Antinuclear

Australian news, and some related international items

Australian cities not prepared for the coming heatwaves- poor urban planning

The urban heat dome

The heat is coming and we are not prepared for it.

It is not just that large houses on small blocks leave no room for trees,….. The little space left between them provides no room for recreation and serve to increase heat, with side-passages often home to air-conditioning systems that spew heated air across dividing fences.

When he looks at new developments on the fringes of Australian cities, Pfautsch says residents have been abandoned to wholly predictable heat extremes caused by global warming but exacerbated by poor planning regulation.

We’re ending up with dark-roofed, back-to-back, nose-to-front, housing suburbs on the outskirts of Melbourne. And if you add dark, asphalt and concrete surfaces you’re going to get really hot suburbs,”

Why a killer US heatwave points to a stifling future for our cities. Brisbane Times, By Nick O’Malley and Miki Perkins, July 17, 2021 It was the hellish evening temperatures that finally caused the authorities to start busing the homeless into heat shelters where they had access to fans, air-conditioning and water.

Three hours from sundown last Saturday the temperature in Las Vegas peaked at 47.2 degrees, equalling a record set in 2017. By dawn, the temperature had bottomed out at a stifling 34 degrees and begun to rise again.

One person was treated for burns after walking on a pavement and the homeless were bussed from an outdoor shelter to indoor cooling centres in response.

West of the city at Furnace Creek in Death Valley a temperature of 54.4 degrees was recorded. Experts are still checking the reading and debating over whether this was the hottest temperature ever recorded on earth.

In the town of Lytton in British Columbia, a Canadian heat record was set at the end of last month when the temperature hit 49.6 degrees and lingered up there over three days. Authorities attributed hundreds of deaths across the region to the heat, even before wildfire arrived and burnt most of the village to the ground, killing two more.

Before the flames approached one local, Lorna Fandrich, told the New York Times that she’d noticed green leaves dropping off the trees, apparently unable to tolerate the heat. On the coast to the west, millions of mussels and oysters cooked and died in superheated shallow waters.

From his home outside Sacramento Ken Pimlott, the recently retired head of Cal Fire, the agency responsible for fighting wildfires across the state of California, watched on with dread. The height of the northern fire season, he noted, has not even arrived yet.

These temperatures, Pimlott told The Sydney Morning Herald and The Age, are no longer outliers, but spikes in a new normal in a world not prepared to manage them.

The temperatures have already extended the North American fire season, causing exhaustion among crews who can’t get enough rest from the fire lines and difficulties in keeping up with maintenance demands on equipment. Aircraft once shared with nations like Australia were under greater demand as fire seasons overlapped, he said.

Pimlott’s dread was shared in Australia.

Dr Sebastian Pfautsch, a specialist on urban heat at Western Sydney University, says though Australian attention has drifted from the terrible summer of 2019 and 2020, he fears for the future of residents of some suburbs in Sydney and Melbourne.

The heat is coming, he says, and we are not prepared for it.

Stephen Livesley is an associate professor in forest sciences at the University of Melbourne, and an expert on the benefits of urban forests. “It’s possible we’re going to end up with large neighbourhoods which people in 20 or 30 years’ time will simply avoid,” he says.

This concern is not misjudged, says Professor Christian Jakob, a Monash University atmospheric scientist.

His analysis of the heatwave that struck North America shows that it originated with an unremarkable rainshower on the other side of the Pacific Ocean, not far from Japan.

The shower caused an atmospheric disturbance that in turn created what scientists call a Rossby wave, which was guided towards North America by the jet stream, amplifying as it travelled before breaking upon the shores of the Pacific Northwest.

There the wave caused a high-pressure system. As Jakob explains, air heats under pressure. On the ground, temperatures soared. What caused the temperatures to reach such extremes, though, and what made the system linger long enough to cause such misery and destruction beneath it, cannot yet be explained by science says Jakob.

Until better computer models are created all we can know is that as the climate heats due to global warming such heatwaves will in some areas increase in intensity and duration.

Areas particularly prone to the phenomenon include northern Europe, North America and south-eastern Australia, he says

On the day that Penrith became for a time the hottest place on earth, with temperatures hitting 48.9 degrees on January 4 last year, Keith Heggart’s air conditioner conked out by midday. The manual said it sometimes did that in extreme heat and recommended hosing it down, but due to bushfires water use was banned. Heggart and his young family closed windows against the smoke and the blinds against the sun and sheltered in the living room where a fan pushed around the hot air.

Watching the news from America these past few weeks, Heggart has fretted about the summers to come. His street in Penrith is older than others and there is some shade, some gaps between the houses, but when he looks at the new developments nearby, he despairs.

“There are no trees, there is no shade,” he says. “You could reach out your window and touch the house next door.

When he looks at new developments on the fringes of Australian cities, Pfautsch says residents have been abandoned to wholly predictable heat extremes caused by global warming but exacerbated by poor planning regulation.

Council areas such as Blacktown, Penrith and Campbelltown in Sydney and suburbs like Wollert, Mernda and Mickleham in Melbourne are compelled to absorb growing populations by state governments, but are failing to impose proper planning regulations. Strapped for cash, they have allowed property developers to shape the built environment, he says.

…….. It is not just that large houses on small blocks leave no room for trees, Pfautsch says. The little space left between them provides no room for recreation and serve to increase heat, with side-passages often home to air-conditioning systems that spew heated air across dividing fences.

But Pfautsch sees other wilful mistakes. Unshaded black roads absorb heat during the day only to radiate it at night, extending the heat of day into the evening. This contributes to the urban heat island effect.

Roofs, exterior walls and even driveways created by developers in currently fashionable dark shades serve to exacerbate the impact, he says.

But, according to Pfautsch, the problems begin even before the new suburbs are laid out, when developers clear new sites of all existing trees, ponds and watercourses to maximise space and save on construction costs.

What greenspace remains is often not connected to homes by shaded foot or bike paths.

“It is inhumane to expect people to live like this in the temperatures we anticipate,” he says. “I can’t say it more strongly than that.”………….

Overall, Melbourne lost 0.3 per cent of its canopy between 2014 and 2018. Almost 2000 hectares of trees were cut from the east and south-east, mostly at residential properties……….

We’re ending up with dark-roofed, back-to-back, nose-to-front, housing suburbs on the outskirts of Melbourne. And if you add dark, asphalt and concrete surfaces you’re going to get really hot suburbs,” he says. “When you have high-temperature events intersecting with urban heat islands, you have really, really high temperatures.”

According to Pfautsch, even a concerted effort to increase tree coverage in the suburbs most prone to the heat-island effect will only have limited impact in the years to come………

All this raises thorny questions of environmental and climate justice, Livesley says, as the suburbs most affected are often the most affordable.

“We are pushing some of the most vulnerable people in our society into these low tree, low services environments, with poor public transport infrastructure.”…………

In Mildura, a town near the border in north-west Victoria, temperatures have increased in line with worldwide heating trends. Between 1998-99 and 2018-19 the number of days each year where the temperature went above 35 degrees increased by about 20 days, and the number of heatwaves rose from six to nine.

For residents living in public housing – who faced huge bureaucratic hurdles to having air conditioners installed – recent summers have been a nightmare,………..

not only should we be tackling climate change, we should be totally re-imagining how we build our suburbs.  https://www.brisbanetimes.com.au/environment/climate-change/why-a-killer-us-heatwave-points-to-a-stifling-future-for-our-cities-20210716-p58ae9.html

July 19, 2021 - Posted by | AUSTRALIA - NATIONAL, climate change - global warming

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