George P. Mitchell missed by six weeks the chance to see an unmistakable example of how he changed the world. In early September, President Barack Obama pushed Congress to authorize air strikes against Syria, roiling the international community and igniting a firestorm on Capitol Hill. In the past, the mere hint that a U.S. president was considering military action in the largest oil-producing region in the world would have been enough to drive traders into a frenzy and send prices soaring. This time, the only measurable effect was a three-day blip in which prices jumped by about $2 a barrel, then quickly settled back.

We owe this ho-hum stability to the fact that domestic energy production is at its highest level in more than two decades. In 2005 the United States was importing almost 65 percent of its oil. Today, that’s slipped to about 40 percent. After forty years of reckoning with increasing scarcity, the country is suddenly basking in abundance; some forecasters even predict that we could surpass Saudi Arabia as the world’s biggest oil producer. We have enough crude in reserve to last 269 days, compared with 150 days five years ago. Add in oil from Canada (our largest source of imports), and we could hold out against a seventies-style OPEC embargo for more than a year.

It’s a stunning reversal, and all of it comes back to Mitchell, the Houston oilman who died July 26 at age 94. It was under Mitchell’s leadership that geologists developed the process for using hydraulic fracturing, or fracking, to unlock previously unreachable reservoirs of oil and natural gas. Their techniques became the blueprint for the biggest innovation to hit the oil patch since 1947, when the Kerr-McGee Corporation launched the offshore drilling industry by plunking down a rig ten miles off the Louisiana coast. The oil business is indisputably prone to hyperbole, but there’s no denying that fracking has transformed our energy outlook. In Texas, it has unleashed a boom unlike anything we’ve seen for more than a generation, and it hits Americans in the one place everyone cares about: the pocketbook. According to a recent study by the research firm IHS, real disposable income rose by $1,200 last year, not because wages increased but because utility bills and the prices of consumer goods decreased, thanks to plentiful and inexpensive energy. It’s changing global petro-politics as well. Saudi Arabia, the world’s oil cop for four decades, now watches U.S. shale production as intently as U.S. analysts once monitored production in the kingdom’s oil-rich Eastern Province.

The laboratory for Mitchell’s innovation was 350,000 acres in North Texas covering a geologic formation known as the Barnett Shale. It was here that he discovered how to profitably extract gas from source rock. Mitchell is often dubbed “the father of fracking,” but it’s not an entirely accurate label. Fracking—in which water, sand, and chemicals are injected under high pressure into shale rock to cause fissures that release natural gas or oil—was first used in 1947 in southwestern Kansas. But it was inefficient and cost-prohibitive, and it relied on far more dangerous techniques—at the time, sand was mixed with napalm rather than water. Mitchell took the idea and improved on it dramatically. He tried it at different depths, with different amounts of pressure, in different reservoirs, constantly tweaking the blend of the fracking fluid. On its face this may not sound like much, but the result of this experimentation puts Mitchell in the pantheon of oil industry stalwarts whose contributions redefined energy development.

“George is Colonel Drake,” said Dan Steward, one of Mitchell’s geologists, referring to the former railroad conductor who drilled the country’s first oil well, near Titusville, Pennsylvania, in 1859. So widespread were the critics who dismissed Drake’s idea to bore a hole in the ground with iron pipe in the hopes of extracting oil that the enterprise became known as Drake’s Folly. If Drake had his folly, Mitchell had his “hobby,” which was how the board of directors of his company, Mitchell Energy and Development, sometimes referred to the fracking research project during the seventeen years it took to develop. Like Drake, Mitchell pushed the limits of technology when others said it wouldn’t work. Drake precipitated the industry; Mitchell reinvigorated it, and nowhere more resoundingly than in North Texas.

