New climate 'feedback loop' discovered in freshwater lakes
Methane emissions from lakes in the northern hemisphere could almost double over the next 50 years because of a novel "feedback loop" say scientists. Climate change is boosting the proportion of cattail plants growing in and around freshwater lakes they say. But when debris from these reed beds falls in the water it triggers a major increase in the amount of methane produced. The gas is at least 25 times more warming than CO₂ in the atmosphere.Freshwater lakes play an important but relatively unrecognised role in the global carbon cycle, contributing around 16% of the Earth's natural emissions of methane - compared to just 1% from all the world's oceans. The gas is produced by microbes in the sediment at the bottom of lakes who consume organic matter that falls into the water from plants a...