Yesterday I noted that Judith Lewis’ otherwise excellent piece on nuclear power elided what is, from the environmentalist’s point of view, the central question: Could we achieve the same power shift away from fossil fuels without nuclear power?

Latter-day green proponents of nuclear power say we couldn’t, but that’s all they do: say so. Why can’t we get some kind of definitive answer? Lewis, in an email, says the question is just too damn vexed:

The thing is, I could find people who could show you the math that says wind and solar could replace coal next year, and an equal number of sane and competent experts who would argue, convincingly, that they aren’t. I don’t think we’ll know who’s right until someone actually does it — someone with huge piles of cash to pour into distributing renewable power on a large scale.

That sounds about right to me. I’ve seen confident claims that plug-in hybrids alone could solve the energy problem, and equally confident claims that nothing — no mix of solar, wind, nuclear, whatever — is going to make up the difference from oil. I’ve seen a lot of confidence, but nothing that strikes me as dispositive.

So how to puzzle through this question?

The first thing to note is that only necessity would argue in favor of nuclear power. The people with the most direct interest in its success — investors — want nothing to do with it. A powerpoint presentation from EarthTrack (via Jeff) shows that "60-90% of the cost of new nuclear power is the result of public subsidy rather than private investment." (Take a look — good stuff.) The immense problems with safety and waste disposal simply have no economically viable solutions, at least at present. Perhaps some day they will. When that happens, investors will line up at the door.

But at this point, nuclear is a mutant, stillborn industry, mostly rejected by the public, kept alive by an IV of taxpayer money. Its devotees are mostly politicians eager to deal with what they know: A behemoth, centralized industry, a source of donations, a cozy collection of golfing buddies. Socializing risk, privatizing profits: It is the soul of politics. As I’ve argued previously, decentralized power is not only a technical challenge but a political threat.

The government’s choice to back nuclear over clean energy is a public-policy choice, not some sort of inevitability.

So it would certainly be preferable to achieve our power shift using some judicious combination of conservation, solar, wind, and hydrokinetic power. We’ll swallow the nuclear pill if we have to, but only if we have to. Do we have to?

My inclination is to say No. We haven’t seen anything close to the innovation that’s coming down the pike, and with an initial boost, clean energy technology will fragment, a thousand flowers will bloom, and soon we’ll wonder why we ever had this argument. With the attention and public money nuclear now gets, clean energy could exceed all current expectations.

Let’s have no illusions, though: It’s a leap of faith. All power to those who try, but no amount of number crunching will ever capture the cascading innovations and tipping points required to do the job.

If you’re going to take a leap of faith, though, why not throw your faith behind human ingenuity and good will instead of a pinched, defensive embrace of yesterday’s discredited technology?

Why not choose hope over fear?