Natural gas had been found in Wise County in the forties; the following decade, a college buddy of Mitchell’s introduced him to the play. Mitchell formed a company with the unimaginative name of Oil Drilling Inc. and began raising money to lease three thousand acres in the southwest part of the county. Oil Drilling had success with the first well it drilled, and Mitchell and his partners expanded their holdings. They soon realized they had tapped a sizable reservoir that would require extensive drilling to fully exploit, but to justify the high cost of the endeavor, they needed a long-term buyer. In those days, gas sales in the area tended to be seasonal and inconsistent, based on how much Lone Star Gas was buying to supply the Metroplex in the winter. So Mitchell signed a deal in 1955 with Natural Gas Pipeline to move gas from North Texas to Chicago for 13 cents per thousand cubic feet, which was higher than the local market price.

Mitchell, who later bought out his partners and changed the company’s name, would supply gas under this contract for the next 38 years, but at the start his geologists were doubtful about the future productivity of the reservoir. They predicted that in the Barnett Shale they could meet the contract demands and replace production for a decade, but after that, output would decline, even with new drilling. This presented two problems: not only did Mitchell have to meet the contract’s annual production demands, he also had to replace all that gas every year. The value of any oil and gas company is based on the amount it holds in reserve. As an asset is pumped, those reserves fall, so companies have to find new reserves every year to replace what’s been extracted. Reminding his people that the company’s success depended on it, Mitchell pressed them to find a way to keep the production flowing.

In early 1981 the company drilled the C.W. Slay No. 1, which produced moderate results. Mitchell wasn’t satisfied. He knew the Barnett held lots of gas, and he was determined to find a drilling technique that could release it. The company had used hydraulic fracturing in 1979, doubling the production of a conventional gas well in Limestone County, and Mitchell decided to try it again.

At that time, geologists knew that shale was a source for oil and natural gas, but the prevailing theory was that such deposits could be extracted only through natural fractures. Most of those occurred close to the surface. Mitchell decided to try fracturing the rock artificially at greater depths. The early attempts at fracking were all made in vertical wells, and while Mitchell found that production increased significantly, he still thought he could do better.

“The fracking technique was born almost entirely out of necessity,” said Robert Gray, an energy investor and longtime tennis buddy of Mitchell’s. “He took grade-C resources and figured out how to make money with them.” During the next seventeen years, the company’s wells would become a fracking test bed, an exercise in trial and error.

“The guy just wouldn’t give up,” said Dave Pursell, a managing director with the Houston investment banking firm Tudor, Pickering, Holt and Company. “It was tweaking the frack design, and it was dogged determination.” By the time Mitchell and his geologists perfected the process, they had unlocked a mammoth play. To date, the Barnett Shale has produced 12 trillion cubic feet of gas, and it could hold as much as 86 trillion cubic feet, according to a recent study by the University of Texas.

Other companies soon adapted Mitchell’s technique to shale formations around the country. Houston companies Petrohawk and EOG Resources used it to find oil in the Eagle Ford Shale. Oklahoma City–based Chesapeake Energy gobbled up acreage around the country, while others, such as Continental Resources, used fracking to tap the huge oil reserves of North Dakota’s Bakken Shale. Today, fracking operations stretch from upstate New York to offshore California. (Mitchell himself sold his company to Devon Energy for $3.5 billion in 2002.)

The economic benefits of this nationwide shale boom have been gargantuan, in part because of its exquisite timing. Together, the plays unleashed by Mitchell’s innovation have created one of the few areas of significant job growth during a period of severe financial turmoil and recession. Since early 2007, oil-industry employment has jumped by more than 40 percent, compared with a 1 percent increase in overall private-sector jobs. The shale boom also came online just as the Arab Spring destabilized the Middle East and caused crude prices to soar. “I like to think the Barnett happened because mankind needed that gas,” said Steward, who oversaw Mitchell’s fracking project. “It was a gift from God.”

The shale boom has also changed the global marketplace for oil. Because the United States is the largest consumer of oil, our 37 percent reduction in OPEC imports since 2008 has rattled the cartel. If the trend continues, the United States will edge out Russia to become the largest non-OPEC oil producer. And that’s just the beginning. Foreign oil companies have invested in joint ventures in the United States to learn fracking techniques, and domestic companies are applying the technology to foreign prospects. While it’s not yet clear if the fracking boom will materialize overseas to the same degree it has here, the revolution that Mitchell triggered may someday bring the same benefits to energy-poor countries that it has to the energy-depleted United States.

