Natural gas may be cleaner than coal, but it isn’t cleaner than nuclear or renewable energy

More than one-fifth of the world’s energy is drawn from natural gas. That part varies around the world: as low as 14% in France; around 33% in the U.S., Canada, and UK; more than 65% in countries like Algeria, Iran, and Uzbekistan. Those numbers don’t only include natural gas power plants – we also use natural gas to cook food, heat buildings, manufacture chemicals, and more.

Natural gas is a fossil fuel. When we burn it, we emit greenhouse gas that warms the atmosphere, harms the environment, and threatens human livelihoods^[1]. To stop emitting greenhouse gas, the world will need to transition away from fossil fuels, natural gas included. But it’s often claimed that natural gas is a ‘clean fuel’ or that it is ‘cleaner’ than other fossil fuels like coal and petroleum. 

One such claim, which has gathered more than 100,000 views on Facebook since 1 March 2025, states that gas is a “clean-burning fuel”. The claim shares a video posted by the CO2 Coalition, a nonprofit known to receive funding from and share personnel with the fossil fuel industry. (The CO2 Coalition has a history of making misleading statements about climate change – we have previously covered some of their claims.)

Is natural gas really “clean-burning”? How does natural gas compare to other fuels, fossil or otherwise? As we’ll show in this article, the claim that gas is “clean-burning” is misleading on multiple counts. 

Data shows that natural gas power plants are cleaner than coal, but not cleaner than renewables

Natural gas is, again, a fossil fuel. Like any other fossil fuel, burning natural gas emits greenhouse gases such as carbon dioxide (CO₂) into the atmosphere. The data says that gas power plants are significantly more emissions-intensive than generating the same electricity with nuclear or renewables.

In 2021, the United Nations Economic Commission for Europe (UNECE) estimated the life cycle greenhouse gas emissions for different electricity sources. Life cycle emissions do not just include emissions from burning fuel, but also emissions associated with constructing power plants, supplying them, maintaining them, and dismantling them at the end of their lives. 

According to UNECE’s estimates, natural gas plants are responsible for 403 to 513 grams of CO₂-equivalent per kilowatt-hour, depending on location (a kilowatt-hour is enough to power the average U.S. household for around 50 minutes). That’s about half the emissions from coal plants (753 to 1,095 grams per kilowatt-hour), but several times those from hydroelectric dams (6.1 to 147), solar panels (7.4 to 83), wind turbines (7.8 to 23), or nuclear power plants (5.1 to 6.4). 

“CO₂-equivalent” accounts not just for CO₂, but also for other greenhouse gases, often more potent ones. Natural gas is a significant source of methane, for example; over a century, a certain quantity of methane causes about 28 times more warming than the same amount of CO₂. Burning natural gas also emits nitric oxide (NO) and nitrogen dioxide (NO₂) – together known as NO_x – even more potent than methane, with over 200 times the warming impact of CO₂. To represent these other greenhouse gases, scientists convert their warming potential into a single number: CO₂-equivalent. 

In other words, across the world, natural gas contributes more on average to global warming than an equivalent amount in renewables or nuclear.

Data from the U.S. National Renewable Energy Laboratory (NREL) agrees. According to NREL, natural gas power accounted for 486 grams of CO₂-equivalent on average for every kilowatt-hour of electricity – less than half of coal’s 1,001 grams, but still many times greater than solar cells’ 43 grams, wind power’s 13 grams, or nuclear power’s 13 grams (Figure 1).

Even when UNECE and NREL accounted for the possibility that gas power plants might install carbon capture and storage, a largely unproven technology, their estimates still placed gas power’s emissions above those from nuclear or renewables.

In the short-term, methane emissions may make natural gas as warming-intensive as coal

What we call ‘natural gas’ is actually a mix of different gases. The most common – at least 85% – is methane. We’ve mentioned that an amount of methane will cause about 28 times more warming than the same amount of CO₂. But while CO₂ lingers in the atmosphere for centuries, methane tends to dissipate within a decade. So, when we look at the first several years after it’s emitted, methane may be up to 80 times as potent as CO₂^[2].

This is problematic, because whenever we extract and transport natural gas, some of its methane invariably leaks into the air, even if we don’t burn it.

