NEW YORK (CNN/Money.com) - The world's oil supply won't run out tomorrow, but lawmakers worry so much about the possibility that they're dealing with it today.

A House energy subcommittee met Wednesday morning to learn more about the so-called peak oil movement, which claims that by 2008 humans will have extracted half the earth's oil. In other words, we're using oil faster than we can ever hope to retrieve it.

"We have all been enjoying the greatest party the world has ever seen: the great oil party," said Kjell Aleklett, president of the Association for the Study of Peak Oil, or ASPO, and a physics professor at Uppsala University in Sweden. Aleklett appeared as a key witness at the hearing.

The professor said in a paper last year, "After the climax comes the decline, when we have to sober up and face the fact that the party is coming to an end."

The hangover would mean not only the end of low oil prices but also a slowdown in world economic growth. The morning after could also lead to social and political unrest as many countries try to keep the party going even as oil disappears.

While there is debate over when this peak will occur, said Rep. Wayne Gilchrest, R-Md., everyone can agree on one thing.

"At some point in this century, oil production will peak and then decline," Gilchrest testified. "But more uncertainty calls for more caution, not less. And in this case, caution means finding alternatives."

Witnesses, including Robert Hirsch, senior energy program advisor at Science Applications International Corp., and Robert Esser, a director and senior consultant at Cambridge Energy Research Associates, also testified before the Subcommittee on Energy and Air Quality in an attempt to quantify the true threat of peak oil.

People have predicted the end of the oil age since the first oil well was drilled in the mid-19th century, but as oil production increased in the 1960s the theory was ridiculed.

But recent events -- especially light crude's recent jump to a record intraday high at $70.85 a barrel in the wake of Hurricane Katrina -- have brought ASPO's 24 geologists, physicists and former oil-sector employees into the spotlight.

U.S. government analysts also say that the amount of oil that can be pulled from the planet is finite. But they estimate that global oil production will likely peak in 2037, rather than in 2008.

"All or nearly all of the largest oil fields have already been discovered and are being produced. Production is, indeed, clearly past its peak in some of the most prolific basins," the federal Energy Information Administration said in a recent report on peak oil.

"Over the last 20 years, the size of oil discoveries has fallen off dramatically. We are finding more fields than in the '60s and '70s, but they're much smaller," said Michael Rodgers, ex-oil geologist who is now senior director of PFC Energy, a nonpartisan energy consulting firm. "We're producing three barrels of oil for every one barrel of oil that we find."

Many peak oil critics say it won't happen because technology will keep petroleum depletion at bay.

Anxieties about running out of oil "are not frivolous, given the stark realities evident in many areas of the world," Alan Greenspan said in a speech in Washington, D.C., last October.

But Greenspan ultimately rejected the specter of oil reaching its peak, saying that technology will prevail to ensure the necessary oil supplies as long as technology has a "more supportive environment" -- meaning more money and government support.

"The industry is not standing in place. It's not sitting idle," Fadel Gheit, an oil analyst with Oppenheimer, told CNN. "It is improving exploration, production, development and delivery of oil."

Despite political turmoil, "countries are always drilling and exploring for oil, because there is power in having oil," ASPO's Aleklett said in an interview with CNN/Money.

However, this takes us to the heart of a security issue, said PFC's Rodgers. "It is likely that OPEC can step in and meet demand if a peak in non-OPEC regions happens. But then we'll be even more dependent on parts of the world that aren't stable and reliable."

Even if we don't run out of oil, the federal government admits it may become phenomenally expensive. "Will the world ever physically run out of crude oil? No, but only because it will eventually become very expensive in the absence of lower-cost alternatives," the EIA report said.

Echoing Rep. Gilchrest, analysts said the nation and its lawmakers must turn its focus to conservation. Several witnesses dismissed things like drilling in Alaska, saying such small stopgap measures won't put off the inevitable for long.

However, while politicians may agree that more drilling won't save us, analysts said they are loath to reflect the need for conservation in domestic energy policy because it could have serious ramifications for energy producers, utilities and even automakers.

"People don't want to face this reality," said Rodgers. "Once you accept it as a possibility -- not even as a certainty, but just as one of many possible scenarios -- then you have to make all sorts of changes [in the way you live], because it would not make sense not to."