So first, the good news.
This is a tad more defensible. There has indeed been warming over the last 17 years, but by throwing in the word “significant,” at least Cruz made it more a matter of subjective interpretation, turning on how much warming really counts.
But at the same time — this is the bad news — Cruz brought in some mangled history of science (see this video, around minute 14:30, for the start of Cruz’s comments on climate):
On the global warming alarmists, anyone who actually points to the evidence that disproves their apocalyptical claims, they don’t engage in reasoned debate. What do they do? They scream, ‘You’re a denier.’ They brand you a heretic. Today, the global warming alarmists are the equivalent of the flat-Earthers. It used to be [that] it is accepted scientific wisdom the Earth is flat, and this heretic named Galileo was branded a denier.
You can also just watch the video here:
There are some large problems here. “Galileo did NOT discover that the Earth is round. I know of no competent historian who maintains otherwise,” comments Harvard historian of science Steven Shapin, author of, among other works, the widely read “The Scientific Revolution,” by e-mail.
Galileo actually got in trouble with the Church over Copernicanism, or the idea that the Earth goes around the sun, itself located at the center of the solar system — not the shape of the Earth.
That said, Cruz does seem to be invoking a common trope — that climate skeptics are Galileo figures, brave scientists standing alone, right about things, but effectively quashed by the authorities. The analogy is most directly applied to what happened after the publication of Galileo’s 1632 “Dialogue Concerning the Two Chief World Systems,” which puts all the dumb anti-Copernican arguments in the mouth of a character named Simplicio. The book was banned and Galileo himself was forced to recant by the Inquisition. But Galileo was right in the end, of course, and the Church itself later admitted as much.
Thus, by invoking this analogy, Cruz is more or less suggesting that climate change skeptics, and he himself, are on the right side of the history of science in this instance. Indeed, he’s saying we live in another Galileo moment, where the conventional wisdom is wrong but strongly enforced as authority, and you need a brave heretic to stand up and say so.
So is that really a fair analogy?
A number of science historians whom I contacted suggest otherwise. “Galileo was not attacked by his fellow scientists, he was attacked by the Catholic Church, the power structure of his day,” explains Naomi Oreskes, also a Harvard science historian. ” Climate contrarians are on the side of, and are supported by, the power structure of our day, which is the Republican Party and the carbon-combustion complex.”
Indeed, Galileo was nothing if not a brilliant anti-authoritarian and needler of conventional wisdom (who finally went further than the authorities of the time would tolerate). “The leitmotif which I recognize in Galileo’s work is the passionate fight against any kind of dogma based on authority,” wrote Albert Einstein of the “Dialogue Concerning the Two Chief World Systems.”
Other historians take a similar line. “It may be convenient to portray climate change skeptics as the Galileos of our day, but it hardly fits with the available evidence,” says John Durant, a science historian and director of the MIT Museum. “Climate change skeptics are not pointing, as Galileo did, to telling observations that the rest of the scientific community is systematically ignoring; on the contrary, they’re peddling a kind of conspiracy theory that simply invites people to reject or ignore the vast quantities of scientific evidence — freely available in the peer reviewed literature — on which the scientific community bases its current knowledge about climate change.”
In fairness, we can’t be utterly and 100 percent positive that climate skeptics won’t be someday validated. No scientific idea is held with absolute certainty, including the widely accepted and widely ratified idea that global warming is happening now, driven by human-caused greenhouse gas emissions. There is still a possibility — however slender — that the consensus might be wrong.
But more likely is that, along with science, climate skeptics are also getting the history of science wrong in this instance.
“Of course, if you are capable of disregarding the consensus of climate change scientists, you are surely capable of denying the consensus of historians of science,” says Harvard’s Shapin.