We live in the plastic age (the “plasticene”), producing over 300 million tonnes (mt) of plastic every year globally, 5–15 mt of which flow into already polluted oceans. Plastic remains a key material in the global economy, but low rates of collection, reuse and recycling, emissions of microplastic from product wear and tear, and often insufficient disposal measures are leading to far-reaching environmental, health, social and economic impacts. The costs of inaction are unacceptably high. Globally there is a growing recognition of the need to address marine litter and rethink our approach to plastics and plastic packaging within the economy. Measures that enable a transition to a circular economy can avoid waste and reduce marine litter, and contribute to keeping plastics and their value in the economy.