6. Projections of the environmental impacts of the plastics lifecycle to 2060

Plastics generate greenhouse gas (GHG) emissions all along their lifecycle, from their production from fossil fuel feedstock transformed through highly energy-intensive processes, to their management as waste, which requires energy and generates direct emissions. The OECD ENV-Linkages model estimates that in 2019, total GHG emissions related to fossil-based plastics were 1.8 gigatonnes of carbon dioxide equivalent (Gt CO2e), or 3.7% of global emissions.1 As plastics use and waste increase in the Baseline scenario, these emissions are projected to more than double to 2060, reaching 4.3 Gt CO2e (Figure 6.1), or 4.5% of global GHG emissions in 2060. While the plastics sector grows at roughly the same rate as the economy-wide average over the period, the growth of the services sectors (which have relatively low emissions intensity) exceeds the average, to represent a large share of the economy. Meanwhile, some very emission-intense sectors – such as iron and steel, non-metal minerals, mining and livestock production – are projected to have below average growth (Chapter 2). This explains why the percentage of plastic emissions increases over time.

Emissions from producing polymers and converting them into products account for around 90% of the lifecycle emissions of fossil-based plastics, both in 2019 and 2060. However, the level of emissions varies depending on the polymer (OECD, 2022[1]). The largest contributors to emissions are fibres used for textiles and clothes, followed by polypropylene (PP), used for a large variety of applications, including food packaging and moulded parts in vehicles. Production of low-density polyethylene (LDPE), used for instance in plastic bags or dispensing bottles, is the third-highest emitter. The increase in emissions between 2019 and 2060 is largely driven by these polymers.

End-of-life emissions account for the remaining lifecycle emissions (about 10%) and vary significantly by disposal option. Incineration accounts for more than 70% of the total end-of-life emissions, both in 2019 and 2060, followed by recycling. Recycling however enables the production of secondary plastics that can reduce overall GHG emissions by substituting for primary plastics. The GHG emissions avoided by recycling and the subsequent production of secondary plastics depends on the polymer and region (mostly on the energy mix of the region’s recycling sectors). However, the average reduction of GHG emissions across regions amounts to at least 1.8 tonne of CO2e for a tonne of polymer produced or a reduction of more than two-thirds compared to the production of the primary equivalent. The impact of plastic leakage on greenhouse gases is not incorporated, but recent research (Shen et al., 2020[2]) based on experimental data by Royer et al. (2018[3]) estimated that degradation in the environment and non-sanitary landfilling leads to methane emissions of roughly 2 Mt CO2e per year.

The large growth in GHG emissions from 2019 to 2060 is driven by several factors (Figure 6.2). The increase in the production and conversion of fossil-based plastics accounts for the majority of new emissions (+2.4 Gt CO2e), while the increase in waste contributes a further 0.4 Gt CO2e. Projected changes in polymer and waste management (including recycling) have almost negligible effects. The only factor to sizeably mitigate the emissions over time in the Baseline scenario is the reduction in the GHG intensity of plastics production and conversion (around -0.3 Gt CO2e), and, to a lesser extent, of waste (-0.1 Gt CO2e).

These results suggest that the most straightforward way of mitigating GHG emissions from the plastics lifecycle is to slow down the increase in global plastics use and waste. Other mitigation options include increasing the availability and use of secondary plastics; decarbonising production and conversion; as well as waste treatment processes, by, among others, an increased use of electricity as a replacement for fossil fuels, combined with a decarbonisation of electricity generation.

As with any long-term exercise, these projections are subject to uncertainty. The Baseline scenario in ENV-Linkages assumes a gradual decrease in the GHG intensity of production over time due to the increase in fossil fuel prices relative to electricity. These assumptions are important, given the reliance of plastics production on fossil fuels and its link to the global market for fossil fuels (see Box 6.1). Furthermore, ENV-Linkages assumes general energy-efficiency improvements will be made over the period, without considering any technological breakthrough that would drastically change lifecycle emissions of plastics, While this assumption is plausible for mature technologies for which the emission profile is not likely to change much, it can be challenged for emerging technologies. For instance, chemical recycling could replace or complement mechanical recycling, affecting the GHG emissions from recycling significantly (Civancik-Uslu et al., 2021[4]). However, these emerging technologies are by definition in the early stages, so their efficiency improvements and penetration are too uncertain to quantify soundly their evolution in the coming decades.

