Urban emissions of methane—a potent greenhouse gas—are rising faster than bottom-up accounting estimates anticipated, according to a study led by University of Michigan Engineering. The discrepancy was found with satellite measurements of methane over 92 major cities around the world. For 72 of the cities, there were sufficient data to track changes in methane emissions between 2019 and 2023. Overall, global urban methane emissions in 2023 were 6% higher than 2019 levels and 10% higher than 2020 levels, although they tended to decrease in European cities.