Turns out you can teach an old dog new tricks.

Billionaire oil man T. Boone Pickens, who once pushed natural gas as the only way to get off of oil imports, said at today’s National Clean Energy Project (see live-blogging here):

Diesels should be replaced by natural gas. Light-duty vehicles go to the battery.

Yes, the 80-year-old Pickens has been edging slowly in that direction, since running cars and light trucks on natural gas never made much sense (see here and here). But this was the bluntest I had heard him.

The problem for his messaging, of course, is that even if you replace half of highway diesel use with natural gas over the next decade — a huge accomplishment — that would be under 10 percent of all U.S. petroleum use and barely make a dent in oil imports and the trade deficit 10 years in 2020.

Pickens also said made his prediction that we will be back at $140 a barrel oil in 2 years, which I tend to agree with unless this global recession turns into a global depression, which remains possible.

He also cannot bring himself to acknowledge that it is his fellow conservatives who are the stumbling block to the high-renewable future he advocates. After all the strong, positive comments from so many speakers about the need and the practicality of a clean energy future, he warned:

“Don’t be stopped by that 10% who are going to be opposed to everything.”

Sadly, however, it ain’t 10 percent — it is closer to 41 percent in Congress, where it matters — and they are all his political allies, as I have noted many times:

He told the story of this 90-year-old guy would lived his entire life in a small town in Texas. A reporter said to the guy, you must’ve seen a lot of changes in your life, to which he replied, “Yes, and I was against every one of them.”

That is the conservative weltanschauung (see here).

If we do make the transition to a clean energy economy in time to avert catastrophic warming, it will be because of leadership by the kind of progressive who were at today’s summit. If we don’t, it will be because Pickens conservatives pals have succeeded in blocking action, demagoguing the issue, and convincing enough of the media and the public that business as usual is the best strategy.

I’m glad Pickens is pushing renewable energy, but he doesn’t need to preach to our choir, he needs to preach to his flock.

This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.