Scientists find the climate and health impacts of natural gas stoves are greater than previously thought

Humans have been cooking with fire for thousands of years. Natural gas appliances warm the planet in two ways: generating carbon dioxide by burning natural gas as a fuel and leaking unburned methane into the air. Methane leaking from natural gas-burning stoves in US homes is comparable to the carbon dioxide emissions from 500,000 gasoline-powered cars, according to a new study.

The extra warming from home methane leaks contributes about a third as much as the carbon dioxide generated by the stove's natural gas, and sometimes exposes users to respiratory disease-triggering pollutants. Natural gas hookups are not allowed in new construction in at least one state.

Eric Lebel, the lead author of the study, said that there are very few measurements of how much natural gas escapes into the air from inside homes and buildings.

A contributor to a growing problem.

Methane's global warming potential is at least 25 times as great a century after its release as carbon dioxide is over a 20-year period. An estimated 1 million premature deaths are caused by respiratory illnesses every year due to exposure to tropospheric ozone, which is caused by methane. Since the beginning of the Industrial Revolution, the concentration of methane has grown twice as fast as that of carbon dioxide.

Natural gas-burning cooking appliances have received less attention than the leaks of natural gas.

More than 40 million homes cook with gas. Unlike other gas appliances, such as space and water heaters that are usually placed away from living quarters, cooking appliances directly expose people to their emissions, which can cause asthma, coughing, wheezing and difficulty breathing, sometimes resulting in hospitalization. A survey shows that home cooks use hoods for only 25% of the time, even though they help reduce pollutants in the kitchen air.

There are findings and implications.

The researchers measured methane and nitrogen oxides released in 53 homes in California, not only during combustion, ignition and extinguishment, but also while the appliance was off, something most previous studies had not done. 18 brands of gas cooktops and stoves ranged in age from 3 to 30 years.

The highest emitting cooktops used a pilot light instead of a built-in electronic sparker. The amount of methane emissions from the puffs of gas that were emitted while the burner was on was equivalent to the amount of unburned methane that was released during about 10 minutes of cooking with the burner. There was no evidence of a relationship between the age of a stove and its emissions. More than three-quarters of methane emissions occurred while the stove was off, suggesting that gas connections and in- home gas lines are responsible for most emissions, regardless of how much the stove is used.

The researchers estimated that natural gas stoves emit up to 1.3 percent of the gas they use as unburned methane. Methane emissions from residential natural gas appliances are not reported by the EPA. The researchers estimated total methane emissions to be more than the emissions currently reported by the EPA for all residential sources.

The larger the stove, the higher the rates of nitric oxides. The researchers estimated emissions of nitrogen oxides and found that people who don't use their range hoods or have poor ventilation can exceed the EPA's guidelines for exposure to nitrogen dioxide outdoors within a few minutes.

The senior author of the study, Rob Jackson, a professor of Earth system science, said that he didn't want to breathe any extra nitrogen oxides, carbon monoxide or formaldehyde. It will cut greenhouse gas emissions and indoor air pollution.

Citation: Scientists find the climate and health impacts of natural gas stoves are greater than previously thought (2022, January 27) retrieved 27 January 2022 from https://phys.org/news/2022-01-scientists-climate-health-impacts-natural.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.