Oil rig with American flag © Martin Rogers, Photographer's Choice, Getty Images

We've come a long way since the oil shock of 1973, when Arab countries raised the price of oil while cutting production -- throwing the U.S. into crisis.

Now, the American energy story is completely different. Our oil imports are tumbling, and consumption is down. Part of that is due to the struggling economy, but also because our cars are extremely fuel-efficient, and more of them skip gas altogether. Plus, we now produce more of our own energy, moving the country from oil junkie to oil exporter. 

If the Middle East decided to cut us off again, we'd still feel the sting. But it wouldn't be nearly as devastating as it was three decades ago. The U.S. is now the fastest-growing oil and natural gas producer in the world.

Our new energy boom is destroying the notion of "peak oil" -- the idea that the world's oil production is headed downhill from here. And it's leading many to wonder if the U.S. is approaching the long-sought goal of energy independence. Could we finally take care of ourselves?

Still a net importer

Before we go down this road, let's look at the current energy picture. The U.S. still imports a lot of petroleum -- about 10.6 million barrels a day last year from some 80 countries. Those imports made up about 40% of the petroleum used in the U.S. (Petroleum includes crude oil, gasoline and such biofuels as ethanol and biodiesel.)

But the situation is changing fast. Those net imports are declining sharply, and last year were the lowest since 1991. Domestic oil production surpassed 7 million barrels a day in February for the first time in two decades. Deepwater drilling in the Gulf of Mexico has rebounded after 2010's deadly Deepwater Horizon oil rig explosion.

Now, the U.S. is on track to produce more crude oil than it imports by next year, according to the U.S. Energy Information Administration.

Line graph of US oil consumption, production and imports, 1950-2012

This is a big deal. And it's creating ripple effects across the country, adding hundreds of thousands of jobs and boosting our gross domestic output. It has the potential to shake up global oil markets, rattling the oil cartel known as OPEC.

But the U.S. is making some huge trade-offs on the road to energy independence. Some worry that the new energy boom is causing significant and long-lasting damage to the land. People on both sides of the aisle are deeply opinionated, leading to intense political divides in Congress.

To understand what's happening, look no farther than Pennsylvania, one of the states that, along with North Dakota, is at ground zero of America's new energy boom.

Fracking crazy

About 60% of Pennsylvania rests on the Marcellus Shale, a vast sprawl of sedimentary rock that holds enormous amounts of untapped natural gas. It may be the second-largest natural gas find in the world -- and it was mostly off-limits to energy companies because it was too difficult and too expensive to get at.

The advanced technologies that make "fracking" possible changed all that. This high-volume hydraulic fracturing starts by drilling deep down into the ground, then turning the drill 90 degrees and fanning outward horizontally. It's a pretty ingenious way of getting at shale formations that are hundreds of millions of years old.

A mixture of water, sand and chemicals is forced into the ground, shattering the shale rock and drawing out precious oil and natural gas. Some water comes back up, too, but it's incredibly toxic at this point, carrying chemicals, acids, heavy metals and other material that's poisonous to humans and wildlife.

The good news: Fracking the richness of the Marcellus Shale has turned Pennsylvania's economy around. Pittsburgh is a global destination now for oil companies, and its population is growing for the first time since the 1940s. Shale gas has boosted Pennsylvania's economy by about $7 billion, and that could double by 2015, according to research firm IHS.

The bad news: Stories abound about how fracking has ruined lives in Pennsylvania. Well water became contaminated and corrosive. Animals lost their hair and died. Fish were poisoned. Arsenic and carcinogens have been found in the soil.

State officials and energy companies say they've cleaned up the messes left behind, and that in some ways the experience in Pennsylvania is shaping new fracking policies with a greater focus on the environmental impact. "Before our eyes, the U.S. is moving toward dramatically more energy independence," wrote former Pennsylvania Gov. Ed Rendell in a broad defense of fracking in The New York Daily News earlier this year.