Assessing the potential of large-scale urban forest projects as a natural climate solution

Urban forests are considered a nature-based solution for climate change by cities and countries worldwide. However, the effectiveness of large-scale urban forest projects as a natural climate solution has been rarely assessed. In this study, we utilized a unique opportunity from Beijing's actions to implement a large urban forest project since 2012 to examine the effectiveness of the proposed solution. We collected vegetation structure data in two extensive field surveys to track the growth of the newly formed urban forest. Using field data and allometric equations, we estimated carbon sequestrated by the urban forest. We found that between 2013 and 2020, the urban forest grew rapidly, with the average increase of DBH and height reaching 0.95 cm and 0.47 m annually, respectively. The 16,667 ha of trees and shrubs sequestrated 423,074 tons of carbon in ten years, or 42,307 tons annually. The result showed that large-scale urban forest projects have the potential to be used as a natural climate solution (NCS). Nevertheless, planning and developing specific management techniques are needed to fully realize this potential.