Highly read on www.agu.org the week of 1 Aug
Urbanization is responsible for roughly 24% of the warming observed in eastern China during the past three decades, thanks to the build up of heat in cities — known as the urban heat island effect.
Baode Chen at the Shanghai Typhoon Institute and his colleagues analysed monthly mean temperature data from 463 meteorological stations in a range of urban and rural settings between 1981 and 2007. Using both raw and reanalysed data, the team found that urbanization contributed up to 44% of the temperature increase (almost 0.4 °C per decade) in metropolises with populations of more than 1 million. The largest increase in the urban heat island effect came after the early 2000s, coinciding with a period of rapid growth of cities in China.