He's gone from one of the world's most powerful politicians to one of its greatest environmental activists, and on Saturday former U.S. Vice President Al Gore hit Toronto's Green Living Show where he took aim at Ottawa's new environmental plan.

"This generation alive today has a moral obligation to discharge on behalf of us, and we have an obligation to choose the hard right over the easy wrong," Gore told a massive crowd.

Once the second in command during Bill Clinton's time as president, Gore's now become better known for his film "An Inconvenient Truth" and has stepped away from politics, though you wouldn't know it by listening to the scathing criticism of the federal government's plan to cut greenhouse emissions.

"In my opinion it is a complete and total fraud," he said. "It is designed to mislead the Canadian people."