Biobased plastics are derived from biomass such as corn, sugarcane, wheat or residues of other processes. Their production therefore generates fewer greenhouse gas emissions than fossil-based plastics. In the Baseline scenario, the use of biobased plastics2 is projected to increase but remains limited. The biobased plastics market share is projected to remain around 0.5% in 2060, with the use of plastics from biobased feedstock increasing from around 2 Mt in 2019 to 6 Mt in 2060.

The net environmental effects of the substitution of fossil-based plastics by biobased plastics are not straightforward, as explored in Box 2.2 in Chapter 2 of the OECD Global Plastics Outlook: Economic Drivers, Environmental Impacts and Policy Options (2022[1]). In particular, any additional demand for land for growing the feedstock for biobased plastics might drive land use changes such as deforestation that could lead to significant GHG emissions, as well as biodiversity loss, eutrophication and acidification (referred to as indirect land use effects). Furthermore, production of biobased plastics often relies on additives, whose production also contributes to GHG emissions and other environmental impacts (Zimmermann et al., 2020[5]).

This section compares the evolution of biobased plastics in the Baseline scenario with two alternative scenarios (the Mandate and the Efficiency scenarios). In these scenarios, policy makers take additional measures to pursue a 5% market share of biobased plastics in five economic regions that together represent 60% of global biobased plastics production – People’s Republic of China (hereafter ‘China’), the United States, the EU, Brazil and Thailand. A market share of 5% in these regions therefore translates into a global market share of around 3%. The Mandate and the Efficiency scenarios differ in the way that the higher share of biobased plastics is achieved. The Mandate scenario taxes the consumption of fossil-based plastics while subsidizing the consumption of bioplastics. In the Efficiency scenario, investment in technology increases the factor productivity for agricultural raw materials and reduces the land needed for biobased plastics production (Table 6.1). These improvements reflect the upscaling of technologies that enhance biomass utilization efficiencies, for example via pathways based on non-food feedstock (e.g. algae, perennial crops or waste) or cascading uses and closed-loop approaches (e.g. in integrated biorefineries). The scenario comparison uses the computable general equilibrium model CGE-Box (Britz and van der Mensbrugghe, 2018[6]) and builds on earlier research by Escobar and Britz (2021[7]) (see Annex B for methodological details).

In both scenarios, biobased plastics production expands at the cost of fossil-based plastics. The effect is larger in the Efficiency scenario as this scenario reflects the use of technologies that make the production of biobased plastics more efficient and thus biobased plastics more competitive. This scenario leads to regional shifts in biobased production, while the Mandate scenario only targets the specified biobased production of 5% in each of the concerned regions. In both cases, the economic consequences of achieving a higher share of biobased plastics are very small. These small GDP losses are driven by the contraction of fossil fuel sectors, while production factors are shifted towards agriculture and livestock production, which have lower value added.

The higher demand for biobased plastics increases global demand for feedstock crops, driving up cultivated land (Figure 6.4, Panel A). This comes at the expense of both managed land uses (pasturelands and forest plantations, shown in Panel B in Figure 6.4) and unmanaged land uses (e.g. natural forests, shown in Panel C in Figure 6.4). But an additional effect emerges: as crop prices increase due to the increased demand for cropland, livestock feed becomes more expensive, leading livestock producers in Arctic regions, central Asia and some tropical zones to extensify their production, i.e. use more land for pasture. Thus, the pressure on unmanaged land comes from both crop and livestock production. Global cropland area increases most in the Mandate scenario, especially in the United States and the EU, but also in major grain-producing regions such as Canada, Australia and New Zealand, which export grains internationally, mainly to China and the EU (Figure 6.4, Panel A).

