No longer content just to claim to be “skeptical” of scientific findings they find disagreeable, Republican politicians have moved on to a more alarming anti-science strategy: confuse the public about what science even is, claiming it’s just someone’s opinion and ignoring the importance of evidence.

Marco Rubio’s recent remarks about climate change epitomize this new era, with conservative politicians deciding that “science” is whatever they say it is. “I don't agree with the notion that some are putting out there—including scientists—that somehow, there are actions we can take today that would actually have an impact on what's happening in our climate,” Rubio told ABC’s Jonathan Karl. “I do not believe that human activity is causing these dramatic changes to our climate the way these scientist are portraying it,” he added.

By making climate change a matter of what he “believes” or “agrees with,” Rubio was implying that climate change is a matter of opinion and not of evidence or fact. There’s the old saying, “Everyone is entitled to his own opinion, but not his own facts.” Conservatives have figured out a workaround: redefine the facts as opinions, and by golly, now you get to have your own facts!

James Taranto of the Wall Street Journal was even more blunt in asserting that scientific findings should be regarded as more opinion than fact in his defense of Rubio, portraying Rubio as a rebel “for refusing to submit to scientific authority.” In a sleight of hand, Taranto portrayed the debate as one of scientists simply asserting, from authority, and Rubio as just someone disagreeing. But Rubio isn't disagreeing with the opinions of scientists; he’s disagreeing with the conclusions derived from the evidence. Even if all the climate change scientists died tomorrow, the planet would still be heating up. This isn’t a matter of one person’s opinion versus another. It’s a man being presented with facts and refusing to believe them.

But it was Rubio’s followup to this debacle that made it clear this isn’t just about those bought off by oil and gas lying to protect lobbyist interests. This has become broader than that, and is now a full-blown attempt to degrade the word “science” until it doesn’t mean anything at all. When pressed on the issue of his climate change denialism, he tried to punt by saying, “All these people always wag their finger at me about science and settled science,” he whined, as if accepting that the sky is blue is too oppressive if you prefer to believe it’s yellow. “Let me give you a bit of settled science that they'll never admit to. The science is settled, it's not even a consensus, it is a unanimity, that human life begins at conception.”

Well, no. That is yet another example of conflating Marco Rubio’s opinion with what he wishes “science” said. The claim that “human life” begins at conception is not one asserted by science, but by religion, as many religions believe that’s when God injects a soul into a human body. But science is pretty clear that, by the scientific and not religious definition of “life,” life does not begin with conception. In order for life to begin, it has to be non-life turning into life. Since both the sperm and egg are alive, by the measure of science, it’s not life beginning. It’s really just life continuing.

As biologist P.Z. Myers explains, “We can trace that life all the way back to early progenotes with limited autonomy drifting in Archean seas, to self-perpetuating chemical reactions occurring in porous rocks in the deep ocean rifts. It’s all been alive, so this is a distinction without meaning.”

Nor does science agree that “conception” makes a distinct human person, as opposed to simply a cell that, like the sperm and egg that made it, has a unique combination of DNA. As Myers notes, “Conception just adds another level of semi-random rearrangement of a random assortment of genes that were made during oogenesis and spermatogenesis.” Indeed, sometimes a zygote splits into two separately developing individuals after conception, ones that have the same DNA but will be born as two separate people. We know them as “identical twins.” If “science” believed that “life” begins at conception, then science would argue identical twins are the same person. Science clearly does not believe that identical twins are one person because they have the same DNA.

Between his blatherings about conception and climate change, it’s clear that Rubio is asserting a worldview where “science” is whatever he wants it to be. Religious belief about ensoulment is “science”. Blunt denials of the overwhelming evidence for climate change is “science.” Science, in Rubio’s estimation, is just a matter of opinion.

The problem is that science is actually the opposite of opinion. So often our opinions are shaped by what we want to believe, so the scientific method was established to remove the influence of opinion from the examination of the evidence. “The good thing about science is that it's true whether or not you believe in it,” as the astrophysicist Neil deGrasse Tyson famously said.

Let’s be clear: No one probably wishes more than climate scientists that global warming wasn’t true. If someone was able to prove conclusively tomorrow that all the models of climate change were wrong and we aren’t experiencing manmade global warming, climate scientists would throw the biggest party imaginable, ecstatic that their fears of doom and gloom turned out to be illusions. Unfortunately for them and for all of us, global warming is happening, whether we believe it or not. Sorry, Marco Rubio. Climate change can’t be made untrue simply by claiming you disagree. And science is a process and an amassing of evidence, not just a matter of your opinion.