One of the main contenders vying for the mayor's chair is pushing climate change onto the agenda as one of his key campaign issues.

Clive Doucet, a long-time crusader for the environment, says the City of Ottawa is far behind when it comes to addressing climate change. He says cities that don't act now, will get left behind economically.

"When it comes to climate change, our city council suffers from a grave lack of urgency. It's as if we were locked in 1960 instead of 2010. Climate change is the greatest single challenge our city and every other city on the planet will face in this century," Doucet told supporters on Tuesday.

Doucet says he intends to set aside five per cent of all his campaign contributions to an energy efficient project in the city.

Doucet announced his intention to run for mayor last month. He is currently councillor for the city's Capital Ward.