Prime Minister Scott Morrison has not yet committed to achieving carbon neutrality by 2050 but is laying the groundwork to adopt it as policy, following allies such as the United States.

Canavan, who is a staunch advocate of coal-fired power and the mining industry which is a major employer in Queensland, said it was a “mythical target”.

“I am opposed to it,” the former minister told the ABC on Monday.

“I can’t stop a government signing a piece of paper. But as a senator for Queensland, I’ll make sure that all my votes in the parliament represent their interests.”

Asked whether he would cross the floor in the Senate, he said: “Absolutely I would, if that was in the best interests of Queensland.”

He said the exclusion of agriculture – which is being discussed within the Nationals as a bargaining chip with their Liberal colleagues – would not change his approach to the issue.

“Let’s focus on real things – I find this a massive distraction,”Canavan said.

Excluding agriculture would put Australia in line with New Zealand’s net zero by 2050 plans, which places a lower target on reducing methane levels.

Agriculture made up 13 per cent of Australia’s greenhouse gas emissions last year and the percentage is expected to rise to 2030 as the effect of the drought eases.

But Nationals senator Bridget McKenzie later said her colleagues will have no opportunity to cross the floor because the goal will not need to be legislated, as the government can simply sign Australia up at a United Nations conference in Scotland later this year.

“My understanding is there will be actually no legislative requirement if the government decides to head off to Glasgow and sign this up,” McKenzie said.

The target has been adopted by Australia’s major allies including the United States, but locally it’s creating fractures between the Liberal and National parties in government.

The target has been adopted by all Australian states and territories, and is also federal Labor’s policy.

The Nationals Farmer Federation supports net zero by 2050 but wants to ensure the sector isn’t left worse off.

Greens leader Adam Bandt said on current trends Australia was set to heat by a catastrophic four degrees during the lifetimes of today’s primary school students.

“Climate change is already hurting people who are putting food on our table,” he said.

The European Union’s ambassador to Australia has confirmed a free trade agreement between the two partners will not include climate tariffs.

Michael Putch said everything the EU does is to support climate action.

“But a free trade agreement is a free trade agreement and our cooperation on climate change activities are separate from them,” Dr Putch told ABC radio.

“Although, in the free trade agreement we have a chapter on sustainable trade which is very important to us.”

-with AAP