount of work NOAA has put into the USHCN dataset to increase the agreement between neighboring stations, I don’t have an explanation for this result. I have to wonder whether their adjustment procedures added more spurious effects than they removed, at least as far as their impact on temperature trends goes.
And I must admit that those adjustments constituting virtually all of the warming signal in the last 40 years is disconcerting. When “global warming” only shows up after the data are adjusted, one can understand why so many people are suspicious of the adjustments.
“Nick Stokes says:
April 14, 2012 at 5:57 am
Yes, water vapor feedback amplifies the temperature increase due to any forcing.”
The rather obvious problem with the +ve WV feedback is that the oceans are an unlimited source of WV. A +ve WV feedback would immediately cause runaway warming. Which means even a small net +ve WV feedback is impossible (at current temperatures).
Let us not forget that any large sample of adjustments for instrument error and external factors should average out to zero, meaning about half up and half down, by similar spreads. No such thing is happening; the adjustments display clear patterns, always in the direction of propping up AGW.
There is only one plausible cause for this. The adjusters want it that way.
Philip Bradley says: April 15, 2012 at 1:24 am
“A +ve WV feedback would immediately cause runaway warming.”
No, that is a misunderstanding of the meaning of positive feedback. The current estimate is that the feedback factor due to water vapor is about 2. You can think of it working this way. If an initial forcong increment of 1 W/m2 is applied, that will increase wv producing an initial 0.5 W/m2 added forcing. That extra 0.5 ups the wv further, producing an extra 0.25. And so on. The sum of the added increments is 1; the total forcing with wv feedback is 2 W/m2.
Of course if the wv initially produced by 1 W/m2 extra forcing itself adds more than 1 W/m2 forcing, then you get runaway.
Removing the rate of growth of the population density in the US temperature data is a rather complicated way of demosntrating a corellation between temperature trends and US population.
The corellation does not prove causation.
Looking at another measure of temperature where changes in population are very unlikely to influence the trend might indicate if the trend is real or just a matter of local causation from population changes.
Is the UAH LT record affected by the US population density increase, or would it make any sense to correct the UAH record with the population metric Roy Spencer has used ?
Nick Stokes says:
April 14, 2012 at 5:03 pm
“But it’s not just me. Lots of people have studied the global temp record. Not just a few counties in California.”
Nick the good thing about UHI is that the population growth has almost stopped in the temperate and arctic regions where it matters most.
We all know the UHI effect is real, you and your kind want to deny that UHI has any statistical effect on the temperature trend measured. In the work linked by you Berkeley denies that the growth of human population from1 billion to 7 billion has any effect on the temperature trend in human locations – which I simply do not believe. Just look at their map of the USA temperature trends and you will simply identify locations where population has increased based on red spot accumulation.
Here how I try to explain on why they got erroneous results – there is a comparison of a localized rural trend against a global trend (mostly North America, Scandinavia, Russia and some Austrialian locations). Furthermore the selection of very rural location is enough to introduce bias – as was shown here at WUWT – so I trust their work is in error. It does not compare rural versus urban trend for the same region with clearly identified no-UHI locations.
I trust that if we measure city per city we find a growing difference between the temperature outside the city and the city which would be depending on the city population. Of course there will be also need to compare like with like as it will very much depend on location, country, type of development.
In the coming years population growth is to further settle, urbanization reached very high levels in many countries so there will be less and less UHI effect on trend. The trouble you and your thinking alike will have is to explain the cooling effect of big cities, as UHI will simply remain stationary for most big cities, only some small location will grow increasing their UHI in the temperate and arctic regions, this also limited.
The “cooling effect” is simply the missing of further warming effect.
So basically the discussion is really less and less relevant for future temperature measurement and another shot in the knee by CAGW.
Philip Bradley says:
April 15, 2012 at 1:24 am
“Nick Stokes says:
April 14, 2012 at 5:57 am
Yes, water vapor feedback amplifies the temperature increase due to any forcing.”
The rather obvious problem with the +ve WV feedback is that the oceans are an unlimited source of WV. A +ve WV feedback would immediately cause runaway warming. Which means even a small net +ve WV feedback is impossible (at current temperatures).
