‘Green cover’ refers to a broad range of strategies to integrate green, permeable and reflective surfaces into cities and towns, which are home to 89 per cent of our population.
Surface temperatures in urban areas can be 10°C to 20°C higher than in the air temperatures because buildings, roads and other hard surfaces absorb and store heat. High temperatures, due to climate change, will further intensify the impacts of urban heat.
A thermal image at the corner of Jones and Thomas Street looking towards Central Park Tower, Chippendale, Sydney. Numbers on the temperature scale indicate degrees Celsius. (Photograph: courtesy of Jonathan Fox, UNSW).
Unlike hard surfaces, trees and vegetation (sometimes called green infrastructure) provide shade, and cool and clean the air by evapotranspiration. Other benefits are better health and wellbeing for urban-dwellers, more biodiversity and wildlife in urban areas, and better regulation of localised flooding.
Types of urban green cover include bushland, private and community gardens, parks, greenways, habitat corridors, street trees, roof gardens and plant-covered walls, as well as reflective and permeable walls, pavements and other surfaces. Protecting local green spaces, designing eco-friendly buildings and creating urban networks of green space can help to minimise the impacts of urban heat in our cities and towns.
|Green and cool roofs have surfaces that are vegetated, light coloured or reflective.||
Green walls are vegetated systems grown on the vertical walls of a building.
New green cover resources
In partnering with Clean Air and Urban Landscapes (CAUL) Hub, we have delivered a baseline dataset to assess urban heat and green cover in the Sydney Greater Metropolitan Area.
With information on urban heat and green cover in their area, planners and policy makers can assess opportunities to adapt urban areas to create more liveable cities.
We are providing tailored data to assist local decision makers understand and monitor vegetation cover (trees and shrubs) in local government areas. This enables decision makers to:
- Examine green cover at street level in their districts and measure their progress towards urban greening targets.
- Monitor changes in vegetation cover over time using satellite imagery and determine impact on surface temperatures in different urban spaces, including commercial precincts, industrial estates, residential areas and parklands.
The Urban Heat and Green Cover Baseline Assessment has mapped urban vegetation and tree canopy cover down to the street level across the Sydney Greater Metropolitan Area, Summer 2015/16.
Data from the Urban Heat and Green Cover Project is made available through the NSW Government’s Sharing and Enabling Environmental Data portal (SEED).
Please visit the SEED portal to access datasets on urban vegetation cover, land surface temperatures and areas of heat vulnerability.
Other green cover resources
- The NSW Government has produced Technical Guidelines for Urban Green Cover in NSW to provide practical advice on best practice. The purpose of these guidelines is to increase the resilience of NSW settlements and communities to climate change, specifically to increasing temperatures in urban settings.
- School microclimates report – developed in partnership with NSW Government, Western Sydney and Macquarie Universities, this resource provides practical suggestions to manage the impacts of heat on children’s physical health and learning capacity in outdoor environments.
Landscape design principles:
- The Green Cover Demonstration Project, led by us in collaboration with the NSW Government Architect’s Office, showcases leading landscape design principles for urban green cover.
Comparing urban micro-climates:
- The Urban Micro Climates study, by Urban Climates Research in collaboration with the CRC for Low Carbon Living, compares micro-climates in Sydney, Melbourne and Adelaide on architectural, precinct and city scales.
Policy and planning decision-support tool:
- With support from the CRC for Low Carbon Living, University of New South Wales’ High Performance Architect Research Cluster is developing an Urban Heat Island Mitigation Decision Support Tool to inform policy and planning practices related to interventions for mitigating urban heat.
Networks and related projects
- Clean Air and Urban Landscapes Hub – Takes a holistic view on the sustainability and liveability of urban environments, to help deliver better cities.
- NSW Department of Planning and Environment’s Greenfield Housing Code – Sets out the requirements for landscape areas which can support urban tree canopy.
- Five Million Trees (5MT) – Another NSW Government initiative which aims to plant five million trees for a greener Sydney by 2030.
- Greener Spaces Better Places - A national initiative that brings together academia, business, government, community groups and the green industry to share knowledge and work together to grow our green spaces.
- Government Architect NSW’s Sydney Green Grid – Maps out the network of high-quality green space in Sydney that connects town centres, public transport hubs, and major residential areas.
- Greater Sydney Commission – Aims to increase urban tree canopy to create a Greater Sydney Green Grid and connect communities to the natural landscape as part of its A Metropolis of Three Cities plan.
- Wollongong City Council – Developed an Urban Greening Strategy 2017-2037 to improve the amenity and liveability of urban spaces during a time of significant urban renewal and growth.
- World Green Infrastructure Network (WGIN) – Promotes the use of green infrastructure in cities.