Twelve candidates for the leadership of the Conservative Party of Canada take the stage in Saskatoon tonight for their first debate, but only one plans to use the occasion to argue that climate change is not the result of human activity — and really isn’t worth getting worked up about.

“I don’t believe there is substantial major man-made climate change occurring in our world today,” said Brad Trost, the most outspoken member of the party’s social conservative wing running for the leadership.

Trost joins former MPs Chris Alexander and Andrew Saxton, Winnipeg physician Daniel Lindsay and MPs Maxime Bernier, Steven Blaney, Kellie Leitch, Deepak Obhrai, Erin O’Toole, Lisa Raitt and Andrew Scheer in a Saskatoon hotel ballroom tonight at 7 pm ET for the inaugural debate of the race.

In an interview with iPolitics, Trost said his view of climate change — that it’s “all or mostly natural” — will be one of the things that sets him apart from the other candidates.

“I don’t believe man-made climate change is a problem in our society. I don’t believe it’s an environmental issue,” he said.

Trost said his views stem back to his university days, when he was trained as a geophysicist.

“And with my scientific background, I don’t buy into what I consider to be the political consensus on the science of climate change. In fact, I don’t believe there is a consensus on the issue as to why the climate is changing.”

So what would this mean for environmental policy under a Trost government? It would mean no carbon pricing, no cap-and-trade, no cutting carbon emissions by 30 per cent. And the Paris Accord? Trost would shred it.

He said he would concentrate on other environmental problems, such as cities dumping raw sewage into rivers and straits.

“So it’s a matter of priorities and I think its bad environmental policy to concentrate on some things,” he said. “I think it’s oversold and I’m skeptical about whether or not it’s a scientific fact. I’m the geophysicist on the stage.

“If we’re going to be honest as conservatives about the climate change issue you can’t say you want to cut emissions thirty per cent and it won’t harm the economy. You can say what I say — it’s not an issue. Or you can say what Michael Chong says — ‘It’s an issue and we have to do something about it.’ But that middle ground I don’t find that intellectually proper.”

Chong has a markedly different view, of course. He’s said more than once that Conservatives need to have a credible policy on reducing carbon emission, one based on conservative principles.

“I believe in a revenue neutral carbon tax where all revenues are used to significantly reduce income taxes, and I think that allows us to not only achieve the outcome of reducing emissions, it also allows us to get the economy back on track, create economic growth and jobs,” he said on Tuesday. Chong said he’s looking forward to debating environmental policy in Saskatoon.

While the environment is shaping up to be a contentious issue in the debate, in an interview with iPolitics earlier this week, Scheer said it’s tough to determine what topic will be the most controversial.

“My overall goal myself is to present a common sense Conservative view towards these issues,” said Scheer. He wants to present himself as the one candidate who can unify the party and represent “all kinds of different Conservatives together in one movement and get the party ready for 2019.”

Scheer hopes that people watching the debate will see a “very dynamic party with a diverse group of people seeking to lead it.”

“I hope that a lot of people who didn’t vote Conservative last time watch that debate and (I) hope they feel there’s a home for them in our movement. That’s the best thing for our party for our entire caucus,” he said.

Chong agrees — but he argues the CPC can’t sell itself to those voters without proving first that it has a plan to tackle climate change.

“I hope viewers look at the candidates on stage and say there are candidates here I can vote for in the next election, there are candidates here that will build Conservative party, that are serious about environmental policy and serious about being more open and democratic, fiscally conservative, which will get Canada back on track.”