Abstract
Cities around the globe search for solutions to tackle the challenges of climate resilience and energy consumption. The potential of green roofs representing a nature-based solution in mitigating urban heat and related energy consumption at the urban scale is given limited attention. Here we apply a comprehensive framework integrating urban climate modeling, urban building energy modeling and statistical analysis with empirical data to address this research gap through a case study in Seoul. The findings highlight that the efficacy of nonirrigated extensive green roofs is significantly influenced by meteorological conditions, underscoring the importance of considering those factors in green-roof design and implementation. Moreover, the cooling effect of green-roof implementation at the urban scale causes monthly urban building energy use intensity reductions of up to 0.64 kWh m−2 (7.7%). The insights from this research have broad implications for cities around the world experiencing the challenges imposed by urban heat.
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Data availability
The ERA-Interim reanalysis dataset for WRF simulations was accessed from https://rda.ucar.edu/datasets/ds627.0/dataaccess/. Building properties such as total floor area, height and number of floors, essential for the development of the urban building energy model, were collected from the official building registry (https://open.eais.go.kr/main/main.do). The monthly records of gas and electricity consumption for Seoul were accessed from the local online repository66. The AWS meteorological data were downloaded from the Korea Meteorological Administration (KMA) database59. Source data are provided with this paper.
Code availability
The analysis of urban climate conditions was performed using the WRF model (version 4.3). The latest version of the WRF modeling system’s source code can be obtained from the public WRF-Release page on GitHub, accessible at https://github.com/wrf-model/WRF/releases. The UBEM was performed using CitySim Pro software (version as of 3 May 2021), developed at EPFL. The tool can be accessed from its official website at http://www.kaemco.ch/download.php. The results were graphed using OriginPro (version 2022b 9.9.5.167 (Academic)). The Python (version 3.10.9) script used for WRF output processing and conversion is available at the repository with identifier https://doi.org/10.6084/m9.figshare.24998669.
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Acknowledgements
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (no. 2020R1A2C1099611, G.Y.Y.). This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (no. RS-2023-00217322, G.Y.Y.).
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I.A.: conceptualization, methodology, investigation, formal analysis, visualization, writing—original draft, and writing—review and editing. M.S.: conceptualization, methodology, supervision, and writing—review and editing. G.Y.Y.: conceptualization, methodology, funding acquisition, supervision, writing—original draft, and writing—review and editing.
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Adilkhanova, I., Santamouris, M. & Yun, G.Y. Green roofs save energy in cities and fight regional climate change. Nat Cities 1, 238–249 (2024). https://doi.org/10.1038/s44284-024-00035-7
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DOI: https://doi.org/10.1038/s44284-024-00035-7