The post below on Dr. Roy Spencer’s blog that contains responses from Spencer and Christy deserves wide distribution and attention, because it shows just how badly Ben Santer and John Abraham want to squelch this dataset. Particularly amusing is the labeling of a graph in an Andrew Freidman article at WaPo as alisting of “corrections”, when in fact it is nothing more than the advance of the trend in step with the graph below.
Addressing Criticisms of the UAH Temperature Dataset at 1/3 Century
by Roy W. Spencer, Ph. D.
The UAH satellite-based global temperature dataset has reached 1/3 of a century in length, a milestone we marked with a press release in the last week (e.g. covered here).
As a result of that press release, a Capital Weather Gang blog post by Andrew Freedman was dutifully dispatched as damage control, since we had inconveniently noted the continuing disagreement between climate models used to predict global warming and the satellite observations.
What follows is a response by John Christy, who has been producing these datasets with me for the last 20 years:
Many of you are aware that as a matter of preference I do not use the blogosphere to report information about climate or to correct the considerable amount of misinformation that appears out there related to our work. My general rule is never to get in a fight with someone who owns an obnoxious website, because you are simply a tool of the gatekeeper at that point.
However, I thought I would do so here because a number of folks have requested an explanation about a blog post connected to the Washington Post that appeared on 20 Dec. Unfortunately, some of the issues are complicated, so the comments here will probably not satisfy those who want the details and I don’t have time to address all of its errors.
Earlier this week we reported on the latest monthly global temperature update, as we do every month, which is distributed to dozens of news outlets. With 33 years of satellite data now in the hopper (essentially a third of a century) we decided to comment on the long-term character, noting that the overall temperature trend of the bulk troposphere is less than that of the IPCC AR4 climate model projections for the same period. This has been noted in several publications, and to us is not a new or unusual statement.
Suggesting that the actual climate is at odds with model projections does not sit well with those who desire that climate model output be granted high credibility. I was alerted to this blog post within which are, what I can only call, “myths” about the UAH lower tropospheric dataset and model simulations. I’m unfamiliar with the author (Andrew Freedman) but the piece was clearly designed to present a series of assertions about the UAH data and model evaluation, to which we were not asked to respond. Without such a knowledgeable response from the expert creators of the UAH dataset, the mythology of the post may be preserved.
The first issue I want to address deals the relationship between temperature trends of observations versus model output. I often see such posts refer to an old CCSP document (2006) which, as I’ve reported in congressional testimony, was not very accurate to begin with, but which has been superseded and contradicted by several more recent publications.
These publications specifically document the fact that bulk atmospheric temperatures in the climate system are warming at only 1/2 to 1/4 the rate of the IPCC AR4 model trends. Indeed actual upper air temperatures are warming the same or less than the observed surface temperatures (most obvious in the tropics) which is in clear and significant contradiction to model projections, which suggest warming should be amplified with altitude.
The blog post even indicates one of its quoted scientists, Ben Santer, agrees that the upper air is warming less than the surface – a result with which no model agrees. So, the model vs. observational issue was not presented accurately in the post. This has been addressed in the peer reviewed literature by us and others (Christy et al. 2007, 2010, 2011, McKitrick et al. 2010, Klotzbach et al. 2009, 2010.)
Then, some people find comfort in simply denigrating the uncooperative UAH data (about which there have been many validation studies.) We were the first to develop a microwave-based global temperature product. We have sought to produce the most accurate representation of the real world possible with these data – there is no premium in generating problematic data. When problems with various instruments or processes are discovered, we characterize, fix and publish the information. That adjustments are required through time is obvious as no one can predict when an instrument might run into problems, and the development of such a dataset from satellites was uncharted territory before we developed the first methods.
The Freedman blog post is completely wrong when it states that “when the problems are fixed, the trend always goes up.” Indeed, there have been a number of corrections that adjusted for spurious warming, leading to a reduction in the warming trend. That the scientists quoted in the post didn’t mention this says something about their bias.
