Nicola Warwick

TL;DR: The increase in the methane burden began in 2007, with the mean global mole fraction in remote surface background air rising from about 1775 ppb in 2006 to 1850 ppb by 2017, at rates not observed since the 1980s as discussed by the authors.

TL;DR: The isotopic evidence presented in this article suggests that the methane rise was dominated by significant increases in biogenic methane emissions, particularly in the tropics, for example, from expansion of tropical wetlands in years with strongly positive rainfall anomalies or emissions from increased agricultural sources such as ruminants and rice paddies.

TL;DR: In this article, an off-line three-dimensional tropospheric chemical transport model, parallel-Tropospheric Off-Line Model of Chemistry and Transport (p-TOMCAT), has been extended by incorporating a detailed bromine chemistry scheme that contains gas-phase reactions and heterogeneous reactions on both cloud particles and background aerosols.

TL;DR: Using data from seven cruises over a 10-year span, the authors reported marine boundary layer mixing ratios (i.e., dry mole fractions as pmol mol 1 or ppt), degrees of surface seawater saturation, and air-sea fluxes of three short-lived halocarbons that are significant in tropospheric and potentially stratospheric chemistry.

TL;DR: The atmospheric methane burden is increasing rapidly, contrary to pathways compatible with the goals of the 2015 United Nations Framework Convention on Climate Change Paris Agreement as mentioned in this paper, and urgent action is required to bring methane back to a pathway more in line with the Paris goals.