BY NOW, it is just a question of which heart-rending image you choose. There is the hawksbill turtle struggling to free itself from a plastic bag. The sea of polystyrene trash floating over a Caribbean nature reserve. Or the sperm whale washed ashore in Spain, its stomach filled with plastic waste.
Since the introduction of mass-produced plastics in the early 20th century, humanity has produced an estimated 8300 million tonnes of the stuff. Around three-quarters has been thrown away, and 80 per cent of that has drifted into the environment or gone into landfill. Eight million tonnes a year end up in the ocean â 5 trillion pieces and counting.
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It is an environmental catastrophe and a human one, too, as some people in parts of the developing world live ankle-deep in filthy, non-biodegrading plastic trash. The long-term health implications for all of us remain uncertain, as ingested plastic works its way up the food chain.
Everyone agrees something must be done. From banning plastic straws to rebooting recycling systems to harnessing plastic-munching bacteria, there is no shortage of touted solutions. It is less clear what would work best. But fixing the plastic waste crisis is going to take some seriously joined-up thinking. If we make the wrong decisions now, we risk making the problem worse.
If plastics didnât exist, we would have to invent them. Generally made of oil-derived polymers, they can be hung with different chemical groups and spiced up with additives to give them wildly differing properties such as hardness, strength, density and heat-resistance. This makes them just the thing for everything from colourful, durable kidsâ toys to throwaway wrappings and foils.
You can argue the rights and wrongs of deriving materials from fossil fuels, but it is this throwing away that has excited the recent attention. The persistence of plastics in the environment if they arenât properly disposed of makes them incredibly bad news.
The nature of the problem varies according to where in the world you live. Five countries in Asia â China, Indonesia, the Philippines, Thailand and Vietnam â are responsible for 55 to 60 per cent of all the plastics that leak from land to ocean, by Ocean Conservancy and the consultants McKinsey. Another study in 2017 found that was coming from just 10 rivers, eight of them in Asia.
The 2015 report calculated that three-quarters of plastic leakage from the five Asian countries comes from uncollected waste. The rest is waste that was gathered but ended up illegally dumped or put into sites too close to coasts or rivers. It is a stark reminder of global inequalities, says , a waste specialist at Imperial College London. âThere are 2 billion people in this world who donât have proper waste collection systems.â
A big part of any effective solution lies in helping these countries improve their waste management. But that doesnât let richer countries off the hook.
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In richer nations, says Cheeseman, the plastic problem starts with many people simply not caring. A parliamentary report in 2017 concluded that end up as litter every day, for example.
But it is what happens to the rest that is more telling. Transparent plastic drinks bottles are principally made of polyethylene terephthalate, or PET. Globally, some 50 per cent of PET is collected for recycling, but , according to a report co-authored by the Ellen MacArthur Foundation. And PET is the poster child of plastics: it melts at a low temperature and can be reformed without much damage to its polymer chains. Of all plastics, just 14 per cent is collected for recycling around the world, with still less actually reprocessed. The rest is destined for incineration or landfill, where it will persist for centuries.
Why? Because once discarded, plastic is essentially worthless. It is cheaper to start afresh.
âItâs the dark secret of the recycling bin: waste plastic is essentially worthlessâ
This is the dark secret of the recycling bin. For many, the solution is to give waste plastic a value. That is the philosophy behind deposit schemes, for example, in which consumers pay a small refundable fee for plastic bottles. These have transformed disposable bottles into collectibles in several US states and European countries. The UK looks set to follow suit, while most of Australia should be operating deposit schemes by 2019.
The bigger vision is to create a . Out goes âtake-make-disposeâ, a one-way journey from oil to landfill or incineration. In comes a system where producers are incentivised to make reusable, recyclable or compostable products, while the recycling industry learns to scoop up all the detritus so no piece of litter is left behind.
What you can do
In our personal drive to reduce plastic waste, we should beware easy, but false, solutions
Cutting out single-use plastic â water bottles, straws, disposable plates and so forth â is a good place to start reducing waste. But make sure you arenât inadvertently increasing your carbon footprint. A cotton tote bag must be used 131 times before its environmental cost falls below that of a disposable plastic bag, mostly because of the impact of growing cotton. Similarly, you must use a steel water bottle 500 times for its carbon footprint to shrink to less than that of a disposable PET bottle. One found a permanent plastic bottle to result in less carbon emissions than a stainless steel one.
Reducing the packaging you use by buying large containers and, for example, avoiding single-serve yogurt pots, also helps. And switch to bar soap. It is a complicated life-cycle analysis, but than liquid soap from a dispenser.
Buying concentrated forms of products such as detergents is also a case of more bang for less packaging. Life-cycle comparisons show they , too.
