Jeb Bush has been having a rough time, offering an evolving series of not-quite-coherent answers on the question of whether the Iraq War was a good idea. It's catnip for journalists, and they've hounded him about it relentlessly.

If the public or journalists cared as much about climate change as they do about the Iraq War, they'd take note of a series of Bush comments on that subject just as incoherent and unstable. His position can't stand up to the slightest scrutiny; his only hope is that it doesn't get any.

What's interesting about Bush's current stance on climate change is not that it's wrong (though it is), but what it says about the prospects of developing a climate change message that can help a GOP candidate survive the primary without hurting in the general election. So far, things are not looking good on that front.

Jeb Bush on climate change

Bush was asked about climate change at a house party last week and sketched out his position. It is roughly as follows:

The climate is changing, but we don't know why. "I don't think the science is clear of what percentage is man-made and what percentage is natural. It's convoluted," he said. It is "arrogant" to claim human responsibility for climate change has been determined. "For the people to say the science is decided on this is really arrogant, to be honest with you," he said. "It's this intellectual arrogance that now you can't have a conversation about it, even." Climate change is not a high priority, but we should do something about it. "The climate is changing. We need to adapt to that reality," he said. "I don't think it's the highest priority. I don't think we should ignore it, either." We shouldn't solve climate change Obama's way. "The president's approach is, effectively, reduce economic activity to lower our carbon footprint," he said. "That's not what he says, of course, but that's the result of his policies." Instead, we should subsidize fracking. Rather than focusing on carbon emissions, Bush said, the federal government should provide more incentives for lower carbon-producing forms of energy, like hydraulic fracking and horizontal drilling.

Why Jeb Bush is wrong

Bush's position is nonsense.

First, we do know why the climate is changing: humans are doing it. In the fourth report of the Intergovernmental Panel on Climate Change, in 2007, scientists put the probability that humans have caused "most of the observed increase in globally averaged temperatures since the mid-20th century" at 90 percent. In 2013's Fifth Assessment Report, the IPCC upped it to 95 percent. Some 97 percent of climate scientists agree on this point.

Outside of basic physical laws, very little in science boasts this degree of confidence. It's roughly how confident we are that smoking is linked to lung cancer. Does Bush think it "arrogant" to call that matter settled?

If the climate is changing but humans are not contributing to it, then all we can do is, as Bush says, "adapt to it." But then why would we subsidize "lower carbon-producing forms of energy"? Why would we make any attempt to lower carbon dioxide emissions at all? If human CO2 emissions aren't causing climate to change, there's no reason to reduce them.

And finally, as a conservative, if you did want to reduce CO2 emissions (even though you were uncertain they were causing any problem), why, instead of adopting a market-friendly carbon tax like some in your party have proposed, or at least industry-wide performance standards like EPA is implementing, would you choose to subsidize a select few favored technologies? That seems like old-fashioned industrial policy, not free-market conservatism.

ClimateDesk made a helpful video guide to Bush on climate:

Why Jeb Bush has chosen this particular nonsense

Jeb Bush is positioning himself as the "moderate" in the GOP field, based on the longstanding assumption that the median voter is toward the center and must be captured for any chance of general-election victory. (Ted Cruz and Scott Walker, by contrast, are basing their candidacies on the premise that offering a clear contrast as an unapologetic conservative can yield a national majority, which is probably wrong.)

Presenting as a moderate in today's GOP elections is no easy task, because a) the most active primary voters are the party's least moderate, and b) Bush endorses roughly the same (increasingly radical) economic policies as the rest of the candidates. If he didn't, he wouldn't get a Koch audition. So he has to choose his heresies carefully.

Climate change might seem like a good candidate. The GOP's unanimous climate change denial, which has held firm since 2010, is beginning to fracture under pressure. Establishment conservatives have been calling on GOP candidates and elected officials to tone down the science denialism, which puts the party at odds with every demographic group except Tea Party Republicans and makes them look backwards and cranky.

