Opposition Leader Bill Shorten says climate scepticism is embarrassing Australia on the world stage ahead of the G20 summit.

Australia is seen as the climate sceptic capital of the world ahead of the G20 summit, Opposition Leader Bill Shorten says.

The Abbott coalition government has scrapped Labor’s carbon pricing scheme and is working on a new Direct Action plan to cut emissions by five per cent on 2000 levels by 2020.

But climate change won’t be on the agenda of the G20 leaders’ summit in November in Brisbane.

Mr Shorten has committed to Labor to rolling out an emissions trading scheme if re-elected, which has led the Liberal Party to accuse him of wanting to bring back the carbon tax.

He said the government needed to think about the future, not the next opinion poll.

“We’ve got the G20 coming up. Most nations in the world at the G20 are dealing with climate change. Yet we’re the climate sceptics capital of the world,” Mr Shorten told reporters in Melbourne on Monday.

He said Labor would not be introducing a carbon tax if re-elected.

“The rest of the world is moving towards taking real action on climate change, yet we’ve got a government who’s slammed the nation into reverse gear and retreating away from action.”