Abstract
Abstract Methane (CH4) concentration will unavoidably exceed zero, even though the Paris Climate Agreement (PCA) mandates a rapid reduction in new greenhouse gas emissions to achieve net zero by 2050. Because of its large sources, it is impossible to eliminate CH4 from the environment; however, it might be possible to restore pre-industrial concentrations (0.7 ppm). This study presents a structured comparative review of emerging methane mitigation technologies, examining both source-based strategies and atmospheric removal approaches. About 246 peer-reviewed publications were screened using predefined inclusion criteria across major scientific databases. Technologies were evaluated based on removal efficiency, scalability, technological maturity, environmental risk, and cost implications. Source-based strategies such as anaerobic digestion and improved rice-water management demonstrate reduction potentials of 30–90% at relatively low implementation costs. Meanwhile, atmospheric oxidation techniques exhibit modeled removal efficiencies of 0.80–4.30% of global methane, with a 13–17% oxidation enhancement, though with higher uncertainty and governance challenges. The least-cost intervention identified is enhancement of natural oxidative sinks, estimated at < 2 USD per tCO2- equivalent under limited deployment conditions, albeit with unresolved ecological and health risks. The findings suggest that methane mitigation effectiveness depends strongly on regional emission profiles, governance capacity, and socio-economic conditions. It is recommended that a diversified portfolio combining source reduction with cautiously evaluated atmospheric removal technologies be adopted, as they offer the most feasible pathway toward CH4 reduction and climate stabilization under Sustainable Development Goal-13.