NSW Treasurer Dominic Perrottet has doubled down on comments where he claimed government spending on climate change is a "gratutious waste".

In a speech to conservative think tank the Centre for Independent Studies in 2015, Mr Perrottet took aim at the economics of the changing climate.

"An example of gratitous waste is the almost religious devotion of the political left to climate change,” he said at the time.

NSW Treasurer Dominic Perrottet has doubled down on comments he first made in 2015 about climate change spending being a 'gratuitous waste'. (9news)

When challenged, the Treasurer today said he believes in the “science” but not how it’s being tackled.

“Labor likes to talk about climate change and all these environmental concepts but they never have the financial capacity to invest properly.” Mr Perrottet told reporters.

Opposition Leader Michael Daley said the views are “prehistoric” and proof the Liberal Party does not take it seriously.

“They don’t want to do anything on climate change, it’s this uncaring ‘get whatever you can’ attitude," he said.

Opposition Leader Michael Daley said the views are “prehistoric” and proof the Liberal Party does not take climate change seriously. (AAP)

The speech, made while Mr Perrottet was Finance Minister in the Baird Government, recited text from an American author that linked divorce rates to welfare handouts and lambasted the ABC as a "mouthpiece of the left".

“It (ABC) is in breach of its social contract with mainstream Australia,” he said .

"The ABC distorts the national conversation around important issues by amplifying some voices and virtually ignoring the rest.”

Mr Perrottet is a panelist on the ABC’s NSW Election coverage on Saturday night.

Today he claimed he “loved the ABC”, but thinks it’s important the broadcaster “represents mainstream Australia.”