This problem of "peak oil" was first outlined by Shell Oil's research director M. King Hubbert during the 1950s. He was ridiculed when he predicted in 1956 that the United States, then the world's biggest source of oil, would experience a production peak between 1966 and 1972, followed by decline.
But Hubbert was proved right when oil production in the lower 48 states peaked in 1970 and then started to drop, despite increased drilling, Richard Heinberg wrote in The Party's Over: Oil, War and the Fate of Industrial Societies.
Canada's oil production peaked in 1974, Egypt's in 1993, Syria's in 1995, Ecuador's in 1999, Yemen's in 2001 and Mexico's in 2004, among other countries now in decline. Overall, oil production is past peak in 33 of the world's 48 largest oil-producing companies, according to data compiled by Schwartz.
Even Saudi Arabia, with the world's largest petroleum reserves, may have peaked. The kingdom is pumping increasingly large amounts of water into the globe's largest oil field, called Ghawar, trying to get the remaining fuel out if it, industry historian Matthew R. Simmons wrote in Twilight in the Desert: The Coming Saudi Oil Shock and the World Economy.
Simmons, a former oil adviser to Vice President Dick Cheney, is no tree-hugging alarmist. But he says Saudi oil production "is likely to go into decline in the very foreseeable future."
The well-known oil investor T. Boone Pickens concluded that the world passed its peak oil production in 2005, echoing the rough time frame laid out by Hubbert and several oil geologists. Even the buttoned-down investment firm Merrill Lynch has predicted that world oil production will peak in 2015.
To plan for this inevitable downturn, nations must quickly shift toward renewable fuels, including solar energy and wind, Schwartz said. The United States must start to conserve energy and change living patterns so that people no longer commute from sprawling suburbs. People need to walk to work, use mass transit and start eating food from local farms so they don't depend on fish and fruit flown in from Asia and South America, he said.
"Countries are not prepared for this at all," Schwartz said. "And because they are not prepared, they will tend to go toward temporary solutions like burning more coal and oil shale that will only make climate change worse."
It's possible that an oil shortage could mean better health. When petroleum supplies were cut off to Cuba in 1989 because of the fall of the Soviet Union, Cubans had to start walking and biking to work and farming in their neighborhoods. The nation's obesity rate dropped by half, and fewer people died of heart attacks and diabetes, said Dr. Manuel Franco, another Johns Hopkins researcher.
Still, replacing oil isn't easy. It's more dense with energy than most alternatives. Burning one barrel (42 gallons) provides the same energy as 12 farm laborers working every day over a year.
The Stanfields burn the equivalent of about 1,400 gallons a week in their diesel-powered tractors and combines during harvest. With cheap oil, father and son have been able to work the fourth-generation family farm as a twosome. But without diesel, they would need scores of field workers.
Although Americans are keenly aware of rising fuel prices, Edward B. Stanfield doesn't believe they're yet ready to trade in golf clubs for scythes.
"It would take hundreds of people with back-breaking work to operate this farm," Stanfield said. "And where would these workers come from? Our society today is lazy. People just want to go to the store and buy their food. They don't want to know where it comes from."