The heat is on Melbourne, Brisbane and Sydney to increase urban vegetation and prevent scorching summer temperatures.
Regions with higher levels of vegetation are cooler regardless of population density, according to Monash University’s temperature check report.
Researchers compared Sydney’s Liverpool city with a population density of 774 people per sq km to the Northern Beaches with 1076 people per sq km.
They found the Northern Beaches with 63 per cent green cover only experienced a 1.1C heat change across the region.
Meanwhile Liverpool had 4.1C more heat in some areas as a result of a so-called urban heat island and only 33 per cent vegetation cover.
Urban Heat Island effect
^Source: Temperature Check - adapted from City of Parramatta material
Tree cover in Australia’s capital cities declined in every capital city except Hobart between 2013 and 2020, according to the report.
The report, released by the Australian Conservation Foundation, found temperatures could regularly reach 40-50C in cities in a phenomenon known as the Urban Heat Island effect in the next 30 years.
However, these projections are not that far away —in Penrith last year temperatures soared to between 45.6C and 48.9C in suburban versus vegetated areas.
Capital city green infrastructure
^Source: Temperature Check via Hurley, J, et al. 2020
Monash University report co-author Lucy Richardson said tree cover reduced the economic burden of heat-related impacts and the heat differences across cities.
“Heatwaves kill more Australians than any other natural disaster and these will get more severe as our climate continues to change,” Richardson said.
“Protecting and expanding urban vegetation is good for human health and wellbeing, reduces heat-related deaths, creates jobs and helps combat climate change by absorbing more carbon dioxide from the air.
“Our research shows increasing urban vegetation will become essential for our three largest cities—Sydney, Melbourne and Brisbane—to reduce serious heatwave impacts by 2060-2080.
“Natural infrastructure takes time to establish to its maximum effectiveness, so acting early is critical for meeting future needs.”