A few years after I graduated from college, I drove with a friend to Southern California, a place I’d never been. I saw a little of Los Angeles, then went north and spent a few days bumbling through the San Joaquin Valley. Going about Bakersfield one night, I got hopelessly lost and ended up at a chain-link fence. Behind the fence were thousands of oil pumps, nodding up and down like so many giant plastic drinking birds. Enshrouding the pumps was a spiderweb of pipes and electrical wires, vast and complex beyond reason, lights and machinery stretching out across the desert farther than I could see. A giant, hypermodern petroleum operation barely 100 miles from Los Angeles! I couldn’t believe it. As I stood gawping, a policeman drove by. I asked him when this complex had sprung up. He looked at me like I was an idiot. “They’ve been drilling here since 1899,” he said.
I was standing by the Kern River oil field, one of the best-known petroleum deposits in the United States. Because I had somehow missed geology in school, I had been left with the vague idea that oil is found in big subterranean pools, like the underground lake where Voldemort conceals part of his soul in the Harry Potter series. In fact, petroleum is usually contained in solid sandstone or limestone strata, which are riddled, spongelike, with minute pores. Or it can occur in thin sheets between layers of shale. Looking at the nodding wells, I had the notion that they were drawing a uniform substance from the ground, a black liquid like the inky water in Voldemort’s lake. Instead, petroleum occurs as a crazy stew of different compounds: oil of various grades mixed with methane, ethane, propane, butane, and other hydrocarbons. Squashed into stone hundreds or thousands of feet underground, this jumble of liquid and gas is usually under great pressure. Layers, or “caps,” of impermeable rock prevent it from seeping to the surface. When drilling bores through the caps, petroleum shoots up in orthodox gusher fashion.
For a long time, companies collected oil and discarded the methane that burbled up with it, often by burning the gas in a cinematic flare atop special derricks, or even simply dumping it into the atmosphere. People did use natural gas for energy—gaslights have existed since the days of Jane Austen—but transporting it was costly. Unlike liquid oil, which could be poured into containers and carried on a railroad network that had already been built and paid for by somebody else, gaseous methane had to be pumped through sealed tubes to its destination, which required energy firms and utilities to lay thousands upon thousands of miles of pipeline. Not until the Second World War and war-production advances in welding did this effort gather speed. (Methane can be cooled into a liquid and transported in pressurized tanks that are loaded and unloaded in special facilities, but this is also expensive.) Oil from wells in Texas is readily dispatched via tanker to Europe or Asia, but even today, natural gas from the same wells is often effectively limited to use in the United States.
From the beginning, it was evident that the Kern River field was rich with oil, millions upon millions of barrels. (A barrel, the unit of oil measurement, is 42 gallons; depending on the grade, a ton of oil is six to eight barrels.) Wildcatters poured into the area, throwing up derricks, boring wells, and pulling out what they could. In 1949, after 50 years of drilling, analysts estimated that just 47 million barrels remained in reserves—a rounding error in the oil business. Kern River, it seemed, was nearly played out. Instead, oil companies removed 945 million barrels in the next 40 years. In 1989, analysts again estimated Kern reserves: 697 million barrels. By 2009, Kern had produced more than 1.3 billion additional barrels, and reserves were estimated to be almost 600 million barrels.
What does it mean when oil companies say they have so many million barrels in reserves? How much energy is in the ground? When will we begin running out? As the history of the Kern River field suggests, these questions are not easy to answer. Indeed, Ph.D.‑toting experts have bombarded Americans for half a century with totally contradictory responses. On one side, pessimists claim that the planet is slowly running out of petroleum. “Turn down the thermostat!” they cry. “Stuff insulation in your walls!” “Buy a hybrid!” “Conserve!” From the other side come equally loud shouts insisting that there are vast, untapped petroleum deposits in Alaska and Alberta and off the coast of Virginia, that geysers of natural gas exist in the shale beds of Pennsylvania and North Dakota, and that huge oil patches await extraction in the deep ocean. “Drill, baby, drill!” “The end of oil!” Al Gore or Sarah Palin, Cassandra or Pollyanna, which side is right? The back-and-forth would be comical if the stakes didn’t involve the fate of human civilization.
When gasoline supplies drop, TV news reporters like to wring their hands at the drivers mobbing the corner Exxon. But the motorists’ panic reflects a basic truth: economic growth and energy use have marched in lockstep for generations. Between 1900 and 2000, global energy consumption rose roughly 17-fold, the University of Manitoba environmental scientist Vaclav Smil has calculated, while economic output rose 16-fold—“as close a link as one may find in the unruly realm of economic affairs.” Petroleum has wreaked all kinds of social and environmental havoc, but a steady supply of oil and gas remains just as central to the world’s economic well-being as it was in Churchill’s day. According to the National Bureau of Economic Research, the United States has experienced 11 recessions since the end of the Second World War. All but one were associated with spikes in energy costs—specifically, abrupt jumps in the price of oil.
