Carbon emissions and economic growth decoupling in the city of medellín and its metropolitan area: a longitudinal sectoral analysis (2000–2023)

Abstract As one of the most polluted cities in Latin America, Medellín faces recurrent air quality crises, driven by transportation emissions and topographical constraints that exacerbate pollution retention. At the same time, the city is recognized as a hub for urban innovation, implementing policies aimed at sustainable mobility and green infrastructure. Therefore, we examined the decoupling relationships between economic growth and carbon emissions in Medellín’s metropolitan area, Colombia’s second-largest urban center, from 2000 to 2023. Using the Logarithmic Mean Divisia Index (LMDI) and the Tapio decoupling elasticity model, this study integrated updated datasets, including Copernicus Atmosphere Monitoring Service (CAMS) emission inventories and local air quality monitoring data. Results indicated a predominance of weak decoupling with GDP growth at an annual rate of 5.66% while emissions increased marginally at 0.25%. Sectoral analysis revealed that the tertiary sector, responsible for 72% of GDP and 59% of emissions, exhibited alternating periods of weak (15) and strong decoupling (6), driven by efficiency improvements and structural changes. In contrast, the secondary sector consistently reduced contributions to production and carbon emissions after 2008 configuring 7 instances of strong decoupling in the last years. Population growth was identified as a major inhibitor of decoupling, contributing to rising emissions in the transportation sector, which remains as the primary source of urban emissions. Energy and carbon intensity reductions contributed positively to decoupling, particularly in commercial and service-based activities. These findings highlight the need for deeper targeted policy interventions and sector-specific strategies to accelerate regional decoupling and support sustainable urban development.