The most significant of these problems we discovered in the late 1990’s in which the calibration of the radiometer was found to be influenced by the temperature of the instrument itself (due to variable solar shadowing effects on a drifting polar orbiting spacecraft.) Both positive and negative adjustments were listed in the CCSP report mentioned above.
We are always working to provide the best products, and we may soon have another adjustment to account for an apparent spurious warming in the last few years of the aging Aqua AMSU (see operational notes here). We know the data are not perfect (no data are), but we have documented the relatively small error bounds of the reported trends using internal and external evidence (Christy et al. 2011.)
A further misunderstanding in the blog post is promoted by the embedded figure (below, with credit given to a John Abraham, no affiliation). The figure is not, as claimed in the caption, a listing of “corrections”:
The major result of this diagram is simply how the trend of the data, which started in 1979, changed as time progressed (with minor satellite adjustments included.) The largest effect one sees here is due to the spike in warming from the super El Nino of 1998 that tilted the trend to be much more positive after that date. (Note that the diamonds are incorrectly placed on the publication dates, rather than the date of the last year in the trend reported in the corresponding paper – so the diamonds should be shifted to the left by about a year. The 33 year trend through 2011 is +0.14 °C/decade.)
The notion in the blog post that surface temperature datasets are somehow robust and pristine is remarkable. I encourage readers to check out papers such as my examination of the Central California and East African temperature records. Here I show, by using 10 times as many stations utilized in the popular surface temperature datasets, that recent surface temperature trends are highly overstated in these regions (Christy et al. 2006; 2009). We also document how surface development disrupts the formation of the nocturnal boundary layer in many ways, leading to warming nighttime temperatures.
That’s enough for now. The Washington Post blogger, in my view, is writing as a convinced advocate, not as a curious scientist or impartial journalist. But, you already knew that.
In addition to the above, I (Roy) would like to address comments made by Ben Santer in the Washington Post blog:
A second misleading claim the (UAH) press release makes is that it’s simply not possible to identify the human contribution to global warming, despite the publication of studies that have done just that. “While many scientists believe it [warming] is almost entirely due to humans, that view cannot be proved scientifically,” Spencer states.
Ben Santer, a climate researcher at Lawrence Livermore National Laboratory in California, said Spencer and Christy are mistaken. “People who claim (like Roy Spencer did) that it is “impossible” to separate human from natural influences on climate are seriously misinformed,” he wrote via email. “They are ignoring several decades of relevant research and literature. They are embracing ignorance.” “Many dozens of scientific studies have identified a human “fingerprint” in observations of surface and lower tropospheric temperature change,” Santer stated.
In my opinion, the supposed “fingerprint” evidence of human-caused warming continues to be one of the great pseudo-scientific frauds of the global warming debate. There is no way to distinguish warming caused by increasing carbon dioxide from warming caused by a more humid atmosphere responding to (say) naturally warming oceans responding to a slight decrease in maritime cloud cover (see, for example, “Oceanic Influences on Recent continental Warming“).
Many papers indeed have claimed to find a human “fingerprint”, but upon close examination the evidence is simply consistent with human caused warming — while conveniently neglecting to point out that the evidence would also be consistent with naturally caused warming. This disingenuous sleight-of-hand is just one more example of why the public is increasingly distrustful of the climate scientists they support with their tax dollars.
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>> KR says:
December 21, 2011 at 2:18 pm
Curious. Personally, I think you protest to much… that your data is biased low, that you accept corrections only when overwhelming, and that (as the data show) your temperature record continues to be an extreme outlier on the cool side. <<
Personally, I think you spout dogma too much … that your statements are biased by spending too much time on the believer blogs, and that (as James Sexton showed on December 21, 2011 at 11:41 am) your post continues to quote an extreme (xxx)liar from the warm side.
KR says:
December 21, 2011 at 2:18 pm
Ignore KR, he is either stupid or cannot comprehend english.
