Things are hotting up in the city, literally, with new research from the weather bureau showing that urbanisation is pushing Melbourne’s daytime temperatures higher.
Climate scientist Belinda Campbell, who used 100 years of temperature data for her study, found that Melbourne’s skyscrapers, homes and roads are adding about .5 degrees to the daily maximum temperature.
“We knew that night time temperatures have been warmer because the heat’s retained after sunset,” she told The Age.
“But what we didn’t know was whether city daytime temperatures were also because of urbanisation or whether it was due to the overall warming of the planet associated with the enhanced greenhouse effect.
“We can know confidently say the reason our cities are warmer and warming faster than the surrounding countryside during the day is because of the urbanisation.”
The findings confirm earlier research on the ‘heat island effect’, which describes how Melbourne’s built environment, its roads and buildings and lack of parkland and water, trap daytime heat. Research done at Monash University in 2004 showed the CBD could be three degrees hotter than outlying areas.
But Ms Campbell said that gap is widening. When Melbourne’s daily maximum temperatures were compared with Ballarat, Laverton and 73 other weather stations across the country, the results clearly showed the inner city was getting hotter at a faster rate than the country locations.
The bad news for cityfolk doesn’t end there. Nicholas Low, professor of environmental planning at the University of Melbourne, said unless local councils and the state government start introducing measures to cool the city down, city-folk are doomed to live an ever-hotter environment.
“There’s not much you can do about it because buildings in the central city store heat just like a heat bank, so it’s bound to get hotter,” said Professor Low.
He said if there was a solution “it’s partly a planning issue and partly a building issue”.
“Buildings need to try to diminish their dependence on air conditioning and therefore consider things like green roofs. Natural cooling systems are going to be very important in the future.”
For Professor Low, the solution could lie with local councils, which he said need to work hard to protect their parklands “or if possible extend them”.
“I don’t think drastic action is needed, but constant vigilance to try to protect green spaces in cities is extremely important.”
