PLASTIC ACCELERATES CLIMATE CHANGE

Every stage in the lifecycle of plastics generates significant emissions of greenhouse gasses which drive climate change and undermine the Paris Agreement. The ultimate objective of the Paris Agreement is to limit global warming to below two degrees Celsius above pre-industrial levels, aiming for 1.5 degrees Celsius, by the end of the century (Article 2). Within this framework countries must review and reset ambitious targets every 5 years (Articles 3), with a five-year system of monitoring, verification and reporting of emissions reviewed by a compliance committee. (Articles 13, 14 and 15). In addition, States should contribute funds to meet a $100 billion target by 2020 and include climate finance targets in nationally determined contributions (Article 5). The objective of the Paris Agreement is under threat from the emissions attributable to growth in plastic production and disposal.

While the focus of the Paris Agreement and most national actions has been to substitute fossil fuels such as coal, oil and gas with renewable energy, the plastics sector of the petrochemical industry has mostly avoided scrutiny. As pressure mounts on the fossil fuel industry for its carbon liabilities, its calculated shift to increased petrochemicals and plastic production has become a gamble to protect its increasingly beleaguered extractive assets. However, the plastic lifecycle from extraction through production to disposal has an enormous carbon footprint that threatens to grow apace with increased plastic production.

One estimate of methane releases (fugitive emissions or leaks) from the extraction of natural gas could be as high as 9% of total global production volum. Methane is a potent greenhouse gas approximately 25 times more powerful than carbon dioxide over a 100-year timescale in terms of warming potential. Ethylene is a major basic chemical building block for the production of polymers. Each year more than 133 million tonnes of ethylene are produced from cracking of ethane and naphtha with high carbon emission levels. The cumulative greenhouse gas emissions for the steam cracking of naphtha and ethane amount to 1,135 and 840 kg CO2 /tonne of ethylene respectively .

Incineration of plastic waste is by far the greatest CO2 emissions source of all plastic end of life management options. Based on the energy intensive nature of pyrolysis and gasification – chemical recycling as feedstock will also generate significant net emissions. Converting plastic to fuel via these technologies will sharply increase CO2 emissions even further as with this practice, plastics made from fossil fuels only briefly become plastic products before they are combusted as fossil fuels.

Estimates from the Centre for International Environmental Law (CIEL) indicate that in 2019, the production and incineration of plastic added more than 850 million metric tons of greenhouse gases to the atmosphere—equal to the emissions from 189 five-hundred-megawatt coal power plants .

As noted in other sections of this report, plastic production is set to rise dramatically as oil and gas corporations shift their investment from liquid fuels to polymers and petrochemicals to avoid the growing carbon liabilities associated with combusting fuel. If production growth rates increase as planned, CIEL estimate that by 2030 CO2 e (carbon dioxide equivalent) emissions1 will rise to 1.34 gigatons2 which is equivalent to the output of 295 new 500-megawatt coal-fired power plants (CIEL 2019). If we are to meet the Paris Agreement objective and limit global warming to 1.5o C then the amount of future carbon that can be emitted to atmosphere is strictly limited. As carbon accumulates in the atmosphere over time, the amount of carbon already released from the industrial revolution through to the present does not leave much room to add additional carbon. The remaining amount of carbon that can be added without exceeding the 1.5o C target is known as the ‘carbon budget’. The current carbon budget is 420–570 gigatons of carbon and it is being rapidly depleted. By 2050 the emissions from plastic production and incineration could reach  gigatons of CO2 e which is equivalent to 10–13 percent of the entire remaining carbon budget.

This enormous emission source is not entirely based on the carbon emitted during the extraction and production phase of petrochemicals (although this represents the largest fraction) but is also attributable to end of life management of plastics. Incineration of plastic waste contributes significantly to overall CO2 e emissions from the plastics life cycle. Combustion of plastic packaging in waste incinerators generated 16 million metric tons of CO2 e globally in 2015 but this figure does not include the fate of an additional 32 % of plastic packaging that does not fall within a formal waste management system and is either open burned (with considerable CO2 e and toxic emissions) or lost to the environment (CIEL 2019).

