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UPDATE: RealClimate’s snarky response to the issue is here, and Keith Briffa, the original researcher, has responded in a much more professional way here.

The Register has reported on what appears to be at best a horrible mistake. Some are calling it a deliberate misrepresentation. In a development sure to rock the established view of climate modeling, it has been revealed that some of the data relied on for climate models is unreliable. The impact? It calls into question many of the assumptions regarding 20th century global warming. If the 20th century isn’t warmer, then human-induced global warming is simply not supported by scientific evidence.

One popular proxy for having temperature measurements of the past centuries is to compare tree ring growth. Its a sophisticated and complex issue to weed out the impact of other environmental factors, but scientists agree the process is a valid method. But one of the most popular series — named Yamal, for the area in Siberia where the trees are located — has to be re-examined:

At the insistence of editors of the Royal Society’s Philosophical Transactions B the data has leaked into the open – and Yamal’s mystery is no more.

From this we know that the Yamal data set uses just 12 trees from a larger set to produce its dramatic recent trend. Yet many more were cored, and a larger data set (of 34) from the vicinity shows no dramatic recent warming, and warmer temperatures in the middle ages.

In all there are 252 cores in the CRU Yamal data set, of which ten were alive 1990. All 12 cores selected show strong growth since the mid-19th century. The implication is clear: the dozen were cherry-picked.

Cherry picking the samples to fit a preconceived idea is not new; it can happen purposefully or by simple “selection bias”, where a preconception exists but isn’t apparent to the researcher. We can admit the cherry picking or selection bias has happened without casting aspersions.

The deconstruction is the work of Steve McIntyre of ClimateAudit.org, a very technical site. While the Register’s accounting of the controversy is brief and easy to read, following it on ClimateAudit.org might be daunting. We are in luck, however, as the Bishop Hill Blog has a more detailed, yet easily comprehended recap of the entire controversy, with this summation:

McIntyre therefore prepared a revised dataset, replacing Briffa’s selected 12 cores with the 34 from Khadyta River. The revised chronology was simply staggering. The sharp uptick in the series at the end of the twentieth century had vanished, leaving a twentieth century apparently without a significant trend. The blade of the Yamal hockey stick, used in so many of those temperature reconstructions that the IPCC said validated Michael Mann’s work, was gone.

The history of science is replete with this kind of controversy. What we are seeing is the scientific method at work. As often happens, hypothesis becomes consensus, then someone like McIntyre challenges the established wisdom and the consensus must give way. It usually does so noisily, with great emotion and resistance. But give way it must.

Climate climate change, Scientific Method

One of the canards used by my fellow Christians who actively fight against the idea of evolution is that it can’t be proven because it can’t be observed. Scientists are observing evolution in carefully conducted tests that challenge some of their preconceptions. Those preconceptions, however, do not address the basic core of evolutionary thought, but rather the specific mechanisms under which evolution occurs. One recent experiment with E.coli bacteria is summarized by Panda’s Thumb:

These bacteria have been raised in a constant environment, one which is somewhat less than ideal: they’ve been fed on small quantities of glucose, and nothing but glucose, in a lean regimen that has encouraged selection for somewhat different properties than you’ll find in your gut, one of the normal habitats of E. coli. They have evolved, and even have distinctive morphological characters, and many of their properties are consistent from population to population. There is one property that would be useful for the bacteria, but that has evolved in only one of the 12 populations: the ability to use citrate as a carbon source. There’s plenty of citrate in the medium, and it would be a bit of a coup for any bacterium to acquire the ability to take up and metabolize it, but it just hasn’t happened as often as might be hoped…except in one of the 12 populations, which around the 33,000th generation, suddenly expanded its stable population size by exploiting citrate in its environment.

PZ Myers, the author, explains that the preconceptions that are challenged by this development, and they are not in any way challenges to the general understanding of evolution. We lay people often get it wrong when science discovers something new that “challenges” what has come before; for us, it is hardly a challenge at all, but merely a small correction. The scientists observed that only one of the 12 populations evolved the ability to use the citrate, and it doesn’t appear to be due to a lucky appearance of several different mutations induced by some kind of environmental pressure. What they found was that “the presence of (probably) neutral mutations in one may enable other changes that predispose it to particular patterns of change.”

We often hear that evolution is not provable because you can’t test for it and repeat the tests to verify the accuracy. Yet in this experiment, scientists did just that: because they saved a sample of each population at each stage, they can “roll back the clock” and start the experiment over. By doing so, they were able to establish that three mutations had to occur for the “breakthrough” of citrate uptake in the E.coli, and it only happened in that population. On a verifiable, repeatable basis. This is exactly the mechanism predicted by evolutionary theory.

Myers addresses the Creationist claim that the experiment somehow supports the idea of “intelligent design” from a scientific standpoint. From my theological perspective, this experiment shows that evolution must be true or, as the only alternative, God is being held captive in a lab and being forced to exercise His creative powers on command.

Faith, Science Creationism, Evolution, Intelligent Design, Scientific Method