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The perils of plastic

  • Published at 12:38 am May 17th, 2019
Plastic
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It’s a bigger culprit in warming the planet than aviation

We’re all too aware of the consequences of plastic. 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 life-cycle, 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.

At 380 million tons 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 life-cycle

More than 99% of plastics are manufactured from petro-chemicals, 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. 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. 

The remaining carbon footprint occurs when plastics are thrown away. Incineration releases all of the stored carbon in the plastic into the atmosphere.

As plastics take centuries to degrade, disposal in landfills makes only a small contribution to emissions in theory. However, as much as 40% of landfill waste is burned 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 slow. 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 de-carbonization, 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 plastic, 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 bio-degradable sources. 

However, a massive ramping up in the production of bio-plastics -- which currently make up less than 1% of total plastic production -- would require vast swathes of agricultural land. With the population set to rise dramatically, increasingly coveted arable space may not be able to satisfy demand.

The bottom line, therefore, is that we will need to reduce our demand for plastic. 

According to the study, simply reducing the annual growth in plastic demand from 4% to 2% could result in 60% lower emissions from the sector in 2050. While a life without plastic may seem unimaginable, it is worth remembering that their prevalence is a relativity recent phenomenon. 

If we show a genuine appetite to address plastic pollution, the world could change again just as quickly. 

Governments, corporations, and individuals must make research into alternatives a priority, and support alternatives to needless plastic waste. 

Were most people to carry a reusable water bottle, for example, we could eliminate the need for the estimated 20,000 single-use bottles bought each second around the world.

Of course, any of these solutions alone will not be enough. As the recent study notes, only by combining reduction in demand, top-notch recycling, de-carbonization of energy, and large-scale adoption of bio-plastics can we tackle plastic’s contribution to the climate crisis. 

Laurie Wright is a Senior Lecturer at Solent University. A version of this article was first published in The Conversation UK.