Conservative Estimates of Scientific Skeptics Surpassed By Reality

There’s nothing wrong with being a global warming skeptic. If you believe that global warming is happening just because it feels right, that’s not a good idea; it’s environmental religion. Reason demands reasons. A skeptic holds back from endorsing a theory or its associated hypotheses until the evidence comes in. That makes most environmental scientists in the world global warming skeptics, by the way, since the scientific community has followed a skeptical process of empirical observation. As evidence has accumulated, the Intergovernmental Panel on Climate Change, an international body of climate scientists, has reflected the skeptical consensus resulting from those empirical studies in a series of annual reports.

Some people have reacted to the latest IPCC report by labeling the scientists a group of wild and crazy fools:

…the fact remains that the promoters of the global warming and climate change movement have intentionally distorted whatever scientific basis there might be and persist in making wild and unjustified claims of achieving levels of certainty that are “beyond challenge” so as to make a mockery of any actual science mis-used to justify the claims of their political and social movement.

The scientists of the IPCC are biased. But the above passage shows a misunderstanding about the sort of bias climate scientists harbor. Climate scientists actually harbor a conservative bias. Theirs is a probabilistic science, in which theoretical models are built and assessed against available data. A model is typically accepted only if the probability of observations matching reality by chance alone is less than 5%, or less than 1% for claims of strong statistical significance. The bias in this approach is highly skeptical, only willing to embrace a model when the probability of it being wrong is not just low, or really low, but really, really low.

And so we shouldn’t be surprised when we find out that the scientific consensus on global warming turns out to be, if anything, too conservative:

Arctic ice is melting faster than computer models of climate calculate, according to a group of US researchers.

Since 1979, the Arctic has been losing summer ice at about 9% per decade, but models on average produce a melting rate less than half that figure.

The scientists suggest forecasts from the Intergovernmental Panel on Climate Change (IPCC) may be too cautious.

The latest observations indicate that Arctic summers could be ice-free by the middle of the century.