An alarming report has found temperature increases from climate change and urban growth will make Brisbane “a difficult place to live” within the next 30 years, and more people will be at risk of dying from extreme heat.
The long-term climate modelling also found the number of hot days and nights will double in Australia’s third largest city by 2050, and people will need to avoid outdoor activities throughout most of summer.
The peer-reviewed study, which was published recently in the International Journal of Climatology, investigated the impact of urban growth and climate change on heat stress during summer in Brisbane, from the present day to 2050.
Dr Sarah Chapman’s four-year study found the number of hot days and nights doubled with climate change.
“When we included urban growth, the number of hot nights increased even further,” Dr Chapman said.
“With a doubling of hot nights, more people will be at risk of illness and death.
“The definition of ‘hot nights’ that we use has been linked to an increase in mortality of 20 per cent in elderly people.”
The report also found that two-thirds of summer nights would become unbearably hot.
“It’s going to be unpleasantly hot most nights in summer,” she said.
“What we’d consider unusually hot in the present-day becomes normal in the future.
This isn’t a path we want to be on
She said the study also looked at how increases in temperatures would affect people’s ability to work and play outside.
“We found the majority of summer days became ‘high’ heat stress days,” Dr Chapman said.
“This means that outdoor work and sport will need to be limited, even in shaded conditions, otherwise there will be a high risk of illness.
“When we looked at heat stress, we calculated it with average temperature, not maximum temperature … so unfortunately this means that it’s not just the hottest part of the day that is a problem. This will be a problem throughout most of the day.”
‘I’m alarmed by the findings’
Dr Chapman completed the study as part of her PhD at the University of Queensland, and said she was “alarmed by the findings”.
“Unless we make some big changes, it means the climate in Brisbane is going to become harder to live and work in,” she said.
“It’s not just at-risk groups, such as the elderly and the very young that will be affected.
These results show that even healthy adults will need to avoid outdoor activity throughout most of the summer.
While Dr Chapman was worried about the forecast, she said there was still time to make changes.
“Climate change is the biggest factor and there’s still something we can do but we need to move very quickly,” she said.
“We need to take serious action to cut greenhouse gas emissions and mitigate climate change.
“The way Brisbane develops in the future can also alleviate some of the impact or even make it worse.
“Getting rid of green space means increasing the temperatures not just in the city but surrounding areas, so the amount of green space in the city is a very important factor in urban temperatures.”
Call for political intervention
Dr Chapman also called for political action, as findings from another study published earlier this week, found regardless of action on climate change, monthly temperature records will continue to be smashed for the next two decades.
“I don’t think our politicians are doing much at all or not nearly enough at the moment unfortunately and that’s one of the reasons I’m so concerned,” Dr Chapman said.
Last summer was the hottest on record in Australia and the research published in Nature Climate Change found that record-breaking weather will continue for at least the next 20 years.
The Queensland Government recently commissioned a report on the long-term risk of heatwaves in Queensland and is planning for more extreme weather in the future.
Fire and Emergency Services Minister Craig Crawford said the Queensland State Heatwave Risk Assessment would serve as a blueprint for future hazard planning, as all levels of government prepare for an increase in the frequency of extreme weather events.
Severe heatwaves catalyst for fires
The catastrophic bushfires in central Queensland in November last year were analysed as part of the report, which explored the relationship between heatwaves and bushfire activity.
During the fires, parts of Queensland experienced the highest daily maximum temperature on record for November.
“What we saw last November was persistent, high temperatures creating severe heatwave conditions and forming a catalyst for fire activity,” Mr Crawford said.
“When we look at the report and the forecast for the future, it highlights the necessity for us to start preparing now.
“With a warming climate we can expect to see an increase in the frequency of heatwaves and so it is vitally important to prepare local and State Government for the effects of this hazard.”
Dr Chapman is now a research fellow at the Institute of Climate and Atmospheric Science at the University of Leeds in the UK.
The Brisbane-raised academic said she still considered Brisbane her home, but is questioning if she’ll want to live in the Queensland capital in the future.
“I might have to move further south if I did go back to Australia,” she said.