In rapidly warming cities, it's the poorer suburbs that are most at risk

Children play in a New York heatwave. Image: Getty.

Australian cities are getting hotter. The many reasons for this include urban densification policies, climate change and social trends such as bigger houses and apartment living, which leave less space for gardens and trees. But some areas and some residents of cities are more exposed to heat than others.

The concentration of poorer people in hotter places is known as “thermal inequity”. Our recently published research has found this is a real concern on the Gold Coast, one of Australia’s fastest-growing urban regions.

Urban heat is known to increase rates of injury, death and disease. This is why the federal government recently established an urban greening agenda.

The central city tends to be hotter than surrounding suburbs and rural areas – the urban heat island effect. Perhaps because of this, much of the research focus has been on the urban core. But what about heat effects in the suburbs?

What is thermal inequity?

Research from North America and Australia shows people who live in greener, leafier suburbs tend to be wealthier. We know that urban greening can cool ambient air temperatures.

Plentiful street trees, well-designed parks and other types of green space also tend to increase residents’ physical activities and social interactions. This makes greener neighbourhoods healthier and happier.

Unfortunately, the opposite often occurs in poorer suburbs, meaning residents suffer more heat stress. This is a consequence of fewer street trees, less green space and denser urban design. Our research found thermal inequity is a real concern in Upper Coomera, a suburb in the northern growth corridor of Gold Coast city.

The Gold Coast has been coping with explosive rates of growth. The population is expected to double to more than 1m in the next two decades. Growth-management policies are increasing densities in many suburbs.

On the suburban fringe in places like Upper Coomera, land clearing for development typically removes much of the native vegetation. This in turn increases heat.

The trend in the Gold Coast, like many cities, is for comparatively disadvantaged people to seek more affordable housing in outer suburbs. Less affluent householders become concentrated in suburbs where housing is packed tightly with fewer trees and less greenery.

Hotter houses and neighbourhoods lead to residents paying more for electricity to keep cool. Excessive heat can also increase healthcare expenses and reduce productivity.

Research shows residents are struggling

As we explain in the video abstract for our article, we used a mail-back survey of 1,921 households to examine three questions:

1) Are residents aware of climate change?

2) Are residents concerned about climate change?

3) Do residents understand the potential of green infrastructure to help neighbourhoods adapt to climate change?

Video abstract for Environmental Research Letters article on thermal inequity.

We found more than 90 per cent of residents were aware of climate change and almost 70 per cent were concerned about it. Residents living in townhouses were particularly worried. Paradoxically, those living in dwellings with dark roofs were less worried, as were those with larger families.

We also found that more than 90 per cent of respondents had air conditioning. Using statistical analysis, we determined that renters are especially vulnerable to associated energy costs, as are those with kids.

Interestingly, we found that people living in townhouses were less likely to consider buying energy-efficient devices to lower household energy expenses, as were those with more children. This could be because renters and those with larger families may be struggling financially.

In sum, we found that more disadvantaged households with less disposable income were living in dwellings that were more vulnerable to heat.

Next, we examined the attitudes of residents to urban greening to help combat heat in their neighbourhood. We found almost two-thirds favoured tree planting. More than half felt local streets lacked shade.

Few trees to be seen: residential landscapes in Upper Coomera. Image: Jason Byrne/author provided.

While 90 per cent of surveyed residents saw that shade was a key benefit of trees, just over half understood that trees can lower air temperatures. Although most residents recognised maintenance costs of trees as a disadvantage, they still favoured more urban greening.

So what can be done?

Our findings have important repercussions for urban policy. As we have previously noted, urban greening has many advantages for climate change adaptation. It is comparatively inexpensive and is politically palatable.

However, higher-density neighbourhoods like Upper Coomera often have less land available for greening. Yards are smaller and verges are typically dominated by on-street parking.

We advocate for education campaigns about the benefits of urban greening and better urban design guidelines to make it easier for developers to increase neighbourhood greenery. Better knowledge about species selection is needed to reduce maintenance issues.

Urban greening initiatives should also use technologies like permeable paving to limit pavement uplift and capture rainfall on-site.

Thermal inequity exists but it can be reduced. After all, if urban greenery can benefit all residents, why should the poor miss out?

The authors wish to acknowledge the contribution of Chloe Portanger, Information Analytics Specialist with Climate Planning, to the research on which this article is based.The Conversation

Jason Byrne is associate professor of environmental planning at Griffith University. Tony Matthews is a lecturer in urban & environmental planning, Griffith University.

