A senior NSW Liberal Minister has broken ranks to call for stronger action on climate change and criticised those that treat the issue as a "matter of religion" rather than science.

As Sydney choked on hazardous smoke on Tuesday, State Environment Minister Matt Kean delivered a speech to the Smart Energy Summit saying the unprecedented bushfires had been caused by climate change.

"Let's call it for what it is, these bushfires have been caused by extreme weather events, high temperatures the worst drought of living memory - the exact type of events scientists have been warning us for decades that would have been caused by climate change," Mr Kean told the audience.

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His comments are in stark contrast to the handling of the bushfire crisis by other Liberals, including Prime Minister Scott Morrison and Premier Gladys Berejiklian, who have refused to link the ongoing emergency to climate change.

The Environment Minister doubled down on his comments on Wednesday morning.

"We've got to stop making climate change a matter of religion, we've got to start making it a matter of science and the science says that we need to reduce the impact of global warming by 2 degrees and in order to do that we need to get to net-zero emissions by 2050," he told ABC radio.

Earlier on Wednesday morning, NSW Education Minister Sarah Mitchell said now was the time to focus on supporting the victims of bushfires and firefighters, rather than having "philosophical debates" about what caused the bushfires.

But Mr Kean said he was not going to wait until the end of summer to have a "meaningful conversation" about the causes which he said was necessary in order to begin to address them.

Asked if he agreed with his state Liberal colleague, federal minister Paul Fletcher stopped short of linking bushfires and climate change.

"We know that the issue is temperatures, dryness and all of these are clearly relevant factors. I don't pretend to be an expert in this area," Mr Fletcher told ABC News Breakfast.

He said the government was committed to meeting its carbon emissions reduction targets under the Paris Agreement.

.@Matt_KeanMP comes out swinging:



“it’s not time to end the climate war... it’s time to win the climate war!”#smartenergysummit pic.twitter.com/seoNgRzoNM — 💧simon holmes à court (@simonahac) December 9, 2019

NSW Opposition Leader Jodi McKay dismissed Mr Kean's speech as a trick to get media attention.

"Get Matt Kean out to say a few soothing words, meanwhile the entire Berejiklian and Morrison Governments are led by climate do-nothing and deniers," Ms McKay tweeted on Wednesday.

In his speech, Mr Kean promised NSW would go it alone if Canberra refused to step up to decarbonise the economy.

"It's not time to end the climate wars. It's time to win them."

He said Australia had the potential to become an energy superpower.

"We have the land, the wind, the solar, as well as the supply lines, expertise and infrastructure. We cannot allow ideology and politics to get in the way."