The natural gas revolution has been busily disrupting energy markets (and also transforming North Dakota’s economy and lighting up the state so much it’s actually visible from space). Now, a report from Citigroup analysts predicts that the rapidly expanding natural gas industry will upend a long-running prediction about the future of oil. Bloomberg reports:

“The shift from oil to gas is already under way in the U.S.,” Seth Kleinman, the head of European energy research at Citigroup, and five other analysts wrote yesterday in a report. Other countries are poised to follow suit, they wrote, as gas becomes more plentiful and anti-pollution efforts intensify…

“Oil demand growth may be topping out sooner than the market expects,” Kleinman, based in London, and his colleagues wrote. Greater fuel economy may combine with the shift toward gas to cause global demand to level off at about 91 million barrels a day, the report said.

In other words, we may never hit the doomsday scenario described by the “peak oil” theory. The idea of “peak oil” really took off in the 1960s, and it’s about as intuitive as it is controversial: it claims that because the world’s oil supply is finite, we’re bound to reach a point where oil production hits a peak and begins declining. That, in turn would lead to soaring oil prices, collapsing economies, and a generally chaotic future.

Many believers in the theory thought that we would hit that peak decades ago. Fortunately for us, technological advanced have steadily improved our ability to access more and more difficult-to-reach oil, staving off the arrival of that day when we can no longer extract enough oil to meet global demand.

Now, the steady march of technology has unlocked vast quantities of an alternative fuel source, and if the Citigroup report proves accurate, we may soon see a scenario that peak oil believers never would have expected: hitting peak oil demand before we reach peak oil supply. Right now, oil is about 4 times as expensive per BTU as natural gas. But, if plentiful natural gas can take the place of oil for more purposes, we would likely see the cost per BTU of both to come closer to parity. In other words, a significant decline in oil prices and a corresponding increase in natural gas prices.

Of course, there are still many uncertainties that could prevent Citigroup’s crystal ball gazing from coming true. But the natural gas boom is certainly changing the energy market in ways that few could have predicted just a few years ago.