Recently, Prof. Zhuang Guangchao’s team and Prof. Yang Guipeng’s team from OUC’s Frontier Science Center of Deep Ocean Multispheres and Earth System made new progress in the study of biogeochemical cycling of marine methane. The research was published as ‘Aerobic oxidation of methane significantly reduces global diffusive methane emissions from shallow marine waters’ in Nature Communications.
As an important form of greenhouse gas and a major component of natural gas hydrates (combustible ice), the production and metabolic processes of methane play an important role in the global carbon cycle. Methane emissions from the oceans to the atmosphere range from 6-12 Mt per year, accounting for approximately 1-10% of natural global emissions. The near-shore area (0-50m) is the main site for the release of marine methane. The aerobic oxidation process of methane is the final barrier before its release into the atmosphere. However, there is currently a lack of quantitative assessment on the effect of methane oxidation in controlling marine methane release at the global scale.
Using the Radioisotope Tracing Laboratory of OUC’s Key Laboratory of Marine Chemistry Theory and Technology, the research team established a concrete method to determine the rate of methane oxidation through radioactive hydrogen isotopes (3H) for the first time in China. The team also mastered key techniques aimed at quantitative analysis of the methane oxidation process, and estimated the total methane consumption in shallow water by simulating the distribution pattern of methane oxidation rate in near-shore areas worldwide. The results further elucidated the mechanisms of methane production and emission in the offshore, and revealed for the first time the significance of the aerobic process of methane oxidation in controlling its release from the ocean. The study facilitates the understanding of the biogeochemical cycling of marine methane and the reduction of marine methane emissions, both help achieve the common goal of carbon neutrality.
