In our Behind the Scenes series, CNN correspondents share their experiences in covering news and analyze the stories behind the events. CNN's Frank Sesno explores America's addiction to oil in the CNN Special Investigations Unit "We Were Warned: Out of Gas," airing Saturday and Sunday, 8 p.m. ET.
WASHINGTON (CNN) -- This was, to be honest, simply a different kind of journalism. I've never done anything quite like it.
Nearly half of Brazil's sugarcane crop becomes ethanol and three-quarters of cars sold are flex fuel vehicles.
It was time travel, globe-trekking and fact-checking all rolled into one. It was about oil and our addiction to it, how we keep it flowing and what happens if the supply is interrupted.
At every turn, I discovered something new and saw the complexity and the global nature of it all.
My time travel revolved around a series of events we set in 2009 -- a hurricane followed by a terrorist attack that disrupts the flow of millions of barrels of oil, plunging the world into chaos.
We devised the scenario after talking with experts who have gamed out this type of thing. As a journalistic experience, it was as instructive as it was chilling. Envisioning the future -- stepping into it -- made the hypothetical real.
As for the present, we just traveled the world.
It started with a helicopter ride -- 90 minutes over the choppy waters of the Gulf of Mexico, out to some of the deepest waters in the region. As I watched the sun rise in the distance and the dark water pass below, I realized how desperate we are. Where will U.S. go if prices continue to climb?
We are totally dependent on oil, and there's practically no place we won't go to get it. Interactive: How much do you need to work to pay for your gas? »
In the distance, I glimpsed a speck. As we got close, its outline took shape. It was a drill ship called the Deepwater Millennium -- our first stop on a global tour that would impress upon me the dimensions of technology, determination and exploration now required in the high-stakes, high-profit quest for oil.
On this day, the ship was drilling in two miles of water and into the seabed below. It can go down a total of 30,000 feet -- nearly six miles. Using remarkable technology, the crew can home in on the precise spot where geologists think there may be oil or natural gas. The drill ship and the crew cost the exploration company, Anadarko, $300,000 a day.
But here's the number that became my real frame of reference: The world uses 84 million barrels of oil every day. Every day. And demand is expected to grow by 40 percent in the next 20 years as America's appetite grows and China and India modernize. China is shopping for oil »
As I traveled, I kept asking myself, "Where will it come from?"
The answer: Everywhere.
It will have to come from the giant oil fields in the Middle East as well as remote locations producing what's called "unconventional oil."
So from the Gulf of Mexico off the Louisiana coast, my next stop was the frigid extremes of northwest Canada and Alberta's vast oil sands.
This, too, is hostile territory. But now the region produces one million barrels of synthetic crude every day. The oil sands cover nearly 58,000 square miles. Geologists think the oil could last for 100 years and they've barely scratched the surface. But what a scratch it is.
The oil sands are extracted in huge open pit mines -- vast holes in the ground. In the mine I visited, there are miles of roads, hundreds of pieces of equipment and more places where they dig and dump than I could see. I kept picking up chunks of earth. It smells like asphalt.
I stood down in the pit as the giant shovels clawed the earth. I climbed up into the cab of the largest truck in the world -- three stories high, able to haul 400 tons of oil sands at a time. Behind the wheel was a petite young mother of two. She works 12 hours a day. It's the best job in Fort McMurray, Alberta.
Again, I was struck by the vastness of it all, by the constant motion, constant work. It was like an ant colony on steroids -- indicative of an overwhelming instinct to toil and an insatiable demand driving it.
Are there alternatives?
Yes, and I saw one of them in the most surprising place I visited: Brazil, where sugar cane covers millions of acres. Watch a report on Brazil's "sugar boom" »
"A green ocean" was how my Brazilian host described it. About half of it becomes sugar. The other half becomes ethanol for cars and trucks. "Alcool" was sold at every gas station I saw. It is cheaper than gasoline and when you fill the tank, it smells like molasses.
The real eye-opener: The car I drove, a made-in-Brazil Chevrolet, was a 'flex fuel' vehicle that can run on either gasoline or ethanol. Three quarters of the cars sold in Brazil are now flex fuel vehicles.
And an astounding 40 percent of the transportation fuel used in Brazil is ethanol. Brazilians say within the next year, they won't need to import a drop of oil. Independence. One official who was in on the ethanol program in its earliest days 30 years ago smiled impishly and told me, "We won."
In the U.S., ethanol represents only 3 percent of the fuel we burn.
I also saw prototype hydrogen vehicles, plug-in hybrids and other things. But at the end of it all, I realize we'll need oil for a long time.
There's a lot of it out there. But the supply chain is stretched thin and demand is growing rapidly. Environmental concerns deepen. We are vulnerable. We know we have to come up with another way to power the planet.
How long we have is the big question. It's time to get serious.