Why Greens’ urban infill utopia will make our cities hotter

By Leith van Onselen

With scientists claiming that Sydney and Melbourne need to prepare for 50℃ days by the end of the century, The Conversation has produced an interesting podcast examining ways to make our cities cooler, with the main solution being to plant more trees, especially deciduous ones.

One area that does not receive enough attention in the podcast is the loss of green space from urban infill, which is creating a ‘heat-island’ effect. Back in July, Bloomberg published an interesting article explaining the ‘heat island’ phenomenon:

Cities have most cause to sweat. Because of the so-called urban heat island effect, their temperatures tend to be several degrees higher than surrounding rural areas, particularly at night as buildings and roads trap heat.

About 80 percent of global GDP is generated in cities and more than half the world’s population live in one, which is expected to reach two-thirds by 2050.

We’re about to find out what happens when you cram billions of people into urban areas and crank up the heat.

Economically, the most immediate problem could be worker productivity. Employees are more irritable and distracted when hot… Plus, heat can kill, particularly if it’s humid…

For now, urbanization continues apace…

For now, populations (and property prices) are still swelling in places like Phoenix and Sydney, despite summers that feel like a furnace. But there are limits to human adaptability.

Previously I have lambasted The Australian Greens for supporting mass immigration while also lobbying strongly against urban sprawl in favour of in-fill development, which I argued was totally inconsistent with their policy goal of affordable housing.

This quote from former Greens senator, Scott Ludlam, encapsulates the party’s position:

“The National Institute of Labour Studies reported that Sydney and Melbourne will need more than 430,000ha of new land by 2050 on current migration levels – but this is also based on current building and planning practices,” said Senator Ludlam. “We need to develop more medium and high density energy-efficient housing in our cities, with improved public transport to reduce congestion and the need for parking space.””Better urban planning will reduce urban sprawl, protect valuable agricultural land, take the upwards pressure off housing prices and reduce the reliance on cars for transport.”

It’s hardly rocket science: the Greens’ infill utopia of jamming thousands more people into a given area will necessarily chew-up green space as backyards, trees and open space are removed to make way for additional dwellings and infrastructure. And this will necessarily exacerbate the ‘heat island’ effect afflicting our cities, in turn raising energy use (think air conditioners).

Indeed, back in February 2014, a group of Melbourne and Monash University academics produced research arguing that the loss of vegetation from urban consolidation is causing heat-island effects, in turn raising temperatures and energy use:

Ever-growing houses, on ever-shrinking plots, mean that the average backyard has shrunk. Population growth has driven up property prices so that residential blocks are being subdivided for units or townhouses.

Meanwhile, larger green open spaces are being sold and developed…

Then in January 2015, Helen Brown – Lecturer in Health, Safety and Environment at Curtin University – published an article in The Conversation arguing that the lack of trees in new housing developments is significantly increasing the use of air conditioners and energy use:

The population of major Australian cities is expected to double in the next four to five decades. Planned increases in urban density are likely to result in the removal of a significant number of trees from urban areas.

Fewer trees in cities help create urban heat island effects – that’s when buildings and footpaths absorb the sun’s heat and then radiate it back out. Increases of up to three degrees are common and, in extreme cases, night-time increases of up to 12 degrees have been recorded.

And in March last year, Griffith University academics, Tony Matthews and Jason Byrne, posted an article in The Conversation urging Australia’s planners to develop urban greening strategies to overcome the “heat island effect” and cool Australia’s cities.

The fact of the matter is that The Greens’ position of supporting never-ending mass immigration and population growth, as well as increased urban density, is seeing backyards, trees and green space disappear in order to accommodate new housing and infrastructure.

It is worth also noting that housing developments built in the 1950s, 1960s, 1970s, 1980s and 1990s (represented below on the right) typically have large blocks, ample green space, and lots of tree cover. In short, they are a desirable places to live and do not suffer from the “heat island effect”. Now compare these 20 to 60 year-old developments with the cluttered rubbish produced today (represented below on the left), which are proliferating:

ScreenHunter_1037 Jan. 30 06.55

Clearly, maintaining green infrastructure in our major cities is not consistent with the projected explosion of their respective populations along with planning rules that force increased population density.

