The climate change mitigation impacts of active travel: Evidence from a longitudinal panel study in seven European cities

•First study of lifecycle carbon emissions effects of changes in active travel in cities.•Changes in active travel have significant lifecycle carbon emissions benefits.•Active travel substitutes for motorized travel – not just additional travel.•Largest benefits from shifts from car to active travel for business, social, commuting.•Methodology, metrics and findings are applicable to many cities across the globe.