CANBERRA, May 21 (Xinhua) -- Australian researchers have called to add climate change as an official cause of death after a study found that heat-related deaths have been under-reported.

The study, published by Australian National University (ANU) on Thursday, found that excessive natural heat has been responsible for at least 50 times more deaths than recorded on death certificates.

A statistical analysis found that 36,765 deaths in Australia over the past 11 years could have been attributed to heat but only 340 were.

"Climate change is a killer, but we don't acknowledge it on death certificates," Arnagretta Hunter, a co-author of the study from the ANU Medical School, said in a media release.

"If you have an asthma attack and die during heavy smoke exposure from bushfires, the death certificate should include that information.

"We can make a diagnosis of disease like coronavirus, but we are less literate in environmental determinants like hot weather or bushfire smoke," Hunter said, adding that heat is the most dominant risk posed from climate change in Australia.

According to the study, excessive natural heat was responsible for approximately 2 percent of all deaths in Australia.

Hunter said the country's death certificates must be modernized to capture the impact of global warming.

"Climate change is the single greatest health threat that we face globally even after we recover from the coronavirus.

"We know the summer bushfires were a consequence of extraordinary heat and drought and people who died during the bushfires were not just those fighting fires - many Australians had early deaths due to smoke exposure," she said.