On their way to discovering the double helix structure of DNA, James Watson and Francis Crick drew important inspiration from an unauthorized glimpse at the unpublished research of a third scientist, Rosalind Franklin.

Yet when James Watson published his famous memoir in 1968, he made scant mention of Franklin’s contributions—holding her up instead to vicious and misogynistic mockery.

Scientists—even brilliant ones—are not better than other people. They are at least as prone to vanity, malice, groupthink, charlatanism, and outright dishonesty as those in any other line of work. Happily, science is bigger than the scientists. Nobody would respond to Watson’s bad behavior by saying, “See—that proves that DNA does not exist!”

Yet that is just the kind of debate we are having in the wake of the exposure of hundreds of e-mails from the Climate Research Unit at the University of East Anglia. These e-mails depict the scientists of the CRU in the worst possible light: manipulating data to reach preordained conclusions, disparaging critics, stonewalling legitimate requests for information.

Climate change skeptics have seized on the misconduct of the East Anglia scientists as confirmation of all their doubts about man-made global warming. You can see why! The case for global warming has often been pressed with disgracefully reckless and manipulative language. Again and again, climate alarmists like former Vice President Al Gore have indulged in apocalyptic exaggerations that their own allies have had to repudiate.

For example:

No, we are not in imminent danger of a 7-meter increase in sea levels—or the disappearance of the Gulf Stream. It’s not planetary climate change that is drying up Lake Chad or melting the snows of Kilimanjaro. The polar bears are doing just fine. In the wake of the exposure of the CRU e-mails, such overstatements now look less like overzealous mistakes and more like conscious fabrications.

But as with James Watson, so with the East Anglia CRU: The abusive behavior of scientists does not invalidate the confirmed facts of science.

Whatever those shifty scientists were doing in East Anglia, it’s still a fact that there is a lot more carbon dioxide in the atmosphere than there used to be—about 35 percent more than at the beginning of the Industrial Revolution. (We know this by comparing the atmosphere of today with the atmosphere preserved in the lower archaeological layers of glacier ice.)

We also know that the burning of fossil fuels is an important cause of this atmospheric change. Every year, the burning of coal, oil, and natural gas releases some 27 billion metric tons of carbon dioxide into the air.

We know that carbon dioxide and other so-called greenhouse gases entrap more of the sun’s warmth on Earth.

And we have observed that over the past half-century, until about the year 2000, temperatures in the northern hemisphere trended upward, peaking in 1998. The warming trend seems to have abated over the past decade, but rising carbon emissions give reason to fear that it will resume in the future. Those fears remain intact despite the moral defects of any group of scientists.

So what’s the lesson of this story? It’s that the environmental realists like Bjorn Lomborg are right. Climate change is a problem, not an emergency; climate models are frail human guesses, not attested facts; knowledge is uncertain; costs matter.

Better still: The CRU scandal points us away from bad policy choices to better ones. Paying an enormous economic price to halve carbon emissions by 2050 looks even more like madness this week than it did last week. But imposing a moderate tax on carbon emissions still makes sense. Such a tax will encourage investments in efficiency and improve the competitive position of nuclear and renewable technologies.

Oh—and it will raise revenues that a government in trillion-dollar deficit desperately needs, and do so in the least economically harmful and most politically acceptable way. Americans already pay environmental excise taxes at the gas pump and often on their hotel rooms. A tax of, say, $5 per ton of carbon rising to $15 over a decade will not unduly burden households. (It’s the equivalent of a $2 levy on a barrel of oil rising to $6.) And it will offer a much better fiscal solution than the increases in income taxes and capital taxes headed our way in 2010, or the increases in payroll taxes contained in the Senate health-care bill.

In fact, whether you believe in global warming or deficit reduction, a carbon tax is still the solution!