Trees Keep Cities Cool

Thursday, February 23, 2017

Road surfaces, pavements and buildings all contribute to keeping urbanized environments hotter than surrounding non-urbanized areas. The urban heat island effect occurs around the clock as dense dark surfaces such as asphalt on roads and building materials accumulate and store heat during the day and then release it at night. One of the simplest solutions to reducing the urban heat island effect is to provide more shade with trees.

Dr Melissa Hart, graduate director of the ARC Centre of Excellence for Climate System Science at the University of New South Wales, takes this issue seriously and added that, "If the minimum temperatures are much warmer at night and not cooling down then that can have health implications”. Hart says. In 2009, 374 people died across metropolitan Melbourne in one heatwave.

To combat this problem, many cities are ramping up tree-planting initiatives. In 2012 Australia's Melbourne City Council vowed to plant about 3,000 new trees every year, doubling the tree canopy cover from 22 percent to 40 percent by 2040. The city of Sydney, Australia has also committed to a 50 percent increase in tree canopy by 2030.

Lighter-colored pavement or green roads, walls and roofs also help keep cities clean and cool.


Learn more about the benefits of urban and community forests at