Tycoon T. Boone Pickens on Wednesday took his case against foreign oil to a prestigious TED conference known for backing ways to break the world's addiction to fossil fuels.

"I'm a believer in global warming," Pickens said. "But my subject is national security; we have to get off our dependence on OPEC oil."

He argued that the fortune spent by the US buying oil from the Middle East was "the greatest transfer of wealth in history" and added into the equation the massive cost of military operations there to safeguard crude exports.

"We have found ourselves to be the world's policeman," Pickens said of US intervention in the region to protect oil shipping channels.

"We in the US use about 25 percent of the oil used in the world a day for four percent of the population; somehow that doesn't seem right."

He lamented that the world's largest consumer of oil lacks a national energy plan, and urged a scheme that makes a priority of domestic natural gas.

"Natural gas is the bridge fuel," said Pickens, who built a prosperous empire on the oil business.

"I don't have to worry about the bridge to where at my age," continued Pickens, who was born in May of 1928. "That is your concern."

Pickens recounted losing millions on an investment in wind power generation after the price of natural gas dropped so low that the renewable alternative couldn't compete.

"I lost $150 million on wind, but I'm game for it," Pickens said. "Wind, solar -- I'm for anything American. There ain't nothing wrong with nuclear: we have to have energy."

He advocated starting with using natural gas to power trucks now using diesel fuel, noting that nearly three-quarters of the oil used in the United States goes to transportation.

"The days of cheap oil are over, the Saudis made that clear," Pickens said.

"We are headed to natural gas; it is cleaner, more abundant and ours."

When pressed by TED curator Chris Anderson on how switching from one carbon-based fuel another wouldn't solve the life-threatening problem of climate change, Pickens said he hadn't given up on renewable energy.

"How do we get off natural gas at some point?" Pickens asked rhetorically, placing a hand on Anderson's shoulder. "That is your problem."

Scientist, activist and author James Hansen argued at TED that imposing fees for carbon released by fossil fuels would go far to putting the brakes on climate change and inspiring advances in renewable energy.

Money brought it could be divvied up equally between citizens, stimulating economies and by extension creating jobs, he argued.

"The tragedy about climate change is that we can solve it," Hansen said.

Pickens scowled at the notion of a tax on carbon, contending he didn't trust government to responsibly run such a program.