Day-to-day changes in CO₂ emissions from human activities, in particular fossil-fuel combustion and cement production, reflect a complex balance of influences from seasonality, working days, weather and, most recently, the COVID-19 pandemic. Here, we provide a daily CO₂ emissions dataset for the whole year of 2020, calculated from inventory and near-real-time activity data. We find a global reduction of 6.3% (2,232 MtCO₂) in CO₂ emissions compared with 2019. The drop in daily emissions during the first part of the year resulted from reduced global economic activity due to the pandemic lockdowns, including a large decrease in emissions from the transportation sector. However, daily CO₂ emissions gradually recovered towards 2019 levels from late April with the partial reopening of economic activity. Subsequent waves of lockdowns in late 2020 continued to cause smaller CO₂ reductions, primarily in western countries. The extraordinary fall in emissions during 2020 is similar in magnitude to the sustained annual emissions reductions necessary to limit global warming at 1.5 °C. This underscores the magnitude and speed at which the energy transition needs to advance.

_{人类活动（尤其是化石燃料燃烧和水泥生产）产生的 CO 2}排放量的日常变化反映了季节性、工作日、天气以及最近的 COVID-19 大流行的影响的复杂平衡。在这里，我们提供了 2020 年全年的每日 CO ₂排放数据集，该数据集根据库存和近实时活动数据计算得出。我们发现，与 2019 年相比，全球CO ₂排放量减少了 6.3%（2,232 MtCO ₂ ）。今年上半年每日排放量的下降是由于大流行封锁导致全球经济活动减少，包括交通部门的排放。然而，每天的 CO ₂随着经济活动的部分重新开放，排放量从 4 月下旬开始逐渐恢复至 2019 年的水平。2020 年末的后续封锁浪潮继续导致较小的 CO ₂减排量，主要是在西方国家。2020 年排放量的异常下降与将全球变暖限制在 1.5°C 所需的持续年度减排量相似。这凸显了能源转型需要推进的规模和速度。