Abstract

Biography:  After completing a BSc in Physics (minor in Meteorology) and MSc in Meteorology at Ludwig-Maximilians-Universität Munich, Laura pursued a PhD on “The role of methane for chemistry-climate interactions” at the German Aerospace Center, Institute of Atmospheric Physics, where Laura remained for a year as post-doctoral researcher. In April 2025, Laura joined the University of Cambridge as Research Associate to work on the FETCH4 project – an international collaboration focusing on a better understanding of the methane cycle.

Abstract: Methane (CH₄), the second most important greenhouse gas directly emitted by human activity, is removed from the atmosphere through chemical decomposition, which depends on temperature and atmospheric composition. This seminar examines how changes in the chemical sink under a warming climate feed back on atmospheric CH₄ using a CH₄-emission-driven setup of the chemistry–climate model EMAC . This approach allows CH₄ mixing ratios to evolve explicitly in response to changes in emissions, climate, and atmospheric chemistry. Results from perturbation simulations driven either by increased CO₂ concentrations or by increased CH₄ emissions will be presented.

Increasing CH₄ emissions leads to a substantial rise in CH₄ mixing ratios. Remarkably, the factor by which CH₄ mixing ratios increase exceeds the factor of the emission increase, due to the extended atmospheric lifetime of CH₄. In contrast, the individual effect of global warming is to shorten CH₄’s lifetime, thereby reducing its mixing ratios. The explicit evolution of CH₄ mixing ratio also enables secondary chemical feedbacks on the hydroxyl radical (OH) and tropospheric ozone (O₃).