Doctors, nurses and other health workers from 90 different countries have added their name to the letter, which says making public health a key recovery consideration will help avoid future crises and make the world more resilient to them.

The leaders of the world's 20 largest economies - including Prime Minister Scott Morrison and US President Donald Trump - have been asked to prioritise investment in clean air and water and a stable climate.

The letter says such investments would reduce air pollution and emissions, build greater resilience to future pandemics and create more sustainable jobs.

The signatories include health groups from across the globe including the World Medical Association and the Climate and Health Alliance from Australia.

The Alliance's executive director Fiona Armstrong says to prevent further health risks, the government must not invest in polluting fossil fuels.

"The federal government listened to health experts and trusted the science in its response to the COVID-19 health crisis, they must do the same for the climate crisis," she said.

"Our health depends on it."

Health professionals must help develop economic stimulus recovery packages, the letter says.

By following their advice, G20 leaders will encourage healthier diets, more renewable energy, more walking, cycling and zero-emissions public transport, the health workers say.

Australian Associated Press