Certainly journalists are hungry for heretics on this subject. The slightest glimmer of sanity on climate change by a Republican is celebrated as breaking news; witness coverage of Chris Christie's bold "climate change is real, but we shouldn't do anything about it" stance (which is unchanged from at least 2011). In recent months, Slate's Eric Holthaus has written stories calling Bob Inglis (a Republican who lost his House seat to a Tea Party challenger in part because he supported a carbon tax) America's "best hope for near-term climate action" and Lindsey Graham (whose chance of winning the GOP primary is, to put it gently, remote) "uniquely qualified to lead our country to a brighter, cleaner future."

But while journalists are keen for some Republican sanity on climate, the right-wing base is not, and those are the folks most likely to vote. And although polls show notional support for climate action among more moderate Republicans, the intensity of their preference on that issue pales before the unanimous right-of-center opposition to taxes and regulations. (There's a reason Republicans call any climate policy they want to kill — cap-and-trade, clean-air regulations, light-bulb standards — a "backdoor climate tax.")

So the conservative climate position in the GOP primary is clear: denial à la Cruz. But what's the moderate climate position? It needs to tone down the science denialism while staying well clear of any commitment to new regulations or taxes.

The gambit has been to say that the climate is changing, but we don't know why, so it's not worth doing anything about. Here's Mitt Romney in 2011: "We don't know what's causing climate change, and the idea of spending trillions and trillions of dollars to try and reduce CO2 emissions is not the right course for us."

In fact, this has become something like official Republican policy. In January, the Senate voted 98-1 for an amendment saying "climate change is real and is not a hoax." Why did every GOP senator but one vote for it? Because James "Greatest Hoax" Inhofe (R-Okla.) told them to. Really:

Inhofe and his aides drew up 54 notecards — one for every Republican in the Senate ... The card said: Inhofe recommends a Yes vote because 1. The climate has always been changing and 2. There is no consensus that human actions and emissions levels have significant, negative impacts on global climate change

This amounts to a crude attempt to escape the "denier" label without conceding to any need for policy. And it's the ground Jeb Bush is currently standing on.

Why Jeb Bush's nonsense can't last

It looks like Jeb Bush is "moderating" on climate change only from a great distance. Any closer and you see the denial is as robust as ever. After all, the key scientific finding is not that the climate is changing — thermometers can tell us that — but that humans are responsible. To deny that is to reject an overwhelming scientific consensus, i.e., to be a denier.

The problem is, once you accept anthropogenic climate change — as Lindsey Graham has, as George W. Bush did — you're on a slippery slope. You are effectively accepting that policy is inevitable, which is how it was seen in 2008, when John McCain was running on a cap-and-trade proposal (or in 2000, when GW Bush was running on one).

That's precisely what the right-wing base rebels against, the notion of cooperating with Democrats on an issue that has long since been coded as part of the culture war.

And once you acknowledge the science, you have a metric against which to judge policy. How much warming is too much? The countries of the world have agreed on 2° Celsius as the threshold to be avoided. Is that an appropriate target? If not that, how much? 3°C? 4°C? If you agree that lowering carbon emissions is the right thing to do, how much should we reduce them? And how fast?

Even to stay below 3°C would require large-scale, aggressive government policy to change the trajectory of emissions — a lot more than some subsidies to the fracking industry. Most policy experts agree it would take a combination of a price on carbon, targeted performance standards, and substantial spending on energy RD&D.

If Jeb Bush accepts anthropogenic climate change, he'll have to offer a policy to address it. And the fact is, carbon tax dreaming aside, there is simply no policy acceptable to today's Republican Party that would substantially reduce US carbon emissions. There is no way to thread that needle.

So Bush may be able to tip-toe through the Republican primary with this dog-whistle denialism, but then what? What will he do when he's on a national stage with Hillary Clinton, with millions of non-Tea Partiers watching, and she challenges him to propose a serious climate change policy?

That's when Bush can no longer dodge the dilemma. He either sticks with science denialism and makes his party look archaic or accepts anthropogenic climate change and has to propose some sort of policy that sounds credible but doesn't offend the financial interests of his big-money backers.

It won't be easy. Bush can sneak through the horns of that dilemma only if nobody much cares, if nobody presses him on climate change or pays attention. But in 2016 that may no longer be a safe bet.

Further reading: "There’s an emerging right-wing divide on climate denial. Here’s what it means (and doesn’t)"