Sally Gillespie
Global temperatures are rising. And nowhere is this felt more than in cities and suburbs where landscapes can be anywhere up to 10 degrees hotter than nearby rural or coastal areas. This ‘heat island’ effect in urban areas is caused by concrete buildings and asphalt roads absorbing and radiating heat, as well as vehicles and air conditioning units pumping out waste heat. The results can be deadly. When a hot day translates in to a sweltering city, there is a higher rate of hospitalisations and deaths, especially amongst the elderly. In the US and in Australia heatwaves kill more people on average than any other natural disaster.
Australia knows the ‘perfect storm’ of heatwave conditions very well. One day in January last year, the Western Sydney suburb of Penrith recorded a temperature of 48.9 degrees, the hottest temperature on Earth that day, while Canberra clocked in at 44 degrees. More and more over 40 degree temperatures are being recorded in Melbourne and Adelaide. Increasing heatwaves are a call for all of us to act. Not only in terms of increasing pressure on Governments for more effective and committed policies to lower greenhouse gas emissions that cause global heating, but also by getting behind initiatives to green our cities and suburbs.
Trees and other plantings have a substantial cooling effect on streets, as anyone who walks down a shady avenue on a hot day will experience. In addition, vegetation in cities and gardens reduces the effects of noise and glare creating a calming, natural setting which benefits mental and emotional wellbeing. Plants absorb carbon dioxide and other pollutants, exchanging them for revivifying oxygen. They also slow down stormwater flows, while providing habitat, food and safety for wildlife. The benefits of greening our cities and streets are many and systemic.
If we want to cool down, we need to be planting everywhere. Gardens, parks, street verges, green rooftops and walls, balcony pots and street planter boxes, all bring down temperatures and help keep moisture in the air, making our home, cities and suburbs more live-able and healthier places. Increasing vegetation also reduces the need for air conditioning saving many dollars and greenhouse emissions.
All cities in Australia now have policies to increase their tree canopies. You can support this movement to green our cities by encouraging your local Council to plant more, and by giving them positive feedback about any greening work they do carry out. There are so many unloved bits of land in our streets and around apartment buildings which are calling out for some attention and life in the form of plants. Talk to your neighbours about getting together to create green oases in your street or apartment complex. And look around your own garden and balconies to see how you can increase green canopy and planting density. Your home and neighbourhood will become cooler, healthier and friendlier when surrounded by trees, shrubs, grasses, flowers and vegetables.
To become more engaged with initiatives to cool and green our cities you can:
Fill out the survey on the Sweltering Cities website about your experience of heat in your city https://swelteringcities.org/community-survey/
Checkout gardening information at https://www.sgaonline.org.au/what-gardeners-can-do-about-climate-change/
