"We were able to really quantify each of the different phases of operation," said Eric Lebel Ph.D., lead author on the study.
Lebel, says the Stanford team, including senior author Prof. Rob Jackson, measured the methane release in a more complete way, using sample stoves of different brands and ages in homes around California.
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By deploying a large sample chamber, they were able to calculate methane levels both while the stoves were being used and when they were turned off.
"Even while you're turning it on and off, you know, like when you turn the knob and you hear the clicking sound, and sometimes you can smell a little gas. Well, sure enough, there is gas being emitted during those phases. And you're able to really put a number on how much that is every time we did it," Lebel explains.
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Accounting for leaks, the Stanford team's estimates that a significant fraction of the natural gas used by stoves are released as unburned methane. Equal they say, to the climate impact of the annual carbon dioxide released by half-a-million gasoline powered cars.
"So the momentum is really huge, especially in the Bay Area," says Laura Feinstein, sustainability and resilience policy director for the environmental nonprofit SPUR.
Feinstein says some 50 cities and counties around California are now working to phase out gas appliances in new construction. But stoves in particular are tricky.
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"And so I would say that the real low hanging fruit is definitely getting people to change to zero emission furnaces and hot water heaters first, and the stoves and the ovens, that's harder," Feinstein believes.
She says limiting gas hook-ups on new construction will help.
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But advocates believe phasing in a new generation of electric appliances, with subsidies and incentives for businesses and homeowners of different income levels is also critical. And perhaps essential to limiting the amount of greenhouse gasses reaching our atmosphere.
For more on the Stanford study, you can visit this page.