Christopher Hanley says:
December 21, 2011 at 2:45 pm
The 33 year UAH trend of +0.1.4C/decade looks, to my untrained eye, very similar to the simple linear trend of HADCRUT over the 50 year period of predominately human impact as claimed by the IPCC:
http://woodfortrees.org/plot/uah/plot/uah/trend/plot/hadcrut3vgl/from:1950/trend
=============================================================
Christopher, attribution for the warming has yet to be shown. But, even to a trained eye, the 33 year trends for all of the data sets….. UAH, RSS, HadCrut, and GISS look remarkably similar.
http://suyts.wordpress.com/2011/12/21/delusional-scientists-and-bloggers-fail-at-character-assassination-attempt/
“Robt319 says:
December 21, 2011 at 2:53 pm
@KR You could do a tiny bit of research before posting.”
Well Rob, it’s obvious he can’t.
We should remember there are two significant volcanoes at the beginning of this record. This has the affect of increasing the trend versus what it would have been in the absence of the volcanoes (this is similar to Bob Tisdale’s recent post on sea surface temperatures).
Adjusting out the impact of the volcanoes, the average of UAH and RSS then falls to 0.094C per decade in terms of a trend. The impact of the ENSO also becomes much more clear.
http://img190.imageshack.us/img190/4235/volcadjuahrssensonov11.png
The climate models predict that the UAH/RSS atmospheric level should rise by 1.2 to 1.4 times that of the surface (the tropical hotspot in particular). So the climate models would have this level increasing at over 0.28C per decade while it is just 0.094C (after taking into just one external variable).
If one adjusts out the volcanoes, and also the ENSO and AMO influences, the trend then falls to 0.042C per decade (now that is less than 15% of the climate models predicted trend for the lower troposphere).
http://img832.imageshack.us/img832/7739/warmingvolcensoamouahrs.png
“R. de Haan says: December 21, 2011 at 11:44 am
When you find yourself in a hole, stop digging.”
Or in the case of Ben (Sluggo) Santer, when you find yourself in the ring with Ali, stop swinging.
33 years is half the climate cycle, and it’s been mostly the warming half. So now we enter the cooling half. After a few years of coolth, I think the world will come to the conclusion that warmer is better.
Oh no you di-ent!
KR has a valid point, contrary to the OP. The graph does show a mix of the actual in trend mixed with the corrections to the S&C methodology that cause the UAH to rise in trend. In short, S&C have previously underestimated the trend. However the heading under the figure in the WashPost piece is not correct. It is not “errors that were corrected’ but a “combination of rise in trend and corrections” (those corrections being to correct prior trend underestimations).
It’s pretty weird though that so many people defend a misleading heading calling it corrections. I get the sense that the “rapid response team” writes figure headings a little too rapidly and defends their work a little too rapidly also. I guess they figure 99.99% of the public won’t figure it out.
I just checked out the WAPO blog that Spencer and Christy are replying to. The blog has a total of 43 comments and maybe 3 good ones. I guess the WAPO brand does not count for much in climate science or climate politics.
Jeff Alberts says:
December 21, 2011 at 6:46 pm
It’s about the spankage and butthurt Dessler, Santer, and Abraham have all received from skeptics.
Oh no you di-ent!
===============================================================
lol,….. called it like it was. 😉
There was a time I could provoke discussion on issues such as these with great ease…… they just don’t come out to play anymore. I believe they’ve decided that it really wasn’t the manner in which they packaged their message.
Perhaps one reason for UAH data being cooler is that satellite sensors aren’t cheek and jowl with heat absorbing/emitting tarmac airport landing strips like land-based weather stations are? Proximite to ever-more-powerful jet engines, and increasing number of plane flights?
Perhaps some who knows would share with this poor benighted soul the percentage of weather stations, globally, located at airports?
neill says:
December 21, 2011 at 8:15 pm
Perhaps one reason for UAH data being cooler is that satellite sensors aren’t cheek and jowl with heat absorbing/emitting tarmac airport landing strips like land-based weather stations are? Proximite to ever-more-powerful jet engines, and increasing number of plane flights?
Perhaps some who knows would share with this poor benighted soul the percentage of weather stations, globally, located at airports?
