People around the world are already dying from the climate crisis, and yet all too often, official death records do not reflect the impact of these large-scale environmental catastrophes.

According to a team of Australian health experts, heat is the most dominant risk posed by climate change in the country. If the world's emissions remain the same, by 2080 Australian cities could see at least four times the number of deaths from increasing temperatures alone.

"Climate change is a killer, but we don't acknowledge it on death certificates," says physician Arnagretta Hunter from the Australian National University.

That's a potentially serious oversight. In a newly-published correspondence, Hunter and four other public health experts estimate Australia's mortality records have substantially underreported heat-related deaths - at least 50-fold.

While death certificates in Australia do actually have a section for pre-existing conditions and other factors, external climate conditions are rarely taken into account.

Between 2006 and 2017, the analysis found less than 0.1 percent of 1.7 million deaths were attributed directly or indirectly to excessive natural heat. But this new analysis suggests the nation's heat-related mortality is around 2 percent.

"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," says Hunter.

Read the full article on the Science Alert website, featuring commentary by Dr Arnagretta Hunter