Things to Consider
Life Cycle Thinking
The current debate around waste plastics has focussed on the impacts on marine pollution and has brought some people to question the long-term viability of a single use throwaway society. However, some of the alternatives to single use plastics may be more impactful on climate change. Considering using alternatives such as non-plastics and reusable containers can result in counterintuitive consequence.
Life Cycle Thinking will be essential to ensure that reusable replacement products don’t have a greater environmental impact than disposable alternatives. By considering all stages of a product’s lifespan, including extraction of raw materials, construction, use and disposal, we can ensure that measures taken at one stage do not lead to unintended consequences in another.
For example, results from life cycle assessments suggest that:
- cotton bags need to be used 173 times before they become more environmentally friendly than a single use plastic bag
- paper bags can decompose but have a higher carbon footprint than plastic ones, because the process of making them uses more energy
- a stainless steel water bottle needs to be used several hundred times before it is better for the environment than a single-use plastic one.
Compostable items
In many sites, compostable plastics have been seen to be a good alternative to SUPs. However, compostable plastics tend to exhibit similar aesthetic and physical properties as non-compostable plastics meaning that they are almost impossible to distinguish at a composting plant. There is no way for plant operators to determine whether they should be accepted in the process or screened out as contamination. Conversely, this same confusion arises at plastics recycling facilities which cannot differentiate between compostable and mainstream target plastic types.
A key limitation of compostable plastics is that a period of six months is required to break down the material. This is unlikely to be realistic for composting facilities in the UK which typically process material over an eight to twelve-week period.
In principle, compostable cups appear to be environmentally preferable. However, under current arrangements it is likely that the majority of compostable cups end up in landfill where their breakdown produces methane, a greenhouse gas 25 times more damaging than carbon dioxide.
In light of the above, it is recommended that focusing on waste prevention via reuse as the preferred option for cups. If the council opts to use compostable items, then the only way to ensure these are correctly disposed of is to have suitable compostable facilities onsite or nearby, windrows, typically utilised for green waste are not suitable.