世界气象组织：2021年世界气象组织温室气体公报（英文版）

The latest analysis of observations from the WMO GAW in situ observational network shows that globally averaged surface mole fractions(1) for CO2, methane (CH4) and nitrous oxide (N2O) reached new highs in 2020, with CO2 at 413.2 ± 0.2 ppm(2), CH4 at 1889 ± 2 ppb(3) and N2O at 333.2 ± 0.1 ppb. These values constitute, respectively, 149%, 262% and 123% of pre-industrial (before 1750) levels. The increase in CO2 from 2019 to 2020 was slightly lower than that observed from 2018 to 2019, but high