Average daily CO2 emissions from 5 February to 6 May 2020 (red area) and average of the previous years during the same period (grey area) for three European cities. The dark grey horizontal bars cover periods of official lockdown, while the light grey bars indicate periods of partial lockdown or general restrictions (for example, school closures, reductions in personal contact, mobility constraints). Data: Integrated Carbon Observation System, 2020. Graphic: WMO