Former Prime Minister Malcolm Turnbull has declared people need to cut Scott Morrison some slack, as his successor tries to navigate both international policy and a Coalition that remains largely split on climate change policy.

Key points: The former prime minister says emissions reduction is a very difficult issue for the Coalition

The former prime minister says emissions reduction is a very difficult issue for the Coalition Australia has stymied efforts by small island states to get Pacific-wide consensus for action on climate change

Australia has stymied efforts by small island states to get Pacific-wide consensus for action on climate change Mr Turnbull says the Pacific Step Up program has not been undermined

Australia has stymied efforts by small island states to get Pacific-wide consensus on their declaration for stronger action on climate change, which led to criticism that Mr Morrison was putting politics ahead of Australia's island neighbours.

Mr Turnbull was toppled as leader of the Liberal party last year, with some blaming his approach to the National Energy Guarantee.

Conservative backbench MPs publicly spoke out against the policy, and Mr Turnbull ultimately ditched the commitment to legislate for an emissions reduction target in a bid to save his leadership.

On ABC Radio on Friday, Mr Turnbull defended Mr Morrison's approach to climate change, saying he "had to operate in the real world".

"Emissions reduction is a very difficult issue for the Coalition, and you've got to cut Morrison some slack on this, or give him some understanding.

"He's not a dictator or a president, he's a prime minister, like I was," Mr Turnbull said.

The former prime minister said Mr Morrison was "alert to the political realities".

"There is a very strong minority within the Coalition and the media and community that is ferociously opposed to taking action to reducing greenhouse gas emissions," he said.

Mr Morrison replaced Mr Turnbull as Prime Minister last year in a Liberal leadership spill. ( ABC News: Matt Roberts )

After marathon talks at the Pacific Islands Forum (PIF) in Tuvalu, Australia could not reach an agreement with the smaller Pacific nations over the mention of phrases relating to coal, and in reducing emissions.

Mr Turnbull said while it was a disappointing outcome, he believed the Pacific Step Up program had not been undermined.

"These communiques are essentially political documents, and it's important to achieve consensus and a resolution around them, and I'm sorry there wasn't more consensus around the language," Mr Turnbull said.

"But the reality is Australia is the Pacific's best friend, we are by far the Pacific's best donor."

Turnbull critical of Alan Jones

During his interview on ABC Radio, Mr Turnbull also criticised Australian broadcaster Alan Jones for his comments about New Zealand Prime Minister Jacinda Ardern.

On Thursday, Jones said Mr Morrison should "shove a sock down [Ms Ardern's] throat" after she said "Australia had to answer to the Pacific" on climate change.

Mr Turnbull said the comments were unacceptable.

"I think his pattern of using abusive and violent language against women, particularly women politicians, is disgraceful," Mr Turnbull said.

"He is an appalling misogynist in the way he talks about women.

"This is appalling language, and at a time when we are doing everything we can as a national priority to stamp out violence against women and children, you have this broadcaster who uses the violence against women as part of his regular rhetoric — it's disgraceful."

On Thursday evening Jones released a statement saying he had meant to say "put a sock in it", and repeated the statement again to his 2GB listeners on Friday morning.