The tension was palpableObvious or able to be felt. The word comes from a Latin verb meaning to touch gently. as the heads of Britain's top industries met business minister Lee Rowley yesterday. The situation, said one managing director, was "quite incredible": his glass company faced a rise in its annual fuel bill from £40m to £100m. Government help was needed - but there was little sign of any. Some firms, he warned, were "very close to the edge".

The UK is far from the only nation threatened by an energy crisis. In Lebanon, most of the country suffered power cuts after fuel shortages shut down two power stations. In China, thousands of households in Liaoning provinceA district in north-east China which is part of its industrial heartland. have been subjected to blackouts.

"Make no mistake, this winter is going to be shocking," warns Bill Blain, author of the financial newsletter Blain's Morning Porridge. "People are going to die of cold. As the price of energy goes higher, the costs will fall disproportionately upon the poorest in society."

The crisis is partly the result of trying to protect the environment. Governments have been encouraging a move away from traditional fuels. But the technology for renewables still has a long way to go, and natural sources are proving unreliable. In Europe, calm weather has reduced wind farms' output; in Brazil, low rivers have affected hydroelectric supplies.

This has left the world dependent on gas, which produces 50% less CO2 than coal. Because investors do not see it as a long-term prospect, storage capacity has been allowed to decline. Until three years agoBritain's largest storage facility, off the east coast, was closed down in 2018.  , the UK could store enough gas for 15 days' demand in winter; now that is down to five.

Production at Europe's largest gas field, Groningen in the Netherlands, has been reduced by 75% in response to small earthquakes. "Europe principally has two options for additional gas supplies as it is so heavily reliant on imports," says one expert: "Russia or cargoes of liquefied natural gas [LNG]."

But LNG, which comes from the Middle East and the USA, is much in demand from AsiaDemand there has increased by 50% over the last ten tears..  "Every year China connects up to 15 million homes in its coastal cities to the gas grid," says another expert. "So when it gets cold in China, the gas price goes upGas prices in Europe and Asia have risen by 250% since January. in the UK and Germany."

This leaves Russia, which supplies more than a third of Europe's gas, in a strong position. It has been accused of restricting output in order to push up prices.

Some believe the crisis could have a positive result, forcing world leaders to focus on the problem of climate change and agree on a far-reaching programme at the COP26Cop stands for  Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change conference next month.

Yes. Politicians have been dragging their feet in introducing green technology because they do not want to spend money. A hard winter will result in voters pressurising them into speeding up the process.

No. The crisis will simply force people back to reliance on non-green energy: China has already ordered more than 200 of its coal mines to increase production. The economic damage done will make it harder for nations to afford clean technology. Most worrying, it may cause ordinary people to lose faith in renewable energy.