Plastic warms the planet twice as much as aviation – here’s how to make it climate-friendly
We’re all too aware of the consequences of plastics in the oceans and on land. However, beyond the visible pollution of our once pristine habitats, plastics are having a grave impact on the climate too.
Newly published research calculates that across their lifecycle, plastics account for 3.8% of global greenhouse gas emissions. That’s almost double the emissions of the aviation sector. If it were a country, the “Plastic Kingdom” would be the fifth-highest emitter in the world.
Demand is set to rise, too. At 380m tonnes a year, we produce 190 times more plastic than we did in 1950. If the demand for plastic continues to grow at its current rate of 4% a year, emissions from plastic production will reach 15% of global emissions by 2050.
Plastic across the lifecycle
More than 99% of plastics are manufactured from petrochemicals, most commonly from petroleum and natural gas. These raw materials are refined to form ethylene, propylene, butene, and other basic plastic building blocks, before being transported to manufacturers.
The production and transport of these resins requires an awful lot of energy – and therefore fuel. Greenhouse gas emissions also occur during the refining process itself – the “cracking” of larger hydrocarbons from petrochemicals into smaller ones suitable for making plastic releases carbon dioxide and methane. According to the study, about 61% of total plastic greenhouse gas emissions comes from the resin production and transport stage.
A further 30% is emitted at the product manufacturing stage. The vast majority of these emissions come from the energy required to power the plants that turn raw plastic materials into the bottles, bin bags and bicycle helmets we use today. The remainder occurs as a result of chemical and manufacturing processes – for example, the production of plastic foams uses HFCs, particularly potent greenhouse gases.
The remaining carbon footprint occurs when plastics are thrown away. Incineration releases all of the stored carbon in the plastic into the atmosphere, as well as air pollutants such as dioxins, furans, mercury and polychlorinated biphenyls, which are toxic and damaging to human health.
As plastics take centuries to degrade, disposal in landfill makes only a small contribution to emissions in theory. However, as much as 40% of landfill waste is burnt in open skies, dramatically speeding up the release of otherwise locked-up carbon.
Making plastic climate-friendly
If we are to combat climate breakdown, reductions in plastic emissions are clearly needed. Thankfully, the solution with the biggest potential is already in motion, albeit snow. In showing that transitioning to a zero carbon energy system has the potential to reduce emissions from plastic by 51%, the study provides yet another reason to rapidly phase out fossil fuels.
However, beyond urgently required global decarbonisation, we need to reduce our seemingly insatiable demand for carbon-based plastic. Increasing recycling rates is one simple way of doing this. The highest-quality plastics can be recycled many times, and nearly all plastic can be recycled to some extent – but only 18% was actually recycled worldwide in 2015. Although each recycle process requires a small amount of new plastics, we can greatly increase the life cycle of the material by efficiently reusing what we make.
A more fundamental solution is to switch to making plastics from biodegradable sources such as wood, corn starch, and sugar cane. The materials themselves are carbon neutral, although renewable power is essential to eliminate the climate impact of energy costs during production, transport and waste processing.
However, a massive ramping up in the production of bioplastics – which currently make up less than 1% of total plastic production – would require vast swathes of agricultural land. With the population set to arise dramatically, increasingly coveted arable space may not be able to satisfy demand.
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