The Green Party is pushing for climate change to be formally acknowledged in all government legislation.

Co-leader James Shaw has unveiled the policy at an international Greens congress in Wellington today.

It would make it mandatory for new laws and law changes to include climate change impact statements.

Mr Shaw said the measure would mirror the current use of regulatory impact statements.

"So the government makes a lot of decisions all the time, and we have no idea of what the impact is on climate change, or how climate change impacts on those decisions."

He believes there is the skill within the public service to make such assessments accurately.

"I mean the government has some very smart boffins available to them. I think that when they're doing the regulatory impact statements it wouldn't be too hard to flick something across to one of the existing agencies.