Climate resilient city

The number of days over 40°C is projected to double by 2050. The frequency and duration of heatwaves is project to increase.

In the City of Adelaide, temperatures in the built-up areas can be as much as 8^oC hotter than in the surrounding Adelaide Park Lands (Guan et al., 2013).

The difference in temperature is caused by heat captured in roads, footpaths and buildings, and heat emitted from sources such as vehicles and air conditioning units. This is known as the urban heat island (UHI) effect.

Keeping the city cooler will require more shade, less hard, dark surfaces and higher soil moisture. This can be achieved through well-designed buildings, fewer and narrower roads and hard surfaces, and using light coloured, natural and permeable materials.

Cool Roads

In 2020, the City of Adelaide with Climate-KIC Australia and the Department for Environment and Water (DEW) undertook the Cool Road Adelaide project to test heat reflective seal coats that may help combat urban heat now and in the future.

Three seal coats on the same road (Bowen Street West, Adelaide) were trailed to understand the advantages and disadvantages of the products, taking into consideration urban heat, road preservation and community perception. The seal coats were tested for both land surface and air temperature. The results showed varying success of between a 2.9^oC and 8.7^oC difference in reduced surface temperature.

View the Cool Roads final report.

Cool Roofs

Rising temperatures are creating hotter and drier climate conditions making the city more vulnerable to the urban heat island effect. ‘Cool’ roofs are a climate mitigation and adaptation tool used in various ways and to varying extents worldwide. Whilst the topic is often raised anecdotally or generally there is a lack of clear local research, and clear local advice. Australia wide we lack any standards pertaining to the design or performance of cool roofs.

To build the Council’s knowledge and understanding on the subject, we partnered with the University of Adelaide to undertake a trial and study using a ceramic cool roof coating. Key findings of the Cool Roofing trial were:

• The cool roof coating is shown to reduce the surface temperature of conventional dark roof facing west up to 17°C.
• The cool roof coating resulted in an average air temperature reduction of 1.2°C at 200mm above the roof surface and 1.1°C inside the roof space with insulation below the metal roof sheets and 1.4°C indoor space cooling.
• The cooling impact of the cool roof coating is the highest in warm and sunny weather conditions. With metal having high thermal conductivity and thin profile on roofs, the cooling impact of the coating is reduced in colder ambient temperatures and under cloudy sky.
• This is beneficial since there will be less cooling penalty in colder months of the year than the benefit on the hotter months.
• The cool coating can effectively maintain the indoor air temperature up to 6°C lower than the outdoor air temperature during heatwaves.

Results from the study informed the development of priorities within the Integrated Climate Strategy 2030 adopted by Council in June 2024.

View the Cool Roof Adelaide final report.

Green Infrastructure

We are increasing street tree canopies and green infrastructure, in city hot spots and public spaces, to cool the City. The Council has an annual street tree planting program and has committed to further greening, principally trees, to continue its efforts.

But planting trees can be challenging in some locations due to narrow footpaths, car parking, awnings and verandas, and underground utilities, such as water, electricity, and sewerage, often located in the verge area. Green infrastructure comes in various shapes and forms and could be anything from unique trellises, green walls, planter boxes, arbours and green screening,

Examples of green infrastructure are:

Two structures on the corner of Hutt and Hallifax Street. Trees are unsuitable at this location and these structures are a lightweight tree canopy-shaped trellis in a round planter base. They are three (3) meters tall, and five (5) meters wide at the top, and were planted with chocolate vine (Akebia quinata), which should fill each trellis.

This corner was found to reach temperatures over 47 degrees Celsius, on the 36 degrees Celsius day that the heat mapping fly over was conducted in March 2018. The new 40m2 of canopy that these structures can create, should provide cooling through shade and plant transpiration.

Along Grey Street, there are green screens that demonstrate another alternative way to green and cool the City where trees are not suitable.

With support from Green Adelaide, Council is exploring other alternatives to increase greening in contested streetscapes, such as Gray Street

Natural Grass vs Synthetic

The City of Adelaide undertook a review of natural grass versus synthetic for recreation and sport.

Outdoor sports have traditionally been played on natural grass fields, though over the past few decades synthetic turf has also become popular.

The use of synthetics, however, has caused concern due to associated negative environmental and health impacts. This report explores the benefits and disadvantages of the two surfaces.

The study was conducted through University of Adelaide’s Industry Engaged PhD Program with an intern hosted at the City of Adelaide.

The findings suggest natural grass has multiple health and environmental benefits, while synthetic options can withstand more use. Read more here.

Tree Tags

It’s official, trees are awesome! We all know the relief of finding a cool spot under a tree or walking along a shady, tree lined street on a hot day. Trees are vital for our wellbeing especially in urban areas where there are more hard surfaces, as they provide shade and reduce the impact of radiant heat. That’s why we are planting more trees to keep our City cool and liveable. Through our Tree Tags Project, we have calculated the value of some individual trees and are promoting their benefits to the community.