Critically analyse the environmental significance of the ozone layer and the dual challenges posed by stratospheric ozone depletion and tropospheric ozone pollution. (Answer in 250 words)

The stratospheric ozone layer acts as a protective shield by absorbing biologically harmful ultraviolet radiation, while ground-level ozone in the troposphere functions as a toxic pollutant. Together, ozone depletion and ozone pollution pose complex environmental and public-health challenges in a warming world.