Eric Johnson, Director of Atlantic Consulting in Switzerland, recently completed an independent research called “PET’s carbon footprint – to recycle or not to recycle” with the aim to address users and producers of PET as well as regulators and policy makers.
According to the study, for regions with adequate space and little recycling infrastructure like the UAE (even though a high-income economy), disposing of bottles in landfill generates a lower carbon footprint than recycling or incineration. The ever-present PET bottle, used around the world to package drinks, may best be buried after use rather than burnt or reconverted into a second-life product. According to the study, the footprint of recycling is lower than that of landfills only if at least half of the plastic ends up being valorised. That’s right: only if about 50% or more of the used PET actually displaces production of new PET, will recycling deliver the lowest footprint.In recycling programs using curbside collection, typically less than 50% of the used bottles end up displacing new PET. Programs using take-back obligations, separate collection or bottle-deposits, however, tend to report much higher displacement rates – some in the range of 75%!
How about incineration then? Charging used plastic bottles to waste incinerators converts them largely to carbon dioxide (greenhouse-gas), which then goes straight into the atmosphere. This footprint debit can be reduced partially by generating power and heat from the incinerator. Yet, waste incinerators even at their best are inefficient power generators, so the net effect is still far more ‘carbon positive’ than either recycling or landfilling.
What the study suggests are two important points for policy makers. One, in regions that already have a recycling infrastructure (easily done in a country like the UAE as long as there is real will), the low-carbon aim should be to boost used PET’s displacement of new PET significantly above 50%. The key to this is not in raising curbside collection rates, but in improving yields, especially in sorting and to a lesser extent in reprocessing. It is a no-brainer: collecting clean, as pure as possible used-material yield a much cleaner recyclate than collecting heaps of mixed materials. The technology for cleaning and sorting plastics rather poor and unlikely to improve dramatically – so the fix must be in collection.
Second, in regions or countries without a recycling infrastructure whatsoever (as is in most developing countries), the lowest-carbon choice may well be to landfill plastic bottles. Happily for them, it will tend to be the cheapest choice as well (which is the case in the UAE as well as we do not have any waste tax, funny enough). Call it ‘carbon capture and storage’ if you will, on an economy budget. And the carbon really is stored: degradation of plastics in landfill, even under wet conditions, is very minor.
There are two other significant points made: one is the correction of a misperceived conventional wisdom. Habitually it is said that the common practice of shipping baled plastic bottles to China for recycling is an ecological nonsense, that it overrides the benefits of valorisation. Not true, says the study. Sure, the transport adds to the footprint, but not nearly as certainly as displacement. If the travelling bottles end up substituting what would have been new PET, then the journey was well worthwhile.
The study found that PET recyclate has a lower carbon footprint than virgin PET. Manufacturers making product from recycled PET – e.g. straps, films and fibres (for fleeces and similar garments) – should be able to claim that they are lower-carbon than alternatives made from new PET. Hopefully governments or consumer groups could help out by awarding such products low-carbon labels.
The idea from the study is clear: push your government to establish a solid network of recycling centers and make sure you collect and give away all your plastic bottles for recycling. More importantly though, make sure recycling is obligatory at is it only then that solid quantities are amassed. Segregate your recyclable waste at source and clean it before you throw it away (e.g. throw the milk remnants from the bottle before putting in in the recycling bin). Now, there is an essential caveat – we should actually minimize our consumption of bottled water and waste overall. I will soon write more on the topic. In the meantime, remember to: Live Green, Minimize Consumerism and your Waste!
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