Boycotting mixed packaging, which often canât be recycled, may also help: for instance, crisp bags and stand-alone pouches that are all the rage for baby food. Avoid black plastic food trays, whose colouring confuses the infrared detectors used to distinguish plastics in most recycling plants. Go for brands that have made meaningful packaging changes, such as the few drinks companies using 100 per cent recycled PET.
Taking any recyclable waste home with you helps if, as in the UK, kerbside recycling is much easier and cheaper for local authorities. If you tip it into a public bin, itâs unlikely that anyone will take the time to separate it out for recycling.
A PET bottle, for example, might be brought into an endless âclosed loopâ in which it quenches your thirst, surfs through the recycling plant and emerges as pristine PET from which it is moulded into a new bottle, time and time again. That is good not just for waste, but also for the climate. Producing a tonne of recycled plastic generates between 1 and 3 tonnes less CO2 than a tonne made fresh from oil.
The idea has been taken up with enthusiasm by some governments, charities, scientists, manufacturers and retailers. At the World Economic Forum in January, the initiative, spearheaded by the Ellen MacArthur Foundation, announced a list of companies that have sworn to make all their packaging recyclable, compostable or reusable by 2025. âWeâre talking about the survival of some of these big brands,â says Edward Kosior of recycling consultancy , highlighting pledges such as that of Danone, the food giant behind products such as Evian water, to move to 100 per cent recycled bottles. âWhat the brands are saying is: âThe problem is not with the plastic weâre using, itâs with the way we have mismanaged the materialâ.â
But significant obstacles lie in the way. Oil is still cheap â currently around $68 per barrel, down from $140 in 2008 â while recycling is expensive and complex. Take that PET bottle again. Many are encased in a sleeve made of another plastic, confusing the infrared detectors used for sorting. âThe more complex the bottle, the less recyclable it is,â says Kosior. PET meat trays contaminated with other layers of plastic foil are another problem, as is the requirement that all PET for new drinks bottles be âfood gradeâ. PET that once held paint thinner and the like must be laboriously separated out. Then there are brands that prize their bottles being colourless, so wonât accept recycled PET visually tainted by previous generations of coloured bottles.
Nextek has developed one solution: invisible fluorescent markers, including one for food-grade PET, that manufacturers could incorporate into their product labels and that could be detected by kit retrofitted in recycling plants. Then there are emerging technologies that aim to break plastics down chemically into the monomer units they are built from. , a spin-out company from Eindhoven University of Technology in the Netherlands, has developed a system that heats PET mixed with a magnetic smart liquid. A magnetic field then scrapes contaminants off, creating pristine PET free from colourants, adhesive and the patina of age.
Short-sighted solutions
All good stuff, but these high-tech solutions are just about PET, and are ill-suited to developing economies with limited recycling set-ups. Another concern, says Tom Domen of Ecover, which makes less environmentally damaging cleaning products in plastic packaging, is that the fixes focus on improving an existing situation â perhaps at the expense of more radical, longer-term solutions, such as developing better biodegradable plastics (see âBiodegradable plastic: Waste that eats itselfâ).
âYou have the camp of the technical cycle that sees recycling as the ultimate answer and then you have the camp of the biological cycle, which sees biodegradability as the final answer,â says Domen. âUnfortunately, those two are often head to head when they should not be because both solutions are there for different purposes.â The fear is that short-sighted investments in infrastructure could make better, future options too expensive to adopt. Similar claims and counterclaims swirl around the case for incinerating plastic to recover energy from it (see âGone in a puff of smokeâ).
, an industrial ecologist at the University of California, Santa Barbara, and leading cruncher of plastic statistics, adds another objection. In a paper about to be published, he and his colleague Trevor Zink of Loyola Marymount University in Los Angeles argue that an obsession with recycling encourages single-use products rather than the best option: reducing consumption. If you know your bottle is going to be recycled via a bottle-deposit scheme, why bother taking your reusable one with you?
The truth is that recycling is beneficial only if it reduces the production of virgin plastic from oil, says Geyer. âA lot of people just take it for granted that every tonne of material recycled reduces primary production, but this is a market-mediated thing,â he says. âThereâs no law of physics that says it will.â
In fact, standard economic theory suggests that flooding markets with recycled material boosts supply, driving the price down and increasing demand for virgin plastic, too. It is nearly impossible to prove such causality, says Geyer, but this assertion seems to be backed by the data. Even as we get better at turning used bottles into new ones, more and more are being made â from new and old plastic. Global plastic bottle production is between 2016 and 2021.
