Satellite-driven assessment of methane trends, seasonal variability, and emission hotspots in Botswana’s Central and Ngamiland Regions

This study investigates methane, a potent greenhouse gas linked to global warming, using high-resolution satellite data from the Sentinel-5P TROPOMI between 2020 and 2023. The research analyzed trends, seasonal changes, and emission hotspots in two different regions of Botswana: Central and Ngamiland. These areas have different methane sources, including human activities and natural processes. The results indicate significantly varying mean CH₄ concentrations ranging from 1750 to 1900 ppb. The Central region has greater variability in concentrations with values between 1832.93 and 1888.86 ppb, compared to Ngamiland which has CH₄ distribution ranging from 1837.92 to 1872.99 ppb. Increased summer CH₄ levels are attributed by higher temperatures and wetter conditions that stimulate methanogenesis. In winter, levels lower due to cooler temperatures and dry conditions that reduce biological activity. Time-series analysis indicated an upward trend in both regions, suggesting an increase in emissions. The Mann-Kendall tests these significant upward trends in both areas. In late 2021, both regions showed positive anomalies, indicating potential methane risks in subsequent months/years. The ongoing rise in methane concentrations poses serious environmental and health threats to Botswana without effective action. Thus, this study supports focused mitigation strategies and seasonal management that aligns with Sustainable Development Goal 13 (Climate Action). This approach provides policymakers and environmentalists with valuable insights to combat climate change and support healthier, more sustainable communities.