The overall impact on global GHG emissions is small. The Mandate scenario sees a small net increase in emissions, while the Efficiency scenario sees a slightly larger net decrease (Figure 6.5). In both the Mandate and the Efficiency scenarios, the main increase in GHG emissions comes from land use change, while the main decrease comes from lower CO2 emissions due to the substitution of fossil-based plastics. Another small increase in emissions in both scenarios is due to the additional use of fertilisers in agricultural production. In the Mandate scenario the increase in emissions from land use (43 Mt CO2e by 2060) is projected to largely offset the emissions reductions from lower production of fossil-based plastics and the associated reductions in fossil fuel production (40 Mt CO2e). Conversely, in the Efficiency scenario GHG emissions decrease overall (Figure 6.5). In this scenario, while direct CO2e emission reductions from plastics production (44 Mt CO2e) are similar to the Mandate scenario, GHG emissions from increased land use are limited to 15 Mt CO2e globally, mostly coming from the loss of unmanaged forest.3

The analysis highlights that any policy approach to stimulate biobased plastics must be chosen carefully to limit implications for land use and GHG emissions. The overall environmental outcome of upscaling biobased plastics will only be positive when a combination of global commitments and locally enforced regulatory measures succeeds in restraining the conversion of natural areas into agricultural land. Moreover, investing in research into more efficient biobased plastics production pathways that reduce the amount of agricultural feedstock used could significantly improve the potential to mitigate global GHG emissions.

In addition to plastic leakage to the environment and GHG emissions, the plastics lifecycle is linked to a variety of other environmental and human health pressures. This section presents the results of a life cycle assessment (LCA) carried out by the Sustainable Systems Engineering Group of Ghent University4 (see Annex A for the methodology). LCA is a widely recognised methodology for assessing environmental impacts associated with the different stages of a product’s lifecycle (Eunomia, 2020[8]). It involves a thorough inventory of the energy and materials required across the industry value chain of a product, process or service, and calculates the corresponding impacts on the environment.

The assessment includes the global production from cradle to gate and the end-of-life stage of seven commonly used polymers (polypropylene, PP; high-density polyethylene, HDPE; low-density polyethylene, LDPE; polyvinyl chloride, PVC; polystyrene, PS; polyethylene terephthalate, PET; and polyurethane, PUR), which make up for 65% of total plastics use. The analysis excludes the environmental effects relating to the manufacturing or use of products derived from these polymers. It also does not take into account any future technological changes related to the production of these polymers. The LCA considers numerous environmental impacts, including land use, ozone formation, eutrophication, ecotoxicity, toxicity and acidification (see Annex A for a description).

Owing to the multitude of environmental aspects related to the lifecycle of plastics, not all environmental impacts can be calculated from databases commonly used for LCA. Since the database used (Ecoinvent 3.6) only contains sufficient information on recycling across environmental impact categories for HDPE (relying on data for polyethylene) and PET, Figure 6.6 presents the environmental impacts of these polymers for the following two lifecycle stages:

  • Production: the polymer can be produced from primary or secondary material.

  • End-of-life: the polymer can be mechanically recycled, incinerated without energy recovery, landfilled, dumped or burned in an open pit.

The most circular lifecycle, secondary plastic that is recycled at its end of life, scores best for almost all environmental impact categories for both polymers (Figure 6.6). Nonetheless, this circular lifecycle still has considerable impacts on land use and both freshwater and marine eutrophication. These impacts mainly come from the energy needed to prepare, process and transport plastics in a circular loop (see also the plastics lifecycle GHG emissions related to recycling as presented in Section 6.1.1). Since eutrophication comes from emissions such as NOx from the energy combustion, improvements in clean energy production and energy efficiency would reduce the environmental impacts of circular plastics further. The impact on land use is driven by the relatively high levels of biomass feedstock in the energy mix of the countries with the highest recycling rates. As discussed in Section 6.1.1, research to limit the land use needed for biobased fuels and materials could improve their environmental footprint considerably.

In the ‘transition to a circular economy’, most plastics are still made from primary plastics while recycling increases steadily. Unfortunately, primary plastics that are recycled not only score worse for most impact categories than secondary plastics that are recycled, but also than the primary plastics that are landfilled or incinerated. Indeed, the energy needed to collect, sort and pre-process end-of-life plastics is taken into account, but the gains of using secondary plastics are not. This highlights the importance of high quality recycling and closing material loops.

