Before revision:  Here we show that the decrease in global fossil CO2 emissions during the first quarter of 2020 was of 5.8\% (542 Mt CO2 with a 20\% 1- {\sigma} uncertainty) .
After revision:  Here we show the unprecedented decrease in global fossil CO2 emissions during the first quarter of 2020 was of 5.8\% (542 Mt CO2 with a 20\% 1- {\sigma} uncertainty) .