Harvey defies attribution to global warming

Writing in the New York Times, Stanford professor Noah Diffenbaugh says we cannot tie Hurricane Harvey to manmade global warming. Who is Diffenbaugh and why do we care what he says? Well, he is one of the leaders in the latest alarmist pseudoscientific gimmick, which is falsely called “attribution science.” These folks claim to find the footprint of global warming in specific bad weather events. So if he can’t tie Harvey to global warming then nobody can.

Just a few months ago Diffenbaugh’s team published a major paper claiming to find that global warming has already increased the odds of record-setting heat waves across more than 80 percent of the planet. Actually even that hyperbole is just where we have reliable observations, which is not a lot of places. He also claims that human caused global warming has influenced record-setting wet and dry events across half that area. None of this is true but that it is being claimed as science is important, something to watch out for and resist.

The climate change literature is now awash with this junk. Last year the ever-alarmist National Academy of Science put out a lengthy report extolling the bogus virtues of this emerging money maker called extreme event attribution. Not surprisingly its sponsors included Obama’s NASA, NOAA and DOE.

There is no science here but it is important to know what these so-called scientists are up to. Plus if they cannot tie Harvey to global warming then no one can.

Here is how the attribution game goes. These studies typically use one of two basic methods, or a combination of both, neither of which works. The first method is to take whatever historical record is available and derive a probability from it. Then if recent events occur more frequently the increase is simply attributed to human caused global warming. The human cause is given the fraction of probability that lies outside the falsely assumed natural envelope.

Mind you the statistical math is fairly hairy but the bogus reasoning is just that simple. The assumption is that if an event is unexpected, given relatively short term data, then it must be due to human cause global warming. There is no scientific basis for this assumption, but never mind.

The second method is to use a climate model to define the probabilities. This is if anything worse because we know that today’s climate models are highly inaccurate. In particular they predict far more warming than actually occurs, which means they are weighing human emissions incorrectly. In fact they typically allow for little to no long term natural warming, so they assume that all such warming must be due to humans. If they then conclude that the effects of warming are human caused, they are simply concluding with their assumptions. This is rightly called circular reasoning.

Given the long hurricane drought the occurrence of Harvey is nothing like unexpected or unusual. That Harvey was followed by Irma is also touted as unexpected, but ironically a big part of the Harvey attribution problem is Irma. She spun up to cat 4 in waters that were well below the supposed threshold temperature for hurricanes to form at all. So the warming ocean argument for alarmism went right down the hurricane drain. Nature has a way of falsifying hasty generalizations, which are the faulty foundation for alarmism. In short, hurricane driven alarmism is absurd.

No wonder that Diffenbaugh and others have concluded that the attribution of Harvey is “complex,” as though the rest of climate is not. All of this alarmist attribution stuff is junk science personified. We are seeing nothing that is outside of normal natural variability. As my father used to say, figures don’t lie but liars sure can figure.


About the Author: David Wojick, Ph.D.

David Wojick is a journalist and policy analyst. He holds a doctorate in epistemology, specializing in the field of Mathematical Logic and Conceptual Analysis.