RIVERSIDE, Iowa — Harry Braun is not a politician, and he said so himself in front of nearly 30 people on Sunday.

But Braun “believes” in science. And science, he said, is the driving force behind his decision to run as a Democratic challenger in the 2012 election against incumbent President Obama.

“We’re passing the tipping point of no return,” said Braun, who has worked as an energy analyst for more than 30 years.

The 62-year-old candidate said America’s “mindless addiction” to fossil fuels is leaving the Earth with little time before it becomes uninhabitable.

He wants to eliminate fossil fuels and rely instead on hydrogen. The switch, he said, would eliminate carbon emissions, pollution, and end global warming.

“Hydrogen is the Holy Grail of all energy,” he said.

In order to achieve broader use of hydrogen, Braun said, he would rely on another major goal of his campaign — rallying support for a constitutional convention.

Braun said he believes the U.S. is currently operating as a republic instead of a democratic republic. A constitutional convention would give citizens the power to approve all legislative and judicial decisions — not their elected representatives.

While incumbent presidents sometimes garner in-party challengers, said Tim Hagle, a University of Iowa political expert, the general public may not always hear about them. Often, people less experienced in politics campaign to promote a particular issue in hopes that other candidates will adopt their positions, he said.

“Does this person actually believe he’s got a chance? My political assessment is no,” he said. “But maybe that’s not necessarily his goal.”

Hagle also said Braun’s constitutional convention proposal is “unworkable.”

“With 300 million people, we can’t hold an election every time something comes up,” he said, noting that such a convention would be expensive.

Dennis Roseman, the former head of the Johnson County Democrats, said he was contacted by Braun’s campaign several times. And although Roseman said he is a “strong Obama supporter,” he read through Braun’s platform.

Despite being passionate about several issues, Roseman noted Braun lacked any political experience and that only one GOP candidate for president, Herman Cain, also never held office.

“I appreciate good ideas and new ideas,” Roseman said. “But in terms of being a candidate, you need more than that.”

But even a fringe candidate can have an effect on an election’s outcome, Hagle said, such as in the 2000 general election when Ralph Nader edged enough votes in Florida to leave Al Gore just shy of beating George Bush.

Hagle said he doubted a similar situation would arise again anytime soon, but he said wild-card candidates shouldn’t be dismissed.

“Sometimes, they hit on a particular issue, and it just resonates with people,” he said.