Sewers have been hiding a climate problem in plain sight, and this new tool finally exposes its true scale

Methane is the second-largest greenhouse gas after carbon dioxide. According to the Climate and Clean Air Coalition, anthropogenic methane emissions account for nearly 45% of current net warming, making it an important factor in global warming. An international research team led by a scholar from City University of Hong Kong (CityUHK) has broken through the overlooked role of sewers as a source of methane, developing the first-ever globally applicable estimation tool and offering a new perspective on mitigating climate change.