Reassessing plastics for Earth Day: Why we need to stop demonising them

This year’s Earth Day falls on Monday, 22nd April. Every year EARTHDAY.ORG picks a theme to raise awareness about the importance of environmental conservation and sustainability. This year’s theme is Planet vs. Plastic. To coincide with Earth Day, our Co-Director, Professor Tony Ryan OBE, wrote a guest blog for our Green Watch team to share his thoughts on the topic and explain why it’s time to reassess our views on plastics. 

Why we need to stop demonising plastic

The theme of Earth Day this year is Planet vs. Plastics. EARTHDAY.ORG are unwavering in their “commitment to end plastics for the sake of human and planetary health.” This is sadly misguided. Plastics are completely embedded within public health and modern medicine, among other crucial sectors. Ending plastics by replacing them with other materials would do even more damage to planetary health. This is because in most cases the paper, metal or glass that replaces them causes even more greenhouse gas emissions even if they are recycled too.

The commitment to end plastics misses out a crucial word ‘pollution’. It’s not plastics that are harmful to our health and environment, but our irresponsible behaviour in relation to them. We have become addicted to convenience, and sadly it is often cheaper to use plastic once and throw it away because we never pay the full price of disposal. This is as true about packaging as it is about fast fashion. Almost every statement on the Earth Day website could be made right by the insertion of the word ‘pollution’ after the use of the word ‘plastic’.

The inconvenient, invisible truth about plastic

There are industries whose whole development is based on advances in plastic packaging and the enabling of products and services that wouldn’t otherwise be possible. How could we have survived Covid without all of the single use plastic in PPE, the ventilators that kept people alive, and in the syringes that deliver the vaccines? In fact, without the use of plastics, those vaccines could not have been created.

It is true that plastic forms an intrinsic part of a consumption driven market economy that values short-term profit over long-term environmental sustainability. However, plastic pollution is a convenient and visible truth that hides many inconvenient and invisible truths. In this respect, I am far less worried about plastics than I am about air pollution and rising carbon dioxide levels. Interestingly, it is the oil and gas industry that is driving all three of these problems – air pollution, rising CO2 levels and plastics production – because we use their fossil feedstocks for fuel and petrochemicals.

Is plant-based plastic the answer?

Diagram showing how plastics can be made from plants
Nature Reviews Chemistry 6 1-3 (2022)

It’s quite clear that we produce far too much single use plastic and do not have the systems to deal with it. Here at The University of Sheffield we have been working on reusable plastic packaging and ways of keeping plastics in circulation for longer, but we have come to the conclusion that the much vaunted circular economy of plastic is unfeasible. There is too much of it, it is too cheap, and ultimately it becomes too degraded to be useful.

But plastics could actually be a viable way to sequester CO2 from the atmosphere. Rather than making plastics from oil and gas, we could actually make them from plants. Photosynthesis is the best carbon capture technology we have. It is also far more scalable than any government funded or industry promoted CCS scheme. If we collected 20% of agricultural waste – stalks, leaves and other non-food biomass – we could convert this into carbon feedstock for the production of plastic, and replace the fossil oil and gas.

At the end of the life of this plastic, even if it was single use plastic, it would contain CO2 that had been sucked out of the atmosphere that year. Collecting and curating this plastic provides an easy route to capture that carbon as a solid, which is so much easier to store than CO2 gas.

Every ton of plastic made from plants contains at least two tons of plastic carbon dioxide sucked from the atmosphere. If all the plastic was made from plants, we could capture a billion tonnes of carbon dioxide from the atmosphere every year. This would make use of the unpalatable visible truth of plastics to mitigate the devastating, often invisible and truly inconvenient truth of CO2 emissions and their resultant galloping climate change.

Is there a future for plastic?

So what would we need to do? The most difficult part of the solution would be a global plastics collection strategy that prevented unmanaged disposal and litter. We need to make it economically viable to collect and store carbon in the form of plastics. The fossil petrochemicals industry would need to be transformed into a biochemicals industry that takes the CO2 absorbed by plants and turns it into carbohydrate, making it available to make all the plastics we know and love. That change is already happening. You can buy green polyethylene and PET plant bottles and, as long as you keep them as a solid and don’t incinerate or compost them, you’re contributing to carbon sequestration.

Solve the problem of making fossil-identical bioplastics profitable, and ensure that we collect it all without people causing plastics pollution, and we can completely turn the problem around. We just need solid global governance to put the right policies in place and not let unfettered free-market capitalism continue to destroy everything that’s good in our world. And, we need short-sighted, ill-informed plastic-haters to shift their thinking around the health and well-being of human beings and the planet they share with the rest of the biosphere.