Australia's Cities Getting Hotter by 3.7 Degrees

Some areas of Australia's cities will be up to 3.7 degrees hotter by 2050 due to the growth of urbanisation according to new research data

Australia will experience the "urban heat island effect" in which temperatures will rise in built-up areas with more asphalt and concrete. Researchers from the University of NSW say the rising temperatures will enhance the effects of climate change.

Lead author of the study Daniel Argueso says if a person lives near the edge of the city, a change in temperature may be observed particularly during the night. The researchers completed the study at the Centre for Excellence in Climate System Science.

Researchers also found evidence that urban canyons cause winds to stop moving around freely to cool the things on the surface.

For decades, scientists have been observing the effects of urban heat. They say one simple way of testing city temperature is to touch the surface of a brick wall under the heat of the sun and check if it remains warm throughout the night.

Artificial structures especially in the city areas can retain and absorb heat longer than undisturbed natural soil or rocks. Artificial structures absorb less moisture which means they don't cool fast enough through evaporation.

Cities in general also give off more heat due to greater road traffic density, electrical generators and industry activity. All of these when combined can generate heat and remain in the air for extended periods.

According to University of NSW's paper, Temperature Response to Future Urbanisation and Climate Change, the ground heat flux cycle rarely changes in surrounding areas but it increases significantly over highly urbanised areas.

The data of the study validates the picture of a surface with an increased in heat storage capacity in which ground heat is released during the night.

Researchers made use of climate models to forecast future changes in temperature for the entire Australia and cross-referenced data with urban planning models.

NSW researchers say changes in temperature can be observed throughout the year but peak temperatures are noticeable especially during the winter and spring. Researchers propose planting more trees within the cities and building more parks.