Primary plastics that are landfilled tend to score better than when incinerated for most impact categories, apart from land use and marine eutrophication. The impact on land use is logically related to the land needed to operate the landfills. The eutrophication impact is higher for landfilling than for incineration because the used Ecoinvent database does not include any direct marine eutrophication emissions from incinerating or burning plastics. It is also important to note that the energy recovered from incineration in waste-to-energy plants and the related environmental benefits are only accounted for as part of the overall energy mix, and are not allocated to the incinerating category. Consequently, the incineration results are only representative for incineration without energy recovery.

Unsurprisingly, dumping and burning have worse environmental effects than the properly engineered disposal alternatives, landfilling and incinerating. However, they score slightly better than landfilling and incinerating for environmental categories where the benefits of having well-managed infrastructure are low due to the energy needed to manage waste in a proper way. For example, land use for a landfill or dumpsite will be similar, but the energy needed to build and operate a sanitary landfill will generate some small additional impacts on land use elsewhere in the supply chain. Since the data on pathways and impacts of leaked plastics are still scarce in LCA (Boulay, Verones and Vázquez-Rowe, 2021[9]), leakage to the environment originating from improper or informal waste collection is not taken into account. Nevertheless, Chapter 5 shows that dumping and generally mismanaging waste are the main sources of plastic leakage to the environment.

Projections for seven polymers that make up 65% of all plastics use (Figure 6.7 and Figure 6.8) show the potential negative impacts of plastics on a wide range of health and environmental areas. They also stress that impacts will worsen substantially between 2019 and 2060. This trend is driven by the increase in plastics use, with the total use of the seven polymers almost tripling (with growth of around 170%) by 2060 (Chapter 3). The biggest increase is for LDPE, which triples; while HDPE and PET see the slowest growth (about 150% growth to 2060). In line with these trends, the environmental impacts of all polymers worsen, but the impacts of LDPE are worse than for HDPE and PET. These trends confirm that restraining plastics use is a key lever to address the environmental challenges related to plastics.

As waste management will improve between now and 2060 even in the Baseline scenario, some mismanaged waste will be reduced by more recycling and safe disposal options. As secondary plastics have lower impacts overall than their primary equivalents (Figure 6.6), the shift towards more recycling means that the environmental impacts grow more slowly than plastics use. For example, the terrestrial acidification impact of production increases 5% less by 2060 than the volumes produced owing to the increasing market share of secondary plastics. Moreover, the shift away from mismanaged waste reduces impacts such as Ecotoxicity, ozone formation, carcinogenic toxicity and non-carcinogenic toxicity following the reduction of open-pit burning and less dumping. For instance, the freshwater ecotoxicity effects of the end-of-life stage increases 33% less than plastics use by 2060 thanks to improved waste management practices. These results highlight the importance of speeding up investments in recycling and safe waste management.

PET and PS have relatively low total impacts (Figure 6.7). However, these two polymers only represent around 5% of plastics use each in 2060. PP (16%), LDPE (13%), HDPE (11%) and PVC (11%) are a larger part of production (see Chapter 3) and have therefore more environmental impacts overall. PP, the most produced polymer, generates per tonne less environmental impacts than the average assessed polymer for each of the categories. In contrast, only 4% of all plastics are made of PUR but in this sample of seven polymers, it is a relatively large contributor to eutrophication, acidification and ozone formation. However, comparing the environmental impacts of these polymers or drawing conclusions with respect to the potential effect of substitution of polymers, is challenging because the polymers are used for different applications.

Production drives the results for most impact categories (Figure 6.6 and Figure 6.8). By 2060, production is responsible for more than 85% of the impacts on ozone formation, acidification, human non-carcinogenic toxicity and land use. However, for freshwater ecotoxicity the end-of-life stage contributes more than 40% of the lifecycle impact, due to mismanaged waste and, to a lesser extent, incineration. In particular, the relatively high impacts of mismanaged PUR waste and of incinerating PET drive up the end-of-life impacts on freshwater toxicity. Similarly, the end-of-life stage makes up a quarter of the terrestrial ecotoxicity impact and one-third of the marine ecotoxicity impact. The end-of-life stage also contributes 39% to the total human carcinogenic toxicity impact due to the effect of mismanaged waste, and especially mismanaged PVC waste. PUR also contributes strongly to this impact category, but is mainly driven by production.

