The Green Party co-leader expects an historic deal will be signed on climate change in Paris - but questions whether it goes far enough.

LISTEN: Green Party co-leader James Shaw speaks to Mike Hosking about the Paris climate summit

It's hoped a tangible agreement will be signed by world leaders at the United Nations Climate Change Summit which starts on Monday

40,000 delegates are expected at the 12 day summit.

James Shaw told Mike Hosking the deal is the first of its kind but is unlikely to achieve anything tangible.

"I think that what you'll get is all the countries in the world signing up to a binding global agreement - that's the good news."

"My problem with it is that the targets that people are going to be signing up to are non binding."

New Zealand is on a sticky wicket at the big climate change talks in Paris this weekend.

Our former UN Climate Ambassador thinks it's going to be tricky to show we're making a decent effort on the issue, because the Emissions Trading Scheme doesn't work.

Victoria University's Adrian Macey told Rachel Smalley the ETS is broken because carbon prices are too low.

He said we've not done much in the past few years, and the review of the scheme should be put into a wider context.

"Just how are we going to do this transition away from fossil fuels for New Zealand, and so we really have to have something that is more effective in the coming years."