The concerns about sustainability of plastic material is somewhat exaggerated. Processing of many natural materials (glass, paper, wood, metals) consume far more energy and thus lead to greater consumption of fossil fuels.
Additionally, research and development work currently in progress globally will provide future opportunities to make some of the plastics from biomass and other renewable sources. Thus, plastic manufacture will become even more sustainable in the years to come.
It is fair to say that plastics replace several naturals, which are either scarce, consume more energy for processing or cause damage to the eco-system during their production. Thus use of plastics makes positive contribution to the sustainability of earth’s resources.
Another issue that is often discussed is whether because of their non-biodegradability, plastics will cause damage to our eco-system. The signature of all natural materials made by biological process is that they are biodegradable and bio-assimilable. The long life and desirability of plastics, which have made them, a material of choice for many applications is seemingly a disadvantage when it comes to their disposal.
However, when handled properly, plastics do little damage to our environment. Plastics have the advantage that they can be easily reprocessed and recycled.
Plastics offer the unique advantage that one can recover the fuel value contained in the hydrocarbon polymer after its use. Plastics can also be made environmentally degradable, especially for packaging applications.
There are expectations that in the near future plastics will be made even biodegradable and compostable so that waste plastics can be handled the same way as wet food waste and agricultural waste.
The overall eco-friendliness of plastics becomes apparent when one evaluates the total "life cycle", namely, an analysis of raw materials, energy, effluents, methods of disposal etc. of a material from its origin to its final disposal.