CO₂ shortage: why a chemical problem could mean more empty shelves

21.08.2023 - 11:44 / theunconventionalgardener.com / guest

Header image: NV77/Shutterstock

Mark Lorch, University of Hull

As far as the environment goes, carbon dioxide is probably public enemy number one. This makes it all the more ironic that the UK is currently suffering from a shortage of the gas, which experts warn will affect a variety of industries, most notably food and drink.

In the right setting, CO₂ is an extremely useful gas. When added to beverages it gives them their fizz. Trap it in high pressure bubbles in sweets and you get popping candy. Compress it in a cylinder and you have a fire extinguisher. Freeze it and you produce dry ice which is used to keep medical materials (including COVID vaccines) chilled during transport.

The microbial organisms that cause food to perish need oxygen to survive, so packaging salad leaves with CO₂, not oxygen, keeps them fresh. Meanwhile, in the meat industry, high concentrations of the gas are used to replace oxygen in the air animals breathe, rendering them unconscious before they are slaughtered.

Given our need for CO₂ in one area, and the excess of it in another, the obvious question is: why don’t we simply pull carbon dioxide out of the air? The simple answer is that, despite its detrimental impact, there’s relatively little carbon dioxide in the air. Though we have 50% more of it in our air than before the industrial revolution, CO₂ still only makes up 0.04% of air content.

This makes CO₂ extremely difficult to “find” and then remove from the air. There’s plenty of work going on to capture the gas from the air, with a view to countering CO₂ emissions, but at the moment this isn’t a viable source of the gas for industry.

Instead, the main source of CO₂ for industrial uses is from the production of nitrogen-based fertilisers, which