Of course, that’s only if it doesn’t fizzle out. How long the fracking boom will last is probably the hottest debate in the oil patch these days. One of the most outspoken skeptics is Sugar Land geologist Art Berman. While he holds Mitchell and his achievements in high regard, Berman doubts that the boom will live up to the hype. The wells are expensive to drill compared with traditional ones, and the production tends to decline much faster, which makes the cost of replacing that production much greater. Simply maintaining the same level of production will require more and more wells and billions of dollars in new investment. In the Eagle Ford, for example, just replacing what’s being produced now will require drilling some eight hundred new wells, Berman estimates, at a cost of as much as $8 billion. Increasing the production will cost even more. And there’s another concern: as production rises, prices may fall, making the most expensive wells uneconomic.

Environmentalists are skeptical of fracking for a different reason: they claim it contaminates groundwater. Pollution concerns have spawned a vibrant anti-fracking movement, in part because the oil industry has failed to appreciate public alarm. Many of the new reserves accessible by fracking are in heavily populated areas, and the industry’s collective hubris and disregard for public opinion have fed suspicions about the content of fracking fluids and the potential environmental hazards of the drilling process. Rather than opt for transparency, many companies have denied and evaded.

Nonetheless, the biggest beneficiary of fracking could turn out to be the still-half-baked alternative-energy sector. Thus far, our efforts to develop renewable fuels have been hampered by a mishmash of policy contradictions, financial reversals, and technological fits and starts. Over the time it took Mitchell to refine fracking (largely on his own dime), the federal government devoted billions of dollars to subsidies and tax credits for alternative fuels—wind and solar power, ethanol, and biofuels—that still aren’t economically viable and that meet little more than a sliver of our overall energy needs. Were the U.S. economy forced to rely on them for power today, it would collapse. By giving us at least another couple of decades of abundant energy, the shale boom has extended the horizon for these efforts to mature. And in the short term, the natural gas produced from shale may do more to reduce carbon emissions than all those renewables programs too. Already, electric utilities are replacing dirty coal-fired generating plants with cleaner natural-gas-powered ones, and more delivery trucks, buses, and other fleet vehicles are being converted to run on natural gas.

All of which is fitting, considering Mitchell’s unusual relationship to the environmental movement. In addition to his work in the energy business, Mitchell was a real estate developer, and in 1974, on 17,000 acres of timberland he owned just north of Houston, he opened a master-planned community that would prove to be hugely influential to the development of the modern suburb. Just as the Barnett wells were his fracking lab, The Woodlands would become a place where Mitchell worked out the theories of sustainability that he considered equally important. The project featured wildlife habitats and protected green space amid the housing and office development. In the seventies, this was still unheard of, which has led many in environmental circles to consider Mitchell the father of sustainable development. He never saw this dual parentage of sustainability and fracking as a contradiction. Jurgen Schmandt, who wrote a biography of the oilman called George P. Mitchell and the Idea of Sustainability, described it as “the Mitchell Paradox.”

“Mitchell’s engagement with sustainability was sometimes as contradictory as it was committed,” Schmandt wrote. “He was concerned about overpopulation but had ten children. He believed in clean energy but with a businessman’s point of view. He promoted natural spaces but with a developer’s mind-set.”

Fracking also has something in common with many green-energy start-ups: entrepreneurial spirit. Mitchell and his band of fiercely loyal employees were obstinate in their pursuit of fracking. And whether this was due to diligence or stubbornness, it reinforces the truism that most technology advances in the energy industry have come from the independent producers, not the majors, who flooded into shale plays only after the success of Mitchell and others.

That success has given us a reprieve from the scarcity that’s governed energy policy for the past forty years, but as even Mitchell knew, fossil fuels are finite, and global demand for energy only continues to rise. In the eighties, a popular Texas bumper sticker said, “Please God, let there be another oil boom. I promise not to piss it all away next time.” Thanks to George Mitchell, another boom is here, possibly the biggest boom in Texas history. It’s up to us not to piss it away.

Loren Steffy is a former business columnist for the Houston Chronicle and a contributor to Forbes.