Green paradise for Australasia

In her song ‘Big Yellow Taxi’, Joni Mitchell laments the destruction of paradise to make way for a parking lot. Over the 50-plus years since the penning of her song, paradise’s footprint has shrunk ever further as our cities grow bigger and urban populations increase. On the upside, many cities, including some in Australasia, are bringing paradise back by clothing the exterior (and interior) of buildings in greenery.

As the uptake of green roofs and walls increases, so does the demand for excellence in their design, installation and maintenance. We have all lamented the demise of a favoured pot plant and wondered what went wrong. When greenery covering an entire building is poorly designed, installed or maintained it will eventually fail, become an eyesore and get pulled down — an outcome that is the opposite of sustainable urban design.

For the most part, the challenges and benefits of transforming cities into greener places are now well understood. An increasing number of buildings in Australia and Aoteroa New Zealand are being clothed with plants. However, the synergy of people and ideas across government, research and the ‘green infrastructure’ sector in Australasia is still limited.

Australian author, journalist and broadcaster Tracey Spicer AM has observed that “sometimes challenges seem enormous, but if you can connect with others working towards the same goal, it becomes more achievable”.

To this end, my colleague Gail Hall and I co-founded a Community of Practice in 2021 to build a network of people across government, academia and industry with a common interest in green infrastructure. In late 2022, we incorporated the Australasian Green Infrastructure Network (AGIN) and along with a core group of volunteers, we have launched a webpage and are preparing for our inaugural annual general meeting.

In addition to growing AGIN over the next 12 months, our volunteers will support the creation of an online knowledge hub. We will make representations to government on the need for better policy supporting the uptake of well-maintained green infrastructure and we will organise an online seminar with international presenters in the second half of 2023.

There are a range of climate-resilient solutions that work hand in hand with green infrastructure. In the Feb–March 2022 edition of Sustainability Matters, the article ‘Cool roofs’ noted the increasing rate of heat-related deaths across more than 500 cities globally due to the ‘urban heat island’ effect. In the article, Professor Mattheos (Mat) Santamouris, of the University of New South Wales, cited a study of ‘super cool’ roofing materials that reduced the surface temperature of a trial roof to just 25°C on a day where the ambient temperature was 42°C.

In some circumstances, a building structure is not capable of supporting a green roof or wall and in those circumstances, super cool roofs provide excellent opportunities to reduce the urban heat island effect. For buildings that can support green roofs and walls, a suite of benefits can be provided in addition to cooling our cities.

Junglefy Roof at Roche, Sydney, NSW. Image credit: Junglefy, ©Remy Brand.

Green roofs can also absorb stormwater when it rains, and green roofs and walls provide habitat ‘stepping stones’ for migratory birds as well as for local birds and insects. When green roofs are combined with solar panels, the ‘bio-solar’ combination improves energy-generating efficiency by 3% on average, and the solar panels provide shade for plants. Green roofs have been shown to improve health and wellbeing of people by filtering air and providing pleasant views.

The cities of tomorrow can look and feel like paradise — we just have to connect with each other in better ways to make it happen.

*Ben Nicholson, together with Gail Hall, is co-founder of the Australasian Green Infrastructure Network (AGIN) — a new peak body formed to bring government, industry and researchers together to facilitate the scalable adoption of green infrastructure such as green roofs, walls and facades in Australia and New Zealand.

Top image caption: Junglefy Breathing Walls at Manly Vale Car Park, Manly Vale, NSW. Image credit: Junglefy, ©Remy Brand.