[2026] PTE Academic Reading - Multiple Choice, Multiple Answers

The ozone layer is a thin part of the Earth's atmosphere that absorbs most of the sun's harmful ultraviolet radiation.In the late 20th century, scientists discovered that certain human-made chemicals, specifically chlorofluorocarbons (CFCs), were depleting this protective layer.CFCs were commonly used in refrigeration, air conditioning, and aerosol sprays.The depletion of the ozone layer leads to increased levels of UV radiation reaching the Earth, which can cause higher rates of skin cancer and cataracts in humans.Furthermore, increased UV exposure damages marine life, particularly phytoplankton, which forms the base of the aquatic food web.In 1987, the international community responded by signing the Montreal Protocol, a landmark environmental agreement.The protocol aimed to phase out the production and consumption of ozone-depleting substances.This treaty is widely considered the most successful environmental agreement to date, as it has led to the gradual recovery of the ozone layer.However, challenges remain, as some banned substances have long atmospheric lifetimes and continue to persist for decades.Additionally, the transition to hydrofluorocarbons (HFCs) as alternatives has introduced new concerns, as HFCs are potent greenhouse gases that contribute to global warming.