Such a brilliant, succinct statement of something I’ve been trying to articulate, you leave me stunned. People who postulate positive feedback for a stable system simply don’t understand what the word means. And in this case there is coupled positive feedback — the warmer the oceans the more CO_2 and/or methane they release to complete a vicious cycle of self-amplifying runaway positive feedback.
However, the conclusion is still not precisely correct, because WV feedback could be positive but overall feedback could still be negative. Also, because the Earth’s climate is a self-organized chaotic system, altering WV concentrations could move stable attractors up or down or sideways (and probably does). Still, this argument places a strong burden of proof on those who assert positive feedback to explain in detail why there isn’t an upward trail to Venus-like conditions with the oceans boiled away precisely like Hansen has been idiotic enough to assert as his worst-case doomsday scenario! Oh, wait, this is what they think will happen.
Which is why they should not be taken seriously by anyone with common sense. It’s all well and good to make B-grade science fiction movies that show the Earth’s climate self-organizing overnight into a giant refrigerator that cause glaciers to instantly form or into a hothouse that boils away the oceans, all because Humans Did It with their silly little thing called “civilization”. Sensible people look at the actual data from the paleontological climate record over the last billion or so years as recorded in life forms and other proxies, and recognize that first of all, the Earth itself does have the capacity for catastrophic climate change all by itself on hundred-million-year timescales due to forces or forcings over which we have not the slightest shred of control.
Second that the “catastrophes” visible in that record are without exception in one of two catagories — cold phase/ice age, a disaster beyond our imagining — and atmospheric climate catastrophes brought about by things like the Siberian Traps or Supervolcanos, million year long extrusions of magma dumping enormous amounts of aerosols and dust into the air, or asteroid collisions ditto. Even the latter have not managed to kick the Earth into an ocean-boiling state, with many times as much CO_2 and other GHGs in the atmosphere, and the only thing that humans can do that might trigger a similar event is start a global thermonuclear war or go into space and push an asteroid down ourselves deliberately as an act of war.
The probability of global thermonuclear war is at its lowest point since the invention of thermonuclear weapons — at the moment, it is utterly implausible even if the North Koreans or Iranis or Pakistanis lob a bomb at South Korea or the US, at Israel, at India. It would also be much more likely to trigger a nuclear winter, not runaway heating. Yellowstone could, naturally, decide to wake up and spew magma for 50,000 years at any moment, but there is damn all we can do about it if it decides to do so. Similarly, if a rogue asteroid appears all we’ll be able to do — if we see it in time — is draft Bruce Willis, send up a thermonuclear armed space shuttle to try to deflect it (oh wait, we don’t HAVE a space shuttle any more, damn) and pray.
Beyond that, we are in the only visible warm phase in the climate record. It gets as much as 2 or 3 K warmer, depending on parameters we do not understand, possibly things like the actual positions of the continents and oceanic currents, however, those warmer temperatures appeared to become completely and systematically unstable over a stretch that ran from 4 to 1 million years ago, and are now almost completely stable in an ice age. Our current warm phase is part of a transient, obviously geologically unstable excursion and is very likely approaching its end, although we cannot really predict this without knowing why the Earth warms up in this way in the first place (or why it went cold in the first place) and we haven’t a clue about either one.
We are obsessing over the wrong catastrophe. There is essentially zero chance of a still hotter stable state, and if there were — and it were truly stable, the premature end of the current ice age — it would be the best thing possible for the human race and all species of animal life! If you want to see extinction events galore, bring back the glaciers. Humanity came of age in the Holocene, and the advent of Fimbulwinter once again, ice giants and all, would condemn countless species to a massive die-off as the temperate zones they now inhabit become intemperate and frost reaches towards the equator.
Stability analysis is such an obvious step in climate science, and yet all we have there is not “science”, it is the mad ravings of Hansen.
rgb
“Ian W says: ” – kJ/kg at a temperature.
I agree completely. kJ/kg, at a temperature, is the only accurate way to measure atmospheric energy/heat content. Just measuring temperature as a proxy for energy is silly. It takes energy to create storms, not just temperature.
