8 million tons of plastic waste ends up in oceans a year

02 December 2015 Consultancy.uk 5 min. read

Every year, 8 million tons of plastic waste makes into the oceans. 150 million tons of plastic is now estimated to be afloat, of which 95% is unrecoverable. In a bid to prevent plastic waste entering into ocean ecosystems, Ocean Conservancy and the McKinsey Centre for Business and Environment consider practical steps that the 5 largest polluters can do to stem the tide. Their research finds that practical solutions could decrease total waste entering oceans by 45% by 2025, and sustain effort could eliminate leakage almost completely by 2035.

Plastic waste is a blight on the world’s oceans. Estimates show that the total plastic waste that has leaked or has been dumped in the world’s oceans now stands at 150 million metric tons. By 2025, this is projected to reach 250 million tons, which means that for every three tons of fish in the oceans there will be one ton of plastic. This plastic waste persistently and negatively affects the ocean ecosystem, entering the ocean food web to cause diseases in ocean dwelling organisms. 

The production of plastic is only set to increase in the coming decades as more and more consumers start buying products encased in plastic. Plastic is in most instances part of a linear economic cycle – use and discard. The collection and disposal of discarded plastic waste is for many emerging economies a quagmire, as its population’s use of plastic lags behind the mechanisms to deal with discard. As it stands, efforts to clean waste once in the oceans is extremely problematic, even cleaning the beaches and dealing with the “Great Pacific Garbage Patch” would collect only 5% of the total 95% of waste the is unreachable below the ocean waves. 

In a recent report, titled ‘Stemming the Tide: Land-based strategies for a plastic-free ocean’, by Ocean Conservancy, the Trash Free Seas Alliance* and the McKinsey Centre for Business and Environment, the lifecycle of plastics as they move from discard into the oceans is explored and concrete measures for stemming the tide are considered.

Progress of yearly ocean plastic leakage

Plastic leakage

The report highlights that the vast majority (80%) of plastic waste entering the oceans comes from land based sources. In terms of location, the majority of waste (between 55% and 60%) comes from five countries: China, Indonesia, the Philippines, Thailand and Vietnam. These countries have been enjoying rapid economic growth in recent decades, yet in many the infrastructure to deal with the waste generated by the prosperity has lagged behind. At the moment, a total of 8 million metric tons makes it into the oceans per year, which in a ‘business as usual’-scenario will increase rapidly over the next 20 years to 30 million metric tons per year by 2035.

The profile of how waste enters the oceans differs considerably between countries, and is in part related to the economics surrounding disposal. The research shows that the largest waste enters from plastic waste that has low residual value, such that there is little incentive in recycling it. This plastic enters the oceans from a number of different sources, and collection is not always a guarantee of success.

China plastic leakage

In China for instance, where a relatively strong recycling system exists, the majority of waste flows from uncollected discard, where of the 48.1 million tons, 60% is not collected, of which 14%, or 4.2 million tons makes it into the ocean. Of waste that has been collected, only 0.8% makes it into the oceans. The loss to the sea is often the result of poorly placed and open dump sites near the ocean.

In the Philippines, the numbers disclose a different story. Of the 2.7 million tons, 84% is collected once it is discarded. However, once collected it is not properly dealt with, such that 17% ends up leaking into the oceans. Of the 16% not collected, 31% makes it into the ocean. Given that the Philippines tends to be closely located to the sea, 70%-90% of waste dumped illegally by companies looking to cut costs before it reaches dump sites tends to end up in the oceans.

Philippines plastic leakage

Stemming the tide

Besides quantifying the level of waste, the researchers sought to identify how best to stem the tide from land-based sources and identified 21 ‘levers’ that can be used to improve the level of waste that makes it into oceans. The reports models the net effect of the 21 levers to find out how easy or difficult each is to implement, and how effective they would be in reducing waste.

Interestingly, the most effective measures also tend to be the easiest to implement. The five most effective measures following from the analysis are to increase collection services, cover dump sites, and optimise the hauler system, gasification, and electrification. Improving collection would reduce leakage in the five countries considered by 23%, while improving storage would reduce leakage by a further 26%. Combining all levers would result in the reduction of 60% in the five countries, and of 45% across the world.

21 leavers to stem the plastic tide

The cost

The total cost of reducing plastic leakage into the oceans for the 5 countries by 60% would cost an aggregate $5 billion per year. Particularly collection costs add between $4.5 and $5 billion, while properly policing dump sites would add up to around $600 million per year. Not all techniques result in a net deficit, with electrification adding up to $300 million to coffers.

* The Trash Free Seas Alliance consists of Algalita Marine Research and Education, the Coca-Cola Company, Covanta Energy, the Dow Chemical Company, ITW, Keep America Beautiful, the Marine Mammal Centre, the Ocean Recovery Alliance Project, AWARE Foundation, American Chemistry Council, Bank of America, Dart Container Corporation, Georgia Aquarium, NatureWorks, Nestlé Waters NA, Procter & Gamble, REDISA, Vancouver Aquarium, World Animal Protection, and World Wildlife Fund.