Planet Earth

Climate-Friendly Water Heating

A San Mateo County Guide

Why 'natural' gas is horrible

'Natural' gas - we're all conditioned to think that it's clean and friendly, not like coal or gasoline. But that's a myth: natural gas (methane) is every bit as nasty as coal, maybe even worse. Terrible for the planet, and bad for your own health too.

Gas is nice and clean, not like coal. Or is it?

Bad for the Planet

Burning methane produces twice as much energy as coal, for the same amount of CO2 emissions, so it has been promoted as a cleaner fuel. BUT... methane leaks, everywhere from fracking, from transport, and even in your house, as this recent Stanford study showedThat methane is over 80 times more potent as a greenhouse gas than CO2[1]., so when you burn gas, the emissions from methane are more than twice as bad as those from the COthat you produce. These methane leaks reverse most or all of the benefit over coal, so 'natural' gas may be as bad or worse than dirty coal[2].

Water heaters in US houses alone release 91,000 tonnes of unburned methane each year, equivalent to 7.8 million tonnes of CO2. Ouch! 

Bad for your health

The health impacts of methane are only recently emerging. Small leaks of unburned gas and impurities remaining after burning are both bad for your lungs. Gas cookers are very strongly associated with increases in childhood asthma (SlateConsumer Reports,  Paper) and are faulted for 20% of asthma cases in California. Even the American Medical Association is now warning about gas cooking in the home. Burning gas releases other pollutants and multiple studies have shown a small but reproducible effect on cognitive ability of children living in houses with gas cookers. A 2022 study in California [PaperNBC News report]  showed high indoor levels of benzene and other carcinogens from natural gas, even when stoves were turned off, up to 7 times the California legal limit.

Gas also causes about 4,200 home fires and 40 deaths in the US each year, not least the horrific 2010 gas pipeline explosion here in San Bruno that killed 8 people. Hundreds more are killed from carbon monoxide poisoning.

So, don't let yourself be fooled by the marketing. 'Natural' gas is destroying nature, and we need to stop our addiction to it. Fortunately, there are a lot of easy, even profitable, ways that each of us can do that. For starters, check out our guide to saving money and the planet by replacing your gas-fired house water heater.


[1]. Methane is 84-times worse than CO2 for warming the planet over the course of 20 years. Methane doesn't last in the atmosphere so long, so over centuries, it's not so much worse. Since the climate crisis will peak within 20 years, that's the standard used. 

[2]. That study showed that 2.3% of methane leaked from the supply. Since it's 84 times worse than CO2 for warming, the leaked methane is even worse than the burning of the remaining methane. That would make it worse than coal, except for other recent research that shows that coal mining also releases substantial methane!


Back to the San Mateo County Guide to Climate-Friendly Water Heating.