Trees have been identified as a significant climate solution due to the discovery that microbes living in tree bark are absorbing methane from the atmosphere on a large scale. A recent study published in the journal Nature revealed that trees are absorbing as much, if not more, methane than soil, which was previously the only known natural sink for the potent greenhouse gas.
The lead author of the study highlighted that trees' climate benefits have been underestimated, emphasizing this as a new nature-based climate solution. With both natural and human-made methane emissions increasing from various sources like wetlands, cows, landfills, and fossil fuel combustion, the importance of reducing methane emissions and utilizing natural methods to remove it from the atmosphere is crucial.
While trees are well-known for their role in absorbing carbon dioxide and releasing oxygen, their ability to interact with methane is more complex. Researchers were surprised by the findings, which were compiled over a decade by an international team studying methane absorption from trees in different countries.
Initially, trees in Amazon floodplains were found to emit more methane than they absorbed. However, further research in tropical, temperate, and boreal forests above floodplains revealed a different trend, with tropical trees showing the highest methane absorption rates due to favorable warm conditions for methane-eating microbes.
The study estimated that trees' woody surfaces make them approximately 10% more climate-beneficial than previously believed. By quantifying the surface area of tree bark globally for the first time using terrestrial laser scanners, researchers found that if all tree bark were laid flat, it would cover Earth's land surface.
It was calculated that trees may be removing between 25 million to 50 million tons of methane from the atmosphere, potentially surpassing the methane released by melting Arctic permafrost. This discovery helped reconcile discrepancies in the global methane budget, as satellite data indicated lower methane emissions compared to ground-level findings.
The study emphasized that tree woody surfaces introduce a new dimension to Earth's interaction with the atmosphere, teeming with life and surprises. The research sheds light on the significant role trees play in mitigating climate change through methane absorption, offering a promising nature-based solution to combat global warming.
