For several years, many voices, including Texas energy baron T. Boone Pickens, have been touting natural gas as the best energy source to form a bridge between the current fossil-fuel economy and a renewable energy future. Proponents contend that not only is natural gas a cleaner-burning fuel than coal, producing lower greenhouse gas emissions, but that reserves of natural gas are far greater than previously believed because of vast reserves trapped throughout the U.S — and around the world — in huge underground formations of shale.
Recently, the Wall Street Journal ran its own fawning ode to shale gas: “Shale Gas Will Rock the World.” The author, Amy Myers Jaffe — a fellow in energy studies at Rice University — wrote, “I am convinced that shale gas will revolutionize the industry — and change the world — in the coming decades.” She even suggested that the abundance of natural gas in shale deposits worldwide will slow the transition to a renewable energy future.
“It may be a lot harder to persuade people to adopt green power that needs heavy subsidies when there’s a cheap, plentiful fuel out there that’s a lot cleaner than coal, even if gas isn’t as politically popular as wind or solar,” Jaffe wrote.
The water pollution concerns alone should be sufficient to make the U.S. and other countries rethink future reliance on shale gas. Separating the gas from the shale, a process known as hydrofracturing, involves forcing a mixture of water, chemicals, and sand at high pressure down a well bore and into rock formations, creating small fractures that release the trapped gas. The process uses a huge amount of water — the New York State Department of Environmental Conservation estimates as much as 1 million gallons per well — at a time when water is already a limiting and precious resource. Second, hydraulic fracturing fluid may come back to the surface, or near enough, to affect groundwater supplies. This fluid is a mixture of chemicals including friction reducers, biocides to prevent the growth of bacteria that would damage the well piping or clog the fractures, a gel to carry materials into the fractures, and various other substances. Returning to the surface, it could also bring other environmentally damaging materials, such as heavy metals.
Advocates for shale gas claim that these effects will be minor. Others, including those in charge of water supplies, are not persuaded. In Pennsylvania, wells claimed to be safe have leaked natural gas into local domestic water supplies, with the gas bubbling out of faucets. Also in Pennsylvania, fracturing fluids have leaked before they have been sent underground and have also contaminated drinking water. These problems suggest that returning fracturing fluids to the surface could cause similar problems on a large scale.
That shale gas exists in abundance — in the U.S., Europe, Australia, China, South Africa, and other regions — is beyond question. The Marcellus Shale region in the eastern U.S. reportedly contains enough shale gas to meet U.S. natural gas demand for a century. MIT released a report last week forecasting that, in part because of the exploitation of abundant shale gas reserves, natural gas will go from making up 20 percent of he U.S.’s energy supply today to 40 percent within several decades.
But what is the reality behind the optimistic claims for shale gas? The U.S. Geological Survey lists natural gas “reserves” — the amount believed to be in the ground — in four categories: readily available with current technologies, which accounts for only 1 percent of the known natural gas in U.S. territorial limits; technically recoverable (5 percent); marginal targets for accelerated technology (6 percent); and unknown but probable (84 percent). Shale gas shares the fourth category with coal gas and methyl hydrates. The latter are a kind of water ice with methane embedded in it and occur only where it is very cold, in Arctic permafrost and below 3,000 feet in the oceans.
How long would the natural gas in each of the four categories would last if we obtained it independently — that is, only from U.S. territory? Just using our 2006 rates of use of natural gas consumption — not including any major transition to fueling our cars and trucks — the “readily available” gas within the United States would be exhausted in just one year. That, plus what is called “technically recoverable” gas, would be gone in less than a decade. What is termed “unknown but probable” would last about a century.
This means that any significant increase in our consumption of natural gas will have to come from the “unknown but probable” reserves, much of which will be from formations of shale, a sedimentary rock formed from muds in which bacteria released methane. Most of this gas is so deep underground or otherwise not very accessible that nobody is really sure that we can get at a lot of it, or of how high an environmental price we must pay to retrieve it.
Currently available wind and solar energy technologies, on the other hand, are up to the job right now. There just aren’t enough wind and solar installations, so today they provide less than 1 percent of the nation’s energy. We will need to rapidly scale up, so that by 2050 we can receive the Solar and wind do not have the enormous environmental and economic costs of developing shale gas. majority of our energy from wind and solar power. That’s an enormous task: The U.S. Census Bureau forecasts that our population will reach 440 million by 2050 — nearly a 50 percent increase from today. That’s 150 million more people, each hoping to live at the standard of living we have grown accustomed to. When that happens, the amount of fossil fuels we use today, and which provide 86 percent of America’s energy, would provide those 440 million with less than two-thirds the energy they would need, if per-capita energy use remains the same as today.
Contrary to standard criticisms of solar and wind, providing this much energy in the future would not use up a lot of land. Based on current installations, less than 1 percent of U.S. land area would be required. Right now, 22 percent of U.S. land is in agriculture, not counting grassland pasture and range used by grazing animals.
What about costs? Wind is the cheapest energy source, with installation costs as low or lower than coal’s. There’s no need to pay for fuel, and no huge costs to repair the environmental damage caused by strip-mining and underground mining, let alone costs involved to try to develop “clean-burning coal.” As for solar power, the costs of producing new cells — photovoltaic or otherwise — are moving rapidly down, and increased research and development will inevitably lead to a similar decline in installation costs.