Everyone loves a courtroom drama–especially one that pits a feisty, but a determined criminal defense attorney against the awesome power of a prosecutor who has the resources of the state behind him or her. We see such David and Goliath stories every week on television.

We cheer as the defense attorney pokes one hole after another in the case of the prosecutor, raising what the audience now perceives as reasonable doubt. But will the jury see it that way? We’ll return after these messages….

This is just the sort of metaphorical setting into which the climate change denial lobby is trying to place the debate over climate change without the public or even most policymakers realizing it. The deniers in the fossil fuel industry and elsewhere are attempting by sleight-of-hand to get both the public and policymakers to abandon the preponderance of evidence standard used primarily in civil trials–and which is similar to evidence-based public policymaking–in favor of another judicial standard designed for criminal trials, namely, beyond a reasonable doubt.

So long as the deniers get to claim the role of defense attorney in this public fight, their task will be much easier. The reason that the deniers want to change the standard of proof, of course, is because climate scientists have already shown through an overwhelming preponderance of evidence that human activities are a major cause of climate change. The deniers have no hope of winning the intellectual argument if this standard of proof is used.

Drawing from tactics permitted to defense attorneys in criminal proceedings, the deniers are freed from the need for consistency, clarity or comprehensiveness. Instead, they pursue several lines of contradictory rebuttal in hopes that one or more will stick since they believe they need only to poke holes in climate science to win. The deniers as defendants are not called upon to offer their own coherent theory of climate change. That’s why they simultaneously claim that there is no global warming, that global warming is caused by nonhuman forces, and that global warming is good even if it is caused by human activities.

Some people wrongly treat the fossil fuel industry and carbon dioxide itself as if they are both somehow involved in a quasi-criminal proceeding. They think any one piece of evidence–even in isolation–that might suggest, however tenuously, that neither is implicated in climate change leads to reasonable doubt and a verdict of not guilty.

But, this kind of criminal trial thinking is not relevant to public policy deliberations. It is based on longstanding jurisprudence as expressed by the great English jurist William Blackstone who said: "It is better that ten guilty persons escape than that one innocent suffer." The principle at stake is that the freedom of the innocent is so precious that society should make every effort to ensure that no one is wrongly deprived of his or her personal liberty–even if it means that the courts are skewed toward letting some guilty defendants go free. But neither fossil fuel corporations nor carbon dioxide are actual living individuals, and so no one is going to be deprived of his or her personal liberty–that is, be imprisoned–by greenhouse gas emission regulations.

Probably the single most important question one can ask about this move by the deniers is whether they would accept the role of the prosecution. That would oblige them to offer an internally consistent theory of climate change supported by bona fide scientific evidence which somehow explains away all the evidence for human involvement in climate change.

As defendants in this hypothetical turnabout, climate scientists would only need to poke one or two holes in such a theory to prevail and win the case for the regulation of greenhouse gases. (This would roughly be the equivalent of the precautionary principle in action.) You can be assured the deniers only want to play the role of the defense in this faux courtroom drama. This is because they simply cannot marshal a winning prosecutorial case with the meager evidence they have and a story that is all over the map and riddled with holes.

There are only a tiny number of bona fide climate scientists who still say that the evidence is inconclusive concerning human contributions to climate change. There are none–so far as I know zero–who say that climate science PROVES that humans are NOT causing climate change–which would imply that these skeptics have a comprehensive, evidence-based theory of climate change which does not merely suggest nonhuman causes (which are already accepted by climate science), but which successfully refutes the enormous and growing evidence for human activities as a major cause.

Climate change deniers would like the public to believe that regulating greenhouse gas emissions should only be undertaken when we are 100 percent certain of their role in global warming. But anyone familiar with public policy knows that such regulatory policies are never undertaken with anything approaching 100 percent certainty–though the role of greenhouse gases in causing climate change comes closer to a 100 percent certainty than perhaps any previous scientific finding used to justify public policy action.

Where uncertainty remains concerning the possible consequences of climate change, that uncertainty–far from supporting inertia–actually cries out for significant and aggressive action in an effort to avert possible catastrophe. If the future of climate change meant merely that we all risked getting a hangnail, perhaps waiting would be an option. However, the history of climate change shows that we have consistently underestimated its pace and consequences. The changes already apparent and which climate change models forecast suggest that we are risking nothing short of the stability and even survival of modern civilization if we do not act now. To wait would be akin to a cruise line deciding that lifeboats for its vessels will only be ordered when a ship starts sinking.

And, now back to our program (mentioned at the beginning)….We return to the courtroom, but it turns out to be a courtroom of the future. As the planet burns outside, the prosecution is asking for the imprisonment of scores of defendants who denied the dangers of climate change and delayed effective responses to it. These defendants are charged with crimes against humanity.

In this case the proper standard for a guilty verdict is "beyond a reasonable doubt" because the personal liberty of each defendant is at stake. The prosecution tries to prove that the climate change deniers knew they were lying to the public about climate science and understood that the future consequences of climate change might be severe, even catastrophic, but acted with reckless disregard for the safety of humanity.

The jury is not convinced "beyond a reasonable doubt" and frees all of the defendants. As the now freed defendants leave the courtroom, they thank their lucky stars that the court could not invoke the preponderance of evidence standard–a standard that would likely have landed them all in prison.

Image: "Ned Kelly in the Dock – A Scene from Life" Ned Kelly in the dock during his trial. Wood engraving published in The Illustrated Australian News. Date 28 August 1880 Source State Library of Victoria Pictures Collections, Accession number IAN28/08/80/145 Author Published by David Syme and Co., Melbourne. Via Wikimedia Commons.