While re-iterating that recycling is GOOD but reduction of plastic use is BETTER, here are the various costs of recycling plastics:
- Plastic needs to be cleaned to be recycled which requires water & energy, not to mention the general public's time.
- Plastic waste needs to be collected from homes which involves transport (emissions, etc.)
- Plastic needs to be sorted - not all plastics are the same. This may be done by machinery which has costs.
- In the UK, plastic is shipped to China (and other countries) for recycling which has associated transport costs. It is also reported that a lot of plastic may be incinerated or burnt rather than recycled at its destination.
- Energy & machinery are required to recycle plastic, adding to the environmental cost.
- Water is needed for recycling - water scarcity is already an issue in parts of the world.
- Plastic recycling produces emissions.
Also see http://www.plasticsrecyclers.eu/environmental-economic-social-impact-assessment-increased-plastic-recycling