The resulting evolution of the total environmental impacts shows an increase to 2060 that ranges from 132% –i.e. a value of 2.32 in 2060 – to 171% – i.e. a value of 2.71 – depending on the impact (Figure 6.8). The largest overall increases are seen for indicators related to the energy needed for increased share of recycling in 2060, which also causes GHG emissions (Section 6.1.1). Bioenergy in the energy mix means that more energy consumption leads to a greater impact on land use, while combustion of fossil fuels leads to more eutrophication. The indicators that benefit most from more circular waste management practices, such as freshwater and marine ecotoxicity, experience the lowest increases. Nonetheless, these strongly increasing environmental impacts underline the need for policy action.


[9] Boulay, A., F. Verones and I. Vázquez-Rowe (2021), “Marine plastics in LCA: current status and MarILCA’s contributions”, The International Journal of Life Cycle Assessment, Vol. 26/11, pp. 2105-2108, https://doi.org/10.1007/s11367-021-01975-1.

[6] Britz, W. and D. van der Mensbrugghe (2018), “CGEBox: A Flexible, Modular and Extendable Framework for CGE Analysis in GAMS”, J Glob Econ Anal, Vol. 3/2, pp. 106-177.

[4] Civancik-Uslu, D. et al. (2021), “Moving from linear to circular household plastic packaging in Belgium: Prospective life cycle assessment of mechanical and thermochemical recycling”, Resources, Conservation and Recycling, Vol. 171, p. 105633, https://doi.org/10.1016/j.resconrec.2021.105633.

[7] Escobar, N. and W. Britz (2021), “Metrics on the sustainability of region-specific bioplastics production, considering global land use change effects”, Resources, Conservation and Recycling, Vol. 167, p. 105345, https://doi.org/10.1016/j.resconrec.2020.105345.

[8] Eunomia (2020), Plastics: Can Life Cycle Assessment Rise to the Challenge? How to critically assess LCA for policy making, Eunomia, Bristol.

[10] IPCC (1995), Climate Change 1995: A report of the Intergovernmental Panel on Climate Change - IPCC Second Assessment.

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[3] Royer, S. et al. (2018), “Production of methane and ethylene from plastic in the environment”, PLOS ONE, Vol. 13/8, https://doi.org/10.1371/journal.pone.0200574.

[2] Shen, M. et al. (2020), “(Micro)plastic crisis: Un-ignorable contribution to global greenhouse gas emissions and climate change”, Journal of Cleaner Production, Vol. 254, p. 120138, https://doi.org/10.1016/j.jclepro.2020.120138.

[5] Zimmermann, L. et al. (2020), “Are bioplastics and plant-based materials safer than conventional plastics? In vitro toxicity and chemical composition”, Environment International, Vol. 145, p. 106066, https://doi.org/10.1016/j.envint.2020.106066.


← 1. The ENV-Linkages model uses the energy and factor intensity of economic sectors, along with their process emission intensity, to estimate the greenhouse gas emissions in the economy. This generic approach is complemented with information on plastics lifecycle emissions factors. Based on these calculations the greenhouse gases are aggregated using 100-year global warming potentials from the IPCC 2nd Assessment Report (IPCC, 1995[10]).

← 2. Biobased plastics are derived from biomass such as corn, sugarcane, wheat or residues of other processes. Their production generates fewer greenhouse gas emissions than fossil-based plastics.

← 3. These results depend on modelling assumptions, in particular the ease with which industries can replace fossil-based plastics with biobased plastics. The responsiveness of land conversion to price can affect the results on land use and GHG emissions. A higher responsiveness of land-use conversion to price changes would imply more GHG emissions, since cropland would expand more and imply larger losses of natural areas. A higher level of substitution between fossil-based and biobased plastics would imply a higher increase in biobased plastics, as well as in global cropland and GHG emissions.

← 4. The analysis used Simapro v9.1, Ecoinvent database 3.6, cut-off model and lifecycle impact assessment methods: Recipe 2016 Midpoint (H) v1.04 and Cumulative Energy Demand (CED) v1.11.

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