ABUNDANCE OF PLASTIC WASTE

Global Plastic Pollution

In our full entry on Plastic Pollution we provide an in-depth overview of global plastic production, distribution, management, and impacts through data visualisations and explainers. There you should find most of the data and context needed to understand the problem of global plastics.

Here I answer some common questions on plastic pollution:  

How much plastic and waste do we produce?

In 1950 the world produced only 2 million tonnes per year. By 2019, annual production had increased nearly 230-fold, reaching 460 million tonnes. Over the period from 1950 to 2019, cumulative production reached 9.5 billion tonnes of plastic — more than one tonne of plastic for every person alive today.

In our entry we provide data visualisations and explainers on plastic waste by country, plastic waste per person, and importantly for plastic pollution (especially of the oceans), mismanaged waste by country and by region. Overall, it's generally the case that plastic waste per person is highest in high-income countries. However, richer countries tend to have effective waste management systems meaning mismanaged waste is low. Most mismanaged waste tends to arise from low-to-middle income countries where large coastal populations and rapid industrialization means waste management systems have failed to keep pace.

How much oil do we use to make plastic?

Estimates vary by source, but tend to converge on a range between 4 to 8 percent of global oil consumption. 6 percent of global oil consumption is taken as the mid-range estimate. 

(Source: Neufeld, L., Stassen, F., Sheppard, R., & Gilman, T. (2016). The new plastics economy: rethinking the future of plastics. In World Economic Forum. Available at: https://www3.weforum.org/docs/WEF_The_New_Plastics_Economy.pdf.)

Which sectors use the most plastic?

Packaging is the dominant sectoral use of plastics globally accounting for 42 percent (146 million tonnes) in 2016. This was followed by construction with 19 percent (65 million tonnes).

Since packaging tends to have a much lower product lifetime than other products (such as construction or textiles), it is also dominant in terms of annual waste generation. It is responsible for almost half of global plastic waste — the breakdown by sector is shown in the chart here.

Where does the plastic in the ocean come from?

This chart shows how global plastics emitted into the oceans breaks down by region. 

In summary, best estimates suggest that approximately 80% of global ocean plastics come from land-based sources, and the remaining 20% from marine. 

(Source: Li, W. C., Tse, H. F., & Fok, L. (2016). Plastic waste in the marine environment: A review of sources, occurrence and effects. Science of the Total Environment, 566, 333-349. Available at: https://www.sciencedirect.com/science/article/pii/S0048969716310154.)

Marine inputs here are dominated by fishing activity, including discarded nets, fishing lines, and abandoned vessels.

Whilst this is the relative contribution as an aggregate of global ocean plastics, the relative contribution of different sources will vary depending on geographical location and context. For example, our most recent estimates of the contribution of marine sources to the 'Great Pacific Garbage Patch' (GPGP) is that abandoned, lost or otherwise discarded fishing gear make up 75% of 86% of floating plastic mass (greater than 5 centimeters).(Source: Lebreton, L., Royer, SJ., Peytavin, A. et al. (2022). Industrialised fishing nations largely contribute to floating plastic pollution in the North Pacific subtropical gyre. Scientific Reports 12, 12666., Previous studies (notably Lebreton et al. 2018) estimated that plastic lines, ropes, and fishing nets contributed just over half of the plastic mass in the 'Great Pacific Garbage Patch'. More recent studies estimate that this share is higher – giving the 75% to 86% referenced here. Lebreton, L., Slat, B., Ferrari, F., Sainte-Rose, B., Aitken, J., Marthouse, R., … & Noble, K. (2018). Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic. Scientific Reports, 8(1), 4666. Available at: https://www.nature.com/articles/s41598-018-22939-w.)

This research suggests that most of this fishing activity originates from five countries – Japan, South Korea, China, the United States and Taiwan.

What are the environmental impacts of landfills?

One option of handling plastic waste is sending it to landfill. Here, it's important to distinguish between the quality/effectiveness of landfills.

The modern definition of a landfill is of a disposal site for materials through burial. This is typically the case in high-income countries today where landfills are well-managed and effectively regulated. However, across many countries today landfill resources can be poorly-managed; in many cases dumped in open landfills, pits or dumps. Such uncontrolled disposal facilities can make plastics vulnerable to pollution of the surrounding environment and at risk of entering the ocean.

Well-managed landfill facilities have expectations to gather, compact and safely store waste. In many cases this involves covering or burying with soils or other materials. However, such landfills still have negative environmental impacts:

Greenhouse gases: when organic matter decomposes to produce methane (CH4) and carbon dioxide (CO2) — both are greenhouse gases which contribute to climate change. In some landfill sites, methane gas can be captured and 'flared' (burned) for energy production. Plastic, which is hard to break down, degrades over very long timescales (particularly under low oxygen conditions) does not contribute to this effect.

