Environmental Engineering Reference
In-Depth Information
Source: Environmental Protection Agency
Relevant Laws and Treaties
There are many laws and treaties pertaining to the cleanliness and safety of the air and to the protection of
Earth's atmosphere and ozone layer. Those relating to ozone depletion are the Clean Air Act and Montreal Pro-
tocol.
•
United States Clean Air Act (amended in 1990):
The United States signed the Montreal Protocol in
1987, and the 1990 amendments to the Clean Air Act contained provisions for implementing the pro-
tocol. The Clean Air Act mandated that governments reduce smog and air pollution. It was supposed to
curb three major threats to the nation's environment and to the health of millions of Americans: acid
rain, urban air pollution, and toxic air emissions.
•
Montreal Protocol (1987):
The Montreal Protocol was a ground-breaking, international treaty signed by
several countries in 1987 that aimed to protect stratospheric ozone by reducing and phasing out the pro-
duction of ozone-destroying compounds used in refrigeration, aerosols, and foam, most notably CFCs.
The protocol projected that the recovery of the ozone would return to pre-1980 levels as early as 2050;
however, contributing factors such as greenhouse gases make this estimate less certain. The treaty has
been modified seven times since its origination and continues to emphasize the importance of a total
phase-out of CFCs. Since the protocol came into effect, the atmospheric concentrations of CFCs and re-
