Christopher Booker, whom I met in Nice a few years ago and whom I like, wrote the most read Earth-category article in the Telegraph over the last 3 days,
I tend to agree that these adjustments are likely to have made the warming trend look higher – and the case for global warming more robust – than the most accurate data would manage. However, I am not quite certain about the size and relevance of this effect and I feel very uncomfortable about many climate skeptics' knee-jerk emotional reaction showing that they hate the very idea of an adjustment.
For this reason, I also agree with Steven Mosher, an independent climate skeptic (with experience in graduate studies in literature and management in 3D graphics companies) who has also co-authored a book about Climategate. In a guest blog post,
Instead, he explains that adjustments are used because they're good things when they are done right.
Social security may send you more accurate payments adjusted for inflation, adaptive optics improves some telescopes as well as Ronald Reagan's Star Wars, eyeglasses adjust some vision disorders, and similarly adjustments may be applied to remove as accurately as we can the spurious effect of various biases that affect the weather stations – those arising from location changes, the time-of-observation bias, a detectable change of the instrument, and others.
The LBT telescope uses adaptive optics to make "adjustments" and achieves a sharper image than the Hubble Space Telescope. Almost all the distortion caused by the atmosphere is basically removed.
Adjustments are a good thing and the instinctive criticism of all adjustments as a matter of principle is simply not right. I agree with Mosher: these "principled" critics of all adjustments are surely throwing the baby out with the bath water. And by the way, I do agree with the description of those who get crazy whenever somebody mentions the word "adjustment" as anti-science nut jobs, and yes, I do think that a large number of such people exists among the WUWT regular readers (but probably among most laymen in the world, too, and maybe they are a majority among the TRF readers as well, sorry).
Check that the red, green, and blue curves agree almost exactly.
But one essential argument appears at the very end of Mosher's text: Whether or not you apply one of the specified major adjustments or two or none of them doesn't visibly affect the resulting graph at all. It changes nothing about the qualitative picture. So not only is the "principled" criticism of all adjustments conceptually misguided: Even if this criticism were justifiable, the conclusion that "the result of an analysis that used some adjustments is compromised" would still be incorrect because many adjustments simply don't matter for many questions!
I am not saying that the local temperature data are unaffected by such adjustments – they surely are (and I guess that most examples mentioned by Chris Booker plus similar examples probably really mean that the "historical chronicles" give us a more accurate picture than the adjusted temperature records). But when we talk about the global mean temperature, the effect of all these adjustments seems negligible.
It is hard to be too confident about the temperature record from 1850, to mention an example. I am not sure whether it's almost correct or almost completely wrong. But the agreement between the different datasets that treat the homogenization and other issues differently – NASA's GISS, NOAA's NCDC, the Japanese global dataset, BEST, and Hadley Centre + Met Office's HadCRUT4 – leads me to believe that all the methods that these surface weather station scientists apply to the raw data are basically right.
If there's something wrong about the weather record, it must affect pretty much "most" of the raw data from the weather stations. Those raw data are used in pretty much all the datasets mentioned in the previous paragraph – which could explain the high degree of their agreement (even if all of them are very inaccurate). But the global averages seem to be rather robust with respect to the omission of a substantial percentage of the weather stations etc. so I tend to believe that the graph of the surface global mean temperature isn't mainly determined by several "bad apples".
In particular, we have the problem of the urban heat islands. While it is obvious that the urban heat islands do add a temperature change comparable to 1 °C which may depend on time (we know this effect from the Prague-Klementinum station that has been recording the data for more than 200 years; and this downtown Prague weather station is the warmest one in all of Czechia today), I have never believed that this issue was treated very badly or neglected by the folks who evaluated the surface temperature record. For this reason, while I found Anthony Watts et al. project mapping the weather station near asphalt to be amusing, I've never believed that this was really deciding about the "big questions" of the climate debate. My near-certainty that the bulk of the 20th century global warming shown by the surface weather record is not due to the asphalt was growing over the years.
The temperature record resulting from the weather stations differs from the graphs generated by the satellites – not by too much but substantially enough for the satellites to completely deny the claim that 2014 had a chance to have been the warmest year, and so on. But the differences between the satellite and weather-station-based temperature records probably mean that these two methodologies measure "substantially different quantities" (quantities with inequivalent definitions) that shouldn't be assumed to behave equally, and that's why they don't behave equally. The disagreement between the two methodologies isn't necessarily due to any "big error" on either side.
There's been some personal tension between Mosher and Watts – who have been friends in the past – and I won't amplify it by mentioning any details. But while it's true that one must be careful not to apply adjustments incorrectly or selectively in order to push the data in a fixed direction, one must also honestly recognize that many adjustments make the underlying science (or technology) more accurate – and many of these adjustments don't matter much, anyway.
The skeptics who contradict the last two principles are approximately as blinded and as biased as the climate alarmists who have really managed to spuriously increase warming trends by a selective application of would-be clever "adjustments" to the datasets. Well, while they're equally blinded, they don't want us to waste trillions of dollars, unlike the alarmists! ;-)
From most aspects, your humble correspondent is no lukewarmer at all. I think it's fair to say that the recent global mean temperature change is zero for all practical purposes, the percentage of the variability caused by (largely unpredictable) natural drivers is so high that the fact that the human contribution is nonzero may be ignored, and the threat of a significant global disruption coming from the climate change over the next 100 years is basically non-existent, and the proponents of the climate hysteria who have benefited from this hysteria should be treated exactly as all other fraudsters who have stolen tens of billions of dollars and who want much more to come.
But if you talk about the relationship to some basic procedures used in the scientific method and technology, not just in the climate science – e.g. to "adjustments" – I am surely a "lukewarmer", together with Steven Mosher, because the label of the full-fledged skeptics has been hijacked by anti-science nut jobs, indeed.
A reply to a blog post
A blogger named Steven Goddard whose actual name is Tony Heller posted a reaction to this blog post of mine. Here is my answer:
Dear Steve, the satellite record measures a different quantity than the weather-station-based global mean temperature, so there is no good reason to think that their graphs and trends should agree. In other words, the disagreement between these two different types of datasets doesn’t imply that there is a mistake in either of them.
Aside from this flawed argument, you haven’t offered *any* other argument that would imply that the adjusted graphs are wrong and the graphs preferred by you are right. It’s just your emotions and prejudices and the rational content is zero.
I hope it is OK if I think that you are just one of millions of people – on both sides – with equally irrational and biased attitudes to all these questions, so these three paragraphs represent all the time I will dedicate to your blog post.