Vegetated roofs as a nature-based solution to mitigate climate change in a semiarid city

Abstract

• Extensive vegetated roofs (EVRs) sequester c. 0.57 kg C/m2 in semi-arid Córdoba, Argentina. • EVRs reduce energy consumption by c. 40% through the year, especially in summer. • EVRs reduce CO2 emissions and offer a sustainable nature-based solution to climate change. Extensive vegetated roofs (EVRs) are effective in storing carbon and suppressing carbon dioxide emissions to reduce energy consumption in buildings significantly. This study aimed to quantify the carbon sequestration capacity of EVRs and estimate their potential in reducing CO 2 emission in Córdoba city in the semiarid region of central Argentina. For carbon sequestration capacity, we sampled plant and soil materials of three EVRs with similar vegetation but different ages and urban environmental stresses. We measured the carbon storage in the aboveground and belowground biomass and the substrate. To estimate the potential of EVRs in reducing energy consumption and thereby trimming CO2 emission, we simulated the energy consumption reduction by a building with EVRs using the EnergyPlus modeling software. We adjusted the actual data of physical parameters obtained in our study to calculate CO 2 emission reduction compared to a control roof. Our results suggested that EVRs in the semiarid climate could sequester carbon in the order of 2.11 CO2eq/m 2 per year The EVRs achieved a reduction in energy consumption of c. 40%, equivalent to decreasing the emission by 68.38 kg CO 2 /m 2 per year. Since the EVRs can provide an integrative and multifunctional solution to reduce atmospheric CO 2 in urban ecosystems, they offer a promising sustainable nature-based solution with the potential to mitigate climate change effects.