Tony Breton of bioplastics firm Novamont agrees that recycling alone wonât stem the tide of plastic waste. âOne of the big things thatâs lost within a lot of the circular economy discussions is the role minimisation and reuse can play,â he says. âThereâs not a lot of money to be made in reducing consumption, and measures to reduce consumption are generally not politically well-received.â
Efforts are generally piecemeal: France has passed a law to ban the sale of disposable plates and cutlery; Italy insists that are either thick, reusable ones or compostable; Germany has a ; the UK, having introduced a plastic bag tax, is proposing banning plastic straws and cotton buds.
The ultimate solution to the plastic waste crisis will have many strands. It will require coordination between government, retailers, manufacturers and recycling firms for better packaging design, advanced recycling technologies and new plastics â as well as aid for developing countries to improve their waste systems and water supplies. It must also take care to avoid excluding new ideas that might be just around the corner.
âThe big challenge with plastics is not technology, itâs human behaviourâ
One such leap could be the eye-catching promise of bacterial enzymes that have evolved to break down plastic waste. These work at low temperatures, around 30°C, although their efficiency is currently poor. It is even possible that, once split apart, this waste plastic could be turned into other chemicals.
In the end, says Kevin OâConnor of University College Dublin, Ireland, there is no one solution. And while we should keep the pressure up on industry and government to implement sensible, joined-up solutions, the onus must be on us to mend our own ways, too. âThe big challenge is human behaviour, itâs not actually technology,â says OâConnor. âI think the technology will eventually come to maturity. But the big challenge is us.â
Can we clean up the mess?
Efforts to remove plastic already in the ocean are fraught
The robotic filter feederâs mouth gapes, like that of the whale shark that inspired its design. Helpless, a bobbing Coca-Cola bottle drifts into its mouth â and WasteShark glides off down the Dutch canal, leaving a patch of pristine water behind.
WasteShark was born from the irritation of one man, Richard Hardiman of in the Netherlands, at ineffective attempts to remove waste plastic from water. It is not the only such project. In Baltimore, Maryland, has scooped more than 640,000 plastic bottles from the Fall Jones river since mid-2014. Floating âsea binsâ suck in the plastic drifting in UK, Finnish and Spanish ports. Dutch entrepreneur Boyan Slatâs 1-kilometre-long booms are due to start work in the Great Pacific Garbage Patch between Hawaii and California later this year as part of the Ocean Cleanup project. He has claimed that half the patch could be cleared within five years by funnelling rubbish towards a central tank for collection by passing ships.
Others are less convinced. âPeople have knee-jerk responses: âTrash in the ocean? Well go get itâ,â says Marcus Eriksen, co-founder of the , a US non-profit organisation. âThe truth is that itâs so spread out, itâs so fragmented, it doesnât make sense economically to do that.â Even the most well-known ocean clean-up projects are between them removing just 0.5 per cent of marine plastic trash.
Another possibility is to somehow harness bacteria that seem to be evolving enzymes to gobble plastic. Could these be sprayed onto islands of ocean garbage to make them melt away? It is possible they could break the plastics down sufficiently for microalgae to do the rest â but that could create massive algal blooms, as well as release toxic chemicals into the ocean. With the plastics we have already poured into the ocean, it seems we may not like it, but we will have to lump it.
Gone in a puff of smoke
Sometimes simply burning plastic is the best option
Incineration is often derided as the dinosaurâs approach to the plastics problem, belching pollutants into the air. But it has many attractions, particularly as a way of ridding ourselves of plastic that can never be recycled because of its chemistry or small size. In developing countries, it is perhaps the only option.
About 14 per cent of plastic packaging is currently incinerated across the world, with . The plastics are burned in air, producing carbon dioxide and other gases, heat and ash. Incineration with energy recovery harnesses the heat to convert water to steam and drive a turbine, generating electricity. Combined heat and power plants push this one step further, using the remaining heat to warm local homes, schools and offices.
Other related technologies could beat incineration. Around 90 pyrolysis plants scattered around the world heat valueless waste plastic, often from car tyres, to several hundred degrees in the absence of air, breaking them down into a rich fuel. Gasification breaks plastic down into energy-rich gases such as hydrogen, methane and carbon monoxide, which can generate power or be transformed into diesel, ethanol or other chemicals.
Proponents say that modern incinerators employing âscrubbingâ technologies to clean their exhaust gases release only imperceptible amounts of pollutants into the atmosphere. Using incinerators can replace the need to burn dirtier coal, and therefore reduce CO2 emissions, while pyrolysis and gasification release no CO2 at all.
Critics are less convinced, and not just on the CO2 front. Scrubbed-out pollutants are still there in the scrubber or the ash that goes to landfill, they say. And all three techniques lose all the labour and much of the energy that went into crafting the plastic and its product â while making the economics of reusing and recycling plastics even trickier (see main story).
This article appeared in print under the headline âHow to Solve a Problem Like Plasticsâ
