In Praise of Plastic

Carbon, plastic and greenhouse gases: an unconventional solution

Photo: Jasmin Sessler via Unsplash

A nationwide ban on plastic packaging for fruit and vegetables came into effect in France last week.  The country has committed to phase out single use plastics by 2040 and the fruit and veg ban is believed to be able to prevent a billion items of single use plastic being used this year.  Spain will follow with a similar ban in 2023. Chopped and processed fruits are exempt from the ban.

There are a lot of things wrong with our (over)use of plastic.  Pollution from discarded plastic is a major concern.  As we all know, both large pieces of plastic and microplastic particles can have nasty environmental effects.  The other big problem with plastic is that it is mostly made from fossil fuels; carbon-rich materials that we should be leaving in the ground.

But today I am writing in praise of plastic.

There’s a reason we started using plastic to pack food last century: it is very good at protecting food during transport, storage and display. It protects food from spoilage, from damage and from contamination.  Plastic packaging makes it easier for manufacturers, retailers and consumers to transport, store and display and buy food. Compared to non-plastic alternatives, plastic packaging is lighter, cheaper, more impact-resistant and – in some cases – more appealing to consumers.

Products like mass-produced bread rely on plastic packaging to retain moisture so they stay fresher for longer.  Without plastic, many staple foods like mass-produced bread, which feeds millions of people every day, would be much more difficult to transport and display in our stores.  And they would suffer from much shorter shelf lives as well.

I have three big reasons for loving plastic.  My number one reason is its ability to keep food fresher for longer, which reduces food waste.

Secondly, plastic is also effective at retaining nutrients in food.  Compared to other packaging materials like glass and metal cans, plastic packaging needs less energy to make and transport, but can be equally effective at retaining nutrients. Frozen vegetables: I’m looking at you.

My third reason for loving plastic is a little controversial. This sounds crazy, but it’s got to do with the global greenhouse effect. Plastic is an excellent store for carbon.  The very same attribute that makes plastic such a long-lived pollutant makes it an effective means of keeping carbon out of the atmosphere. Plastic is mostly carbon, and it (mostly) doesn’t biodegrade, which means it isn’t converted back into carbon dioxide when it becomes waste. 

Plastic is made almost exclusively from fossil fuels, either from crude oil or natural gas.  More specifically, the building blocks of plastics are produced from the naphtha fraction when crude oil is refined, or from the ethane and propane components of natural gas.

As a result, when we make plastic, we are using carbon from fossil fuels, carbon that – from a greenhouse effect perspective – should have been left underground.

Of course, humans don’t extract fossil fuels just to make plastic.  The part of fossil fuels used for olefin plastics – which are by far the most common type of plastic - are different to the components (“fractions”) we use for other purposes, such as diesel fuel, town gas, heating oil and bitumen.  So, for as long as we are extracting fossil carbon for those purposes, we have access to a cheap and easy supply of components for plastics.

Much of the fossil carbon we extract from the ground gets released into the atmosphere when we burn it for fuel; think gasoline, aviation fuel, heating oil and cooking gas.  If we are going to extract oil and gas, we may as well turn some of it into stuff that doesn’t get burnt, like plastic. 

Not all plastic ends up in our oceans.  While single use plastics create litter and pollution, we also make plastic items that can last a lifetime. Plastic is used in building construction, pipes, cars (16% of an average European car is plastic, by one estimate), carpets and clothing.  The longer a piece of plastic remains intact, unburnt, and not bio-degraded, the longer the carbon it contains is locked up and not contributing to the greenhouse effect. In these forms, it is an excellent, stable store of carbon.

An even better way to store carbon in plastic is to use atmospheric carbon dioxide to manufacture it.  We already have the technology to create plastic from atmospheric carbon dioxide. This can be done using biological processes like plants or algae, where photosynthesis is used to extract the carbon dioxide from the air, or by using synthetic processes powered by renewable electricity. 

Right now, these methods are not economically feasible, but that will change when demand for fossil fuels decreases.  Less than ten percent of global oil production is used for making plastic, so we should expect higher prices for the plastic-producing fractions of crude oil as oil extraction diminishes. The changing economics of fossil fuel production is going to have a significant impact on the traditional plastic industry. 

Plastic is a major pollutant, but it’s also an overlooked carbon storage solution. We need to capture food packaging plastics before they pollute our oceans or break-down into microplastics.  We can capture and bury them in properly designed landfill (not ideal but better than most other options) or recycle them into new items.  It’s my fervent hope that in the future virgin plastics will be made using renewable-energy-powered carbon-capture processes. 

In the meantime, lets recognise plastics as an effective, long-term method for storing carbon.

In short: 🍏 Plastic makes a great carbon store and helps keep fossil carbon from ending up in our atmosphere: crazy but true! 🍏 Also, France banned single use plastic packaging for fruit and veg 🍏

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Sources:

https://www.newscientist.com/article/mg25233632-400-plastic-food-packaging-gets-a-bad-rap-but-does-it-always-deserve-it/

https://www.bbc.co.uk/news/world-europe-59843697

http://www.ciel.org/wp-content/uploads/2018/04/Fueling-Plastics-Untested-Assumptions-and-Unanswered-Questions-in-the-Plastics-Boom.pdf

https://theconversation.com/the-world-of-plastics-in-numbers-100291