For many years, we have known that trees are nature's champions at absorbing carbon dioxide. But now a groundbreaking international study published in Nature has discovered that tree bark surfaces are playing a crucial role in removing methane from our atmosphere.
The research, led by the University of Birmingham and also involving the UK Centre for Ecology & Hydrology (UKCEH), has unveiled a fascinating process: microbes living in tree bark and wood are removing atmospheric methane on a scale comparable to, or even surpassing, that of soil. This discovery reveals that trees are 10 per cent more effective in combating climate change than previously thought.
To understand the global impact of their discovery, the research team used advanced laser scanning methods to measure the global forest tree bark surface area. Preliminary calculations suggest up to 50 million tonnes of methane are absorbed by trees annually. This is equivalent to eliminating all emissions from human landfills or nearly half of all global emissions from cows and sheep.
Why does this matter? Methane is a powerful greenhouse gas responsible for about 30% of global warming since the pre-industrial era. With emissions rising faster than ever before, the Global Methane Pledge, launched at the COP26 climate summit in 2021, aims to reduce methane emissions by 30% by the end of this decade.
Professor Niall McNamara of UKCEH emphasises the importance of this discovery: "Our findings show that trees are even more crucial for efforts to mitigate climate change and achieve global emissions targets than previously thought. This provides additional evidence for increased tree planting and reduced deforestation."
The study involved Prof McNamara and Dr Dafydd Elias of UKCEH and 13 other researchers from the UK, Sweden, Panama, Brazil, USA, Spain and Germany. They examined trees in upland tropical, temperate, and boreal forests, taking measurements in diverse regions, from the lush tropical forests of Amazon and Panama to the serene Wytham Woods near Oxford and the expansive boreal coniferous forests in Sweden.
The research revealed that methane absorption is strongest in tropical forests, likely due to the warm, wet conditions that encourage microbial activity.
Paper information
Gauci at al. 2024. Global atmospheric methane uptake by upland tree woody surfaces. Nature. DOI: 10.1038/s41586-024-07592-w. Open access.
