By Olivia Rosane and Cristen Hemingway Jaynes
Methane, an invisible and odorless gas found everywhere from remote wetlands to livestock pastures and household basement furnaces, has emerged as one of the most critical frontiers in the global fight against climate change. As the second most important contributor to the climate crisis surpassed only by carbon dioxide, methane represents both an immediate threat to a warming planet and our most effective lever for rapidly stabilizing global temperatures.
As the primary component of natural gas—which currently generates roughly 25 percent of the world’s electricity—methane is a hydrocarbon composed of four hydrogen atoms bonded to a carbon atom. It is abundant in nature, forming through both geological and biological processes. Geologically, methane is typically created when heat and pressure are applied to decomposing plant and animal matter over millions of years, forming the source of most natural gas, though it can also form deep underground without organic matter. Biologically, it is generated through methanogenesis, a process where underwater microorganisms called archaea produce methane as part of their oxygen-free respiration. This biological pathway accounts for methane generated above ground, such as in wetlands or within the digestive tracts of cows and termites.
How Is Methane Measured?
Measuring methane accurately remains a fundamental challenge and a vital priority for scientists and policymakers alike. Researchers primarily rely on two complementary approaches: bottom-up and top-down methods.
Bottom-up approaches start on the ground with localized sources and expand outward. These assessments are based either on direct measurements of a specific facility’s emissions or estimations derived from general knowledge of emitting equipment or animals. For instance, to estimate the methane produced by a country’s agricultural sector, analysts multiply the average emissions per cow by the total livestock population. Similarly, this approach calculates releases from regional natural gas infrastructure or oil drilling operations.
Conversely, top-down approaches begin in the sky, utilizing airplanes, high-altitude platforms, and increasingly sophisticated satellites to measure atmospheric methane concentrations. Combining this overhead data with known emission sources and sinks allows scientists to model overall release patterns.
As satellite technology advances, it routinely detects super-emitting incidents completely missed by traditional bottom-up inventories. For example, if a gas company assesses its leaks by multiplying a standard equipment failure rate by the total number of units in service, it will fail to capture the roughly five percent of extraordinary leaks responsible for more than half of all industry-related leakage volume. Direct measurements from the ground and air consistently reveal higher emissions than previously recognized; one major study found that direct measurements of U.S. oil and gas emissions were 60 percent higher than U.S. Environmental Protection Agency inventory estimates. Refining these measurement techniques is essential for understanding and ultimately controlling atmospheric concentrations.
How Does Methane Contribute to the Climate Crisis?
Once released into the atmosphere, methane acts as a potent greenhouse gas, absorbing heat energy radiated from the Earth’s surface and redirecting it back toward the ground. While natural sinks like soil and the troposphere break methane down into carbon dioxide and water vapor, human activities since the industrial revolution—particularly fossil fuel extraction, intensive agriculture, and waste management—have accelerated emissions far beyond the capacity of natural systems to absorb them.
By 2023, the most recent year with complete data available, atmospheric methane concentrations had surged by 265 percent compared to pre-industrial levels, reaching 1,934 parts per billion. Approximately 60 percent of this total stems directly from human activities, driving roughly one-third of current global heating. Without aggressive intervention, emissions are projected to rise another 13 percent between 2020 and 2030.
Controlling methane is uniquely urgent because the gas is far more potent than carbon dioxide, even though it has a much shorter atmospheric lifespan of roughly 12 years compared to centuries for carbon dioxide. Over a 20-year timespan, methane traps 86 times more heat per unit of mass than carbon dioxide, a figure that drops to 28 times over a century. This extreme potency combined with a short lifespan means that cutting methane offers an immediate, high-impact strategy for curbing greenhouse gases. The Global Methane Assessment concluded that curbing methane is very likely the single strategy with the greatest potential to decrease warming over the next two decades, while the Intergovernmental Panel on Climate Change has calculated that emissions must fall by about 34 percent by 2030 from 2019 levels to keep global heating within the 1.5-degree Celsius threshold.
What Are the Main Sources of Methane?
Human-caused sources account for roughly 60 percent of atmospheric methane, while natural sources comprise the remaining 40 percent. More than 90 percent of anthropogenic emissions originate from just three sectors: agriculture, fossil fuels, and waste storage.
Agriculture is responsible for about 40 percent of human-caused emissions, with livestock generating the vast majority through enteric fermentation, a digestive process used by ruminants like cows, sheep, and goats. Manure storage from pigs and cattle further compounds these agricultural releases, which are projected to climb as global meat consumption rises. Rice cultivation represents another major agricultural source, accounting for about eight percent of human-caused emissions due to the flooded paddy environments that foster methane-producing microbes.