Leachate: decomposing material can produce nutrient-rich or polluted waters which — if not properly contained — can leach to the surrounding environment and potentially enter waterways and soils. Well-managed landfills are usually surrounded by protective lining to prevent water leaching to the surrounding environment. However, local pollution can occur where this is not implemented effectively, or the lining breaks down and is not replaced.

Where plastics are not handled correctly, some types of plastic — such as polyvinyl chloride; PVC — can leach chemicals such as additives and plasticiser compounds. (Source: Asakura, H., Matsuto, T., & Tanaka, N. (2004). Behavior of endocrine-disrupting chemicals in leachate from MSW landfill sites in Japan. Waste Management, 24(6), 613-622. Available at: https://www.sciencedirect.com/science/article/pii/S0956053X04000261.)

A report by the European Commission aimed to provide a detailed analysis and overview of the available evidence on the behaviour of PVC in landfills. (Source: European Commission (2000). The Behaviour of PVC in Landfills. Available at: https://ec.europa.eu/environment/waste/studies/pvc/landfill.pdf.)

The study concluded that whilst leachate of substances as either non-detectable or in very low concentrations, a precautionary approach would deem this material only controllable if landfills are equipped with adequate liner and leachate treatment.

What are the environmental impacts of incineration?

Incineration is the burning of a given material — in the case of plastic, this is done at very high temperatures. Incineration is one form of waste management. What are the environmental impacts of incineration?

Greenhouse gases: the incineration of plastic produces carbon dioxide (CO2) — a primary driver of global climate change. However, the incineration process can be integrated as a 'Waste to Energy' (WtE) solution. WtE is a form of energy recovery; in this case energy from the plastics can be stored and utilised for energy. On a net balance, does incineration therefore have a net positive or negative impact on greenhouse gas emissions?

It depends. The relative gains from energy recovery vary depending on the efficiency of the incineration process in addition to the mix of energy sources it's replacing. In countries where the energy mix is dominated by fossil fuels, incineration energy recovery can reduce emissions. However, across many countries — most across Europe — where incineration efficiency is low and the energy mix is lower-carbon, this does provide a net source of greenhouse gas emissions. (Source: Eriksson, O., & Finnveden, G. (2009). Plastic waste as a fuel-CO2-neutral or not?. Energy & Environmental Science, 2(9), 907-914. Available at: https://pubs.rsc.org/en/content/articlelanding/2009/ee/b908135f.)

Air pollution: a common concern of incineration is that it releases toxic emissions to the surrounding environment. The burning of plastics can produce several toxic gases: incomplete combustion of Polyethylene (PE), Polypropylene (PP) and Polystyrene (PS) can release carbon monoxide (CO) and noxious emissions, while polyvinyl chloride (PVC) can produce dioxins. (Source: Verma, R., Vinoda, K. S., Papireddy, M., & Gowda, A. N. S. (2016). Toxic Pollutants from Plastic Waste-A Review. Procedia Environmental Sciences, 35, 701-708. Available at: https://www.sciencedirect.com/science/article/pii/S187802961630158X. and Source: Barabad, M. L. M., Jung, W., Versoza, M. E., Lee, Y. I., Choi, K., & Park, D. (2018). Characteristics of Particulate Matter and Volatile Organic Compound Emissions from the Combustion of Waste Vinyl. International journal of environmental research and public health, 15(7).)

Such gases can be toxic and dangerous to both human and ecosystem health. Open or uncontrolled burning of plastics should therefore be strongly avoided.

Is this also the case in incinerator facilities? It largely depends on the efficiency and environmental control of emissions of the particular incinerator site. In high-income countries in particular, waste management and incinerator sites are heavily regulated with monitoring of emissions and potential leaks to the surrounding environment. Modern incinerators have largely dealt with the problem of dioxin or other toxin emissions. Technologies here include efficient combustion, end-of-pipe treatment, selective catalytic reduction, and the addition of suitable inhibitors. (Source: Mukherjee, A., Debnath, B., & Ghosh, S. K. (2016). A review on technologies of removal of dioxins and furans from incinerator flue gas. Procedia Environmental Sciences, 35, 528-540. Available at: https://www.sciencedirect.com/science/article/pii/S1878029616301268.)

A study in Belgium, for example, reported no difference in dioxin-serum levels of maintenance workers of municipal waste incinerator facilities — individuals who would experience high exposure rates if such methods were not implemented. (Source: De Meester, M., Kiss, P., & Braeckman, L. (2018). 317 Occupational dioxin exposure of workers in municipal waste incinerators. Available at: https://oem.bmj.com/content/75/Suppl_2/A401.3?utm_source=trendmd&utm_medium=cpc&utm_campaign=oem&utm_content=consumer&utm_term=0-A.)

