Landfill could be greener than recycling when it comes to plastic bottles
For regions with adequate space and little recycling infrastructure, disposing of bottles in landfill generates a lower carbon footprint than recycling or incineration...
The ubiquitous 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 an independent study that I and a colleague just completed, 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 better of the used PET actually displaces production of new PET, will recycling deliver the lowest footprint.
In recycling programs using kerbside collection, typically less than 50% of the used bottles end up displacing new PET (an abbreviation of polyethylene terephthalate). Programs using take-back obligations, separate collection or bottle-deposits, however, tend to report much higher displacement rates — some in the range of 75%.
And what about burning it all? Charging used bottles to waste incinerators converts them largely to the greenhouse-gas carbon dioxide, which then goes straight into the atmosphere. This footprint debit can be reduced somewhat by generating power and heat from the incinerator. However, 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.