Estimating The Cooling Potential Of Irrigating Green Spaces In 100 Global Cities With Arid, Temperate Or Continental Climates

Modern agricultural irrigation can produce extensive cooling that is strong enough to mask the current effect of global climate change. Irrigating urban green spaces therefore has the potential to mitigate heat stress in cities. However, the cooling potentials of irrigating urban green space in different climate regions of the world have never been estimated. Here we conducted a systematic literature review to determine air temperature reductions in past experimental, observational and modelling studies (N = 17). We developed an empirical model with the irrigation cooling effect as the dependent variable and background air temperature and rainfall of the study area as the independent variables. The model was subsequently used to estimate the cooling potential of irrigating green spaces in 100 global cities with arid, temperate and continental climates. We predict that 91 of the 100 cities will receive a cooling benefit from irrigating urban green space (mean = 1.09 degrees C), whereas the remaining nine cities will experience a slight warming effect (mean = +0.76 degrees C). The cooling potential of irrigating urban green space is greatest in arid cities (mean = 1.65 degrees C).