The recently published National Climate Risk Assessment delivers confronting predictions of Australia’s environmental future.
The report highlights the far-reaching risks that climate change poses to Australia’s future, with specific attention on urban environments, the escalating threats from heatwaves, sea levels rising accompanied by coastal flooding, and increasing weather variability.
These impacts are expected to place mounting pressure on the nation’s economy, infrastructure and public health, with projections indicating that heat-related deaths in Sydney alone could rise by up to 444 per cent and in Melbourne by 259 per cent.
The assessment's findings reveal the increased vulnerability of urban environments, where rising temperatures are compounded by the urban heat island (UHI) effect. This phenomenon occurs in densely built environments, where hard, dark surfaces, such as concrete, roads and
buildings, absorb and store heat, preventing the environment from cooling down and creating a localised warming ‘bubble’.
This effect is further intensified by human activity, including high
energy consumption from vehicles and air conditioning, compounded by the scarcity of vegetation, large green spaces and tree canopy cover.
Professor Sebastian Pfautsch and colleagues from Western Sydney University (2025) sought to quantify the rate of the urban heat island effect in Sydney by examining the variation and severity of urban heatwaves. His analysis of historic air temperature records revealed a striking trend: between 2000 and 2020, the Greater Sydney Region experienced more ‘hot’ days (exceeding 35°C) than during the entire preceding 120
years combined.
Urban heating is intensifying at an alarming rate, raising urgent concerns for the future of our cities. The pressing question is: How can we slow this trend? Which strategies can help lessen these impacts and protect communities from the growing threats of climate change?
Urban green spaces taking off the heat
Urban green spaces have become a crucial strategy to mitigate heat in built environments, a role increasingly supported by ecological and climate adaptation research. However, many green spaces have been designed primarily around aesthetic values, often dominated by grass and isolated trees, with limited attention to habitat complexity and species diversity (Aronson et al., 2017).
Which plants help the most?
Research highlights that not all forms of urban vegetation contribute equally to cooling or biodiversity outcomes. Duncan et al. (2019) found that urban vegetation, particularly shrubs and trees, provide a substantially greater cooling effect than grass.
Shrubs, in particular, offer a more practical solution for mitigating urban heat, as they grow quickly, thrive in smaller spaces and cool down environments through evapotranspiration, making them a more accessible option for urban cooling when compared to trees (Duncan et al., 2019).
Added impact: Helping biodiversity
Studies demonstrate that multi-layered plantings, which combine trees with shrubs and understory vegetation, also support significantly greater invertebrate abundance and pollinator diversity than tree-only plantings (Sharmin et al., 2024). The incorporation of native flowering plants plays a crucial ecological role for all local urban fauna, not just in cooling environments, but providing food, shelter, and nesting sites for animal communities, including pollinators such as native bees, birds, butterflies, and bats (Threlfall et al., 2015).
Pollinators are essential to urban ecosystems, ensuring native plants and flowering species continue to flourish (Theodorou et al., 2020). By moving pollen between fragmented city landscapes and allowing isolated plant populations to reproduce, pollinators work to boost urban resilience and stitch habitats together, preserving vital genetic diversity (Płaskonka et al., 2024).
Protecting them isn’t just good science, it’s part of our responsibility to create greener, healthier and more sustainable cities.
Some cool ground rules
Some strategies to help cool the environment and foster biodiversity:
- Diversify vegetation beyond canopy trees. Native shrubs can be strategically planted in median strips, small gardens, rooftops, and other under-utilised spaces that do not interfere with recreation or urban infrastructure.
- Maintaining open grassy areas for recreation alongside these plantings ensures that urban greening supports both human well-being and ecological resilience. Companies and property
owners can also play a significant role in cooling our cities by incorporating features such as roof gardens, green terraces, and vertical garden walls.
- Urban cooling and climate mitigation extend far beyond greenery. Cities and built infrastructure can also harness wind corridors to improve airflow, install cool roofs and reflective materials to reduce heat absorption, adopt permeable surfaces to manage stormwater and lower surface temperatures, and transition to clean energy systems to cut emissions (Amjad Azmeer et al., 2024; Ferrari et al. 2020).
Together, these strategies create a multi-layered approach that not only combat urban heat but also enhance sustainability, liveability, and resilience in our rapidly warming urban environments.
Unfortunately, as highlighted in the 2025 Climate Risk Assessment, we are still far from effectively reducing global heat and mitigating the impacts of climate change.
Yet discussing these issues with urgency and generating actionable ideas to address them is just as critical.
Open dialogue, innovative solutions, and proactive planning are essential if we are to slow warming, protect communities, and build more resilient urban environments.
Article by Audrey Bell & Sylvette Robinson
Photo by Mike Greer: https://www.pexels.com/photo/woman-holding-plant-1390371/
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