circular economy sustainability waste

Plastics in a linear economy

Last week I wrote about how we may end up with more plastic than fish in the sea by 2050. It’s a striking projection from The New Plastics Economy report from the Ellen MacArthur Foundation and the World Economic Forum.

We’re on our way to that surreal milestone because a whole third of plastic waste, mainly packaging, goes uncollected or escapes processing systems. Instead, it ends up in the natural world, polluting land or water. But where does the rest of it go? Here’s a flow diagram of where plastic packaging ends up.

plastic-flows

I was surprised to see just how little plastic is collected for recycling, and how little again can be genuinely re-cycled without loss of quality. Just 2% goes back into the mix for new plastics.

This, as the report points out, is the linear economy in a nutshell. Resources – in this case finite supplies of oil – are used to make plastic packaging. It is used once and then thrown away, often irresponsibly. The materials and energy are lost to the industrial economy, which needs new resources to take its place.

There are three main elements to fixing this and bringing plastic use into a circular economy model.

First, we need strategies for plastic after it’s been used. The most obvious is to recycle more, and for that to happen it needs to be more economic. If waste has value, it will be collected and processed. Ways to improve the value of recycling could include more standardisation of packaging formats and materials, innovation around collection and sorting. Some forms of packaging could be reused, especially in business to business levels. Bio-plastics can be composted with the right conditions, but this still represents a loss of materials and recycling would be better.

Second, leakage into the natural environment needs to be reduced. Where countries have developed fast, waste infrastructure has sometimes lagged behind. Consumers have access to convenience foods and disposable goods, but don’t have municipal waste collections, and the result is a rubbish free-for-all. Big investments will be needed, especially in Asian economies where this problem is worst, but waste processing will be much easier to organise if there is a decent market for after-use plastics.

Third, even with recycling rates dramatically improved, there will always be some leakage from the system, so we need a renewable feedstock for plastics. This could be from biomass, but that risks competing with other uses. One avenue of research at the moment is plastics made from waste greenhouse gases, which would capture them and lock them away.

All of this will take time, so unfortunately plastic pollution will be with us for a while yet. Since plenty of damage has already been done, there’s some cleaning up to do as well as reducing further leakage – and how we get plastic back out of the ocean will have to be for another day.

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