Is urbanisation also the culprit of climate change? – Evidence from Australian cities

Abstract

In this study, daily maximum and minimum air temperature (Tmax and Tmin), evaporation and rainfall data (1960–2011 period) were analysed for three Australian metropolitan cities, viz., Sydney, Melbourne and Brisbane, to understand whether urbanisation has influenced temperature, evaporation and rainfall in these cities and thus had an influence on the longer-term local climate variability. A total of nine key locations in each city were considered and one location in each city was a control. A modified segmented regression analysis was employed to understand the overall climate change and linear regression analysis to evaluate the impacts of urbanisation.The study indicates a significant overall climate change during the 1986–2011 period when compared with the 1960–1985 periods, and urbanisation added to the overall climate change. There were statistically significant increases in Tmax and Tmin for Sydney and decreases for Melbourne, decrease in Tmax and increase in Tmin for Brisbane. On the other hand, evaporation values decreased for Sydney and Brisbane but increased for Melbourne. There was a statistically significant increase in rainfall for Brisbane only. The study suggests that climate change adaptation strategies and policies need to consider urbanisation, alongwith greenhouse gases, to cope with future climate change scenarios.