Where does your food come from? The supermarket or a local farm, you might think, or maybe you even grow your own. But really the answer is fossil fuels – and thanks to the ongoing Iran war, you are going to start noticing that.

Some of the hydrogen atoms in your food actually derive from the natural gas used to make nitrogen fertilisers, for example. Many of the sulphur atoms will also come from fossil fuels – that’s what sulphur fertilisers are made from. Diesel almost certainly powered the tractors of the farmers who grew your food and the trucks and ships that transported it to you. The pesticides that the farmers used were made from fossil fuels, as was the plastic packaging that the food came in. The list could go on. It is estimated that go into producing, processing, transporting and storing food.

In a sense, you are eating fossils fuels. This means any sudden spike in oil prices hits food prices, too. In fact, if the Iran war drags on, this could become the worst food shock in the modern era. We will all pay higher prices, but those with the least will be hit hardest.

If the Iran war drags on, this could become the worst food shock in the modern era

There are solutions. Turning less food into biofuels would help limit food shock. Unfortunately, governments are starting to do the opposite. This will make little difference to fuel prices, but will make food much more expensive.

Abandoning intensive farming isn’t an option, as a grow-your-own organic revolution cannot feed the world. But we can end farming’s dependence on fossil fuels and prevent this from happening again – indeed, this has to be done anyway to help slash the massive greenhouse gas emissions from farming.

We already know how to make fertilisers from electricity – that is how they were . All that is needed is government support and a plentiful supply of renewable electricity. But, at the moment, there is no electricity to spare because it is all going into data centres for artificial intelligence. As we start to feel the pain of this food shock, we may want to rethink our priorities.

Mountain ranges could be a potential source of clean energy in the form of as-yet untapped hydrogen. While previous research has suggested this “geologic” hydrogen could be found underground, researchers have only recently turned to mountains as a possible store.

“Certain minerals react with water and can generate hydrogen like a free green energy source,” says at the Helmholtz Centre for Geosciences in Germany.

There are vast amounts of such minerals on Earth, but they are mainly found deep below the surface in a layer known as the mantle, he says, where they don’t come into contact with water. But during the formation and uplift of mountain ranges, some mantle rock can be brought close to the surface, where it can react with water in a process called serpentinisation.

To get an idea of the potential for hydrogen formation, Zwaan and his colleagues modelled the uplift process, looking at how much mantle material reaches areas where there are optimum temperatures and enough circulating water for this to occur. Their results support the idea that under mountain ranges.

Serpentinisation also occurs at mid-ocean ridges – some think it drove the origin of life – but hydrogen formed there is unlikely to be trapped, says Zwaan.  That is because the temperature is lower than 122°C (252°F), and any trapped hydrogen will be “eaten” by bacteria, but under mountains it is possible to drill down to where the temperature is higher.

“Nothing wants to live there, so it’s perfect for the hydrogen to be preserved,” Zwaan told a meeting of the European Geosciences Union in Vienna last week. “And there might even be another option, to drill into what you can call the hydrogen kitchen – the area where the hydrogen is generated.”

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The model results are supported by early findings from studies of some mountain ranges. For instance, at the University of Strasbourg, France, has confirmed there is hydrogen production under the Grisons area of the Alps in Switzerland. But how much there is remains to be seen, he told the meeting. “Our research is just at the very beginning,” he said.

There is also hydrogen seeping up from below the northern Pyrenees, reported at the University of Toulouse, France. This research, too, is at an early stage.