The U.S. Environmental Protection Agency (EPA) estimates a leakage rate of 1.4% – in other words, 1.4% of methane-containing natural gas is lost to the atmosphere before it’s used. But scientists observing methane in the air have found evidence that 1.4% may be an underestimate. Various studies have found leakage rates ranging from 1.2 to 11.0%. 

The higher this percentage, the more planet-warming methane enters the atmosphere – a 2012 study determined that a methane loss rate of 3.2% will put the warming potential of natural gas on par with that of coal^[3].

Where does this leaky natural gas come from? According to 2016 EPA data, in the U.S., 37% comes from gas wells themselves; 27% leaks while collecting gas from wells for processing; 13% from gas processing plants; 16% while storing processed gas or transmitting over long distances; and 7% while distributing gas to homes and businesses.

There are a few reasons why gas wells are responsible for so much methane. Many wells intentionally release unwanted natural gas into the atmosphere, a process called venting. Other wells are extremely prone to leaks – researchers call them ‘super emitters’, and they may result in leakage rates far higher than the average^[4]. 

But there’s also evidence that the EPA data underestimates the methane emissions from distribution. A 2021 study that measured methane emissions from tall buildings and towers in the Boston area determined that three times as much natural gas escaped as EPA estimates would suggest. This study found a methane loss rate of 3.3 to 4.7%^[5]. 

It’s likely that the same can be said of other cities, but Maryann Sargent – Senior Project Scientist for the MethaneAIR mission that observes methane concentrations in the atmosphere – told Science Feedback that the exact scale of this problem isn’t well-understood:

“It has been studied in a handful of cities, but I would not consider it well studied or well understood. Infrastructure can vary a lot across cities, so what is true in one city is not necessarily applicable to another.”

Building gas infrastructure may ‘lock’ the world into using gas

Some natural gas advocates claim that natural gas can be a ‘bridge fuel’ – a lower-emissions fossil fuel that can act as a transitional stepping stone between high-emissions fuel fuels like coal and even lower-emissions sources like nuclear or renewables. According to this point of view, we can replace coal with cost-effective gas to easily cut emissions in the short term. Supporting the idea is that switching from coal to gas accounted for one-third of U.S. emissions reductions between 2005 and 2016, according to Carbon Brief.

But many scientists criticize the ‘bridge fuel’ idea. A 2015 study estimated that we could burn natural gas for 1.5 to 2.4 times longer than the equivalent amount of coal while still reducing emissions, but concluded that gas is “not a replacement” for low-emissions energy^[6]. That study’s estimate assumed that 2% of methane-containing gas leaks into the atmosphere, but as we’ve mentioned, the leakage rate could be significantly higher – if the rate is high enough, replacing coal with natural gas may not meaningfully reduce emissions at all^[2,3].

Another problem is that, if the world builds new natural gas infrastructure, it commits to using it for decades. U.S. natural gas power plants typically last anywhere from 25 to 60 years. Newly constructed gas plants that switch on today may easily operate into the 2050s or beyond. Exchanging those power plants’ capacity for nuclear or renewables is then an additional expense, which can discourage authorities from decarbonizing.

That said, with more than one-fifth of the world’s energy coming from natural gas today, other scientists say that we could reduce emissions by upgrading the gas infrastructure that already exists. For example, Sargent told Science Feedback:

“In 2024 the EU implemented a new regulation aimed at pushing imports of natural gas towards gas extracted with fewer emissions. As natural gas (NG) is a valuable resource, some of the changes that could be made to reduce loss from infrastructure could be done at a low net cost, with the recovered gas being sold. While I still think it is essential to move the world away from fossil fuel use as quickly as possible, there are a lot of opportunities to reduce the loss of NG and therefore reduce its carbon footprint, for it to be used as a stepping stone to moving away from fossil fuels.”

Gas cooking is blamed for respiratory HEALTH PROBLEMS

We know that burning natural gas creates fossil fuels. Moreover, both methane and NO_x  in the atmosphere can react with sunlight to form tropospheric ozone, a major air pollutant that can damage materials like rubber and irritate the human respiratory system. NO_x also contributes to smog and acid rain. Burning gas also produces small but harmful amounts of sulfur dioxide, mercury, particulates, and other pollutants.

