Economics of enhanced methane oxidation relative to carbon dioxide removal

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.

Keywords

• oxidation
• removal
• methane
• economics