===================================================
Neil, the thing is UAH isn’t cooler. At the risk of being redundant, go here http://suyts.wordpress.com/2011/12/21/delusional-scientists-and-bloggers-fail-at-character-assassination-attempt/
Ok, technically it is cooler. It is slightly over 2/10,000ths of a degree warmer in the annual trend than RSS (the other satellite temp database)
Here are the numbers for the trends from 1979 to present ………
UAH, slope = 0.0137276 per year……..
RSS, slope = 0.0139595 per year ………
HadCr slope=0.0149354 per year……
GISS slope = 0.0162445 per year …..
(hope the formatting holds) So, the largest divergence is 25/10,000ths of a degree/yr. This is outrageous. 825/10,000ths of a degree divergence from the outlier over a 33 year period of time! With HadCrut, it is much closer. And with the other satellite data gathering group they are spot on! Can anyone legitimately state they hoped for closer agreement? No. What they hoped for was validation of their wild a$$ illegitimate theories about our atmosphere and the role GHGs play. Turns out, GHGs aren’t nearly as important as those imbeciles thought. And when facts invalidate these lunatic theories, they turn to character assassination.
They are wrong intellectually, they are wrong morally. And they willfully choose to remain in such state. There isn’t much else to be stated.
There is one other thought that should be vocalized. If, the contention is that our satellites are wrong…… which it must be the satellites and not the interpreters because of such close agreement with the two separate groups gathering satellite data,(gosh I love typing that! 🙂 )…….. then, our satellites are wrong about much more than just temps. The assumptions and spacing with the temp gathering are the same for all satellites with other functions. There would be only a very small part of the process that was unique to the process of gathering temps as opposed to say……. sea levels, or ozone measurements or gas spectrometry, or ……
I am very, very curious about the views of Dr. Spencer on why the troposphere isn’t warming as fast as the surface, and why he thinks the models are unanimous in predicting the troposphere should warm faster.
I have my own theory about both these points, I’ve posted a paper about it on my blog. But given how busy Dr. Spencer is, I don’t expect him to read and comment on random papers in the blogosphere. I’d really just like a paragraph or two summarizing his view, or a link to same.
How about it, Dr. Spencer? What are the physics in this case?
And while we’re at it, has anyone else got a theory?
All that linear trend comparisons are useless, since tropospheric data are much more sensitive to positive ENSO events than the surface record – see the 2010 El Nino on HadCRUT and UAH.
This is CRUTEM3 vs MSU above land vs Reynolds SST since 1979:
http://blog.sme.sk/blog/560/252537/uhi_glob.jpg
As long as the “mainstream” climate scientists continue to claim publicly that Mann’s Hockey stick (or any of it’s clones) is an accurate representation of temperatures for the past 1000 years they will continue to have zero credibility.
I suppose the human fingerprint is supposedly the changes in observed 13C to 12C. One argument is no biological source of carbon would be depeleted in 14C. A better argument is biological sources of CO2 are enriched in 12C, and fossil fuels supposedly come from plants originally. Consequently, burning fossil fuels enriches 12C. Is that necessarily true? And even if it is true, it doesn’t mean that CO2 has anything to do with observed warming trends.
http://www.esrl.noaa.gov/gmd/ccgg/newsletters/newsletter_2011.pdf
The ratio of 14C to 12C is decreasing in the atmosphere. 14C is cosmogenic (ignoring atmospheric testing of nuclear weapons) and has a half-life of about 5700 years. After 5 half-lives, only 3% is left. Methane seeping from the ground either on land or in the sea easily could be old enough. However, what we are looking for is something that may be a consequence of more recent events, not a constant contributor. It must explain a change in the observed isotope ratios,
Perhaps methane clathrates, accumulated during the last glacial maximum, are still being released. More recent isotope ratio changes might be explained if the methane release rate from the ocean was slowed during the LIA. Another source might be recenty thawed permafrost that had frozen 15,000 or more years ago. Thawed ground could now be producing methane with little 14C. Permafrost melting may be caused by factors other than atmospheric CO2 increases. It is well known that atmospheric CO2 concentration increases and decreases follow changes in average temperature, and that clear observation is ignored by alarmists.
