Microbial Methane on the Rise as Fossil Fuel Emissions Plateau

A recent analysis of atmospheric methane has upended a long-standing assumption about the primary source of this potent greenhouse gas. The study indicates that methane emissions originating from fossil fuel extraction and use have been on a downward trend since the 1990s and have remained steady since. In contrast, methane generated by microbial activity—such as that from wetlands, agriculture, and waste—has been steadily increasing.

This shift in source dynamics comes as the atmospheric concentration of methane today stands at three times its level from 300 years ago. Methane is the second most abundant human-caused greenhouse gas after carbon dioxide, but its warming potential is significantly higher. Over a century, its global warming potential is 28 times that of CO2, and this figure is even greater over shorter timeframes.

The gas is a major driver of climate change, accounting for an estimated 15–35% of the rise in human-induced greenhouse gas emissions. Recent data shows a sharp uptick in emissions, rising from 15 to roughly 21 parts per billion between 2020 and 2024. The findings underscore the need to understand and address all sources of methane, not just those tied to the fossil fuel industry, to effectively mitigate its impact on global warming.