Risk of the hydrogen economy for atmospheric methane.

Bertagni, Matteo B; Pacala, Stephen W; Paulot, Fabien; Porporato, Amilcare · Nat Commun · 2022

basic_science · Level V

Where this comes from

Abstract

Hydrogen (H<sub>2</sub>) is expected to play a crucial role in reducing greenhouse gas emissions. However, hydrogen losses to the atmosphere impact atmospheric chemistry, including positive feedback on methane (CH<sub>4</sub>), the second most important greenhouse gas. Here we investigate through a minimalist model the response of atmospheric methane to fossil fuel displacement by hydrogen. We find that CH<sub>4</sub> concentration may increase or decrease depending on the amount of hydrogen lost to the atmosphere and the methane emissions associated with hydrogen production. Green H<sub>2</sub> can mitigate atmospheric methane if hydrogen losses throughout the value chain are below 9 ± 3%. Blue H<sub>2</sub> can reduce methane emissions only if methane losses are below 1%. We address and discuss the main uncertainties in our results and the implications for the decarbonization of the energy sector.

Medical subject headings