Visiting green spaces can reduce considerable carbon emissions during summer: Evidence from Chongqing, China

Outdoor activities can reduce the time residents spend at home, which can reduce their power consumption resulting from the usage of air conditioning, electric fans, and other electrical facilities, especially in hot summers. This study aims to investigate whether and how much power consumption can be saved by visiting green spaces (VGS) during summer, which is converted into carbon emission reduction (CER) to compare with the carbon sink by vegetation. Taking Chongqing, a famous furnace city in China, as an example, questionnaire surveys and visitor records were conducted to investigate visitors' activities in urban parks and their cooling methods at home. The results showed that: 1) The average time of VGS for each respondent was 1.66 h, and the CER generated by the VGS of 469 respondents was 144.56 kg per day. The carbon emission reduction factor of the VGS was 0.187 kg/person/h. A total of approximately 25.90 t carbon emissions, which was approximately equivalent to the carbon sink by vegetation in one year, could be reduced in Shaping Park in one summer. 2) People aged 55-64 had the highest daily CER (0.35 kg/person) due to the longer disposable time that allowed them to spend in the parks. Males had a higher CER than females. 3) Shaded chess squares had the highest daily CER of 34.25 kg, with large areas of tree-shaded space. 4) Combination of spatiotemporal behavior showed that elderly individuals playing chess games in shaded chess squares could generate the maximum CER in the urban park. This study provided some references for urban planners and landscape designers to design green spaces that can attract more visitors and longer stays, thereby achieving more power savings and corresponding carbon emissions.