Chemistry and biodiversity

Single-use polythene bags are a significant contributor to plastics pollution. A new technique could help make them easier to recycle. Credit: Andrey Nekrasov/Barcroft Media/Getty Since Bakelite was revealed in 1907 as the first synthetic plastic — it was used as an electrical insulator — this lightweight, strong and mouldable class of materials has helped to make the modern world. Plastics are a staple ingredient in product design and manufacture, and their use, especially as single-use items such as water bottles and food wrappings, is expanding. The total weight of plastics produced per year currently stands at more than 380 million tonnes and is set to top 900 million tonnes by 2050. But, like the fossil fuels from which they are made, plastics can have negative environmental consequences. By 2050, an estimated 12 billion tonnes of plastic waste will be sitting in landfills or polluting the natural environment. For comparison, this number stood at around 4.9 billion tonnes in 2015. Used plastics also form a large proportion of the fuel fed into energy-generating waste incinerators, which are a source of carbon emissions. Documentary films such as those narrated by David Attenborough have drawn attention to the environmental hazards posed by waste plastics. Footage of discarded water bottles suffocating marine life has also helped to trigger a public outcry and propelled plastics pollution up global agendas. Although many plastics now carry the recycling symbol, in prac...