These days, everybody wants to be green. Everybody, that is, but Bill Gates.

Across the markets, stocks like First Solar (Nasdaq: FSLR) and Sunpower (Nasdaq: SPWRA) are the talk of the town, favorites of momentum investors, and gaining fans even among Big Oil. Giant corporations like General Electric (NYSE: GE) and United Technologies (NYSE: UTX) are betting big on wind power and "concentrated" solar power, respectively. Why, even the ordinarily practical Warren Buffett recently got sucked into the green movement, when Berkshire Hathaway (NYSE: BRK-B) invested mega-millions in a Chinese electric car start-up.

Actually, Gates himself is no slouch in the save-the-world department. A proponent of "creative capitalism," he's doling out his Microsoft (Nasdaq: MSFT) billions on projects to end the AIDS epidemic in Africa, equip developing-nation youths with PCs, and wipe out cholera. It's really only the green energy industry he's got a bone to pick with.

Last week, he damned the industry with faint praise at a NYC conference, calling wind and solar energy "cute," but hardly the solution to our problems. Says the original Mr. Softy, it doesn't matter how efficient wind and solar technology become. Neither tech possesses the necessary oomph to "deal with our climate problem … because the climate problem requires more than 90% reduction of CO2 emitted, and no amount of efficiency improvement is enough." For every one step forward developed nations make in becoming more energy efficient, the billions of energy consumers coming on-line in the developing world will take the globe two steps back -- and they'll use dirtier fuels to do it.

So we're doomed, right?
It sure sounds like it. But remember that Gates is all about creative capitalism. Solar and wind may not pack enough punch to reverse global climate change -- but don't lose heart. "There is an app for that." (Not the precise phrase he used.)

Gates's solution: Nuclear.

Last year, Gates joined other investors in providing a $35 million cash infusion to TerraPower, a start-up that has designed a nuclear reactor capable of running 50 years without refueling. That's assuming the absence of any 9.0 earthquake-cum-tsunami scenarios, I presume. But even admitting the risks, nuclear's advantages seem to outweigh them. Consider that, over in France, nuclear power suffices to provide 80% of that country's electricity. Compare that to "green" boosters here in the U.S., who optimistically argue we might satisfy 10% of our electricity demand with wind … and geothermal and biofuels combined, and I think you'll see what Gates is driving at.

Foolish takeaway
Fukushima Daiichi notwithstanding, nuclear's still the answer.

Disagree? Hey, it's the Fool -- feel free. If you've got a contrary view, scroll down and sound off.

Fool contributor Rich Smith has no position in any stocks named above. The Fool owns shares of Berkshire Hathaway and Microsoft. Motley Fool newsletter services have recommended Berkshire Hathaway, Microsoft, and First Solar. Motley Fool newsletter services have recommended creating a diagonal call position in Microsoft. Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.