However, such incinerator technologies and standards are not implemented everywhere — in countries where environmental regulation is less strict, unsafe or open burning of municipal waste remains common. This typically occurs in low-t0-middle income countries. Studies in India, Kenya and Thailand, for example, report notable pollution from the burning of waste (including the generation of dioxins). (Source: Nagpure, A. S., Ramaswami, A., & Russell, A. (2015). Characterizing the spatial and temporal patterns of open burning of municipal solid waste (MSW) in Indian cities. Environmental Science & Technology, 49(21), 12904-12912. Available at: https://pubs.acs.org/doi/abs/10.1021/acs.est.5b03243, and Source: Shih, Y. H., Kasaon, S. J. E., Tseng, C. H., Wang, H. C., Chen, L. L., & Chang, Y. M. (2016). Health risks and economic costs of exposure to PCDD/Fs from open burning: a case study in Nairobi, Kenya. Air Quality, Atmosphere & Health, 9(2), 201-211. Available at: https://link.springer.com/article/10.1007/s11869-015-0325-8, and Source: Phoungthong, K. (2017). Municipal solid waste management in Thailand. Current Science, 112(4), 674. Available at: https://www.researchgate.net/profile/Khamphe_Phoungthong/publication/315487357_Municipal_solid_waste_management_in_Thailand/links/58d603d8aca2727e5ebe296e/Municipal-solid-waste-management-in-Thailand.pdf)

For incineration to become a universally safe solution, standards and uptake of appropriate technologies and approaches must be adopted globally.

How much of global plastic is recycled?

We cover this question more fully in our entry on Plastics, found here. In summary, it's estimated that in 2015, around 55 percent of global plastic waste was discarded, 25 percent was incinerated, and 20 percent was recycled. Of the plastic waste produced between 1950 and 2015, only 9 percent was recycled.

Can my recycling end up in landfill?

Unfortunately, yes. Some plastics intended for recycling end up in landfill.

There are several reasons why this can occur:

In most countries, some share of plastics intended for recycling are eventually rejected at local or regional waste handling facilities. The most common reason for rejected recycling is the 'contamination' of recycling streams — this can result from high concentrations of non-recyclable items in the waste stream, or contamination of other forms such as food waste. Even in cases where plastic contamination could be dealt within, it is sometimes more economically-feasible to divert some loads to landfill. Processing costs of poorly-sorted or contaminated plastic loads are more expensive, in some cases outweighing profits from recycled materials.The rate of 'rejected recycling' can vary significantly between countries depending on recycling policies, targets and the effectiveness of recycling separation methods (either at the household and local collection level, or at waste handling facilities). For a sense of scale, latest figures For England estimate that between 3 to 4 percent of total household recycling (which is plastics but also paper, metals etc.) was rejected and sent to landfill or incineration.18 In relative terms, this share is relatively low but could be improved through better understanding of how to avoid contamination of plastic recycling streams.

As we describe in our full Plastics entry, recycled plastic is a globally traded commodity. The majority of major exporters are high-income countries. If we look at the top ten exporting countries over the period from 1988 to 2016, we see that collectively they account for 78 percent of global plastic exports (as shown in the chart). All of the top ten exporters are defined as high-income. Collectively, they have exported 168 million tonnes over this period, equivalent to an economic value of US$65 billion. China has been the world's largest plastic importer. Collectively, China and Hong Kong have imported 72.4 percent of all plastic waste (with most imports to Hong Kong eventually reaching China).19 In 2017, China introduced a ban on non-industrial plastic imports in part because of the levels of contaminated plastics in countries' export stream. Some of this imported plastic therefore ended up in landfill (and possibly at risk of entering the ocean).It's challenging to track the ultimate fate of traded plastics, however it's likely that at least some of recycled plastics exported from high-income countries enters landfill in the countries to which they are traded.

Following China's ban on imported plastic in 2017, previous large exporters such as the United States, Canada, Australia and UK have failed to handle the increase in domestic plastic recycling demand. As such, some materials intended for recycling have subsequently been diverted to landfill.

Plastics typically degrade in quality during the recycling process. For most recyclable plastics, they are typically only suitable for recycling once. As a result, most recycled plastic we use eventually reaches landfill, even if it goes through an additional use cycle as another product. Recycling typically delays rather than prevents plastic disposal to landfill or incineration.

Many thanks (by Hannah Ritchie September 02, 2018) to the authors for the great care they have taken in detailing the situation of plastic waste pollution. We are confident that the analysis of the data will lead to effective action plans to tackle this huge environmental problem.

Thanks to the Our World in Data team: Natasha Ahuja, Pablo Arriagada, Daniel Bachler, Matthieu Bergel, Marwa Boukarim, Dr. Saloni Dattani, Antoinette Finnegan, Marcel Gerber, Dr. Charlie Giattino, Joe Hasell, Dr. Bastian Herre, Dr. Bobbie Macdonald, Edouard Mathieu, Sophia Mersmann, Dr. Esteban Ortiz-Ospina, Natalie Reynolds-Garcia, Dr. Hannah Ritchie, Lucas Rodés-Guirao, Valerie Rogers Muigai, Dr. Pablo Rosado, Max Roser Professor, Veronika Samborska, Ike Saunders, Dr. Fiona Spooner, Dr. Christian Swinehart, Mojmir Vinkler, Dr. Lars Yencken, Jason Crawford.