It is less obvious how to explain the observed 13C decline. In photosynthesis, plants capture 12CO2 slightly faster. Actual fractionation depends on gas phase concentrations, but also the concentrations of CO2 or HCO3 dissolved in tissues. Furthermore, there are strong differences in fractionation between terrestrial and aquatic species, and there are strong temperature dependencies. Marine phytoplankton strongly enrich 13C in surface water, and 12C in sediments. This effect is more pronounced in cold water conditions. Thus, the observed decline in atmospheric 13C could be explained by the release of methane in the last century that was produced from sediments that accumulated long ago, perhaps while the oceans were colder.
http://www.geo.cornell.edu/geology/classes/Geo656/656notes03/656%2003Lecture28.pdf
Read much?
Apparently not.
James Sexton says:
I have a graph that shows the trends of all 4 data sets (GISS, HadCrut, RSS an UAH)
James, I always respect your opinion. Maybe you can help me.
My problem is : the datasets that are always quoted, even on WUWT, don’t show me where the extra heat came from. If you look at my dataset:
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
you can easliy see what is happening, because it shows the development of maxima and minima as well….
For example: looking at the SH (on my tables).
Looking at the Means I am finding that there is virtually no warming in the SH since 1974. I heard here that it is apparently the same in the antarctic:
http://www.nerc-bas.ac.uk/icd/gjma/amundsen-scott.ann.trend.pdf
http://www.nerc-bas.ac.uk/public/icd/gjma/vostok.ann.trend.pdf
(does anyone here perhaps know where the original data of these 2 graphs are?)
However, seeing that Maxima rose by an incredible 0.045 degrees C per annum in the SH, and minima are falling by -0.017 degrees C, there must be a nett loss of energy over the whole of the SH.
Now, on the NH, on the other hand, maxima and means and minima are almost on par with each other, all increasing at about 0.027 degrees C per annum since 1974.
the only explanation I can think of is that our current weather systems pick up the warmth from the SH and drop it in the NH. That is all that would explain that maxima and minima and means are rising at almost the same rate here.
Note that I only cut up my results in NH and SH because I was curious. But we cannot cut up earth in 2 pieces to make a point. I have to bring everything back to one global result: 0.0137. Obviously, the final conclusion of all the results in my tables is still that warming is driven by increasing maxima,
i.e. less clouds and/or more intense sunshine, especially so in the SH.
So, what we see is happening from my dataset is that more heat went into the SH oceans and is taken away by current weather systems to the NH.
Now, curiously enough, it seems that my estimate of global warming for the past 37 years is remarkably spot on: mine is 0.0137 degrees C per annum versus the 0.14 degrees C per decade for the past 33 years reported here….
Interesting, not?
The point I am trying to make is that I prefer my datasets – even though I am not yet quoted -because it tells me more of what is happening. Don’t you think so too? So why can’t we get the same information about maxima and minima from your 4 datasets?
All I find on climate bloggs is graphs telling me that average temps. are rising. I know that. I think everyone knows that by now. We need to have more info, telling us why the temps. are increasing.
Unfortunately Dr. Spencer your time period of 33 years, yes I know it is the total satellite period of observation, is about half the climate cycle found in some other research. Within that 60 year cycle there is no warming and even a slight cooling.
I fully expect your research to continue to produce good data.
It is easy to see why this data set needs to be maligned by thye AGW crowd. Put simply over the 33 year period there is no warming trend. Before the super El Nino, temperatures were flat. After the super El Nino temperatures remain flat. The data set shows that all that has happened is that there was a step change around the supoer El Nino.
The data set is completely inconsistent with all land based data sets (save that they appear to largely agree that there has been little warming since the super El Nino).
@Maurizio: “Guess which ones are likely more scientific”
I am going to use this sentence of yours as a stalking horse. Please dont take what I write as aimed at you personally.
