The document “Ozone Layer Depletion” provides a concise yet comprehensive overview of one of the most critical environmental topics for UPSC – the thinning of the stratospheric ozone shield. It covers:
- Science behind ozone (Chapman Cycle, Dobson Unit)
- Catalytic destruction by ODS (CFCs, halons, N₂O)
- Polar Stratospheric Clouds (PSCs) and the Antarctic Ozone Hole
- Impacts on human health, ecosystems, and climate
- Global treaties – Vienna Convention, Montreal Protocol (1987) – hailed as the most successful environmental agreement, and the Kigali Amendment (2016) linking ozone to climate change
- India’s policies (ODS Rules, 2000; HCFC phase-out by 2040; Ozone Cell under MoEFCC)
- Latest updates (2024-25 smaller ozone hole, recovery timeline by ~2040 globally)
- Emerging challenges – N₂O as the largest ODS today, illegal trade, VSLS, space launches
