When the price of crude oil goes through one of its periodic downturns, as it is doing now, it sends a shiver through the oil industry. History promises that higher prices will return. Until then, US shale companies are under severe pressure and big oil companies wonder about the viability of new projects. There is more to worry them this time: not just the 29 percent fall in the price of Brent crude since the start of October as Russia and Saudi Arabia pump more oil, but the fear of this bear market enduring.

The romance of oil exploration is fading at companies such as Royal Dutch Shell, BP and ExxonMobil as they rethink the way they have operated for decades. “Peak oil” used to mean the Malthusian fear that a limited natural resource would run out, leaving the world without hydrocarbon supplies to power economies. Now, it has come to mean the opposite: the prospect of demand peaking in the next 20 years, and reserves being left in the ground because they are not needed. Coal use may already have peaked according to the International Energy Agency.

The consultancy Wood Mackenzie predicts that demand for oil will peak in the late 2030s. For companies that routinely spend tens of billions on big exploration projects that can keep producing oil for several decades, that is not merely futurology. It is a clear and present danger. From society’s point of view, this is welcome. The rise of wind, solar and other alternative energy sources, the switch from internal combustion engines to electric motors in vehicles, and higher energy efficiency all increase the likelihood of being able to limit carbon emissions. But it leaves oil companies as we have known them casting around for a future. One option is to transition from oil to gas, as Shell has done by investing more in gas exploration and operating 13 liquefied natural gas facilities.

Gas is a fossil fuel but gas-fired power plants are better for the environment than coal-fired generators and gas demand is expected to keep rising. This allows companies to carry on doing roughly the same thing, with similar workforces and cultures. Deep water exploration, the speciality of their engineers, will still be required and gas can be a feedstock for their chemicals plants. It is the natural way to go for those wanting to be disrupted as little as possible.

A second option is to transform oil companies into energy companies that are agnostic about sources — they will build wind and solar farms as enthusiastically as drilling for oil or gas. Scandinavian energy companies are heading in that direction. The Danish group Dong sold its North Sea oil and gas assets last year, concentrating on renewable energy including wind, and renamed itself Orsted.