Extreme heat is putting people in Australia at serious risk of heart problems and premature deaths, according to new research. As the climate warms, rising temperatures could more than double Australia’s burden of cardiovascular diseases by 2050, unless greenhouse gas emissions are reduced, and people take measures to adapt to the heat, researchers found.
Cardiovascular diseases like heart attacks and strokes are a leading cause of death globally, including in Australia. Several factors including age, chronic conditions like diabetes, and exposure to air pollution increase the risk of cardiovascular diseases.
Exposure to extreme heat can be an additional risk factor, said study co-author Peng Bi, professor of public health and environmental medicine at the University of Adelaide, Australia. “When you have very hot environment, our hearts have to work harder to pump more blood to [cool] the body,” Bi told Mongabay in a video call.
Bi and his colleagues wanted to know how much hot weather is directly responsible for heart-related problems and premature deaths in Australia. So they used statistical modeling to quantify the relationship between temperature changes from 2003-2018 and the country’s cardiovascular disease burden during that 15-year period. They measured cardiovascular burden using “disability-adjusted life years,” or DALYs , which represents the total years of healthy life lost to illness and premature death due to heart problems.
The study found that 7.3% of the annual cardiovascular burden in Australia was directly attributable to high temperatures — i.e., hot weather contributed to 49,483 healthy years of life lost due to heart problems in Australia annually.
The researchers also looked at Australia’s cardiovascular disease burden under two future climate change scenarios: one in which greenhouse gas emissions peak around 2040 then decline, and one where emissions continue to rise. The models also included scenarios of population growth and aging, as well as human adaptation to heat.
The analysis showed that under both warming scenarios, the number of healthy years lost to heart diseases would more than double by 2050. If emissions keep rising, the number of healthy years lost would reach 95,353 in 2030 and 161,095 in 2050. If emissions stabilize, the increase is less drastic, at 90,779 by 2030 and 139,829 by 2050. When the models consider people adapting to hotter weather, the numbers are lower still.
“Good adaptation means that the most vulnerable populations are looked after well,” Bi said. Such adaptations include encouraging the elderly and those with chronic illnesses to stay indoors during extreme heat. People who work outside, including construction, mining and utility workers, can rearrange their shifts, or use cooling vests or hats, he added.
Bi acknowledged the climate models inherently have uncertainties. However, the projections offer “a big picture of what might happen in the next 20-30 years, which is evidence needed by the government, the health service providers for their decision-making,” he said.
Banner image of people on a Sydney beach on a hot summer day. Image by Neerav Bhatt via Flickr (CC BY-NC-SA 2.0).
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