Fifteen to twenty-five percent. That is the fraction of its pre-war flow at which liquefied natural gas is now moving out of the Persian Gulf, by Goldman Sachs’s estimate, measured against the levels of February 2026, when war broke out between Iran and the United States and Israel. Everything else in the world’s gas market this autumn — the prices, the bidding contests, the quiet return of a fuel Europe had sworn off — hangs off that number.

The International Gas Union, an industry association whose membership covers about 90 percent of the world’s gas producers, expects supply to remain tighter than it should be until next summer at least, with the risk of prolonged demand destruction along the way. “The market right now is saying that they see the conflict getting prolonged,” the IGU’s secretary general, Menelaos Ydreos, told Reuters this week. “Europe is starting to outbid Asia because they need to refill storage levels.”

The bidding war has a purpose. Europe’s heating season has not officially begun, and the bloc is already struggling to cover its winter needs. It is buying against Asian importers for cargoes that, in a normal year, would have sailed west out of the Gulf without contest — a strait Iran has offered to reopen within seven days if Washington lifts its blockade, an offer to which the United States has given no formal answer.

Ydreos acknowledged that the price surge has already destroyed some demand, though whether the loss is temporary or permanent remains unclear. A recent Global Energy Monitor report points toward temporary: countries in Southeast Asia are still building gas-fired power plants, and Asian buyers are still adding LNG import capacity, despite the inflation the Middle East war has driven into the fuel. “There is some short-term demand destruction,” Ydreos told Reuters. “The question is whether it rebounds after everything settles or whether there are some longer-term implications around policy.”

The banker’s arithmetic

Goldman Sachs, for its part, is not too concerned about gas demand’s long-term future, and in a report this week sketched an optimistic winter: European prices could fall from around 70 euros per megawatt-hour to 50 if the flow of LNG from the Gulf improves. The bank’s central expectation, though, is that prices average 70 euros per MWh — roughly $80 — a forecast raised significantly from an earlier range of 30 to 60 euros.

“In the absence of an improvement in exports through the Strait of Hormuz, European gas prices need to increase in order to outcompete importers of LNG elsewhere in the world,” the bank wrote. Samantha Dart, co-head of Global Commodities Research, reduced the mechanism to nine words: “If others stop buying, there is more left to come to Europe.”

Others are not stopping. What is moving instead is coal. Reuters reported this week that coal consumption by European power utilities could rise by as much as 25 percent over the next six months, as gas prices this month touched 80 euros per MWh, the highest in three years. Over the 30 days to September 24, European benchmark gas added more than 17 percent, according to data from EnergyRiskIQ. The fuel that was supposed to be leaving the European grid is being asked back, because the alternative is unaffordable.

Bans and molecules

Two more constraints wait on the calendar. The European Union’s ban on Russian LNG imports, approved earlier this year, takes effect in January. Flows from Yamal LNG will be redirected toward Asia and, Ydreos said, could be sold at a discount — relief for Asian importers, and a thinner supply base for Europe, whose leadership has made clear repeatedly that geopolitical priorities come first and that the bloc should be prepared to bear their cost.

The second constraint is regulatory. The EU’s methane rules require tracking every gas molecule to verify it was produced with care for emissions, and Qatar and the United States — the bloc’s two biggest LNG suppliers — have said repeatedly they will not comply. “We’re for regulations, but they have to be achievable, practical and incentivise compliance,” Ydreos told Reuters. “If regulations go far beyond that and make it extremely difficult for the industry to comply, they’ll look for other regions to send their product.” With Qatar temporarily off the stage, the United States remains Europe’s only hope for LNG supply, whatever the cost.

So the winter’s arithmetic comes back to the one number that opened it. So long as the Gulf ships a quarter, or a fifth, or a seventh of what it did before February 2026, Europe pays 70 euros or 80, Asia pays more or loses the cargo, and the coal plants stay warm.