Fossil fuel operations contribute approximately 35 percent of human-caused emissions. The extraction, transport, and use of oil and gas account for 23 percent, driven by intentional venting and accidental leaks. Coal mining and abandoned coal mines contribute another 12 percent, with underground mines producing the vast majority of those emissions. Certain fossil fuel sites and waste management facilities act as massive super-emitters, releasing monumental volumes of gas through sudden leaks or operational failures that are readily tracked by satellite imagery. Landfills and wastewater treatment facilities round out the major anthropogenic sources, accounting for roughly 20 percent of human-caused emissions through the anaerobic decomposition of organic waste.
Among natural sources, wetlands are the dominant contributor, responsible for roughly one-third of total global emissions. The warm, waterlogged, oxygen-depleted soils of wetlands create ideal conditions for archaea to generate methane. Under the influence of climate change, these natural emissions have accelerated through positive feedback loops, particularly in tropical and Arctic permafrost regions where thawing soils and shifting rainfall patterns expand wetland areas and awaken dormant microbes. Oceans also contribute through marine seepage, seafloor sediments, and the potential destabilization of methane hydrates, though current atmospheric transport from these deep-sea reserves remains unproven.
Methane and the “Bridge Fuel” Myth
The expansion of global gas production, including the rapid growth of liquefied natural gas exports, threatens to trigger future spikes in atmospheric methane. Following the fracking boom in North America, the United States ascended to become the world’s leading natural gas exporter, with export volumes doubling repeatedly over short cycles.
Proponents of natural gas have long defended it as a necessary bridge fuel from coal to renewable energy, noting that burning natural gas emits roughly half the carbon dioxide per kilowatt-hour as coal. However, this narrative overlooks the significant volume of methane that leaks into the atmosphere during extraction and transport. If even a fraction of a percent of produced methane leaks, the climate-warming impact of liquefied natural gas equals or exceeds that of coal. Recent research indicates that when full life-cycle leaks are accounted for, liquefied natural gas possesses a significantly higher global warming potential over a 20-year horizon than coal, undercutting its claimed climate benefits and often displacing renewable investments rather than coal-fired power.
What Are Other Benefits to Reducing Methane Emissions?
Curbing methane delivers critical co-benefits beyond stabilizing the climate. Methane reacts in the atmosphere to form ground-level ozone, a dangerous pollutant that damages human lung tissue, triggers respiratory and cardiovascular ailments, and stunts the growth of vital agricultural crops. This ozone pollution currently contributes to approximately half a million premature deaths worldwide each year. Consequently, every million metric tons of avoided methane emissions prevents thousands of premature deaths and asthma-related emergencies while safeguarding agricultural yields of staples like wheat, soybeans, maize, and rice.
What Can Be Done to Reduce Methane Emissions?
A comprehensive suite of strategies exists across energy, agriculture, and waste systems to rein in emissions. Fully implementing currently available technologies could cut human-caused methane emissions by 45 percent by 2030.
In agriculture, mitigation focuses on transforming food systems by curbing food waste—which currently loses up to 40 percent of all food produced—and shifting toward more sustainable, plant-based diets in wealthier nations. On the production side, improving livestock efficiency, enhancing animal health, and incorporating enteric methane inhibitors like specific chemical additives or seaweed supplements into cattle feed can slash digestive emissions dramatically without compromising animal welfare. Better manure management, such as covering storage tanks or utilizing anaerobic digesters to capture biogas, offers additional reductions, while alternative wetting and drying techniques in rice paddies cut microbial emissions significantly.
Within the fossil fuel sector, the most effective path forward is phasing out fossil fuel use entirely while halting the buildout of new export infrastructure. For active operations, the International Energy Agency estimates that existing technologies can slash oil and gas methane emissions by up to 70 percent, with a substantial portion of those cuts achievable at no net cost through rigorous leak detection and repair programs. Coal sector emissions can be addressed through degasification wells and drainage boreholes, while retired wells and mines can be securely capped and flooded.
Waste sector emissions can be addressed by transitioning toward zero-waste circular economies that prioritize composting and organic waste diversion, alongside major infrastructure upgrades at wastewater treatment plants to capture and reuse biogas. While some scientists are also exploring direct atmospheric removal methods—such as leveraging tree bark microbes or deploying geoengineering techniques—stopping emissions at the source remains the safest and most reliable strategy.
What Progress Has Been Made to Reduce Methane Emissions So Far?
International momentum has grown following the launch of the Global Methane Pledge at the COP26 climate conference, which enlisted 159 nations agreeing to cut global methane emissions by 30 percent from 2020 levels by 2030. Despite these high-level commitments, real-world reductions have lagged behind policy ambitions. Methane emissions broke new records in 2023, and emissions from the oil and gas sector have continued to climb since 2020. Analyses indicate that binding reduction policies currently cover only a small fraction of total global emissions, highlighting an implementation gap that governments and corporations must urgently close to meet international climate targets.
As scientific understanding of methane deepens, the gas remains both a profound hazard and a unique opportunity. Because of its intense near-term potency and short atmospheric lifespan, aggressive action to curb methane provides a vital mechanism for slowing global temperature rise, protecting public health, and buying critical time for the broader transition to a sustainable global economy.
