Bringing down the heat in our ‘hood

Aslan Shand

How well we survive the future depends on our vision for our towns and suburbs – and on how we bring that vision about.

Increasing population in the Northern Rivers is leading to an increase in housing, traffic, and roads, all of which increase the number of hard, non-porous surfaces. These harder surfaces absorb heat and increase the temperature in towns and urban areas, as well as increase flooding.

It is easy to feel the heat impacts with a trip to a large shopping-centre precinct. On a hot day you can feel the heat pulsating off the buildings, roads, and car parks.

Inferior development increases heat

As climate change increases the overall global temperature, the heat in urban areas will continue to rise if there is no action to manage the situation. The same impact is beginning to be felt in smaller towns of the region as higher land values and the value of development increases pressure for housing and business centres.

From traffic congestion and arguments over the value of planting trees vs car parking in Mullumbimby, to the multiple developments now on the cards near the Mercato in Byron Bay – that emphasise filling the sites with flats and shops – to the removal of established trees such as the forest red gum in Tweed Heads West – the value, and risks, of trees and green spaces in our urban environments are being debated.

Issues of ibises roosting in, and defecating from, the forest red gum in Tweed and tree limbs falling were key concerns raised by Tweed Councillor Warren Polglase, who was seeking the removal of the tree. Yet the value of a mature tree in an urban landscape is considerable from the oxygen it produces to the temperature reduction it provides.

Trees are a vital component of keeping our towns and cities cool and liveable, according to WA urban designer Peter Ciemitis, who was quoted in the Architecture and Design website earlier this year.

‘Our cities continue to reach extreme temperatures, and bushfires are occurring more frequently year on year,’ Mr Ciemitis said. ‘There is a growing urgency to mitigate the urban heat island effect, and tree canopies are a vital component to ensure we can reduce temperatures across the country.

Heat and death

‘The Black Saturday bushfires in 2009, for example, sadly resulted in 173 [human] deaths; however, many are unaware that 374 deaths occurred due to heat [stress] during that same week.’

The recent drought, followed by the unprecedented Black Summer fires of 2019/20 have only emphasised these issues. Yet as we seek to create more sustainable towns and cities, green cover in urban areas has declined by 69 per cent in Australia, notes the 202020 Vision benchmarking report that has been tracking the issue since 2014.

Mr Ciemitis also highlighted that ‘suburbs in Sydney’s west grow hotter every year, with some areas reporting temperatures above 50 degrees’.

Nocturnal lives?

Solutions vary from actually taking action on climate change to greening your back yards and planting trees that shade streets. Others include changing our habits to adopt the lifestyles of people in hot European and Asian countries; such as staying indoors during the day and socialising in the evenings, as one way to cope.

However, there are also planning solutions that have the potential to facilitate change if federal, state, and local governments are able to recognise the issues and seek solutions.

Presenting to the WA Local Government Association’s ‘Trees in a Liveable City: An Urban Forest Conference’ Mr Ciemitis and WA planner, Dan Pearce, shared a number of recommendations for increasing urban tree canopies and green spaces. These included recognising the value of existing trees at future development sites and working to retain them on public land.

Create green spaces

As backyards decrease, owing to high-density development, and as infill proceeds they suggest planning for more ‘destination parks’. Finally, there is also the option to minimise tree removal and get the community active in increasing urban canopy.

The effectiveness of green and tree cover was recently highlighted in a report from Macquarie University looking at temperatures in Adelaide during a heatwave in 2017. The analysis ‘suggests urban trees and grasses can lower daytime land temperatures by up to 5-60 during extreme heat.’

The study’s authors say ‘that a simple solution to extreme heat is literally at everyone’s doorstep. It relies on the trees, the grasses and the vegetation in our own backyards.’

Similarly, making our towns liveable will rely on us, as communities, to come together to reduce climate change, and create ways of sustainable living into the future.

A first step could be having green-street visions for the future. Then perhaps we could look at getting cars off our streets with park-and-rides?