In a study of the carbon footprint of projected global plastic use between 2015 and 2050, Zheng and Suh modelled a theoretical situation of 100% recycling of plastic in 2050, and found it had a 25% lower carbon footprint in 2050 relative to the current trajectory (business-as-usual) of plastic use up to 2050. An even greater reduction could potentially be achieved by focusing on transitioning to renewable energies for use in plastic manufacture or by reducing demand for plastic in the economy manufactured by current methods. Recycling plastic was generally better than, or similar to, the benefits of moving to bioplastics (depending upon the feedstocks and certain other conditions). The greatest reduction in the carbon footprint came from implementing a mix of all these activities: the carbon footprint of plastics use in 2050 could be reduced by 93% (relative to the current trajectory up to 2050) by moving to 100% sugarcane-based plastics with 100% renewable energy combined with 100% recycling and reduced demand growth. It is important to ensure that efforts to reduce the carbon footprint of plastics, such as using renewable feedstocks like sugarcane, does not displace food sources – as discussed here.
 Zheng et al., “Strategies to Reduce the Global Carbon Footprint of Plastics,” Nature Climate Change (2019)