Beaches littered with plastic bottles and wrappers. Marine turtles, their stomachs filled with fragments of plastic. Plastic fishing nets dumped at sea where they can throttle unsuspecting animals. And far out in the Pacific Ocean, an expanse of water more than twice the size of France littered with plastic waste weighing at least 79,000 tonnes.
The plastic pollution problem is distressingly familiar, but many organisations are working to reduce it. Alongside familiar solutions such as recycling, a surprising ally has emerged: micro-organisms. A handful of microbes have evolved the ability to “eat” certain plastics, breaking them down into their component molecules. These tiny organisms could soon play a key role in reducing plastic waste and building a greener economy.
The scale of the problem
As a species, we make an enormous amount of plastic. In 2020, the most recent year for which we have data, 367m tonnes were produced globally, according to trade association Plastics Europe. This represented a slight decline compared with 2019, when 368m tonnes were made, but that was probably because of the Covid-19 pandemic: production had previously increased almost every year since the 1950s. A 2017 study estimated that 8.3bn tonnes of plastic had been made in total.
A huge fraction of this goes to waste. In 2016 the world generated 242m tonnes of plastic waste, according to the World Bank. Despite the popular image, only a small fraction of this ends up in the ocean – but the seas may still be absorbing more than 10m tonnes of plastic every year. As well as the dangers of the plastics themselves, they contain a lot of additives that leach out into the water. “Over time we really don’t know what effects these have,” says Tiffany M Ramos of Roskilde University in Denmark.
Much of the rest ends up in landfills. That does not sound so bad, but a lot of it is single-use plastic, which is inherently wasteful. Making plastic requires extracting fossil fuels such as oil from the ground, with all the pollution risks that entails. Plastic manufacturing also releases greenhouse gases that contribute to global warming. A 2021 report found that the US plastics industry alone releases 232m tonnes of greenhouse gases every year, the equivalent of 116 coal-fired power plants.
The solution is not to stop using plastics altogether, because they are incredibly useful. For example, plastic bottles are far lighter than glass ones, so transporting them requires less energy and releases a smaller amount of greenhouse gases. But we do need a revolution in how we handle plastics, and this is where the micro-organisms come in.
Read more: How ‘super-enzymes’ that eat plastics could curb our waste problem