Wastepaper cellulose could replace polyester fibre and packaging films to avoid 270 Mt CO2ea−1

Plastics and fibres produced from fossil feedstocks cause several environmental impacts, including microplastic pollution and greenhouse gas emissions. Although biomass-based plastics may be able to avoid these impacts, there are yet no viable staple substitutes to fossil-based polymers. Cellulose-rich wastepaper can be converted into polymers for clothing and packaging, but the potential environmental benefits of this process are unclear. Here we assess the global availability of wastepaper and demand for polyester fibre and non-food packaging films. We found that current cellulose-rich wastepaper is enough to produce 85 Mt a −1 cellulose products and replace all production of virgin fossil polyester fibre and non-food packaging films, accounting for 23 % of the global demand for polymers. This could eliminate 8 % of global non-biodegradable microplastics and avoid 270 Mt CO 2 e a −1 greenhouse gas emissions. Lyocell fibre and cellulose film production from wastepaper involves an energy-intensive fibre spinning process, which must be decarbonised to achieve maximum savings. • Wastepaper-based products could supply 23 % of the global demand for polymers. • Wastepaper-based fibre could avoid 8 % of global non-biodegradable microplastics. • Wastepaper has a high content of cellulose and can be made to cellulose products. • Using the original polymer chain in cellulose saves energy for chemical conversion.