Contribution of future urbanization to summer regional warming in the Pearl River Delta

The impact of future urbanization on regional climate change in the Pearl River Delta (PRD), one of the largest urban agglomerations in China, has been a major concern. A new generation of future urban expansion projection data provides a guideline for exploring the above question. In this study, future urban expansion data are used with the Weather Research and Forecasting (WRF) model to explore and quantify future temperature change in the PRD in 2030 and 2050. The results show that the urban area will expand from 15.37% to 25.21% and 26.93% over the entire PRD in 2030 and 2050, respectively. The PRD urban agglomeration warms by 0.49 ± 0.14 °C in 2030 and 0.53 ± 0.12 °C in 2050, with warmer nights than days. The outgoing radiation rises by 10.28 ± 2.82 W·m−2 in 2030 and 11.18 ± 2.67 W·m−2 in 2050. The latent heat flux decreases by 39.81 ± 5.64 W·m−2 in 2030 and 44.71 ± 6.21 W·m−2 in 2050. The sensible heat flux increases by 38.45 ± 7.05 W·m−2 in 2030 and 42.43 ± 7.5 W·m−2 in 2050. Urbanization changes the physical properties of the urban surface, causing an increase in surface outgoing radiation and turbulent heat flux, eventually resulting in the warming of the PRD urban agglomeration.