Mortality burden of heatwaves in Sydney Australia is exacerbated by the urban heat island and climate change: can tree cover help mitigate the health impacts?

Abstract

Health Impact Assessment methods were applied to quantify the mortality burden of heatwaves in Sydney Australia, and assess the contribution of the Urban Health Island (UHI) effect to this burden. Using high resolution satellite observations to calculate UHI air temperature excesses and green cover, effects on heat-related mortality were determined. From future climate projections, mortality reduction benefits were estimated from green tree cover. Results show that >90% of heatwave-deaths could be prevented by removing the UHI. Tree canopy reduces urban heat and widespread tree planting could offset the increases in heat attributable deaths as climate warming.