This article was originally published on The Conversation. Read the original article.


Coming soon: CityMetric will relaunch as City Monitor, a new publication dedicated to the future of cities

Coming soon!

Later this month, CityMetric will be relaunching with an entirely new look and identity, as well as an expanded editorial mission. We’ll become City Monitor, a name that reflects both a ramping up of our ambitions as well as our membership in a network of like-minded publications coming soon from New Statesman Media Group. We can’t wait to share the new website with you, but in the meantime, here’s what CityMetric readers should know about what to expect from this exciting transition.  

Regular CityMetric readers may have already noticed a few changes around here since the spring. CityMetric’s beloved founding editor, Jonn Elledge, has moved on to some new adventures, and a new team has formed to take the site into the future. It’s led by yours truly – I’m Sommer Mathis, the editor-in-chief of City Monitor. Hello!

My background includes having served as the founding editor of CityLab, editor-in-chief of Atlas Obscura, and editor-in-chief of DCist, a local news publication in the District of Columbia. I’ve been reporting on and writing about cities in one way or another for the past 15 years. To me, there is no more important story in the world right now than how cities are changing and adapting to an increasingly challenging global landscape. The majority of the world’s population lives in cities, and if we’re ever going to be able to tackle the most pressing issues currently facing our planet – the climate emergency, rising inequality, the Covid-19 pandemic ­­­– cities are going to have to lead the way.

That’s why City Monitor is going to be a global publication dedicated to the future of cities everywhere – not just in the UK (nor for that matter just in the US, where I live). Our mission will be to help our readers, many of whom are in leadership positions around the globe, navigate how cities are changing and discover what’s next in the world of urban policy. We’ll do that through original reporting, expert opinion and most crucially, a data-driven approach that emphasises evidence and rigorous analysis. We want to arm local decision-makers and those they work in concert with – whether that’s elected officials, bureaucratic leaders, policy advocates, neighbourhood activists, academics and researchers, entrepreneurs, or plain-old engaged citizens – with real insights and potential answers to tough problems. Subjects we’ll cover include transportation, infrastructure, housing, urban design, public safety, the environment, the economy, and much more.

The City Monitor team is made up of some of the most experienced urban policy journalists in the world. Our managing editor is Adam Sneed, also a CityLab alum where he served as a senior associate editor. Before that he was a technology reporter at Politico. Allison Arieff is City Monitor’s senior editor. She was previously editorial director of the urban planning and policy think tank SPUR, as well as a contributing columnist for The New York Times. Staff writer Jake Blumgart most recently covered development, housing, and politics for WHYY, the local public radio station in Philadelphia. And our data reporter is Alexandra Kanik, whose previous roles include data reporting for Louisville Public Media in Kentucky and PublicSource in Pittsburgh, Pennsylvania.

Our team will continue to grow in the coming weeks, and we’ll also be collaborating closely with our editorial colleagues across New Statesman Media Group. In fact, we’re launching a whole network of new publications this fall, covering topics such as the clean energy transition, foreign direct investment, technology, banks and more. Many of these sectors will frequently overlap with our cities coverage, and a key part of our plan is make the most of the expertise that all of these newsrooms combined will bring to bear on our journalism.

City Monitor will go live later this month. In the meantime, please visit to sign up for our forthcoming email newsletter.

As for CityMetric, some of its archives have already been moved over to the new website, and the rest will follow not long after. If you’re looking for a favourite piece from CityMetric’s past, for a time you’ll still be able to find it here, but before long the whole archive will move over to City Monitor.

On behalf of the City Monitor team, I’m thrilled to invite you to come along for the ride at our forthcoming digs. You can already follow City Monitor on LinkedIn, and on Twitter, sign up or keep following our existing account, which will switch over to our new name shortly. If you’re interested in learning more about the potential for a commercial partnership with City Monitor, please get in touch with our director of partnerships, Joe Maughan.

I want to thank and congratulate Jonn Elledge on a brilliant run. Everything we do from here on out will be building on the legacy of his work, and the community that he built here at CityMetric. Cheers, Jonn!

In the meantime, stay tuned, and thank you from all of us for being a loyal CityMetric reader. We couldn’t have done any of this without you.

Sommer Mathis is editor-in-chief of City Monitor.