Climate researchers predict that global temperatures will increase by as much as 2 degrees C by 2050 due to growing concentrations of greenhouse gas emissions in the planet’s atmosphere.
But for many of the world’s urban areas, a temperature rise due to the burning of fossil fuels isn’t the half of it.
A new study from the Yale School of Forestry & Environmental Studies (F&ES) projects that the growth of urban areas in the coming decades will trigger “extra” warming due to a phenomenon known as the urban heat island effect
(UHI). According to their findings, urban expansion will cause the average summer temperature in these areas to increase about 0.5 to 0.6 degrees C — but up to 3 degrees C in some locations.
This warming, they show, will increase extreme heat risks for about half of the world’s future urban population — particularly in tropical regions in the Southern Hemisphere, where climate models already project stronger warming due to greenhouse gas emissions and where there is less capacity for adaptation. In these vulnerable regions, the authors argue, policies that restrict or redistribute urban expansion and planning strategies that mitigate UHIs are needed to reduce the effects on human health, energy systems, ecosystems, and urban infrastructure.