While the Prime Minister says the Government isn't opposed to proposing a climate emergency, the National Party's climate change spokesperson isn't sure what that would achieve.

A petition organised by "climate crisis action" group Claxon is calling on MPs to declare a climate emergency.

"The global, irreversible nature of climate change elevates risk of loss to an unacceptable level, mandating extreme, emergency-level action," the group's website says.

Jacinda Ardern said on Wednesday that she wasn't sure why MPs wouldn't want to demonstrate climate change as a matter of urgency.

In May, Green MP Chloe Swarbrick attempted to move a motion to declare a climate emergency, but that was shut down by the National Party.

National's Todd Muller said on Wednesday a declaration is currently just a "feel good statement" with no action behind it.

Several councils, including the Auckland Council, have declared a climate emergency. In doing so, the Auckland Council committed to incorporating climate change considerations into their decisions.