Is Natural Gas Clean Energy?

There’s a lot of confusion about the virtues and pitfalls of natural gas. While climate scientists urge us to stop burning it and some cities banned it in new construction, other state lawmakers are pushing to have it officially declared “clean” or “green” energy.

So what’s really going on? Part of the confusion comes from marketing campaigns, and conflicting definitions for what makes natural gas clean. Here’s what to know about natural gas and clean energy.

What Is Natural Gas?

Natural gas is a fossil fuel composed mainly of methane, a potent greenhouse gas and one of the major contributors to climate change. About 30% of U.S. energy currently comes from natural gas.

Natural gas was formed over the last 550 million years. Layers of organic matter from ancient marine microorganisms, plant matter and animals settled in the bottom of lakes and oceans. Over time, geologic forces drove those deposits hundreds of feet below the surface. The pressure compressed, heated and transformed that matter into natural gas.

“In its purest form, gas is colorless and odorless,” says Paul Arbaje, energy analyst at Union of Concerned Scientists. “The reason we’re able to smell gas leaks in and around buildings is due to the odorants that utility companies put into the gas so that we can safely detect leaks and report them.”

Why Is Natural Gas Used in Homes?

We started using natural gas in homes during the early 1900s, delivered via pipelines. At the time, it was a welcomed upgrade from burning coal, which was more expensive, less convenient and less efficient.

Today, natural gas — and in rural areas, its propane counterpart — are the most common energy sources for home furnaces in the U.S. Both also fuel gas ranges, water heaters and clothes dryers. If your utility company relies on gas-fired power plants, your electricity also comes from natural gas.

Is Natural Gas Safe?

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Not from a health perspective, especially for those who live in apartments and other poorly ventilated homes. Mounting scientific evidence indicates the health risks of burning natural gas for home heating and cooking.

One recent peer-reviewed study attributed 12.7% of childhood asthma cases in the U.S. to gas stoves. Another found 21 volatile organic compounds (VOCs), including the known carcinogen benzene, in gas leaking from stoves and pipelines in Boston. New evidence supports the health benefits of switching from gas to electric stoves.

Besides being a health hazard in home infrastructure, pollution from gas-fired power plants is concentrated in nearby neighborhoods. These are often communities of color, highlighting the environmental injustices, aka environmental racism, associated with natural gas.

On a more existential level, because natural gas is more than 80 times as powerful as carbon dioxide for trapping heat in the atmosphere, continued use creates unsafe conditions for future generations. On the upside, in-home natural-gas explosions are rare.

Is Natural Gas Clean Energy?

“It depends on what your definitions are,” says Diana Gragg, managing director for Explore Energy at Stanford University. “While natural gas is the cleanest-burning fossil fuel, burning natural gas still emits carbon dioxide, which contributes to climate change.”

Because natural gas creates less air pollution and produces less carbon dioxide than coal and oil, some tout it as a stepping stone in replacing coal with renewable energy. And since 2007, U.S. carbon dioxide emissions have actually fallen 15%. That’s due in part to replacing coal with natural gas, along with increasing energy efficiency and use of renewables.

“But it’s nowhere as clean as renewable energy because it still emits CO2,” says Daniel Jacob, professor of atmospheric chemistry and environmental engineering at Harvard University. “Also when natural gas systems leak they emit methane, which is a strong greenhouse gas, so leakage needs to be minimized.”

Currently, those leaks are substantial. Recent research shows the methane released from oil and gas operations is likely high enough to negate most of the benefits of natural gas. “Natural gas, or methane gas, therefore cannot be described as ‘clean’ in any honest or informed manner,” says Arbaje.

Many experts further point out that no matter how clean natural gas is or isn’t, the only way to stop global warming is to stop the cause. That means no longer burning any fossil fuels, including natural gas.

But public confusion over whether natural gas is clean energy also stems from marketing and social media campaigns that many climate advocates tout as misleading. Those campaigns use slogans like the “world’s clean energy future,” without making clear they’re comparing the benefits of natural gas to coal, not cleaner renewables.