Gas stove risks studied
Experts say cooking with gas comes with significant climate and health impacts.
Natural gas stoves release methane - a potent greenhouse gas - and other pollutants through leaks and incomplete combustion. These leaks are known as ‘fugitive emissions’.
New research has found that home methane leaks contribute about a third as much greenhouse gas as the carbon dioxide generated by combustion when the stove is lit.
The leaks could also expose users to pollutants that trigger respiratory diseases.
The findings of the Stanford University study are accessible here.
“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,” says study 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.”
Although carbon dioxide is more abundant in the atmosphere, methane’s global warming potential is about 86 times as great over a 20-year period and at least 25 times as great a century after its release.
Methane also threatens air quality by increasing the concentration of tropospheric ozone, exposure to which causes an estimated 1 million premature deaths annually worldwide due to respiratory illnesses.
Methane’s relative concentration has grown more than twice as fast as that of carbon dioxide since the beginning of the Industrial Revolution because of human-driven emissions.
While pipeline leaks of natural gas, which is more than 90 per cent methane, have been studied extensively, natural gas-burning cooking appliances have received comparatively little attention.
It is expected that these household fugitive emissions originate from leaking fittings or couplings near stoves.
The Stanford study shows that not only is methane emitted while the stove is not in use, nitrous oxides and fine particulate matter (as well as methane) are released during combustion.
These can contribute to respiratory diseases, especially in children and the vulnerable, according to public health physician Dr Kate Charlesworth.
"Children are for a range of reasons more at risk from air pollution," Dr Charlesworth told reporters last week.
“They have smaller lungs … and a higher respiratory rate.
“It's the most vulnerable that are being hit hardest — the young, the elderly, the asthmatic.”
Energy and climate change policy expert Donna Green from UNSW say the fact that so many are still burning fossil fuels in their homes “is nuts”.
“We'll be in shock in decade's time that we actually did this,” Associate Professor Green says.
“There's no excuse other than a lack of awareness and a really good campaign by the fossil fuel industry to sell us something we [don't need].
“Every [house] from now on should be putting in induction, especially because the price of induction stove tops is so cheap now.”
The Climate Council says cooking with gas is responsible for around 12 per cent of the “burden of childhood asthma” and is comparable to household cigarette smoke.