"Like COVID-19, climate change is a public health emergency that must be addressed urgently," DEA honorary secretary Dr Richard Yin said in a statement on Tuesday.
"The post-COVID recovery offers an unprecedented opportunity to reject developments that are destructive to our environment."
The letter says carbon pollution and global warming have "profound" consequences on human health, including clean air, water, access to food, and a safe climate.
It warns Australia has already been exposed to more frequent and severe bushfires, droughts, and storms, which the doctors argue will continue to have a serious impact on physical and psychological health.
The letter makes note of the Black Summer bushfires, which killed 33 people, and claims the associated smoke resulted in more than 1300 presentations to emergency departments with asthma, more than 3000 hospitalisations for heart and lung problems, and 417 excess deaths.
The mental health impacts are likely to linger for decades, the medical groups say.
The doctors argue fossil fuel combustion is a major contributor to air pollution, while water supplies and food-growing capacity are also threatened by climate change.
They've urged the federal government to take a health-centred approach in its COVID-19 recovery by transitioning away from fossil fuels, coal, and gas and instead turn to renewables, electric vehicles, and public transport powered by electricity.
"Redirecting funds from fossil fuel subsidies towards the production of renewable energy would produce cleaner air, significantly reduce emissions and power an economic recovery," the letter said.
"Climate change is a public health emergency. Failing to mitigate and prepare for climate change risks potentially catastrophic health and economic impacts."
The Royal Australasian College of Physicians said it was vital climate change and its impacts on health are central to the COVID-19 recovery plan.
"While COVID-19 poses the most immediate threat to our health, the serious and long-term health impacts of climate change still remain," spokeswoman Associate Professor Linda Selvey said in a statement.
The Australasian College for Emergency Medicine noted the lockdowns imposed on communities during the pandemic reduced CO2 emissions significantly.
"The net result was remarkable, and it shows that where there is political will, it is possible to reduce emissions," ACEM Public Health and Disaster Committee chair Dr Lai Heng Foong said.
"We need collective action, including government response to reduce our CO2 emissions, transition to renewable energy sources and build community resilience. Our future is at stake, and we need action now."