Judith Collins is "sick of everyone having to feel virtuous", saying people shouldn't have to pay for the negative effects their activities have on the climate.
Earlier this week the Government proposed a 'feebate' scheme which would lower the costs of electric vehicles, as well as fuel-efficient petrol-run cars.
On the flipside, gas-guzzlers would be hit with a tax the first time they're sold in New Zealand.
"This is about making more efficient cars more affordable and available, that's something we need to do if we're going to fight climate change," said Associate Transport Minister Julie Anne Genter, calling it "our generation's World War II".
"New Zealand was too small to win WWII. But that didn't stop many of our forebears from putting their hand up. They put their lives on hold, and travelled far away, to be part of a larger effort, because it was the right thing to do."
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Asked on The AM Show on Friday if climate change was being caused by humans, Collins said she didn't know.
"I presume it is. I'm personally not adding to it - I only had one [child]," she told host Ryan Bridge.
Asked if she believed scientists, who are almost unanimous in their view climate change is being driven by human activity, Collins said "some of it" would be.
"Clearly not volcanoes. Volcanoes clearly do help towards climate change, affect climate change, but they are definitely not manmade."
According to scientists, volcanoes emit less than 1 percent of the greenhouse gas emissions released by humans. The type of carbon that's increasing in the atmosphere is also of a type emitted by burning fossil fuels, not volcanoes, scientists say.
'Negative externalities' are rubbish - Collins
Collins also said it was "rubbish" to expect people to pay for 'negative externalities' - the cost suffered by a third party who doesn't benefit from a transaction.
In the case of climate change, that's people whose climates have been negatively affected by the use of gas-guzzling vehicles, but weren't the seller or the buyer so gained no benefit.
For example, the island nations of Tuvalu or the Maldives, which are at risk of going underwater thanks to emissions the rest of the world produced; or future generations, who are going to be living in a warming world and all the problems that brings, but were not even alive when the damage was done.
Collins said she was sticking up for tradespeople in her electorate of Papakura, who rely on cheap vehicles to get around and are already paying extra in fuel thanks to Auckland Council's regional fuel tax.
"They can't stick much of their tools in a little Nissan Leaf, can they?"
Labour MP Michael Wood, appearing alongside Collins on The AM Show, said the feebate scheme would be fiscally neutral.
"Emissions from vehicles are one of the biggest ways in which we contribute to climate change. We can kick that can down the road and do nothing about it, or we can start to take some steps to address it - and that's what this Government is doing.
"This will help Kiwis have more choice and buy the kind of vehicles they want to, but are held back to on price at the moment."
Collins also took umbrage at Genter's comments comparing the fight against climate change to World War II.
"My father fought in World War II - I'd suggest Julie Anne keep away from issues that she is not intimately involved in."
Genter told Newshub her grandfather fought in Italy and Africa during World War II.
"WII was a moment in history where nations big and small fought alongside each other to defend their share values and common humanity.
"Climate change also requires us to look beyond our borders to our common humanity, and do our bit to solve a problem that affects all of us, however big or small we may be."