By Angela Dorizas

Rising temperatures caused by climate change could exacerbate the harmful effects of heat stress in urban communities, according to the latest CSIRO research.

CSIRO scientist Dr Martin Cope has warned that hotter temperatures and higher levels of air pollution will put a strain on health services.

He said CSIRO modelling for Sydney has found that by 2060 hospital admissions due to increased temperatures and ozone pollution will be up to three times the current rate.

“The number of days over 30 degrees Celcius, say around Sydney, may go up by 20 to 25 per cent and days over 40 degrees Celcius may double,” Dr Cope told Government News.

“The number of deaths related to heat stress may double between now and 2060. That’s before you actually take into account the change in the demographics.”

He warned that young children and people with existing respiratory conditions would be vulnerable to heat stress, but the elderly were most at risk.

With the number of people aged 65 years and over expected to double by 2060, heat related deaths across Australia are set to increase.

“That has the biggest effect on the changes in mortality from heat stress,” Dr Cope said.

“We are talking about roughly a doubling of heat-stress related deaths.

“If you then factor in a change in the demographic, you could be talking about a doubling again.”

Air pollution is also expected to increase during periods of extreme temperatures. 

Dr Cope said ozone, a toxic pollutant created through the burning of fossil fuels, paint fumes and grass cuttings, was temperature dependent.

“The reason why you get more ozone is because it generates more rapidly at the higher temperatures,” he said.

“It increases the proportion of people who may be going to hospital, particularly with respiratory disease.”

Dr Cope said a whole of government response would be necessary to mitigate for the increase in extreme temperatures.

“Clearly, the thing to do is to have houses that keep cooler, to have programs in place to look after your vulnerable populations, and to continue to strengthen those programs as time goes on,” he said.

“The adaptation can happen at the council and community level. That’s looking after your more vulnerable population.

“The good news is that we already get heat waves, so we already know what to expect and health authorities are trying to put things into place.”

Although his climate change modelling was focused on Sydney, Dr Cope said heat related deaths were likely to occur in other states and cities.

Nicole Joffe, an honours student from Monash University's Department of Geography and Environmental Science, has conducted a review of research, already in the field, on threshold temperatures linked to heat related deaths among Melbourne residents 65 years or older.

“I've taken those thresholds and looked at the projected number of days above them into the future,” Joffe told Government News.

She projected that between 2081-2100 there could be around 147 days of extreme temperatures linked to mortality.

She also looked at the change in “human thermal comfort” and projected that between 2081-2100 the number of days linked to heat stress could increase by at least 100 per cent and up to 226 per cent above 1981-2000 levels.

The increase in morbidity would put a strain on the State’s health services.

“You’d expect that health infrastructure would struggle, not only from the mortality changes, but from morbidity,” Joffe said.

She said investment in public health infrastructure, health alert systems and sustainable urban design were important steps in preparing for future, deadly summers.