Understanding this dependence, the oil industry was shaken by a speech in 1956 by M. King Hubbert, a prominent geophysicist at Shell Oil. When a company moves into a field, it grabs the easy, cheap oil first. Tapping the rest gets progressively more difficult and expensive. Eventually, Hubbert observed, conditions get so tough that production levels off—it peaks. After the peak, decline is unstoppable, the fall as ineluctable as the rise. Hubbert used his theory to predict that the crude-oil yield in the continental United States would flatten between 1965 and 1970 (he didn’t include Alaska and most offshore oil areas). Coming at a time when estimates by the U.S. Geological Survey and the petroleum industry were constantly rising, this claim was derided; indeed, Hubbert claimed that just before giving his speech, a Shell official tried to get him to back off.
Hubbert, not the least self-confident of men, stood his ground, even after he left Shell and in 1964 went to work for the Geological Survey. Unluckily for him, his most prominent critic was now his boss: Vincent E. McKelvey, a long-serving geologist at USGS who would become its director in 1971. As the University of Iowa historian Tyler Priest has documented, McKelvey’s USGS issued a stream of optimistic assessments about the country’s oil future. So did its counterparts in the oil industry. Meanwhile, Hubbert cranked out papers taking the opposite stance, none of them published by the Geological Survey. Inevitably, the dispute grew personal. Three days after McKelvey became the USGS director, he took away Hubbert’s secretary, a harsh measure in the days before e‑mail. According to Priest, Hubbert ended up having to write all his correspondence in longhand; his wife typed his reports at home. Hubbert struck back by helping to kill McKelvey’s nominations to the National Academy of Sciences and the American Academy of Arts and Sciences.
In a blow to McKelvey, Hubbert’s prediction proved to be correct. As domestic crude-oil production peaked and then fell, former Interior Secretary Stewart Udall mocked the sunny claims from the Geological Survey as “an enormous energy balloon of inflated promises and boundless optimism [that] had long since lost touch with any mainland reality.” If Udall were reappointed Interior secretary, he said, “the first thing I would do would be to kick McKelvey out.” In 1977, newly elected President Jimmy Carter, a Hubbertian, forced McKelvey to resign—the first such ouster, Priest notes, “in the Survey’s 98-year history.”
Hubbert’s message of scarcity resonated at a time when the United States was haunted by the specter of Middle Eastern oil blockades. In a nationwide address, President Carter proclaimed that the planet’s proven oil reserves could be consumed “by the end of the next decade.” To forestall the disaster, he fired a volley of energy-efficiency measures: gas-mileage regulation, home-appliance energy standards, conservation tax credits, subsidies for insulation and weatherization. Congress enacted incentives and restrictions to induce industry to switch from supposedly scarce oil and natural gas to coal, which the U.S. has in abundance.
Alas, petroleum firms found so much crude oil in the 1980s that by the 1990s, prices (after adjusting for inflation) had fallen to one-fifth of what they had been during the Carter administration. Estimates of reserves rose and rose again. Energy conservation faltered; oil and gas were too cheap to be worth saving.
The argument has nonetheless continued, pessimists and optimists hammering at each other like Montagues and Capulets. Most of the Hubbertians are physical scientists; most of the McKelveyans, social scientists. Central to the conflict is their differing concepts of a reserve. Recall, as an example, the Kern River field. Its thousands of nodding pumps are siphoning up oil so thick and heavy that it almost doesn’t float on water. Although drillers knew from the first that the field was abundant, they could barely wrest any of this goop from the ground, a factor reflected in the first estimate of the reserve (47 million barrels of recoverable oil). Between that estimate and the second (697 million barrels), engineers developed a precursor to fracking: shooting hot steam down Kern River wells to thin the oil and force it out of the stone. At first, the process was hideously inefficient: heating the water to produce the steam required as much as 40 percent of the oil that came out of the wells. Burning unrefined crude oil released torrents of pollution: nitrous oxide, sulfur dioxide, carbon dioxide. But it squeezed out petroleum that had seemed impossible to reach.
At the same time, the industry learned how to burrow farther into the Earth, opening up previously inaccessible deposits. In 1998, an oil rig near the Kern River field drilled thousands of feet deeper than any previous attempt in the area. At 17,657 feet, the well blew out in a classic gusher. Flames shot 300 feet in the air. The blast destroyed the well and everything else on the site. Even after the fire burned out, petroleum flooded from the hole for another six months. Energy firms guessed that the blowout hinted at the presence of big new oil-and-gas deposits. Earlier assessments had missed them because of their great depth. Investors rushed in and began to drill.
To McKelveyan social scientists, such stories demonstrate that oil reserves should not be thought of as physical entities. Rather, they are economic judgments: how much petroleum experts believe can be harvested from given areas at an affordable price. Even as companies drain off the easy oil, innovation keeps pushing down the cost of getting the rest. From this vantage, the race between declining oil and advancing technology determines the size of a reserve—not the number of hydrocarbon molecules in the ground. Companies that scrambled to follow the Kern River gusher found millions of barrels of deep oil, but it was mixed with so much water that they couldn’t stop the wells from flooding. Within a few years, almost all the new rigs ceased operation. The reserve vanished, but the oil remained.
This perspective has a corollary: natural resources cannot be used up. If one deposit gets too expensive to drill, social scientists (most of them economists) say, people will either find cheaper deposits or shift to a different energy source altogether. Because the costliest stuff is left in the ground, there will always be petroleum to mine later. “When will the world’s supply of oil be exhausted?” asked the MIT economist Morris Adelman, perhaps the most important exponent of this view. “The best one-word answer: never.” Effectively, energy supplies are infinite.