The United States needs to stop depending on Arabian oil, billionaire oil tycoon and hedge fund manager T. Boone Pickens said at a public lecture Thursday.

In front of a fully packed Yale Law School auditorium, Pickens called for a switch from petroleum to domestically produced natural gas as America’s chief transportation fuel and urged the development of wind power along the Midwestern corridor of the country. The U.S. currently imports approximately 5 million barrels of oil a day while natural gas resources remain largely untapped, he said.

“If we don’t do this, if we don’t stop importing dirty oil from sources that aren’t secure, we will go down in history as the dumbest crowd in town,” he said.

The 82-year-old Oklahoma native started what is now the largest oil and gas company in the United States, Mesa Petroleum, and has a current net worth of over $1.4 billion. Despite his oil wealth, Pickens is the author of the Pickens Plan, a 2008 energy proposal to start replacing oil with natural gas and wind power to ensure the U.S.’s energy future. The plan describes Pickens’ broad vision for America’s energy future, and elements of the plan have received bipartisan support in Congress.

Pickens criticized the U.S. government for not developing an energy plan. The government’s inability to confront the problem, he said, has serious implications for foreign policy, particularly in regard to Saudi Arabia. Today, Saudi oil accounts for just under 10 percent of U.S. oil imports, according to the United States Energy Information Adminstration website. Money from these purchases, Pickens said, is funneled from the Saudi government to the royal family, and finally to rogue terrorists groups like the Taliban that seek to harm the United States.

“We need to get off Saudi oil, and I do view the Saudis as enemies. When you have 18 people on two airplanes that hit two buildings, and they’re all Saudis, that’s not a coincidence,” he said, drawing silence from audience.

The event, which was open to the public, provoked diverse reactions from those in the audience.

Jordan Rogers ’12, like Pickens, is from Oklahoma and said many of his friends are involved in petroleum engineering.

“I see his interest in [natural gas], but I also see how he stands to profit from it very much so,” Rogers said. “I don’t think [natural gas] is the end solution.”

Other students said they felt there were unresolved problems with natural gas as well.

Julie Botnick ’14 asked Pickens about the environmental risks of hydraulic fracturing, or “fracking,” the process by which high-pressure mixtures of water and chemicals are used to open natural gas wells. Environmental groups charge that fracking puts dangerous chemicals in the water table that are toxic to humans, but Pickens responded that he “didn’t know” of any risks associated with the process. By Thursday evening, Botnick had responded by posting a Facebook note, “Don’t Pick His Plan,” urging Americans not to become the generation that causes “the misguided destruction of our water supply” and not to be “blinded” by Pickens’ lofty rhetoric.

But Pickens’ talk was new ground for other members of the audience.

Elizabeth Henry ’14 said she normally does not pay attention to environmental problems, which she views as traditionally liberal issues. But she said she identified with Pickens’ conservative values during the talk.

“I’ve never really considered myself an environmentalist, but hearing him talk made me cognizant of how dire the situation really is,” she said.

Pickens’s visit to Yale also included meetings with University President Richard Levin, former CIA Director and Jackson Institute senior fellow James Woosley, School of Management MBA students and members of the Yale Energy Club.