Annual greenhouse gas fluxes from a thin-layer rooftop lawn

Green roofs are a key solution for increasing green spaces in urban areas covered with impervious surfaces. In recent years, there has been growing interest in the ability of green spaces to reduce greenhouse gas (GHG) emissions and enhance carbon sequestration. To investigate whether green roofs co...

Full description

Saved in:
Bibliographic Details
Main Authors: Shohei Masuda, Takuya Mito, Misago Morii, Takanori Kuronuma, Hitoshi Watanabe
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-08-01
Series:Frontiers in Environmental Engineering
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fenve.2025.1634737/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849393481778200576
author Shohei Masuda
Takuya Mito
Misago Morii
Takanori Kuronuma
Hitoshi Watanabe
author_facet Shohei Masuda
Takuya Mito
Misago Morii
Takanori Kuronuma
Hitoshi Watanabe
author_sort Shohei Masuda
collection DOAJ
description Green roofs are a key solution for increasing green spaces in urban areas covered with impervious surfaces. In recent years, there has been growing interest in the ability of green spaces to reduce greenhouse gas (GHG) emissions and enhance carbon sequestration. To investigate whether green roofs contribute to GHG reduction, it is essential to quantify both carbon sequestration and GHG fluxes. However, few studies have investigated GHG fluxes from green roofs over the long term. To address this gap, this study measured and quantified the annual GHG (carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O)) fluxes from a thin-layer rooftop lawn using clear acrylic automatic open/close chambers. In addition, we calculated CO2 sequestration based on the difference between total carbon contents in rooftop lawns (soil and turf) at the beginning and end of the experiment. The annual CO2, CH4, and N2O fluxes were calculated to be −1762 g-CO2• m-2• year-1, 92.33 mg-CH4• m-2• year-1, and 0.53 mg-N2O•m-2• year-1 respectively, and CO2 sequestration by plants and soil was estimated to be −2,626 g-CO2•m-2•year-1 during the first year after construction. The CH4 and N2O fluxes from the rooftop lawn were significantly lower than those reported in other studies conducted on ground-level lawns. Based on these results, annual GHG emission (total of CO2, CH4, and N2O) from the rooftop lawn were calculated to be −1759 to −2,623 g-CO2e (CO2 equivalents). m-2• year-1, indicating that the rooftop lawn acts as GHG sink.
format Article
id doaj-art-6d3049696a4d4669ad935da0787c6a5b
institution Kabale University
issn 2813-5067
language English
publishDate 2025-08-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Environmental Engineering
spelling doaj-art-6d3049696a4d4669ad935da0787c6a5b2025-08-20T03:40:25ZengFrontiers Media S.A.Frontiers in Environmental Engineering2813-50672025-08-01410.3389/fenve.2025.16347371634737Annual greenhouse gas fluxes from a thin-layer rooftop lawnShohei Masuda0Takuya Mito1Misago Morii2Takanori Kuronuma3Hitoshi Watanabe4Advanced Energy Research and Development Division, Innovative Research Excellence, Power Unit and Energy, Honda R&D Co., Ltd., Haga-machi, JapanAdvanced Energy Research and Development Division, Innovative Research Excellence, Power Unit and Energy, Honda R&D Co., Ltd., Haga-machi, JapanAdvanced Energy Research and Development Division, Innovative Research Excellence, Power Unit and Energy, Honda R&D Co., Ltd., Haga-machi, JapanCenter for Environment, Health and Field Sciences, Chiba University, Chiba, JapanCenter for Environment, Health and Field Sciences, Chiba University, Chiba, JapanGreen roofs are a key solution for increasing green spaces in urban areas covered with impervious surfaces. In recent years, there has been growing interest in the ability of green spaces to reduce greenhouse gas (GHG) emissions and enhance carbon sequestration. To investigate whether green roofs contribute to GHG reduction, it is essential to quantify both carbon sequestration and GHG fluxes. However, few studies have investigated GHG fluxes from green roofs over the long term. To address this gap, this study measured and quantified the annual GHG (carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O)) fluxes from a thin-layer rooftop lawn using clear acrylic automatic open/close chambers. In addition, we calculated CO2 sequestration based on the difference between total carbon contents in rooftop lawns (soil and turf) at the beginning and end of the experiment. The annual CO2, CH4, and N2O fluxes were calculated to be −1762 g-CO2• m-2• year-1, 92.33 mg-CH4• m-2• year-1, and 0.53 mg-N2O•m-2• year-1 respectively, and CO2 sequestration by plants and soil was estimated to be −2,626 g-CO2•m-2•year-1 during the first year after construction. The CH4 and N2O fluxes from the rooftop lawn were significantly lower than those reported in other studies conducted on ground-level lawns. Based on these results, annual GHG emission (total of CO2, CH4, and N2O) from the rooftop lawn were calculated to be −1759 to −2,623 g-CO2e (CO2 equivalents). m-2• year-1, indicating that the rooftop lawn acts as GHG sink.https://www.frontiersin.org/articles/10.3389/fenve.2025.1634737/fullgreen roofturfcarbon neutralsoil fluxcarbon sequestration
spellingShingle Shohei Masuda
Takuya Mito
Misago Morii
Takanori Kuronuma
Hitoshi Watanabe
Annual greenhouse gas fluxes from a thin-layer rooftop lawn
Frontiers in Environmental Engineering
green roof
turf
carbon neutral
soil flux
carbon sequestration
title Annual greenhouse gas fluxes from a thin-layer rooftop lawn
title_full Annual greenhouse gas fluxes from a thin-layer rooftop lawn
title_fullStr Annual greenhouse gas fluxes from a thin-layer rooftop lawn
title_full_unstemmed Annual greenhouse gas fluxes from a thin-layer rooftop lawn
title_short Annual greenhouse gas fluxes from a thin-layer rooftop lawn
title_sort annual greenhouse gas fluxes from a thin layer rooftop lawn
topic green roof
turf
carbon neutral
soil flux
carbon sequestration
url https://www.frontiersin.org/articles/10.3389/fenve.2025.1634737/full
work_keys_str_mv AT shoheimasuda annualgreenhousegasfluxesfromathinlayerrooftoplawn
AT takuyamito annualgreenhousegasfluxesfromathinlayerrooftoplawn
AT misagomorii annualgreenhousegasfluxesfromathinlayerrooftoplawn
AT takanorikuronuma annualgreenhousegasfluxesfromathinlayerrooftoplawn
AT hitoshiwatanabe annualgreenhousegasfluxesfromathinlayerrooftoplawn