Research shows that gas hobs can leak polluting methane even when they are turned off.
The findings suggest that gas appliances may play a larger role in climate change than previously thought.
Stanford University in the US conducted an analysis of emissions from gas cooking stoves in 53 California homes. The hobs were between three and thirty years old.
The research team will test stoves in Europe in the next two years. However, independent experts in the UK informed them that they are not planning to do so. iIt was probable that the results would be the same.
“I don’t see why the fittings or connections for UK stoves would be any better than for the US,” said Dr Phil Symonds from University College London, who studies pollution in buildings.
According to the Stanford study, around 1.3 percent of the gas used in stoves was released as unburned Methane. This has a global warming impact many times greater than carbon dioxide.
The team discovered that although some methane was released after stoves were ignited by a spark, more than three quarters of hidden emissions occurred when the stoves were turned off.
This suggests – for the first time – that gas regularly leaks from appliances and domestic gas lines.
“Surprisingly, there are very few measurements of how much natural gas escapes into the air from inside homes and buildings through leaks and incomplete combustion from appliances,” said lead author Eric Lebel.
“It’s probably the part of natural gas emissions we understand the least about, and it can have a big impact on both climate and indoor air quality.”
The study revealed that stoves with a pilot lamp rather than an electronic sparker were more likely to emit unburned carbon dioxide. There was no relationship between the cost of a stove and its emissions.
Around 60% of UK households use gas hobs. According to the UK Government Figures show a much higher percentage than in the US.
All methane emitted from US gas stoves could have the same climate effect as 500,000 petrol cars. This suggests that methane emitted from US residential sources is much higher than the official figures.