Something unexpected happened during the COVID-19 pandemic lockdowns—and climate scientists are still trying to understand why.
Atmospheric methane concentrations experienced an unprecedented spike during 2020-2021, even as global economic activity plummeted and CO₂ emissions temporarily declined. The surge has continued at elevated rates into 2026, prompting urgent research into mechanisms that could indicate dangerous acceleration of climate feedback loops.
"It's telling us there's something big going on," said Dr. Euan Nisbet, Earth scientist at Royal Holloway, University of London, in comments to Live Science. "This isn't just noise in the data. This is a signal."
Methane's importance to climate change cannot be overstated. Though less abundant than carbon dioxide, methane is approximately 80 times more potent as a greenhouse gas over a 20-year timeframe. Even small percentage increases in atmospheric methane can have outsized warming effects.
The pandemic spike contradicts initial expectations. With industrial activity curtailed, many scientists anticipated methane emissions from fossil fuel extraction and industrial agriculture would decline alongside CO₂. Instead, atmospheric methane rose by approximately 15 parts per billion in 2020 and 18 ppb in 2021—the largest consecutive annual increases since systematic measurements began.
Isotopic analysis of atmospheric methane samples points toward biological sources rather than fossil fuel emissions. Tropical wetlands, particularly in Africa and South America, appear to be the primary drivers. Warmer, wetter conditions associated with La Niña climate patterns during 2020-2021 created ideal conditions for methane-producing microbes in saturated soils.
This finding is particularly troubling because it suggests natural methane sources are responding to climate change in ways that amplify warming—a textbook positive feedback loop. As temperatures rise, wetlands expand and warm, producing more methane, which causes further warming, which affects wetlands, creating a self-reinforcing cycle.


