Tree Bark Found to Remove Methane from the Atmosphere

Tree Bark Found to Remove Methane from the Atmosphere
by Sophie Jenkins
London, UK (SPX) Jul 25, 2024

A recent study published in Nature reveals that tree bark plays a crucial role in removing methane from the atmosphere. While trees are already known for absorbing carbon dioxide, new findings show that microbes within tree bark can also absorb methane, a potent greenhouse gas.

An international research team led by the University of Birmingham discovered that microbes living in tree bark or wood remove atmospheric methane on a scale comparable to, or greater than, soil. This process increases the overall climate benefits of trees by approximately 10%.

Methane has contributed to around 30% of global warming since pre-industrial times, with emissions rising faster than ever recorded since the 1980s. Though most methane is removed by atmospheric processes, soil bacteria that break down methane have been considered the primary terrestrial sink. This study now indicates that trees may play an equally or even more important role.

Professor Vincent Gauci, the lead researcher, commented, "The main ways in which we consider the contribution of trees to the environment is through absorbing carbon dioxide through photosynthesis, and storing it as carbon. These results, however, show a remarkable new way in which trees provide a vital climate service."

The Global Methane Pledge, launched in 2021 at the COP26 climate summit, aims to cut methane emissions by 30% by 2030. This research suggests that planting more trees and reducing deforestation are crucial steps toward achieving this goal.

The researchers studied upland tropical, temperate, and boreal forest trees, including those in the Amazon and Panama, temperate forests in Wytham Woods, UK, and boreal forests in Sweden. Methane absorption was strongest in tropical forests due to the favorable conditions for microbial activity. On average, methane absorption adds about 10% to the climate benefits provided by temperate and tropical trees.

The study also measured methane exchange at various heights, showing that while trees might emit small amounts of methane at soil level, they absorb methane from the atmosphere higher up.

Using laser scanning, the team estimated that global tree bark surface area contributes between 24.6-49.9 million tonnes of methane removal annually. This finding addresses a significant gap in understanding global methane sources and sinks.

Co-author Yadvinder Malhi of the University of Oxford remarked, "Tree woody surfaces add a third dimension to the way life on Earth interacts with the atmosphere, and this third dimension is teeming with life, and with surprises."

Professor Gauci and colleagues are now planning further research to determine if deforestation has increased atmospheric methane levels. They aim to study the microbes involved, their methane uptake mechanisms, and ways to enhance this process.

Research Report:Global atmospheric methane uptake by upland tree woody surfaces