
EnvironmentSeptember 1, 1989
The Changing Atmosphere
Human activity is altering the complex mixture of gases in the atmosphere. Some effects, such as acid rain and smog, are already evident. Unwelcome surprises may be lurking

The Changing Atmosphere
Human activity is altering the complex mixture of gases in the atmosphere. Some effects, such as acid rain and smog, are already evident. Unwelcome surprises may be lurking