Microbial oxidation greatly reduces ocean methane emissions: study

BEIJING, Dec. 3 (Xinhua) -- A team of Chinese scientists and their overseas counterparts has discovered that nearly half of methane in nutrient-rich shallow marine waters is consumed by microbes before its emission to the atmosphere.

"This discovery implies that the role of microbial oxidation for methane removal is more important than we previously thought, as it significantly reduces global methane emissions from shallow waters," said Zhuang Guangchao, a marine chemist with the Ocean University of China and the head of the research team.

Methane is the second most important greenhouse gas, and its global warming potential is over 20 times greater than that of carbon dioxide, therefore, reducing global methane emissions is important to achieve carbon neutrality, Zhuang explained.

"The ocean is a source of atmospheric methane and the shallow coastal waters dominate global oceanic methane emissions, while microbial oxidation acts as a biofilter that can mitigate these emissions," he said.

In this study, recently published in the journal Nature Communications, researchers combined a suite of geochemical and microbial analyses as well as machine-learning models to study methane cycling in the ocean. They quantified methane oxidation rates in global shallow marine waters and estimated their role in oceanic methane emissions.

"This is the first approximation of methane oxidation rates in shallow waters on a global scale, which helps us better understand the cycling of this important greenhouse gas," Zhuang said, adding that the study is also of great significance in helping reduce ocean methane emissions and achieve carbon neutrality.

The research team consisted of scientists from the Ocean University of China, Xiamen University, University College London, Montana State University, and the University of Georgia.