In an otherwise rather lacklustre leader’s debate this morning, the only lively interaction between the candidates was sparked by a call about the issue that has already proven to be one of the hottest topics on the campaign trail -- climate change.

“I’m sitting here and I’m thinking: Neither one of these people understand the science of climate change,” Green Leader Jane Sterk replied.

It was an observation that could have easily been attributed to any of the three leaders.

The nine-minute exchange happened during the listener call-in portion of the CKNW debate. A caller asked B.C. Liberal Party leader Gordon Campbell for his stance on the 11 per cent of carbon that is reportedly emitted through flaring (the in-field burning off of excess or unwanted natural gas).

“There will be an elimination of regular flaring by 2016,” Campbell answered. “We’re going to continue to make sure that as we move ahead in British Columbia, that we become the alternative energy powerhouse,” he continued.

B.C. New Democratic Party leader Carole James responded by saying the process should be ended right away.

“Flaring is a way that we could right now address climate change and address emissions immediately,” she said. “Alberta and Texas have moved in this direction. It’s a way, unlike the carbon tax to do it that’s fair, that’s effective, that makes sure we’re addressing our emissions,” James added.

Green Leader Sterk responded by criticizing both parties for their positions, an approach she took throughout the debate.

“The Premier’s suggestion that we are going to be the leader in renewable energy is laughable because other countries in the world are so far ahead of us,” Sterk said.

“We need to appreciate that we’re all contributing to climate change. We’re not going to excuse us ordinary people that contribute 50 per cent of the greenhouse gas emissions like the NDP is doing and we’re not going to excuse industry like the Liberals are doing,” Sterk continued.

The debate heated up when the next caller, who said he voted NDP in the last election, asked James if she agrees with Shuswap NDP candidate Steve Gunner, who reportedly said in an all-candidates meeting that he supports both a carbon tax and a cap and trade system.

“My position is very clear: We’re going to get rid of the carbon tax,” James replied. “It’s unfair and it’s ineffective. I believe in bringing in climate change solutions that work, that actually address emissions and gets at the big polluters."

Campbell was then asked by host Bill Good if the Liberals support both a carbon tax and cap-and-trade legislation. The Premier confirmed that was the party's position and later said a cap-and-trade system would be in place by 2012.

The Greens are also in favour of using both methods to combat climate change, Sterk said. “We think primarily a carbon tax has to be the first stage and then cap and trade," she said. "We’re not saying either-or. We need both."

Campbell then used the topic to criticize the NDP for voting against cap-and-trade measures in the legislature.

“The New Democrats have actually voted against every single major environmental initiative that’s been taken," Campbell said.

“I think the [Shuswap] NDP candidate is showing once again that there are still some principled New Democrats who believe they should take the right actions right now as opposed to the politically-expedient ones," he added.

At this point James interrupted, stressing her argument that the carbon tax unfairly targets low-income people.

“If you’re passionate about the environment and you’re passionate about fairness you’ll look at a cap-and-trade process. To bring in a tax that’s going to triple, during a recession, during difficult economic times isn’t fair," she said. "It may not matter to Mr. Campbell that people are struggling on fixed income.”

When Campbell got his turn to respond, he challenged James on her analysis.

“Carole, you know there’s a low-income benefit that’s distributed to low-income people and to seniors who may face that so I don’t know why you have to sort of mischaracterize what’s taking place.”

“This is a serious issue that British Columbians deserve to hear," he said. "I think a revenue-neutral carbon tax is critical.”

James shot back with her own challenge of Campbell's facts.

“The only people who believe this is revenue neutral are Gordon Campbell and the finance minister,” James said, before further emphasizing her argument about the unfairness of the tax.

The NDP leader got the last word on the topic before the next caller switched the subject to homelessness.

A replay of the leaders' debate – one of only two broadcast debates scheduled during this four-week election – can be found here.

Garrett Zehr reports for The Tyee.