CHAPTER SIX

Methane Is Still Fossil

LONG AGO, THE oil industry began calling methane gas, produced in conjunction with oil drilling, “natural gas.” This distinguished it from synthetic gas produced in a dirty process from coal a century ago, but “natural” makes it sound environmentally friendly as well. It isn’t. All the fossil fuels are molecules made of hydrogen and carbon compressed underground over the millennia and then dug up and burned. Methane (CH₄) burns more “cleanly” than coal and oil, with fewer toxic by-products, such as the small particles in coal smoke that cause lung cancer and emphysema. (Commercial natural gas also contains less than 10 percent molecules other than methane, which we disregard here.)¹

Methane creates less CO₂ than coal when burned, per unit of energy output—about half. Much of the progress that industrialized countries have made in flattening and modestly reducing carbon emissions in recent years has come about by substituting methane for coal. This is especially so in the United States, where revolutionary methods known as “fracking” (hydraulic fracturing by injecting liquid into rock formations to release gas) have made methane cheaper than coal. This cheap methane is the main factor behind the decline in coal use—not a liberal “war on coal”—and also behind the economic troubles of the nuclear power industry. Neither fuel can compete with US methane, nor can renewables without mandates and subsidies. In fact, methane power plants that can ramp up and down quickly make a handy complement to renewables with variable production, so the addition of renewables to a grid often really means adding renewables and methane.

Internationally, though less dramatically, other countries are also turning to methane. Russia produces large amounts and exports it to Germany and the rest of Europe, though with geopolitical tensions sometimes getting in the way. (Key pipelines go through war-torn Ukraine.) And many countries have started to import and use liquefied natural gas (LNG). It is not as cheap as methane piped from the fracked well to the consumer, because the gas must be cryogenically cooled to liquefy it and then transported in that state in tankers. But still it’s an increasingly popular fuel.

Cheaper and cleaner than coal… What could be the problem? There are two main ones from a climate perspective—in addition to the local problems of water contamination near fracking sites.

First, methane may produce only half the CO₂ of coal, but that’s still a massive amount of CO₂. As consumption rises, so does the CO₂. Yes, a growing amount of methane burned is better than a growing amount of coal, but it still runs counter to the needed rapid decarbonization. Worse yet, investments in methane infrastructure such as pipelines and LNG terminals are multibillion-dollar projects that will take decades to pay back and therefore commit us to a fossil-fuel economy well into the future.

Figure 22. Using methane gas to replace coal and balance renewables means building extensive new fossil-fuel infrastructure, from fracking wells to LNG terminals to pipeline networks. This carrier delivers LNG to Japan to replace nuclear power, 2012. Photo: via Wikimedia Commons (CC Attribution-Share Alike 2.1 Japan).

Then, too, the switch from coal to methane can happen only once, so the gains in limiting carbon emissions are only temporary. While transitioning from coal to gas, a country will make notable progress toward its goals for reducing CO₂, but as that transition finishes, suddenly emissions will stop dropping.

The transition itself can be difficult and expensive, for something that still leaves an economy dependent on fossil fuel. In the United States, cheap fracking makes methane an economical fuel, but only with investment in large-scale pipeline infrastructure. In China the supply of methane is much smaller and the switch from coal more challenging. In 2017 China tried to force a more rapid switch from coal to methane, with authorities dismantling and carting away coal-fired boilers from schools, homes, and businesses. Then winter arrived earlier and colder than usual, and methane shortages quickly developed. Elementary schools were without heat, and a major chemical company could not fulfill its contracts—leading to a world shortage of spandex, used in clothing. By December the government turned a large coal plant back on and shut down big chemical factories for four months to conserve methane for schools and homes.² However, the strategy, in combination with a phaseout of polluting motorbikes and dirty cookstoves, did clean up the air in Chinese cities considerably in the winter of 2018.³

The second major problem with methane is that it leaks, especially at the well but also all along the pipeline system.⁴ Unburned methane is a potent greenhouse gas but breaks down in the atmosphere much faster than CO₂, lasting only decades rather than hundreds of years. In a period of a couple of decades, a ton of unburned methane has more than 80 times more warming effect than a ton of CO₂, and even over a century as it breaks down it is 25 times more powerful. Some experts, though not all, think that the entire shift from coal to methane is not really a gain in climate terms.⁵ Given that much more CO₂ is being released from the burning of gas, unburned methane is less important in contributing to climate change, but it’s a serious issue. The decades when today’s methane leaks are having their strong warming effect are the decades when the climate is destabilizing and we need to be acting quickly to reverse the trend. Unburned methane moves us rapidly in the other direction, and the problem is only getting worse as methane becomes more popular as a fuel.

In Los Angeles in 2015, a massive leak at an underground methane-gas storage facility led to health problems and the evacuation of a whole neighborhood. During the four months it took to control the leak, around 100,000 tons of methane went into the atmosphere (equivalent to several months of CO₂ emissions from the whole Los Angeles Basin).

Cows and other cattle are another major source of greenhouse gases, contributing about 7 billion tons of CO₂ equivalent each year, or about 15 percent of the human contribution to climate change. About half of the cattle contribution is unburned methane gas, primarily from cow digestion (mostly burps). The problem can be reduced with changes in feed, one of a series of changes in agriculture and land use that should be better propagated and funded in order to reduce climate impacts.⁶ (Substituting chicken or pork for beef in our diets or going vegan would also greatly reduce both unburned methane and energy use.)

Figure 23. Los Angeles methane leak seen in infrared photo, 2016. Photo: Courtesy of Environmental Defense Fund.

The concentration of methane in the atmosphere rose ten times more quickly in 2006–2016 than in the prior decade, the fastest rise in recent decades. This increase is largely unexplained, perhaps related to rice production and probably not caused much by fossil-fuel use, but it threatens to set back progress toward reducing global warming.⁷

Less important from a climate perspective, but worth noting, methane gas causes deadly explosions from time to time when it leaks and then combusts. In October 2017, an explosion at a liquefied natural gas facility in Ghana killed seven and injured more than a hundred.⁸ In 2010 a gas pipeline near San Francisco exploded in a residential neighborhood, sending a wall of flame hundreds of feet in the air, destroying thirty-five houses and killing eight people. In South Korea in 1995, a gas explosion killed more than 100, most of them teenagers. In 1937, a methane explosion at a school in Texas killed almost 300 children.

Methane has been marketed as natural, clean, efficient, and cheap. But its role in addressing climate change is limited. It does have a role, but we should not consider it a solution.