FEATURE2 CONSPIRACY THEORY
In 1999, National Geographic magazine announced the discovery of a remarkable fossil. Archaeoraptor, as it was named, was claimed to be a dinosaur with feathers, a missing link of evolution that showed these long-extinct creatures were the ancestors of modern birds.
A year later, however, the magazine was left with a dinosaur-sized portion of egg on its face. Scientific investigations revealed that Archaeoraptor was a fake — a composite of dinosaur and primitive bird fossils that had been glued together.
The episode was seized upon by creationists, yet it has done nothing to dent the fundamentals of evolutionary theory. It survived this fraud — as it survived others such as Piltdown Man — because it is far too broadly attested to be threatened by a single piece of dodgy evidence.
Research in dozens of disciplines — including genetics, anthropology, palaeontology, geology and medicine, to name but a few — shows evolution to be a scientific fact. It is hard to credit the view that all are wrong.
This is worth remembering in the context of the Climate Research Unit (CRU) hacking scandal. For even if the stolen e-mails are shown to reveal scientific misconduct and data distortion — and the out-of-context remarks they contain have so far demonstrated nothing of the sort — they would do little to undermine the broad sweep of climate science.
As with evolution, the case that the world is warming and that human activity is at least partially responsible, does not rest on any one observation that if refuted would collapse a house of cards. It has been built from compelling multi-disciplinary science, with many strands of data that all point the same way.
As the journal Nature put it in an editorial this week: “Nothing in the e-mails undermines the scientific case that global warming is real — or that human activities are almost certainly the cause. That case is supported by multiple, robust lines of evidence, including several that are completely independent of the climate reconstructions debated in the e-mails.”
First, the CRU database that global warming deniers now claim to be discredited is not the only one of its kind. Historical temperature records have been compiled independently by Nasa and the US National Oceaonographic and Atmospheric Administration (NOAA) and they match the CRU’s figures so closely they are statistically identical.
What is more, such temperature data are far from the only evidence for the human-induced warming theory. Polar ice and mountain glaciers are retreating in line with the predictions it makes, or if anything even more quickly. Observations of sea level rise, animal migrations and plant germination match the models, as do changing patterns of precipitation. The oceans are warming and becoming more acidic as they absorb more carbon dioxide.
While natural climate variation is almost certainly a factor in these trends, it cannot explain them entirely. Only when human-induced forcing is included is it possible to account for all these effects.
The underlying physics of climate change is also robust. Nobody disputes the reality of the greenhouse effect, by which gases such as water vapour, methane and carbon dioxide keep our planet at least 30C (58F) warmer than it would otherwise be. When atmospheric carbon dioxide has increased in the past, so have global temperatures. And ice cores show that current carbon dioxide levels are unprecedented for hundreds of thousands of years.
The idea that global warming is an elaborate hoax suffers from the fatal flaw that afflicts most conspiracy theories: the alleged conspiracy is simply too huge and all-encompassing to be taken seriously.
It is possible that a few scientists might have faked or manipulated evidence, like the fossil-maker behind Archaeoraptor, though there is no proof of this in the CRU emails. But the notion that so many different branches of science have all connived undetected to manufacture a falsehood defies belief.
(mark Henderson, Times Online, 4December2009)