Given that all this is true, why do we sometimes call gas a clean cooking fuel?

The ‘clean cooking’ label needs context. Billions of people, mainly in the developing world, cook with ‘dirtier’ fuels: biomass (such as charcoal, wood, or animal dung) and kerosene. When those fuels are burnt indoors, they’re a major risk for respiratory illnesses, lung cancer, tuberculosis, heart disease, and poor pregnancy outcomes^[6,7]. Gas, then, is a definite improvement. But, as we’ve shown, gas is not completely clean. 

Recent research suggests that gas stove pollutants can damage the human respiratory system^[9]. A 2022 study found gas stoves responsible for about 6.3 to 19.3% of U.S. childhood asthma cases^[10], although other research suggests the proportion may be lower^[11]. A 2024 report from researchers at Jaume I University idetermined that the NO₂ emissions from gas stoves EU and UK contributed to some 40,000 premature deaths each year; another study in the same year blamed NO₂ for 19,000 premature deaths in the U.S. annually^[11], as we’ve covered in a prior article.

The same research indicates that electric alternatives to gas appliances do not emit this sort of pollution. Eric Lebel, Senior Scientist at PSE Healthy Energy, told Science Feedback:

“The data suggest that gas appliances can be a source of indoor pollution, both from combustion of the fuel and leaking gas. To help mitigate exposures, it’s always best to use an exhaust hood whenever using a gas stove, or if there isn’t one, open a nearby window to increase ventilation. Our data show that electric appliances do not emit indoor pollution due to the heating process, so switching cooking loads to other electric appliances, such as instant-pots, rice cookers, electric kettles, or portable induction burners, are also ways to reduce indoor exposures.”

This is why some cities want to phase out gas stoves in new buildings in favor of all-electric appliances. Indeed, it’s also why a growing number of clean cooking fuel advocates now back the use of electric cooking instead of gas in the developing world^[12].

Conclusion

Calling gas a “clean-burning” fuel is misleading. The evidence indicates that, while natural gas is less emissions-intensive than coal, it’s still significantly more emissions-intensive than renewables or nuclear. Natural gas is a major source of methane, a far more potent greenhouse gas than CO₂. Additionally, burning gas creates nitrous oxide, tropospheric ozone, sulfur dioxide, mercury, and other pollutants linked with respiratory health issues in humans. If we want a low-emissions energy system, scientists believe that natural gas is not a replacement for low-emissions energy sources like renewables.

References:

1. IPCC. (2022) Climate Change 2022: Impacts, Adaptation and Vulnerability.
2. Kemfert et al. (2022) The expansion of natural gas infrastructure puts energy transitions at risk. Nature Energy.
3. Alvarez et al. (2012) Greater focus needed on methane leakage from natural gas infrastructure. PNAS.
4. Omara et al. (2022) Methane emissions from US low production oil and natural gas well sites. Nature Communications.
5. Sargent et al. (2021) Majority of US urban natural gas emissions unaccounted for in inventories. PNAS.
6. Hausfather Z. (2015) Bounding the climate viability of natural gas as a bridge fuel to displace coal. Energy Policy.
7. Sehgal et al. (2014) Disease burden due to biomass cooking-fuel-related household air pollution among women in India. Global Health Action.
8. Arku et al. (2020) Adverse health impacts of cooking with kerosene: A multi-country analysis within the Prospective Urban and Rural Epidemiology Study. Environmental Research.
9. Lebel et al. (2022) Methane and NOx Emissions from Natural Gas Stoves, Cooktops, and Ovens in Residential Homes. Environmental Science & Technology.
10. Gruenwald et al. (2022) Population Attributable Fraction of Gas Stoves and Childhood Asthma in the United States. International Journal of Environmental Research and Public Health.
11. Kasthan et al. (2024) Nitrogen dioxide exposure, health outcomes, and associated demographic disparities due to gas and propane combustion by U.S. stoves. Science Advances.
12. Seltenrich N. (2023) Breathing Room: Cleaner Fuels for Home Cooking in LMICs. Environmental Health Perspectives.