World Notes UNITED NATIONS

Fifteen years ago, scientists began noticing that the earth's protective ozone layer was being depleted by a group of chemicals known as chlorofluorocarbons. They warned that deterioration of the ozone, which blocks the sun's harmful ultraviolet rays, could lead to an increase in skin cancer and disastrous climatic changes, including an overall warming of the earth's atmosphere.

Despite strong anti-CFC laws in the U.S. and Canada, many countries . continued to allow the compound to be used as a propellant in aerosol products and as a cooling agent in refrigerators, air conditioners and other appliances. Finally, last week representatives of 31 nations, including Britain, West Germany and the Soviet Union, agreed that by 1992 they would cut back on their production of chlorofluorocarbons by 20%. Mostafa Tolba, executive director of the U.N. Environment Program, felt the agreement did not go far enough. He warned, "If we mess up this planet, we can't go and look for another."