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.
In climate policy, as across environmental challenges, urgency must meet solutions—science demands action, but despair achieves nothing. Understanding feedback loops is essential for predicting future warming trajectories and designing adequate mitigation strategies.
Permafrost thawing represents another concerning methane source. Arctic and sub-Arctic regions store enormous quantities of organic carbon in frozen soil. As permafrost thaws, microbial decomposition releases both CO₂ and methane. Recent studies indicate thawing is occurring faster than models predicted, particularly in regions experiencing abrupt collapse rather than gradual warming.
The pandemic methane spike may represent a preview of future conditions. If natural systems are already responding to relatively modest warming (approximately 1.2°C above pre-industrial levels) by releasing significantly more methane, then projections based on human emissions alone are too conservative.
Agricultural sources also contribute significantly. Livestock, particularly cattle, produce substantial methane through enteric fermentation. Rice paddies, which cover vast areas of Asia, are another major source. Unlike wetlands, these sources are theoretically controllable through dietary supplements for livestock and water management in rice cultivation—though implementation at global scale remains challenging.
Some researchers emphasize that methane's atmospheric lifetime is relatively short—approximately 12 years—meaning aggressive reductions in methane emissions could yield climate benefits faster than CO₂ reductions. This has prompted calls for focused methane mitigation strategies alongside carbon reduction efforts.
The United States, European Union, and other nations have launched initiatives to reduce methane leaks from natural gas infrastructure and agricultural operations. The Global Methane Pledge, announced at COP26 in 2021, committed signatories to reducing methane emissions 30% by 2030. Progress has been mixed, with some regions showing reductions while others continue increasing emissions.
Natural wetland emissions present a more difficult challenge. Unlike industrial sources, tropical wetlands cannot be regulated or controlled. If warming conditions consistently favor increased methane production from natural ecosystems, then mitigation strategies must account for this additional forcing.
Scientists are deploying enhanced monitoring systems to better understand methane sources and sinks. Satellite-based sensors can now detect methane plumes at high resolution, enabling identification of specific leak sources. Atmospheric sampling stations across Africa, South America, and Southeast Asia are collecting data to distinguish between fossil, agricultural, and wetland sources.
The question confronting climate scientists is whether the pandemic spike represents an anomaly linked to specific weather conditions or the beginning of sustained elevated methane emissions from natural sources. The answer will significantly affect projections for future warming and the urgency required for emissions reductions.
What remains clear is that feedback loops once considered distant concerns are activating in real-time. The climate system is responding to existing warming by generating additional greenhouse gas emissions through natural processes. This underscores the imperative for rapid decarbonization: the longer emissions continue, the more difficult it becomes to control warming as natural systems amplify human-caused changes.
