The latest victim of the virus? OilPetroleum is a natural liquid that, when distilled and refined, can be burnt for fuel, or used to make plastics, pesticides, and medicine.. And it could be the most serious development yet, in a clear warning we are heading for a huge global recession.

Yesterday, fear seized global stock markets, as investors sold shares at discount prices. It was the biggest one-day fall since the 2008 financial crisis, with one analyst calling it "utter carnage".

Early this morning, the panic looks set to continue for another day.

Why now? On Sunday night, the price of oil collapsed. Two months of Covid-19, quarantined cities, shut factories, and cancelled holidays has slashed demand for the fuel that powers the global economy.

And the world's second-largest producer of oil, Saudi Arabia, has chosen this week to launch a price war with its main competitor, Russia.

If there is no money in drilling oil, countries that produce it will suffer. But even worse: if people don't need oil, it means they're not buying anything else.

This is because oil is the most important commodity in the modern world. When the US began drilling it in 1859, it was a cheap way to heat and light up homes and cities. But the invention of the car, and then the aeroplane, changed everything.

Oil not only keeps society moving, but it also shrinks the globe. Fresh food from South America, cheap clothes and electronics from China are all possible because of the fast, interconnected, oil-fuelled world in which we live.

It is also used to make plastic and thousands of everyday items - from phones to lipstick, to footballs and shampoo. Oil is everywhere. Where it is discovered, countries become rich overnight. WarsBetween 1980 and 2003, Iraq fought a series of wars with its neighbours for the control of oil fields. are fought over it. No wonder it is called "black gold".

But what about the climate crisis? Oil is a fossil fuel and a major cause of CO2 emissions, accelerating global warming. Climate experts insist that we need to weenTo get (someone) used to managing without something which they have become dependent on. ourselves off our oil-guzzling lifestyle on to sustainable and renewableEnergy sources, such as wind and solar power. forms of energy. Besides, there's a finite amount of oil in the ground. At some point in the future, the wells will run dry.

Not any time soon, say the experts. Renewable energy counts for less than 15% of world energy consumption. And the bargain price of Saudi oil, this week, suggests we have far more than we currently need.

Some say this is just stock market jitters, with investors scared of losing their money. In the real world, we are worried about the virus itself and its threat to health. The price of oil has risen and fallen dramatically many times in the last century, and the world has not come to an end. And if the virus means we travel less and buy locally, we may discover we don't need oil quite as much as we thought.

Others are less optimistic. The stark reality is we live in a world that runs on oil and we cannot change that overnight. It powers the trade, travel, and global transport networks that hold society together. Silent factories in China and tankers full of unused oil may feel remote and unimportant right now, but they are early warning signs of harder times to come.