Impacts of land-use change on Sydney's future temperatures: Matthew Adams, Hiep Duc and Toan Trieu 2015
Cities create their own microclimates through influencing the surrounding atmosphere and interacting with climate processes. The most striking characteristic of an urban microclimate is the urban heat island (UHI) effect. The UHI effect results in higher air temperatures in urban areas (2–5°C higher on average but in some cases more than 10°C higher) than those in surrounding non-urban areas (Taha 1997). In Sydney, morning summer surface temperatures in treeless urban areas are on average 12.8°C higher than treed non-urban areas (Adams & Smith 2014). This phenomenon is expected to increase in Sydney due to a growing majority of the NSW population residing in urban areas. According to Taylor et al. (2014), in the years 2011–31 Sydney’s population is expected to rise by over 1.5 million (37%). This population increase is expected to lead to an increase in households of 600,000 (40%). By mid-century, global average temperatures are projected to rise by 0.9–2.6°C in response to unmitigated anthropogenic greenhouse warming (IPCC 2013). Given this, many people in NSW may be exposed to average maximum temperatures several degrees warmer than those currently experienced in adjacent rural areas today.