One problem: If they can’t measure temperature accurately, how would they be able to accurately measure energy; a more complex measurement involving two parameters [kJ/kg and temperature].
Hey Anthony,
I would like to request that you include a correction to the graph that leads off this article. As Phil Clarke has pointed out, the graph is in degrees F, but the explanation below the NOAA graph gives the amounts in degrees C. I know that the explanation is part of the same image as the graph and cannot be easily edited, but a simple note of the labeling error would suffice.
While I hardly believe that the original creator of the image mislabeled the explanation with the intent to inflate the adjustments, that accusation follows the graph and gives the warmest an excuse to throw away every argument that follows.
Furthermore, Nick Stokes has taken the opportunity to proclaim that climate change crisis skeptics aren’t learning anything new and have nothing but the same disingenuous arguments:
“But I agree about the lack of progress. As Phil Clarke pointed out,15 hours ago, the graphic which cites the adjustment slopes as if they were Celsius (though they were Fahrenheit) is from a 2007 post. The false claim was criticised then, but here it is, reappearing as if nothing had happened. And still uncorrected.”
(From: http://moyhu.blogspot.com.au/2012/04/us-temperature-trends.html )
While it is obvious that the error has no real impact or importance to the discussion, it is like throwing a little chum in shark infested waters.
Enthalpy vs. temperatures when making atmospheric measurements seems so obviously superior a method. Let’s see, now how should we adjust those humidity levels…
I understand “raw” station measurement data is something of a dying breed. This is a crime against science. The raw data should be maintained above all else. Derived data can be discarded and regenerated at will as long as someone simply saves the formula.
Has Dr Spencer commented on the fact that his own data set (UAH) gives a statistically significant warming of the US at 0.22C/decade (1979 – present), and is thus quite similar to the CRUtem (0.198C) and USHCN (0.245C) trends, and quite dissimilar from his populaiton density trend (0.013C/decade)?
http://vortex.nsstc.uah.edu/public/msu/t2lt/uahncdc.lt – (UAH decadal trend for ‘US48’ is given bottom right hand corner of this data page)
Josh: “While I hardly believe that the original creator of the image mislabeled the explanation with the intent to inflate the adjustments.”
Nor do I. it was likely a schoolboy error that Meyer missed because it suited his prejudices. However it was pointed out in the very first comment and Meyer did not bother to issue a correction. Embarassing enough for him, if he wants to be taken seriously, arguably even more embarrassing for a ‘science’ site that copies the error without noticing and leaves it uncorrected after it has been pointed out.
Once that has been put right, can we look forward to this ‘paper’ being corrected and withdrawn?
http://scienceandpublicpolicy.org/originals/policy_driven_deception.html
After all its headline premise has been falsified, not least by the BEST project that was contributed to, and endorsed by one of the coauthors.
Don’t hold your breath.
Allan McRae:
I’ve seen lots of temperature graphs. I think knowing the earth’s temperature is tricky business, and applaud Anthony Watt’s efforts here. I admire that and many other things Anthony does.
So, yes I looked at your graph. Does the PDO change the Earth’s temperature? Could be. How is it meant to transport more heat into space? I have no clue.
Regards,
Ed
I’m in what appears to be a growing majority that’s concluded that the posted article is wrong. I think a blog update noting the errors pointed in the comment thread is in order.
Nick has taken the opportunity to slam this blog for it. There is a cure for that. If you don’t like being criticized for making mistakes, stop making so many of them.
rgb:
That doesn’t happen here. Positive feedback systems don’t run away if they are stabilized by a dissipative nonlinearity, such as Stefan-Boltzman sigma T^4 factor here.
Simple example of this is the Van der Pol oscillator. This linear equation runs away:
x”(t) – x'(t) + x(t) = 0, x(0) = 1, x'(0) = 0.
This equation is stable and gives sinusoidal oscillations:
x”(t) + (x(t)^2-1) x'(t) + x(t) = 0.
Just for clarity, this equation is not stable:
x”(t) – x'(t) + x(t) + x(t)^3 = 0.
(So just having a nonlinearity in the system doesn’t imply it will be stable.)
