Anyone who has lived in West Sydney in the summer will tell you that scorching hot days and blazing bitumen feel very different from the rest of the city.
It doesn’t matter what time of year it is generally hotter in the west. For the past 30 years, the average annual maximum temperature recorded in Parramatta was 23.7 ° C, compared to 22.8 ° C at Observatory Hill, just opposite the Harbor Bridge. But those numbers hide the extent of the disparity in the summer months. In January, the average daily high in Penrith, Sydney’s western boundary at the foot of the Blue Mountains, is 31.2 ° C, compared to 27 ° C in the city center.
That can mean extreme temperatures, like January 4, 2020, when Penrith was the hottest place on Earth at 48.9 ° C. Or January 7, 2018, when Penrith recorded the highest temperature in nearly 80 years. , 47.3 ° C.
And the lack of shade and large expanses of asphalt and concrete that trap heat in smaller locations can make conditions worse.
The causes of the discrepancy, both natural and human-influenced, are well known, but since more days of extreme heat are expected due to the effects of climate change, there is little agreement on what can be done to make life in summer be more bearable for people. the majority of Sydney’s population.
Dr Sebastian Pfautsch, an urban heat expert and principal investigator at the University of Western Sydney, says the first and most obvious reason for the heat in the western suburbs is that they don’t benefit from the sea breeze.
“The sea breeze stops [at] over the olympic peninsula [near Homebush] That’s as far as the river goes before it is blocked, ”says Pfautsch.
But the Wild West is also particularly affected by the geomorphology of the city: the lowest point of the city is on the Nepean River, at the base of the Blue Mountains.
“It’s actually like a frying pan, where the lowest depression is towards the river. That is the lowest point. When you drive down that road and you feel like you are going down, it is like a depression that traps warm air, ”says Pfautsch.
The hot air is trapped in the region, making the suburbs of the triangle between Blacktown, Windsor and Penrith the hottest parts of the city.
Some parts of the west also receive up to 400mm less rain per year than the east of the city.
“That leads to less water in the system that can be evaporated or transpired by vegetation,” says Pfautsch. “And this cooling effect that you get from evapotranspiration is not as great as in other parts of Sydney.”
These natural factors have been compounded by the destruction of scrub in the west and its replacement by buildings and roads, which Pfautsch sums up as a “massive conversion from green to gray.”
“Now we have a massive conversion … from green infrastructure to gray infrastructure, from pastures and meadows on farmland to shopping malls, parking lots and residential suburbs.”
Without vegetation that can convert solar radiation into biomass, the region has little or no outlet for heat, rather than absorbing it from roads and buildings, he says.
“When you used to have a pasture with some remaining vegetation, it would have stayed relatively cooler, because it wouldn’t have stored as much energy.
“And because the water could seep into the soil, it became available to plants and would have been evapotranspired, which again provides you with cooling.”
What all of that means is that West Sydney residents face ever-longer spells of dangerous temperatures in the summer.
In 2018-19, a street in Parramatta recorded 13 days of 40 ° C or more, and in 2017 the suburb recorded 28 days of above 35 ° C.
Our bodies are not made to deal with these regular days of extreme heat, says Pfautsch.
“People really need to understand that it is extremely dangerous to live in these kinds of temperatures because the body struggles to cool itself from those extremes.”
Professor Diana Egerton-Warburton, an emergency medicine physician, says that a number of dangers come from exposure to extreme heat, especially for the young and very old.
There are direct consequences, such as heat stroke and exhaustion, but also serious indirect impacts, he says.
“Heat causes many cardiovascular complications, such as a stroke and a heart attack,” says Egerton-Warburton.
“When the temperature is particularly high, especially at night, there are well-defined and well-researched thresholds at which the rates of heart attack and mortality increase.”
Extreme heat can also affect the brain and kidneys.
Can we still live in West Sydney?
Charles Casuscelli, executive director of the Western Sydney Regional Council Organization (WSROC), says the heat is an existential threat to the future of the region.
“This is a habitability problem. It’s not about being comfortable, it’s about asking whether or not I can live in West Sydney, ”he says.
A challenge for local authorities looking to make the region’s environment more tolerable is figuring out where to start.
Some initiatives focus on the immediate task of mitigating the worst effects of extreme days by providing cooler places for recreational and other activities.
Blacktown City Council has implemented a “heat shelter network” that opens up community-managed air-conditioned spaces for vulnerable residents during an extreme heat event.
The Parramatta River Catchment Group, an alliance of councils, government agencies, and community groups, has been working to clean up and transform the Parramatta River into a number of swimming spots.
And in 2020, the Cumberland council introduced the first UV Smart Cool playpen at Merrylands Memorial Park to protect children from heated play equipment.
But in the long run, changes in land use and development will determine whether living in western Sydney becomes more bearable for its growing population.
In 2018, WSROC developed its Reject the heat strategy. Casuscelli says it’s essential that heat mitigation is included in planning and development, from using appropriate colors to making room for greenery and trees.
“We are not yet designing our houses with the right elements to minimize the amount of heat it absorbs,” he says.
“Why the heck do we keep building houses in western Sydney with dark colors? That’s dumb, dumb and dumb. “
New South Wales Premier Gladys Berejiklian announced in December that 40,000 trees would be planted in the greater Sydney area, as part of two funding streams: Cooler Suburbs and Green Innovations.
The initiatives will provide 29 councils with more than $ 8 million to support tree planting, but Casuscelli says the focus should expand from just trees.
“I’m almost sick of how much everyone seems to be focused on planting more and more trees to try to solve this problem, especially in western Sydney,” he says.
Pfautsch says authorities must consider all elements of community life to build sustainable, heat-resistant neighborhoods.
Suggest a complete rethinking of building practices, including apartment blocks that are partially underground.
“We need to stop building a single independent house next to next to next to next,” he says.
“But of course there is a fear that people do not want to live in apartments because when I look at apartments, we have designed them very poorly for 30 or 40 years.”
Pfautsch says apartment blocks designed for comfort and not just to accommodate more people can also be energy efficient and would allow more space for parks and recreational spaces.
“It can offer a different kind of life to those who live in West Sydney,” he says. “But we have to be innovative, be radical.”
George is Digismak’s reported cum editor with 13 years of experience in Journalism