The Plastic Problem

Plastic is one of the most useful materials ever invented. It is cheap, light, strong and can be shaped into almost anything, from medical equipment to the bottle in your bag. Unfortunately, the qualities that make it so useful also make it a serious environmental problem. Plastic is designed to last, and when it ends up in the sea, it can remain there for decades or even centuries.

How much plastic enters the ocean every year? The honest answer is that nobody knows exactly. Estimates have varied widely, from around one million tonnes to more than ten million tonnes a year, depending on the method used. What scientists do agree on is that the amount is very large, and that it has grown as plastic production has increased. Global production is now measured in hundreds of millions of tonnes a year, and only a small share of all the plastic ever made is thought to have been recycled.

Most ocean plastic is believed to come from land. It is carried to the sea by rivers, blown from garbage dumps or washed off streets and beaches by rain. Countries where garbage collection is limited and the population is growing quickly tend to lose more plastic to the environment, but wealthy countries are part of the problem too, partly because some of their plastic waste has been exported to other countries to be processed. A significant amount also comes from the sea itself, in the form of lost or abandoned fishing equipment.

Measuring all of this is surprisingly difficult. Researchers drag fine nets behind boats to collect floating pieces, count litter on beaches and take samples from the sea floor. They also use computer models that combine data on waste, rivers and ocean currents. The results are then compared, and the estimates are regularly updated as better data becomes available.

You may have heard of the Great Pacific Garbage Patch, an area between California and Hawaii where currents gather floating trash. It is often imagined as an island of plastic that you could walk on, but this is a myth. Most of the plastic there is spread out through the water, and much of it is made up of tiny fragments known as microplastics, pieces smaller than five millimeters. According to one study, abandoned fishing nets account for a large part of its weight.

Plastic in the sea causes harm in several ways. Turtles, seabirds and whales have been found with plastic in their stomachs, and many animals are injured or killed after getting caught in old nets. Microplastics have been found almost everywhere scientists have looked, from Arctic ice to the deepest ocean trenches. Their long-term effects on wildlife and on human health are still being studied.

So what can be done? Cleaning up the ocean is extremely difficult, so most experts argue that the priority is to stop plastic from getting there in the first place. Better waste collection in fast-growing cities is considered one of the most effective measures. Charges on plastic bags have been introduced in many countries, and in England, for example, the use of single-use bags in large supermarkets fell dramatically after a charge was introduced in 2015. Bans on some single-use items, deposit schemes for bottles and designing products that are easier to recycle are also widely supported.

Individual choices matter, but they are only part of the answer. It is generally agreed that real progress will depend on governments, companies and international agreements working together. The plastic problem was created by all of us, slowly, over decades. Solving it will probably take just as long.