Memes

Perfectly combusted butane only releases CO2 and water, too. The point of that experiment is showing nothing burns perfectly. Even 100% pure methane burning at 100% efficiency releases CO2, which has measurable toxicity in humans.

That being said, largery hydrocarbons will generally burn less perfectly then smaller ones. Methane has 1 carbon. Butane has four. Gasoline has 8-10, lower grade fuels have more, tars get to 20-30. Coal is a mixture of tars and hydrocarbons with even longer carbon chains.

It does not burn totally clean. All extracts of gas and oil, including that of natural gas (which is methane) are not 100% pure and do not burn at 100% efficiency. If that were the case, there would be no byproducts, such as leftover methane. It also turns into CO2 when burned, which while not as harmful to the environment, is not something you want built up during an inversion and can contribute to climate change.

Even if it were some how burned at 100% efficiency, there is another source of pollution before it ever gets to the power plant: leaks.

Methane is the main component of natural gas; it makes up 70% or more of raw natural gas in the ground and well over 95% of the processed gas we burn for energy. When burned, this methane turns into CO2—but before then, it can escape into the atmosphere from all parts of gas infrastructure, like valves and pipes. And those leaks, too, need to be counted when we calculate how much natural gas is contributing to climate change.

The U.S. Environmental Protection Agency estimates that about 6.5 million metric tons of methane leak from the oil and gas supply chain each year5—around 1% of total natural gas production. At this rate, methane leaks would account for around 10% of natural gas’s contribution to climate change, and CO2 emissions for the other 90%.

In a 2022 study focused on gas production in New Mexico, a group of Stanford researchers estimated that leaks equated to more than 9 percent of all production in the area, based on aerial surveys.7 A 2023 study suggested methane emissions were 70 percent higher than U.S. government figures from 2010 to 2019.8 Plata says there’s no current consensus on the magnitude of methane leaks.

“Leaks are so poorly quantified,” Plata says. “Nobody knows that number for sure. It's hard to sense methane comprehensively and finding those pipe-based leaks can be trickier than it sounds.”

Leaks can start and stop irregularly, in different places along the natural gas supply chain, making them hard to spot even as more methane-sensing satellites are put into space. For now, we’re largely dependent on scientists, industry, or citizen volunteers trying to find leaks one at a time, with equipment that is not consistently accurate.

Methane has a much shorter lifespan than CO2, but traps much more heat while it’s still floating around in the atmosphere. We’ve previously covered the challenge of comparing methane to CO2 at Ask MIT Climate, but in short, the EPA and other organizations usually say methane is about 28 times more warming than CO2—if you look 100 years in the future. Over 10 or 20 years, though, methane is 80 to 100 times more warming than CO2.

Source: https://climate.mit.edu/ask-mit/how-much-does-natural-gas-contribute-climate-change-through-co2-emissions-when-fuel-burned

Natural gas is still a pollutant in multiple ways. While it's cleaner than coal, it is still a contributor to greenhouse gasses, both while burning and in transit to customers (including power plants). "Natural gas" is a greenwashing marketing term from big oil and gas companies. It's methane. That's what it is. It has been shown to warm the climate in multiple ways (CO2 and methane) and is a contributor to children getting life long asthma. It should not be used at all, but especially not in a valley that gets intense inversions which trap the gas.

The Wikipedia page goes into much more detail, under "environmental effects": https://en.wikipedia.org/wiki/Natural_gas