In the fourth part of our series on the problem of plastics in the world’s oceans, we look at what factors determine a country’s contribution to ocean plastics.

This series is based upon articles and data presented by Hannah Ritchie a Senior Researcher and Head of Research at Our World In Data. These articles would not be possible with their hardworking and generous sharing policies.

Why Do Countries Allow Plastic To Pollute Oceans?

We can understand what determines each country’s contribution through three steps.

First, the amount of plastic waste that each country generates in the first place. Rich countries produce much more plastic waste per person than poorer countries. Most produce 0.2 to 0.5 kilograms per person per day.⁹ This compares to 0.01 in India or 0.07 kilograms in the Philippines. Even when we multiply by population (giving us total plastic waste generation), rich countries generate a lot. The UK, for example, generates twice as much plastic waste as the Philippines.

Second, how this plastic waste is managed. Plastic will only enter rivers and the ocean if it’s poorly managed. In rich countries, nearly all of its plastic waste is incinerated, recycled, or sent to well-managed landfills. It’s not left open to the surrounding environment. Low-to-middle income countries tend to have poorer waste management infrastructure. Waste can be dumped outside of landfills, and landfills that do exist are often open, leaking waste to the surrounding environment. Mismanaged waste in low-to-middle income countries is therefore much higher. 

Per capita mismanaged waste in the Philippines is 100 times higher than in the UK. When we multiply by population (giving us each country’s total), India, China, the Philippines, Brazil, and Nigeria top the list. Each country’s share of global mismanaged waste is shown in the map.

Third – and this is where this recent research improves our understanding – is the probability that this mismanaged plastic waste reaches river networks, and then the ocean. The climate, terrain, land use, and distances within river basins affect the probability that mismanaged plastic waste is emitted to the ocean. 

The probability of mismanaged plastic waste entering the ocean by country is shown in the chart. This probability is much higher in countries such as the Philippines (a 7% probability); Malaysia (4.4%); and Sri Lanka (3.4%) than China (0.2%) or India (0.5%). This is why smaller rivers in these countries play a larger role than we might assume.