Economics of enhanced methane oxidation relative to carbon dioxide removal

• Published in: Environmental research letters Vol. 19; no. 6; pp. 64043 - 64051
• Main Authors: Hickey, Conor, Allen, Myles
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01-06-2024
• Subjects: Biofiltration; Biological activity; Carbon dioxide; Carbon dioxide removal; Catalytic oxidation; Climate change; economics; Global temperatures; Global warming; Greenhouse effect; Greenhouse gases; Impact analysis; Life span; Methane; Oxidation; Photocatalysis; Radiative forcing; removal
• ISSN: 1748-9326; 1748-9326
• DOI: 10.1088/1748-9326/ad4898

Abstract
Mitigating short-term global warming is imperative, and a key strategy involves reducing atmospheric methane (CH
4
) due to its high radiative forcing and short lifespan. This objective can be achieved through methods such as oxidising methane at its source or implementing enhanced oxidation techniques to reduce atmospheric CH
4
concentrations. In this study, we use a range of metrics to analyse both the impact and value of enhanced CH
4
oxidation relative to carbon dioxide (CO
2
) removal on global temperature. We apply these metrics to a select group of model studies of thermal-catalytic, photocatalytic, biological and capture-based oxidation processes under different greenhouse gas (GHG) concentrations. Using a target cost of €220-1000/tCO
2
for CO
2
removal, our findings indicate that metrics valuing enhanced oxidation techniques based on their contribution to mitigating the long-term level of warming show these techniques are uncompetitive with CO
2
removal. However, when using metrics that value enhanced oxidation of CH
4
based on its impact on the immediate rate of warming, photocatalytic methods may be competitive with CO
2
removal, whereas biofiltration, thermal-catalytic oxidation and capture-based units remain uncompetitive. We conclude that if the policy goal is to target the immediate rate of warming, it may be more valuable to incentivise CO
2
removal and enhanced oxidation of methane under separate GHG targets.