Landfilling of plastic with mixed municipal waste can result in some plastic based CO2 e emissions but are magnitudes of order lower than incineration. While plastic degrades to some degree in mixed landfill due to the low pH reducing conditions, it remains largely intact. The reducing conditions accelerate the leaching of toxic additives from plastic in landfill converting additives to more toxic compounds contributing to groundwater and surface water contamination and, on balance, these environmental impacts are of far more consequence than the relatively small CO2 e emissions of plastic in landfill. The main driver of landfill emissions are organic materials generating methane – a potent GHG gas. Plastic landfilled without organic materials has very low emissions and very slow degradation rates unless it is combusted on-site. However, ‘monofill’ of plastics (landfill containing only plastic) is not a long -term solution to the plastic waste dilemma, but could provide an interim method of storage that minimises environmental impact in the short-term until other options are developed.

Mechanical recycling also generates CO2 e emissions due to the energy requirements of the process and transport of materials. However, if the processes and transport for mechanical recycling are based on renewable energy then emissions from this sector are extremely low. In addition, the recycling of polymers removes the emissions required to generate virgin plastic that the recycled plastics theoretically displace. As discussed elsewhere in this report, most plastics cannot be economically or technically recycled and coupled with a massive virgin plastic production expansion, recycled plastics unlikely to significantly reduce emissions from the sector.

Chemical recycling of plastic back to plastic, the proposed solution to plastic pollution of major petrochemical companies, has very high energy demands, particularly for pyrolysis and gasification which require high operating temperatures and rely on external fuel sources to maintain process heat. Most market analysis of petrochemical outputs from these processes suggest they will be directed to fuel rather than polymer production. This is due to the high price differential between virgin plastic manufactured with very low-priced petrochemicals and the high cost of chemical recycling.

If burned as liquid fuel made from chemical recycling, the entire CO2 content of the plastic is emitted making the plastic to fuel process a very high emitter of CO2 emissions. The carbon footprint includes energy used in collection and sorting the plastic waste, energy for heating the pyrolysis or gasification process and then burning the petrochemical output as fuel. As noted elsewhere in this report, low oil prices (the main feedstock for plastic production) and well established infrastructure for virgin plastic production can, and frequently does, reduce the price of virgin plastics to the point where recycled plastic struggles to compete on price. This tends to drive ‘plastic to fuel’ production from pyrolysis and gasification. Producing plastic feedstock chemicals instead of liquid fuel from plastic waste has higher costs related to purification steps, rendering the output less competitive on price than fuel outputs.

When these factors are considered, waste incineration remains the highest emission source from plastic end of life management followed by chemical recycling using pyrolysis and gasification. When the entire life cycle of plastic is assessed, it becomes clear that production of plastic must be curtailed to significantly reduce CO2 emissions from this sector.

Despite the plastic industry investment in massive expansion of plastic production, global agreements on climate change and carbon emissions may become instruments that heavily restrict virgin plastic production by mid-century.

If global policy makers intensify their efforts in the mid-term and future carbon emissions are strictly minimised, the production of virgin plastic from crude oil could potentially be heavily restricted or halted. Crude oil consists of several fractions, i.e., gases, naphtha, kerosene, diesel oil, lubricating oil, fuel oil and residue (asphalt) fractions. Plastic is produced from the naphtha fraction of crude oil. If the fractions currently used for fuel cannot be used in the future, it may be practically and economically impossible to only extract the naphtha fraction from the earth’s crust for plastic production. In the framework of the Paris Agreement, net emissions of CO2 should be reduced to zero later this century (after 2050) which means that petroleum cannot be combusted for fuel energy after 2050. Accordingly, crude oil will be impractical and uneconomical to extract and naphtha, a fraction of crude oil, will no longer be available. Consequently, virgin petroleum-based plastics from crude oil may no longer be able to be produced after 2050.

However, plastic production via gas extraction from fracking has been increasing and it may be technically and economically feasible to extract gas for plastic production while keeping oil-based fuel in the earth’s crust. However, shale gas is also “fossil” carbon and incineration of shale-gasbased plastic waste could result in net emissions of CO2 . Long term production of fossil-carbon-based plastics is not consistent with framework of Paris Agreement unless permanent usage of plastics, infinite recycling, or eternal storage of plastic waste takes place. These processes are practically almost impossible and toxicologically risky. This points to very real possibility that the era of fossil-carbon-based virgin plastic will be phased out around 2050.