Landfill mining in the global south as a time-sensitive opportunity for environmental sustainability

Landfill Mining (LFM) is a promising approach for environmental remediation and secondary resource recovery from legacy landfills and dumpsites worldwide. However, LFM’s environmental sustainability depends on trade-offs across impact categories, including climate change, ozone depletion, and human toxicity. To make LFM a sustainable solution, its environmental benefits must be maximized to minimize its environmental burdens. These benefits are primarily linked to (i) avoided greenhouse gas emissions, primarily in the form of methane, and (ii) substitution of conventional fuels and virgin materials with the landfill-mined residues. It is opined that both these benefits diminish over time if decision-making on LFM is delayed, and hence the opportunity for environmental sustainability of LFM would be time-sensitive. This article discusses why LFM presents a time-sensitive opportunity for achieving environmental sustainability, specifically for countries in the Global South that are dealing with the continuous surge in municipal solid waste generation and in the decarbonization of energy and electricity generation. Overall, the benefits linked to avoided greenhouse gas emissions diminish over time owing to the reduced remaining methane generation potential as a result of prolonged waste biodegradation in the landfill. Similarly, benefits linked to substitution of conventional fuels and virgin materials with renewables diminish over a period of time owing to changes in the background energy mix, which are expected to become less carbon-intensive over time. All these aspects have been systematically argued by reviewing and drawing conclusions from European LFM case studies. Finally, waste management policies that support LFM in the Global South have been reviewed to support decision-making on LFM in the Global South.