Emissions and leachate profile of MSW disposal sites of metropolitan cities of Pakistan using LandGEM model

The rapid increase in municipal solid waste (MSW) generation across urban centers in Pakistan, combined with insufficient waste management infrastructure, presents a significant environmental and public health challenge. This study assesses methane emissions and leachate generation from major MSW dumpsites in Rawalpindi and Lahore, two of Punjab province's largest cities. Emissions were estimated and projected over a 50-year active timespan using the U.S. EPA LandGEM model following IPCC 2006 guidelines. Cumulative emissions from Lahore's solid waste disposal (SWD) systems were calculated at approximately 133,446 Gg, equivalent to 108 Mt CO₂-eq, with contributions comprising 26% methane, 73% carbon dioxide (CO₂), and 0.2% non-methane organic compounds (NMOCs). In contrast, Rawalpindi's SWD systems generated 958 Gg (or 7.8 Mt CO₂-eq) over their operational life, exhibiting a similar emissions profile. Two unmanaged Lahore sites-LD2 (1643 Gg CH₄) and MB1 (1383.9 Gg CH₄)-emerged as the most significant methane emitters across both cities. These results underscore the urgent need for targeted waste management strategies, particularly the deployment of methane capture technologies and effective leachate treatment systems. The study highlights the substantial greenhouse gas emissions and groundwater contamination risks posed by unmanaged landfills. To mitigate these impacts and align with national climate goals, the adoption of site-specific policies and sustainable waste-to-energy solutions is imperative.