A limited study in California provides one more reason to ditch the gas kitchen range and convert to electricity.
Researchers estimate that the more than 40 million gas stoves in U.S. kitchens emit significant amounts of methane even when they are turned off. Methane is a major component of natural gas, 86 times as powerful as carbon dioxide for global warming when measured on a 20-year timescale.
The study, published in the journal Environmental Science & Technology late last month, measured the methane released by kitchen stoves in 53 homes. The Stanford University researchers measured leaks when the stoves were off (what they called “steady-state-off”), when the burners were on, and in the transition periods when burners were being ignited or turned off. Between 0.8% and 1.3% of the natural gas that stoves use in all is emitted as unburned methane, adding up to total U.S. emissions of 28 gigagrams (Gg) of methane annually.
“More than three-quarters of methane emissions we measured originated during steady-state-off,” the report says. “Using a 20-year time frame for methane, annual methane emissions from all gas stoves in U.S. homes have a climate impact comparable to the annual carbon dioxide emissions of 500,000 cars.”
In addition to methane releases, stoves also produce nitrogen oxides when stove top burners or ovens are on, which can trigger respiratory disease. In fact, households that do not use range hoods or have poor ventilation can exceed the national standard for nitrogen dioxide with just a few minutes of stove use, especially in smaller kitchens, the report says.
The report comes at a time when cooking and heating appliances that run on natural gas and other fossil fuels are already in the crosshairs in a number of U.S. and Canadian communities as regulators look for ways to slow global warming. More than 20 cities in California, including San Francisco and Berkeley, have passed laws that would prohibit the use of natural gas in new buildings. Earlier this year, New York City got on the bandwagon with a ban on gas connections in new buildings, joining cities in Massachusetts and Washington. In Canada, a requirement for zero-emissions space and water heating went into effect on Jan. 1, in Vancouver, and Quebec outlawed oil-fired heating equipment in new construction at the start of the year.
However, at least 20 states, including Arizona, Georgia, Florida, and Texas, have passed laws that prohibit gas bans. The gas industry also has fought the restrictions, and gas ranges remain popular with many cooking professionals.
Read the full article at Green Building Advisor