There are many mysteries in the Amazon. Until recently, one of the most troubling was the vast methane emissions emerging from the rainforest that were observed by satellites but that nobody could find on the ground. Around 20 million tons was simply unaccounted for.
Then Sunitha Pangala, a British post-doc researcher, spent two months traveling the Amazon’s waterways strapping gas-measuring equipment to thousands of trees. She found that trees, especially in the extensive flooded forests, were stimulating methane production in the waterlogged soils and mainlining it into the atmosphere.
Her 2014 expedition plugged a gaping hole in the planet’s methane budget. And she had discovered a hitherto ignored major source of the second most important greenhouse gas in the atmosphere. It now seems that most of the world’s estimated 3 trillion trees emit methane at least some of the time.
Nobody is arguing that trees are therefore bad for climate and should be cut down. Indeed, in most cases, their carbon storage capability easily outweighs their methane emissions. But in a world where corporations plant trees to offset their carbon emissions, we badly need to know if their numbers add up, or if they are undermined by the complex chemistry of trees and methane.
Read more at Yale Environment 360