As Russia tightens its chokehold on supplies of natural gas, Europe is looking everywhere for energy to keep its economy running. Coal-fired power plants are being revived. Billions are being spent on terminals to bring in liquefied natural gas, much of it from shale fields in Texas. Officials and heads of state are flying to Qatar, Azerbaijan, Norway and Algeria to nail down energy deals.

Across Europe, fears are growing that a cutoff of Russian gas will force governments to ration fuel and businesses to close factories, moves that could put thousands of jobs at risk.

So far, the hunt for fuel has been met with considerable success. But as prices continue to soar and the Russian threat shows no sign of abating, the margin for error is thin.

“There is a very big and legitimate worry about this winter,” said Michael Stoppard, vice president for global gas strategy at S&P Global, a research firm.

Five months after Russia’s invasion of Ukraine, Europe is in the grip of an accelerated and increasingly irreversible transition in how it gets its energy to heat and cool homes, drive businesses and generate power. A long-term switch to more renewable sources of energy has been overtaken by a short-term scramble to make it through the coming winter.

The amount of natural gas coming from Russia, once Europe’s largest source of the fuel, is less than a third of what it was a year ago. This week, Gazprom, the Russian energy giant, throttled back already sharply reduced flows in a key pipeline from Russia to Germany, sending European gas futures prices to record levels.

Within a day of Gazprom’s announcement, the European Union called for a 15 percent cut of gas use throughout the bloc.

This move away from Russian natural gas — almost unthinkable after a decades-long embrace of Siberian gas delivered via pipelines stretching thousands of miles — is sending shock waves through factory floors and forcing governments to seek alternative sources of energy

The multipronged effort to uncover alternatives to Russian gas has largely made up for the shortfall. Despite Gazprom’s cutbacks, supplies of natural gas in Europe in the first half of 2022 have been roughly equal to those of the same period last year, according to Jack Sharples, a fellow at the Oxford Institute for Energy Studies.
The standout performer in this comeback has been liquefied natural gas, chilled to a condensed liquid form and transported on ships. L.N.G. has essentially switched places with piped gas from Russia as Europe’s main source of the fuel. About half of the supply has come from the United States, which this year became the world’s largest exporter of the fuel.

Looking toward the end of the year, European countries are pushing energy companies to fill salt caverns and other storage facilities with gas to provide a margin of safety in case Russia shuts down the pipelines.

Europe’s gas storage has now built up to about 67 percent of overall capacity, more than 10 percentage points higher than a year ago. Those levels create some comfort that European countries might reach something close to the European Union’s target of 80 percent full before winter.

But concerns are still mounting, and there are many reasons the European effort could fall short as colder weather approaches.

Russia is well aware of the European Union’s campaign to store enough gas to fend off a cutoff this winter and wants to impede it, analysts say, by causing pipeline flows to dwindle. And all sorts of weather issues — an exceptionally cold winter, a storm in the North Sea that knocks out Norway’s gas production or a busy Atlantic hurricane season that delays L.N.G. tankers — could tip Europe into energy shortages.

“We are getting close to the danger zone,” said Massimo Di Odoardo, vice president for gas at Wood Mackenzie, a research institution.

Reflecting these worries, European gas futures prices have doubled in the last two months to about 200 euros a megawatt-hour on the Dutch TTF exchange, around 10 times the levels of a year ago.

The astronomical cost of energy in Europe is putting a wide variety of industries on the defensive, forcing changes that may help make the European Union’s voluntary 15 percent gas savings target attainable. The International Energy Agency recently forecast that gas demand in the region would fall 9 percent this year

For instance, a steel mill owned by ArcelorMittal on Hamburg’s busy harbor in Germany has for years used natural gas to extract the iron that then goes into its electric furnace. But recently, it shifted to buying metal inputs for its mill from a sister plant in Canada with access to cheaper energy. Natural gas prices in North America, while elevated by historical standards, are about a seventh of European prices.

“Natural gas costs so much that we cannot afford” to operate in the usual way, said Uwe Braun, chief executive of ArcelorMittal Hamburg.

Few analysts or executives expect the situation to ease in the coming months. Instead, the winter may well prove to be a nail-biter with energy-intensive industries like metal smelters and makers of fertilizer and glass under pressure.