What is the ozone hole?

The ozone hole is not a literal hole, but a large region of severely depleted stratospheric ozone above Antarctica that appears mainly in spring. It was first identified in the 1980s, and researchers linked it to chlorine and bromine compounds released from CFCs and halons. The Montreal Protocol, adopted in 1987, phased out many of these chemicals and is widely credited with putting the ozone layer on the road to recovery. Ozone is important because it absorbs much of the Sun’s harmful ultraviolet radiation.