Six people were called to testify Monday afternoon before the House of Commons finance committee on carbon pricing: an economist, a researcher, three individuals from prominent environmental organizations — and one politician.

A few days after he and the other members of Alberta's United Conservative Party boycotted a vote on creating 'safe zones' around abortion facilities because they did not want to "play games with divisive social issues," UCP Leader Jason Kenney had flown across the country, at the invitation of Conservative MP Pierre Poilievre, to criticize the federal government's approach to climate policy.

Most of the hour and a half that followed was all about Kenney. But the future of humanity wasn't completely forgotten.

Jason Kenney on plans to fight the feds' carbon tax 3:15

"I am here in opposition to Bill C-74," Kenney said, in case anyone was still confused.

For evidence to back his position, Kenney offered up a series of opinion polls in Alberta and talked about a seniors centre worried about its energy bill.

​"The theorists who support [a] carbon tax will generally admit that it is a so-called Pigovian tax,," Kenney said, gesturing to the economist and the researcher on either side of him, "by which they mean that there should be taxation on negative behaviours, like sin taxes on booze and cigarettes.

"Well, Mr. Chairman, most Albertans don't think that heating their homes and driving to work and running their small business is something that should be punished."

It's not a 'sin tax'

A Pigovian tax isn't really a tax on "negative behaviour." It's a tax that attempts to account for a cost to society that isn't included in the price of a good or service.

And Kenney should be quite familiar with the notion that carbon emissions come at a cost. He would have been sitting at the cabinet table when the federal government began using a calculation known as the "social cost of carbon."

Kenney was followed by Dale Beugin, executive director of the Ecofiscal Commission, who said that putting a price on carbon is both "effective in reducing GHG emissions" and the "lowest-cost approach to reducing GHG emissions." Three environmentalists then stepped up to offer their support for the federal policy.

Of the time remaining, Conservative MPs were given 17 minutes to question the witnesses. They asked eight questions — seven of them directed at Kenney.

Hidden within the NDP's support for a carbon tax, Kenney warned darkly near the end of his testimony, "is a desire for government to control people's lives. And I think there is a fundamental philosophical difference here. I believe in empowering people to be more free, not empowering government to make people less free."

At the invitation of the committee chair, Liberal MP Wayne Easter, the other witnesses were invited to interject if they had something to add to Kenney's comments. At a few points, they did.

That the Conservatives would focus on their preferred witness wasn't surprising. But the Liberals seemed just as interested in hearing what was on Kenney's mind.

Kenney's alternative

Liberal MP Jennifer O'Connell used her first two questions to challenge Kenney on his views of climate change and the record of the previous Conservative government.

O'Connell did at least get Kenney to say what he might do differently. Kenney suggested he might, as premier, return to Alberta's Specified Gas Emitters Regulation, a policy that forced the province's largest emitters to pay into a technology fund.

So Kenney's answer to the NDP's price on carbon is ... a different price on carbon. Perhaps Kenney could design his policy in a way that somehow costs less. But there are questions about how well the SGER actually reduced emissions.

A less-effective policy could undermine Canada's ability to meet its 2030 target for emissions reductions — a target adopted by that same Conservative government of which Kenney was a member. In an interview on CBC's Power & Politics on Monday, Kenney suggested he wasn't overly concerned with Canada meeting that target.

Thing is, Andrew Scheer, the federal Conservative leader, says he intends to present a plan that will meet the national target.

An environmentalist's plea

At the end of the third round of Conservative questions for Kenney, Graham Saul of Nature Canada jumped in. After delivering an opening statement, Saul had been completely ignored. Now he wanted to say something.

"I think there is a fundamental, philosophical difference here," he said.

"I mean, what do we really know? We know that those countries around the world that are doing the most around this issue, countries like Germany and Norway, are doing perfectly economically. So the sky doesn't fall. In fact there's evidence that you can perform very successfully economically if you take this problem seriously.

"We also know that provinces in Canada, like Quebec and British Columbia, are doing perfectly well economically and are taking steps to protect the least advantaged ...

"We also know, though, that we have a serious problem on our hands. If you actually believe in the science ... then you have to draw the conclusion that it would be reckless and irresponsible to continue on the trajectory that we are on today. That it would fundamentally undermine the well-being of our children and that it would cause potentially unprecedented harm to our economy and to future generations.

"So the fundamental philosophical difference that we have is, do you actually care about that problem?

"If, in fact, everyone around this table does truly care about this problem ... then every party around the table has a responsibility to come forward with a plan that reflects the fact that they truly want to try to address it. And in absence of that plan it's very difficult to come to the conclusion that we do in fact share a concern about this problem."

In other words, it might be time to stop playing games with divisive social issues.