Science – Solving the plastic problem

It is now clear that plastic waste is ubiquitous around the planet. From the Arctic to the Antarctic, from the peaks of the Himalayas to the depths of the oceans and across almost all populated landscapes, plastic waste is evident. How do we solve this extraordinary problem? For a start, it will be essential that all sectors of society that have contributed to the problem should now contribute to finding a solution: governments, manufacturers, retailers and the diverse public consumer communities.

The fundamental strategy that has emerged is referred to as the “Circular Economy”, a concept that is applicable to all industrial materials but which is more advanced and more applicable to plastics than other common materials. Essentially, the Circular Economy involves reducing the range of plastics used in manufacturing and packaging (many thousands of different commercial plastic types) to only those that can be recycled and then reusing the recyclable plastics from one manufacturing cycle to the next. In theory, the recycled plastics become an enduring resource for many manufacturing cycles for a specific product. In practice, marginal degradation during each cycle will eventually limit the ability to reuse the plastic resource. The ability to recycle plastics depends on the type of plastics involved. At present, only about 15 per cent of commercial plastics are recycled, so the potential for reducing single-use plastic waste is considerable.

The New Zealand Government has recently committed itself to pursuing this Circular Economy strategy. Packaging, construction, textiles, consumer goods and transportation are the leading industrial and retail sectors utilising plastics. If it were possible in one step and across all countries to make all packaging recyclable, and to make such a recycling process mandatory, this would reduce the plastic waste problem substantially and quickly.

Such a global vision is obviously very ambitious. Nevertheless, even if New Zealand by itself sought to achieve 100 per cent plastic recyclability, this would be an exceptionally valuable achievement.

To make the New Zealand 100 per cent recyclability target feasible, a sensible move would  be to focus initially on the dominant plastics sector, packaging. To achieve 100 per cent packaging recyclability it would be essential for product manufacturers, packaging companies, retail companies, recycling and waste management companies to work cooperatively with regional councils, the Government and consumer communities within defined plastics specifications. The experiences in packaging would then inform construction and other leading sectors.

It is important to note that many major multinational companies have already committed themselves to the Circular Economy. These include Dow Chemical (the world’s leading plastic manufacturer), UniLever (which owns 400 brands), L’Oreal, Nestle, Danone, Colgate-Palmolive, Proctor & Gamble, Coca-Cola and PepsiCo. Most of these companies have set themselves a target of 100 per cent recyclability by 2025 or 2030. The role of consumer pressure and Government support will be important in achieving this target.

Emeritus Professor Ralph Cooney
r.cooney@auckland.ac.nz