Rapid shift in methane carbon isotopes suggests microbial emissions drove record high atmospheric methane growth in 2020-2022.

ABSTRACT: The growth rate of the atmospheric abundance of methane (CH₄) reached a record high of 15.4 ppb yr^-1 between 2020 and 2022, but the mechanisms driving the accelerated CH₄ growth have so far been unclear. In this work, we use measurements of the ¹³C:¹²C ratio of CH₄ (expressed as δ¹³C_CH4) from NOAA's Global Greenhouse Gas Reference Network and a box model to investigate potential drivers for the rapid CH₄ growth. These measurements show that the record-high CH₄ growth in 2020-2022 was accompanied by a sharp decline in δ¹³C_CH4, indicating that the increase in CH₄ abundance was mainly driven by increased emissions from microbial sources s

SUBMITTER: Michel SE 

PROVIDER: S-EPMC11536133 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature