Scott Morrison was labelled a "national embarrassment" for not attending the New York summit earlier this week, where 63 world leaders spoke about their actions in tackling climate change.

Mr Morrison was in Chicago at the time.

Home Affairs Minister Peter Dutton defended the prime minister's absence, and said he was right to focus on ocean plastics during a speech to the UN several days later.

"I think that is an incredibly important environmental policy for us," Mr Dutton told the Nine Network on Friday.

"It's a huge issue and I think people would expect us to do both - we're doing both - and I think the prime minister highlighted that."

Labor frontbencher Chris Bowen laid the boot into Mr Morrison for skipping the international climate summit.

Mr Bowen said Australia was the biggest carbon emitter in the world on a per capita basis, and emissions had gone up every year for the past five years.

He also took aim at the prime minister for warning children against "needless" climate anxiety.

"You can do both - you can do oceans, and you can do climate change - and this government has done precious little of either," Mr Bowen said.

Treasurer Josh Frydenberg was on Friday grilled about whether the Liberal and Nationals were on "the wrong side of history" in relation to climate change.

As other world leaders focus on reducing carbon emissions, the coalition government has thrown its full weight behind building the Adani coal mine in the Galilee Basin.

"Well it's not illegal to mine coal," Mr Fydenberg told ABC radio.

"It creates thousands of jobs across regional communities, and particularly in indigenous communities."

Australian Associated Press