Nick Stokes says:
April 14, 2012 at 2:42 pm (Edit)
Much appreciated, I’m back to work but it looks fascinating, I love a chance to learn more about R and about averaging.
w.
Phillip Clarke Says:
“Once that has been put right, can we look forward to this ‘paper’ being corrected and withdrawn?
http://scienceandpublicpolicy.org/originals/policy_driven_deception.html
After all its headline premise has been falsified, not least by the BEST project that was contributed to, and endorsed by one of the coauthors.
Don’t hold your breath.”
Now hold on there a second…
I agree that Meyer’s graph at the top of this article has an inconsequential labeling error that should be corrected, but that has nothing to do with the report you mention above.
First of all, the surface data record is highly complex and the debate on adjustments is far from over. I doubt that the BEST project is the definitive word on the subject, nor do I see how it falsifies the idea that some of the adjustments have been policy driven. The BEST project is not immune to the same policy environment that brought us a lot of the adjustments in question.
Secondly, should Watts and D’Aleo be held to a much higher standard than the authors of the many ridiculous papers that appear in the journals supporting the AGW theory? How many of those have been ‘corrected and withdrawn’ after being almost instantly falsified the minute they went public? Have you called for any of those to be corrected and withdrawn?
If not, then I think you should correct and withdraw your request.
I won’t hold my breath.
I’ll bet in 50 years they will adjust todays temps down again while increasing 2062 temps. Of course eventually they’ll be lowering 1930s iceland temps to absolute zero to make the data fit the theory.
I find it very curious that Dr. Spencer hasn’t even attempted to square-the-circle between his claims here and his UAH satellite data. It appears he cannot.
John@EF says:
April 20, 2012 at 9:51 am
I find it very curious that if someone doesn’t choose to do something according to your personal schedule of what you think they should do and when, you assume that they cannot do so …
w.
@Willis Eschenbach says: April 20, 2012 at 1:29 pm,
It’s been a week, Willis. That question has been asked by many over the past seven days. Do you have an opinion as to why the blaring discrepancy? It seems reasonable that Dr. Spencer would anticipate being challenged on that obvious point and have a ready answer.
John@EF says:
April 20, 2012 at 3:50 pm
Near as I can tell, the question has been asked once, here, five days ago. Maybe it has been echoed by someone else.
Dr. Spencer has not posted to this thread since two days before that. Even if he had posted, that doesn’t mean he’s read every comment. As a result, I have no idea whether Dr. Spencer has even seen the question, and more to the point, neither do you.
You are accusing someone of deliberately ignoring something that you don’t know if he has ever seen. That is underhanded, unfair, and completely unacceptable. All you’ve done is proven that you are wildly biased, which won’t help you get traction for your underlying claim regardless of whether or not it is valid.
You may be right, and I’d be interested in an answer. I’d also be interested in Dr. Spencer’s comments on my post above. But I’m not going to accuse him of anything because he hasn’t answered my or any other post. For all I know, he’s on holiday, or has other work, or hasn’t seen it, or a dozen other reasons. I don’t have a clue, and I’m not guessing.
w.
@Willis Eschenbach says: April 20, 2012 at 5:20 pm
The question has been asked several times and under multiple original posts on Dr. Spencer’s own site, Willis. There are relatively few responses to wade through in those threads. This in addition to questions posed at multiple related sites across the blogosphere. The chances of Dr. Spencer not having seen some of these comments are slim. He’ll be compelled to respond eventually. I’m just surprised he apparently wasn’t armed with ready response.
John@EF says:
April 21, 2012 at 10:47 am
Thanks, John, with that additional information it makes more sense.
w.
Given that there are major changes in population in the US on the county level and lower between 1970 and 2010 (major parts of the midwest west of the mississippi had changes of -50%, the mountain west had major increases, etc,) the idea of using population density from a single year is risible.
Dr. Spencer finally replied on his blog regarding why his new population adjusted US land temperature trend claim varies so starkly with the UAH LT trend. He claimed ignorance. No real explanation. He claims he never considered the UAH LT data. Does anyone here not find that seriously odd and more than just a bit disappointing?