Methane is a potent greenhouse gas and 84 times stronger than carbon dioxide over a 20-year time horizon. However, quantifying and characterizing methane emission from different sources are demanding and require extensive measurements and detailed analysis. There are enormous numbers of methane emissions sources across urban areas, so quantification and characterization of these sources requires deep analysis of several datasets. These methane emissions can originate from variety of sources, e.g. in-complete combustion, gas pipelines leaks, sewer system, facilities, etc. These sources not only contribute in climate change at global scale but also can expose the public to safety hazards in urban areas. This video is based on mobile urban surveys in two European cities; Utrecht, NL, and Hamburg, DE. These measurements aimed to quantify and attribute methane emission sources across these two cities.