A significant step forward, however, was the 1987 Montreal Protocol, which involved an international agreement to phase out chlorofluorocarbons (CFCs) within a set time limit.a Why the concern? Because CFCs are said to be contributing to the rapid depletion of the earth’s protective ozone layer. The ozone in the earth’s upper atmosphere plays a vital role in filtering the sun’s ultraviolet rays, which can cause skin cancer and cataracts. This is a problem not just in Australia. Recently, scientists have detected an 8-percent decrease in winter ozone concentration above some temperate regions of the Northern Hemisphere. Twenty million tons of CFCs have already drifted up toward the stratosphere.

In the face of this disastrous contamination of the atmosphere, nations of the world put aside their differences and took decisive action.