This thesis focused on understanding and mitigating methane emissions from landfills. Chapter 2 analyzed quarterly methane emissions from a municipal solid waste landfill using ordinary kriging in ArcGIS Pro to map spatiotemporal trends and evaluate soil cover effectiveness in reducing methane emissions. Soil covers reduced methane emissions within 10–30 days at certain locations; however, variations in emission reductions highlight the need for additional measures and continued monitoring to assess their long-term effectiveness. Chapter 3 evaluated biochar, compost, and woodchip-amended soil, as well as unamended landfill soil, in laboratory column experiments. Landfill soil showed moderate methane adsorption and low methane removal efficiency. Biochar enhanced methane adsorption and removal due to its high porosity and large surface area, while compost improved methane removal efficiency by supporting the growth of methanotrophic bacteria. These findings underscore the potential of biochar and compost as effective amendments to conventional landfill soil covers for enhancing methane mitigation.