A letter proposing the "fossil fuel non-proliferation treaty" said it could work similarly to the World Health Organization's Framework Convention on Tobacco Control -- except this time the harmful controlled substances would be coal, oil and gas.
The WHO was among the health organizations from around the world who signed the letter.
"The modern addiction to fossil fuels is not just an act of environmental vandalism. From the health perspective, it is an act of self-sabotage," WHO chief Tedros Adhanom Ghebreyesus said in a statement.
The letter called on national governments to develop and implement a legally binding mechanism that would immediately stop all future fossil fuel expansion, as well as phasing out existing production.
It emphasized that the transition should be carried out in "a fair and equitable manner," and that high-income countries should support lower-income nations to ensure the change "reduces poverty rather than exacerbating it".
Air pollution, mostly from burning fossil fuels, has been linked to the deaths of seven million people a year.
Climate change has also spurred more frequent and severe extreme weather events, which can have a lasting impact on health even beyond those initially affected by the disasters, including smoke from wildfires and diseases spread after floods.
The letter also pointed to the heightened health risks faced by the workers who extract, refine, transport and distribute fossil fuels and related products.
Phasing out fossil fuels would prevent 3.6 million deaths a year from air pollution alone, the letter said, adding that "the same cannot be said for proposed false solutions, such as carbon capture and storage."
- Either fossil fuels or health -
Diarmid Campbell-Lendrum, the head of the WHO's climate change unit, said that "from a health point of view, you can't fix a disease without calling out what is causing it".
The call for a treaty was important because it did not "try to use false accounting or imaginary solutions to continue to prop up the burning of fossil fuels," he told AFP.
"We can either have fossil fuels or we can have health -- we can't have both."
Courtney Howard, an emergency physician in Canada's sub-Arctic region who signed the letter, said that the city of Yellowknife had some of the worst air quality in the world when it was ringed by wildfires in 2014.
"We had a doubling of emergency department visits for asthma, a 50 percent increase in pneumonia and one of our pharmacies ran out of one of the breathing medicines," Howard told AFP.
She said that phasing out fossils fuels is "something we need to do for everybody -- for everybody's kids."
Jeni Miller, the executive director of the Global Climate and Health Alliance which helped coordinate the letter, called for international dialogue and negotiation to make the treaty a reality.
"The costs of inaction are increasing," she said.