Spatiotemporal Dynamics of Global Anthropogenic Methane Emissions: Spatial Patterns, Decoupling Trends and...

In recent years, methane (CH₄) emissions have risen faster than carbon dioxide, raising significant concerns. Understanding the spatiotemporal evolution of CH₄ emissions, their inequality, and the decoupling of economic growth from emissions is crucial for developing effective reduction policies. This study applies Moran's I index, the Tapio decoupling index, and the Theil index to analyze global CH₄ emissions from 177 countries and regions between 2002 and 2022. CH₄ emissions increased from 292.38 Tg in 2002 to 347.79 Tg in 2012 and further to 379.12 Tg in 2022, with a consistent yet slightly declining spatial clustering. High-high clusters were concentrated in Russia and China, extending into Eastern Europe and Central Asia, while low-low clusters were mainly found in Africa. Weak decoupling dominated globally, particularly in Africa, Asia, North America, and South America. Oceania shifted from weak to strong decoupling, while South America transitioned to strong negative decoupling. The global Theil index for CH₄ emission intensity showed growing inequality between regions, with greater inequality between regions than within them. Conversely, the Theil index for CH₄ emissions per capita showed a consistent decline, indicating narrowing global inequality, driven largely by within-region differences. Our results highlight the need for stronger reduction policies, especially in high-emission areas like Russia and China. South America, facing negative decoupling, requires sustainable development strategies to reduce emissions. Addressing the growing inequality in CH₄ emission intensity is essential, particularly between regions, and international cooperation is crucial to achieving equitable global CH₄ reductions.