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International agreements – such as the Montreal Protocol and associated Kigali Amendment - have been largely successful in reducing emissions of ozone depleting substances. However, in recent years, some of these emissions have been observed to increase once more. These renewed, unreported emissions raise questions about potential gaps in international agreements and associated scientific monitoring. In this collection, we bring together both research articles on the physical evidence for renewed emissions and their consequences, as well as opinion articles outlining important next steps to secure a recovery of stratospheric ozone.