But this phrase strikes me as being a symptom of a modern (post-modern?) problem; we have taken science – which is simply a rigorous methodology – and applied it as a value judgement.
In this context, “scientific” = “good”.
Now we have the bizarre and troubling spectacle of everyone on all sides of an argument trying to claim to be the **most** scientific, in much the same way people might once have contended to be seen as the most pious. When we join this spectacle, we degrade science, from its proper status as a useful discovery mechanism, to a pietistic social ritual.
But really, a scientific process is merely one in which no obvious mistakes have been made. The results may be good, bad, or indifferent, depending largely on one’s point of view.
(I am, for example, firmly in the “warming is good” camp, believing that less people die when it is warm than when it is cold, and not at all convinced that the alleged damage done by warming is anywhere near as bad as it is painted by some, assuming it exists at all. Others see warming as inherently bad, yet others are indifferent to it.)
The rigour of the process used to arrive at the result tells us nothing about the desirability of the result.
Please can we try to avoid the linguistic and epistemological errors of our opponents, especially while we’re criticising them for their linguistic and epistemological errors?
My view is that sloppy language is a symptom of sloppy thinking.
I’m agin it – generally.
Thanks.
Trend matching as a means to causation is such a low level degree of scientific acumen that I wonder which PhD committee allows such nonsense. That population has risen, development has risen, and CO2 has risen does not automatically render them the first encountered pathology responsible for the fact that global temperatures have risen (though not in regard to development blanketed nocturnal temperatures impinging on ground sensors). I’ve gotten older in concert with the rise in CO2. Is my aging birthdays thus responsible for the rise in CO2 and therefore the rise in global temperatures? Only when I suffer from a hot flash.
Now with the right kind of PhD committee, I just might get away with that spurious connection.
HenryP says:
December 22, 2011 at 2:08 am
James Sexton says:
I have a graph that shows the trends of all 4 data sets (GISS, HadCrut, RSS an UAH)
James, I always respect your opinion. Maybe you can help me.
………….
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
you can easliy see what is happening, because it shows the development of maxima and minima as well….
For example: looking at the SH (on my tables).
…………
Interesting, not?
The point I am trying to make is that I prefer my datasets – even though I am not yet quoted -because it tells me more of what is happening. Don’t you think so too? So why can’t we get the same information about maxima and minima from your 4 datasets?
All I find on climate bloggs is graphs telling me that average temps. are rising. I know that. I think everyone knows that by now. We need to have more info, telling us why the temps. are increasing.
================================================
Henry, thanks for the kind words. And, yes your approach is interesting. Perhaps someone more capable than myself could have a look at the way you’re presenting the data. But, I like how you’ve broke it down in the min/max/mean. And, thanks for reminding me, I’ve been remiss in popping over to see what you’ve been up to. I always enjoy looking at things from a different perspective.
In this particular case, I wasn’t aiming to do any analysis, rather, to simply show the disingenuous characterization of UAH’s data set and by extension what these people were implying about Drs Spencer and Christy. As is often the case when, either writing on my blog or participating in a conversation elsewhere, time is my largest constraint. Because of the fluid nature of discussions and topics, I often opt for expedience. In this particular instance, Paul Clark’s http://www.woodfortrees.org is the place to go. Just to be clear, I’m not doing anything with any data. These aren’t my data sets. Paul Clark links directly to the source and any independent graphic I create uses data directly from the various sources. I prefer to keep the numbers as straight forward as possible. Statistical acrobatics isn’t my forte.
For my particular views on numbers, statistics, and what some have done to my first love, ……..
Read these two in this order…… http://suyts.wordpress.com/2011/11/08/i-wanted-to-be-a-statistician/ and then this one for a specific view of dendro…. http://suyts.wordpress.com/2011/11/29/dividing-by-zero/
Henry, as to why we’re seeing warming, I haven’t a clue. Nor, do I seek to answer that question. While anyone who knows me, knows I posses a rather inflated view of self, it isn’t large enough to believe I can understand all that Nature is doing. I can’t. I’m not sure it is a worthwhile venture.