Twenty-two organisations including the Royal Australasian College of Physicians and the Australasian College of Emergency Medicine have signed a joint statement calling on Scott Morrison and Gladys Berejiklian to combat climate change to protect people's health.

Bushfire smoke has led to air pollution up to 11 times the "hazardous" level in parts of Sydney and NSW.

The RACP's Dr Kate Charlesworth on Monday said just as doctors spoke up on asbestos and tobacco they had a responsibility to speak up on climate change.

"Doctors are increasingly seeing climate-related health impacts on our patients and on our communities, including bushfires, bushfire smoke, drought and heatwaves," she told reporters in Sydney.

"It would be irresponsible of me as a doctor not to talk about the key underlying contributing cause to these horrific conditions, and that is climate change

"Emergency is not a term that we use lightly, but there is overwhelming evidence now that climate change is a health emergency."

The organisations are calling for the federal and NSW governments to prioritise action to help reduce the risks to people's health arising from air pollution.

It's linked to premature births and underweight babies, asthma, heart disease, stroke and lung cancer.

"We call on Mr Morrison and Ms Berejiklian to demonstrate the leadership this public health emergency demands and to implement measures to help alleviate the health and climate crisis," Monday's statement reads.

The medical groups want political leaders to acknowledge the impacts of climate change and commit to reducing greenhouse gas emissions.

They called for a national strategy on climate, health and wellbeing to ensure a co-ordinated approach to tackling "the worsening health impacts of climate change".

But NSW Farmers said there was more to the current bushfires than climate change.

Fuel load management in national parks and land management laws also had to be discussed, the organisation said on Monday.

"Farmers are observing and dealing with the realities of climate change first hand, but this is not the only factor that has allowed these uncontrolled megafires to engulf over two million hectares of NSW," NSW Farmers president James Jackson said in a statement.

The association wants regulations overhauled so they can more easily control regrowth of invasive native species and clear fire breaks on their own properties.

NSW Farmers is also pushing for increased access to managed grazing in national parks.

The Bushfire and Natural Hazards CRC on Monday released a seasonal outlook which said that after an unprecedented start to the NSW fire season, short to medium-term outlooks forecast warmer and drier than average conditions across the state.

This means "above normal" fire potential will continue in forested areas on and east of the Great Diving Range and existing large fires will continue to remain a threat, the outlook said.

Australian Associated Press