Issue Space debris re-entry and launches as a new ozone risk

Summary

Thanks to international controls, the stratospheric ozone layer has recovered substantially since the mid-1990s and sits within its global boundary, though the report observes recovery may have stalled recently. Against this backdrop, this year's ozone information sheet newly addresses emerging risks such as the re-entry of space debris as a research topic. As debris in low Earth orbit accumulates, re-entering fragments generate nitrogen monoxide in the middle atmosphere, which ultimately depletes ozone. Rising numbers of rocket launches and re-entries are also injecting new aerosols into the middle atmosphere. How these aerosols affect ozone concentrations and the radiative balance up there remains poorly understood, and shifts in ozone's vertical distribution also matter for that balance. The report warns that incomplete recovery or new pressures could raise risks to human health, crops, ecosystems and atmospheric circulation.