The Antarctic ozone hole in 2012 was one of the smallest in decades due to warmer temperatures in the stratosphere. This limited the loss of ozone and caused the ozone hole to break down early. The key factor was the Quasi-Biennial Oscillation, which helped disrupt the polar vortex and prevent severe ozone depletion. The ozone mass depleted in 2012 was much lower compared to previous years, showing similarities to years with small ozone holes like 1988 and 2002.