Rather, squeezing an ever-growing population into an existing urban footprint necessarily means that trees, lawns and other green infrastructure will make way to buildings and roads, thus raising temperatures and energy use. At the same time it forces-up land costs, thereby making the building of affordable and energy efficient homes more difficult.

Herein lies yet another contradiction at the heart of The Australian Greens. The only way that The Greens can credibly argue against urban sprawl and environmental amenity is if they also strongly oppose mass immigration. Instead, they hypocritically want to increase immigration even more and create an even bigger Australia!

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  1. 50C will be interesting cos that temp will be measured in the BOM style weather recording station
    In the outside in the sun it will be 60c plus and humans just cant stand that high a temp. It is fatal
    Hottest I’ve been is 47 in low humidity, and the breeze, is like looking into a hair drier.
    if Melb goes to 50 as a BOM temp it will kill half the population, plus animals.

  2. michael francis

    The photo on the right is where the Greens live.
    The photo on the left is where everyone else lives.

    • The photo on the right is where the 1% live. The streets of Malvern, Glen Iris, Camberwell, etc. are fantastic in winter and summer with the deciduous trees. The 1% is more than happy for everyone else to live in the photo on the left. As far as I can tell the Greens live in the white inner city areas and are demeaning of people within the suburbs that resemble the photo on the left..

  3. reusachtigeMEMBER

    Urban infill is by far the best way to go as it adds to an areas vibrancy! You end up with more wine bars and coffee shops and a greater choice of ethnic foods, not to mention relations.

  4. even more offensive to me is the assault that these sorts of plans have on our *built* environment, which the greens have no interest in protecting. some of our suburbs and inner city areas are some of the most architecturally beautiful in the world, and have a real living urban park feel to them. if mass immigration means that these buildings and built landscapes have to go, i’d rather mass immigration go.

  5. Philly SlimMEMBER

    Those photos are a bit cherry picked.

    Paddington has higher density and more trees than a lot of older style suburbs. But it is all linked, high land prices cause dogboxes as you posted yesterday when decent well built terraces like Paddo and other inner city suburbs have provided desirable housing for upwards of 150 years (130 for my place, built 1888).

  6. The Australian Greens party is riven with internal contradictions and weak logic. This sort of untidy, inconsistent and muddled thinking is emblematic of Australians generally though, so not really surprising. 🙄

  7. Allowing urban infill everywhere is just ridiculous as where are children supposed to play? Cities should be split to infill close to the city and keep large family friendly blocks further out. Now it’s near impossible to find a good sized family block where children can play and dig outside which is needed for their health. It’s a disgrace and once again shows lack of brains in our leaders.

  8. Exxon sold its skyscraper in downtown and built a campus on 500 acres for less money. Now the workers can live 5 minutes away on a large lot with lots of trees. Less traffic less noise and a relaxed atmosphere. Less financial strain on all and less strain on the environment

  9. The problem with the greens infill utopia is very few people want to live in medium to high density dwellings.
    I want a reasonable house on 800sqm+ for my family.
    This infill utopia just bids up the price of decent low density housing even further, as there is shrinking supply with increasing demand.
    Another reason why I plan to leave this horrible place called Sydney.

  10. The ‘property boom’ and population ponzi has seen Australian society take out a massive investment in some of the most crap structures the west has ever seen. At the climatic extremes of the 1900s we got away with it, we won’t by the end of this century.

    50oC peak temps will significantly confound many of the specifications and assumptions associated with building materials and design. Air conditioning systems will be inadequate, power systems will be unable to cope, cladding will crack, PVC will become more fragile, water systems won’t meet demand, tar will melt, transformers will blow, etc etc.

    Having green cities will be window dressing. At 50oC temp peaks and droughts water reticulation systems to keep trees alive will be required. Green cities during a sustained drought raise another interesting issue; lest you dump water on the greenery you invite a fire hazard unless you are really careful and base this on good science. Or how does “The Great Fire of Melbourne” sound to you?

    Does anyone think that The Greens and good science go hand in hand? Does anyone think that The Greens will put ideology aside and look at common sense? Because what will really help urban sustainability is having a few million less people by 2100. The Greens are not interested in that one of course even though anyone with half a brain knows that population is the real problem. How long will The Greens pretend otherwise? Or do they only have a quarter of a brain? I am beginning to think so.