Carbon carbon everywhere, yet still a very tricky job to capture it

It seems ironic: we have both too much carbon dioxide and too little, at the same time. As the UN warns that Co2 emissions will continue to rise catastrophically in the next decade, we face possible food shortages because we can’t get enough of the gas in our supply chain.

We think of Co2 as a negative by-product of our fossil fuel consumption, but it has valuable uses in everyday life, from surgical procedures to prolonging the shelf life of food. The difficulty is that 60 per cent of the UK’S supply comes from two manufacturers who create food-grade Co2 during fertiliser manufacturer, a process which uses natural gas.

As gas prices have risen, those fertiliser plants have shut down production, with knock-on effects for the meat industry, as medical uses are prioritised. Supplies of Co2 could now run out within five days, the meat industry has warned, which may mean British pork and poultry disappear from supermarket shelves. And yet the Co2 within our atmosphere continues to warm the planet, with disastrous results. The contradiction goes to the heart of the green dilemma: creating new sources of Co2 is much easier and cheaper than removing it from the atmosphere.

The problem is essentially one of chemistry. The fertiliser manufacturer process leads to the creation of pure Co2, perfect for food-grade uses which demand almost 100 per cent purity.

But in the air, Co2 is 420 parts per million (way above the pre-industrial level of 280ppm), which makes capturing it and turning it into a usable gas for the food industry difficult. That makes the process much more expensive, roughly four times the cost of creating Co2 from fertiliser. Carbon can also be captured from the emissions of fossil fuel combustion, such as coal plants or blue hydrogen production, but this technology does not yet exist at scale. Major economies, including the UK, are pouring billions into research and development, but estimated costs vary widely and it may be some time before either carbon removal or carbon capture are cost competitive. But as economies shift away from fossil fuels, yet continue to require Co2 for specific uses, crunch points like we have seen this week are likely to increase if we do not diversify our sources.

Recent events have underlined a growing recognition that we must “defossilise rather than decarbonise”, says Professor Peter Styring of the University of Sheffield. “The only equitable way to do this is through direct air capture because then you have a supply of Co2 without political or geographical boundaries. The technology is there, but are we willing to pay for it?”

Richard Walker, the boss of Iceland, this week suggested Co2 production was a “matter of national security”, which “should be state-controlled”.

Climeworks, a Swiss-based direct air capture company, says with the right incentives and carbon pricing, it could be cost-competitive with other sources of Co2 within 10 years. The company’s technology is already being used to create the bubbles in sparkling water at a plant in Switzerland.

But at around £600 for a ton of carbon right now, Christoph Beuttler, the company’s head of climate policy, said it only works for companies “that can afford to have a strategic long-term perspective”.

For the meat industry, the bottom line is “all price, price, price and therefore they can’t afford to have it”.

£600

The cost of capturing a ton of carbon dioxide at the Swiss plant Climeworks