The Changes in Heating and Cooling Energy Demand in Beijing and Shanghai under Global Warming

Abstract Climate change significantly influences electricity and energy demand, yet a comprehensive understanding of heating and cooling energy demand in China’s major cities under the impact of global warming remains incomplete. This study utilized monthly electricity consumption and mean air temperature data to accurately determine the base temperatures for Beijing and Shanghai, identified as 18.94° and 19.54°C, respectively. We further established the heating degree-day (HDD) and cooling degree-day (CDD) indices for both cities over the period from 1961 to 2020. The results indicate a declining trend in winter heating demand and an increasing trend in summer cooling energy demand in both Beijing and Shanghai from 1961 to 2020. Notably, the decrease in winter heating demand exceeds the increase in summer cooling demand for each city. The findings indicate a higher sensitivity of electricity demand to temperature in Beijing during summer (+3.5519 TWh °C −1 ) compared to winter (−1.5706 TWh °C −1 ). Similarly, in Shanghai, temperature sensitivity is higher in summer (+5.1133 TWh °C −1 ) than in winter (−1.7133 TWh °C −1 ). This high sensitivity during the summer months implies an overall increase in future energy demand. While Beijing demonstrates a higher demand for winter heating compared to Shanghai, its demand for summer cooling is comparatively lower. Nevertheless, due to Shanghai’s greater sensitivity of electricity demand to temperature compared to Beijing, it is projected that Shanghai’s total energy demand will exceed that of Beijing in the future. Significance Statement Climate change alters the demand for electricity and energy, and a comprehensive understanding of heating and cooling energy demand in China’s megacities under global warming is yet to be attained. By calculating the heating and cooling degree-day indices in Beijing and Shanghai, but using real base temperatures, these indices provide a comprehensive resource for exploring the changes in heating and cooling energy demand in Beijing and Shanghai against the background of global warming. Our study shows a decreasing trend in winter heating demand and an increasing trend in summer cooling energy demand for Beijing and Shanghai from 1961 to 2020, and the total energy demand in Beijing and Shanghai will still increase in the future.