Cookstoves, Heat, Hot Water and Pipelines
A study released by Stanford in January 2022, revealed the disturbing information that natural gas cooking stoves routinely release methane, an extremely potent greenhouse gas. Methane is twelve times more potent than carbon dioxide, though it doesn’t linger as long in the atmosphere. Climate scientists believe that controlling methane emissions in the near-term is crucial to preventing temperature rise as we work to decarbonize our economy. Stanford scientists measured releases from 53 California cookstoves. They found that three quarters of the releases from cookstoves occur while the stove is shut off. This is leaked from loose fittings and couplings that connect the stove to gas pipes. The Stanford study found little difference between brands of stove, and between older and newer stoves. Though newer stoves have less leaking, according to Wirecutter, the fundamental problem occurs behind the stove, in the piping. Stoves using a pilot light leaked less than those using an electronic sparker. Researchers estimated that up to 1.3% of the gas used in stoves leaks into the atmosphere. That’s a trivial contribution per individual household, but since there are more than 40 million gas stoves in the U.S., the emissions have about the same climate change effect as the carbon dioxide from half a million gas cars.
This information has caused much consternation among homeowners, both for environmental and health reasons. For perspective, cookstoves use a minuscule amount of natural gas compared to other household uses. Stoves represent only 3% of home use of natural gas in the United States, versus 29% for water heating and 69% for space heating. The impacts for health are greater, however, because people spend a lot of time in their kitchens and don’t usually cuddle up to their hot water heaters or furnaces. Wirecutter also notes that the health impacts of cooking are somewhat independent of the source of heat. Any kind of cooking gives off fine particles and volatile organic compounds (VOCs) which can cause or aggravate asthma and other lung conditions. The indoor pollutants emitted by natural gas stoves include nitrogen dioxide (NO2), carbon dioxide (CO2), and formeldahyde. NO2 is a toxic gas that can trigger breathing problems even in low concentrations. A 1992 study shows that children living in homes with gas stoves have a 20% increased risk of developing respiratory diseases. RMI (formerly the Rocky Mountain Institute) and three other environmental groups issued a report in 2020 labeling gas stove emissions a threat to human health. This is why ventilation is so important in kitchens. In further bad news, a California study released in October by the journal Environmental Science and Technology showed that natural gas stoves also leak benzene into the home, even when turned off. These are most dangerous in small, poorly ventilated kitchens, but pediatrician Philip J. Landigran told the New York Times that there is no safe threshold for benzene.
What’s a homeowner to do? There are good reasons to turn to electricity for cooking, especially if the grid source is clean and renewable. But not everyone is ready to do that, and many people are genuinely devoted to cooking with gas. It is possible, however, to pull your stove away from the wall and tighten the connectors to the stove and the nearby pipes. The American Gas Association recommends that this be done only by licensed professionals. It’s worth noting that methane leaks occur all along the natural gas supply chain, from drilling and fracking to processing and pipelines. Incentives to tighten the supply chain and eliminate methane leakage form part of the climate initiatives in the Inflation Reduction Act passed in 2022.
One important note: If you happen to cook and heat water with propane, you do not have a methane problem. Propane is a byproduct of natural gas production and does not contain methane. It also emits very little CO2 when burned. The danger with propane is that, though not a poison, it can smother you if inhaled. Heavier than air, it sinks if leaked, and may collect in basements and other low-lying areas, where it is at risk of exploding if ignited. In daily use, however, it is fairly clean. In the big picture, propane is part of the fossil fuel industry, with all its attendant hazards. Fortunately for propane users, there is no methane leaking into your home or your only planet.
Environmental organizations have been focusing on gas stoves because they are considered a ‘gateway appliance.’ Buyers want gas stoves; they usually get gas everything-else as well. If people can be persuaded to replace gas stoves with electric, they are more likely to switch water heaters, clothes dryers, and furnaces to electric, too. Healthcare advocates are also pushing for the switch, and there is increasing evidence to support them.
Jessie Haas lives in an off-grid cabin in southern Vermont with husband Michael J. Daley. She is the author of over 40 books, most recently The Hungry Place.