State of the ozone layer in 2025 1

State of the Antarctic ozone hole in 2025 2

100 years of ozone measurements in Switzerland: Celebrating the world’s longest continuous ozone time series 3

Sustaining the global ozone observing network 4

Cloud-modified local UV forecasts from the RIVM/KNMI UV indexer 5

UV monitoring in the twenty-first century – why we need it and how we can implement it on a large scale 6

25-year UV calibration campaigns (QASUME) 8

Atmospheric monitoring of controlled substances under the ozone treaties and its relevance to the Kigali Amendment to the Montreal Protocol 9

The Kigali Amendment at ten: A cooling success story 10