The past few weeks in the United Kingdom have brought a steady stream of ominous food headlines: Beer is being rationed! (In the middle of the World Cup, no less!) Barbecues might run out of meat! Bakeries have stopped making crumpets! And then our own Yasmeen Serhan checked in for a flight from Europe to find there would be no ice cream.
What all of the above have in common is carbon dioxide. Carbon dioxide makes beer fizzy. It’s used to stun animals before slaughter. It keeps meat and crumpets fresh in their packaging by displacing oxygen. Frozen solid into dry ice, it keeps ice cream cold. And as absurd as it may sound when CO2 is rising in the atmosphere, Europe has been suffering a carbon-dioxide shortage—the “worst supply situation to hit the European carbon-dioxide (CO2) business in decades,” according the industry publication Gasworld.
The culprit? Ammonia fertilizer. And once you tug at the reason Europe is experiencing a carbon-dioxide shortage, you start to unravel the entangled supply chains of modern food production.
Factories can’t turn a profit on making pure carbon dioxide alone. Instead, the gas is made as a by-product of other chemicals, often ammonia fertilizer. That’s because the first step in manufacturing ammonia involves taking a hydrocarbon molecule like natural gas and splitting the “hydro” from the “carbon”: The hydrogen gets turned into ammonia (NH3) for fertilizer. The carbon gets turned into carbon dioxide (CO2), which is captured, purified, and liquified for all sorts of uses. In addition to the aforementioned foods, this CO2 also ends up used in packaged salad greens, soft drinks, coffee, and industrial processes like “enhanced oil recovery” in oil wells.
Ammonia production plants operate on a regular schedule governed by the planting season. Farmers typically don’t apply fertilizer in the summer, so many plants shut down for periods of maintenance in April, May, and June. But this year, higher natural-gas prices have pushed production costs up while the price of ammonia has stayed static, so plants have been in no hurry to reopen. Plus, a heat wave and the World Cup have increased demand for soft drinks and beer. “You’ve got a real perfect storm of supply-chain conditions,” says Rob Cockerill, the global managing editor of Gasworld.
There is, of course, plenty of carbon dioxide in the air—too much, in fact. But at 400 parts per million—the highest it’s been in at least 1 million years—carbon still makes up only 0.04 percent of the atmosphere. “The problem with extracting CO2 in the air is there’s not much there,” says Richard Sachleben, a retired chemist and member of the American Chemical Society. “It’s a tiny, tiny amount.” And that kind of extraction is wildly expensive. Slightly more practical is capturing the CO2 from “clean coal” plants. That CO2, incidentally, can also end up in soft drinks.
The key to preventing future carbon-dioxide shortages is simply having other other sources of CO2. Bioethanol and chemical factories, for example, also produce carbon dioxide as a by-product. But as long as the production of CO2 is tied up with the production of ammonia, it will be demand for fertilizer that the drives the supply of CO2—and the availability of ice cream on transatlantic flights.
The gas world has been through this kind of thing before. Helium is a by-product of natural gas, and it’s been through a number of shortages, most recently because of the Qatar crisis.
The situation with CO2 is easing now, says Cockerill, as plants come back online. It’ll take some weeks for everything to get back to normal. But at least they’ve started making crumpets again.