When coal is mined, processed, or transported, its dust gets into the air, which is why miners get black lung disease. Most coal makes smoke when it is burned, particulate matter that causes breathing problems for people who are exposed to it. A lot of carbon dioxide (CO₂) is emitted from coal fires, relative to the energy produced. Emissions go beyond CO₂, however, and include a variety of toxins. Burning it in the Midwest produced much of the mercury that poisoned the lakes and rivers of New England. Coal ash is toxic, but no really good method of disposal has been developed. So, the ash gets stored in lagoons, which occasionally spill into rivers, poisoning anything living in them.
Natural gas is much better, we have been told by the industry that sells it. And if you limit your observations to coal’s problems and how natural gas compares on those issues, what they say might appear to be true. But natural gas has its own problems, and many scientists who have investigated the effects on the environment say natural gas is nearly as bad as coal. Some say it is worse.
Using natural gas at a building means that it must be piped in. Since natural gas is very flammable and pipes sometimes leak, every once in a while, some building blows up. Really. In 2018, over 40 houses in the Merrimack Valley exploded or burned in a short time, because the pressure in the gas main spiked, causing the gas to leak in many homes.
The methane (CH₄) in natural gas has nearly no smell, so companies add ethyl mercaptan to it to make it smell really bad. That way, people will notice leaks in homes. Unfortunately, most of the homes that burned in the Merrimack Valley did not have anyone home at the time, so nobody noticed the problem. The up side of this was that only one person was killed.
Natural gas leaks are amazingly widespread. Boston University students drove every street of the city in a specially equipped car, and they found 3,300 leaks, most of which were quite small. When scientists did a follow-up study to check the results, they found more.
Natural gas leaks are not just a fire hazard. CH₄ that escapes into the environment is about 84 times as potent as CO₂ as a greenhouse gas over a twenty-year span. And Boston’s problem is not the worst of it. Natural gas leaks happen in the gas fields, especially where fracking has been done. The oil and gas companies sometimes say they are not losing much gas in the fields, but carefully conducted studies show the leaks are a multiple of what they admitted.
Long distance pipes leak and so do storage facilities. Since depleted oil wells and caverns left after salt was removed from salt domes are used for storage, the amounts that can be in a storage facility can be huge. The Aliso Canyon gas leak of 2015 released about 100,000 tons of natural gas from this type of underground storage.
In addition to being a powerful greenhouse gas, the CH₄ in natural gas is a powerful toxin. Trees near small CH₄ leaks sometimes die because of them. Animals can also suffer and die, including human beings.
One of the interesting aspects of natural gas is its place in the market. Historically, huge profits have been made with drilling, extracting, and selling natural gas. Of late, that has not been true. Wall Street observers have called the oil and gas industry one of the worst investments a person can make. The Dow Jones Oil & Gas Index is off about 50% from what it was four years ago, despite help from the federal government. And that index just represents the larger companies; small companies have had far worse problems.
Some larger companies in the oil and gas sector have been looking at ways to improve their business plans. One way they have tried to do this is to move from selling fuels to making plastics from oil. But plastics are so bad for the environment that they are not likely to make more money in the future.
Another possibility is to use skills in slightly different fields. One of these is the manufacture of green hydrogen (see the article on this page). Another is for those with experience on offshore drilling to work in the offshore wind industry. Danish Oil and Natural Gas switched its focus entirely to renewable energy, especially offshore wind power. Renamed Ørsted, it recently announced that it had no fossil fuels assets left at all. And Ørsted, unlike the companies that remain in oil and gas, is making money.