Autonomous gas sensing platforms have been developed to facilitate the long-term continuous monitoring of landfill gas concentrations. The analysis of a municipal landfill site in Ireland forms part of an on-going collaboration with the Environmental Protection Agency in monitoring the migration of greenhouse gases, i.e. methane and carbon dioxide, emanating from the landfill site. Target gas concentrations were automatically recorded via infrared gas sensors calibrated for the respective gases, with this data being logged remotely every six hours to a central base-station. The autonomous platform with its web-based portal interface provides a flexible alternative to the existing labor-intensive, manual monitoring routines. Frequent occurrences of 70% v/v methane and 6% v/v carbon dioxide were substantially in breach of the regulatory limits of 1.5% v/v and 1.0% v/v, respectively. These excessive levels of gas migration were analyzed with respect to SCADA flare data, on-site measurements and meteorological data.