Strat City, USA
Overexposure to ultraviolet (UV) radiation is a threat to human health. It can cause skin damage, eye damage, and even suppress the immune system. UV radiation overexposure also interferes with environmental cycles, affecting organisms, such as plants and phytoplankton, that move nutrients and energy through the biosphere.
In the 1970s, scientists discovered that Earth’s primary protection from solar UV radiation, the stratospheric ozone layer, was thinning. The cause was the emissions of chemicals that contained chlorine and bromine, which when broken down can destroy ozone molecules. The most common of these ozone-depleting substances (ODS) is a class of chemicals called chlorofluorocarbons (CFCs)...
In 1987, the United States signed the Montreal Protocol, the international treaty that protects and restores the ozone layer by phasing out ODS.
In 1990, the Clean Air Act (CAA) Amendments, including Title VI, Stratospheric Ozone Protection, were signed into law. Title VI directs the EPA to phase out ODS and includes complementary measures to reduce emissions and smooth the transition to alternative chemicals and processes that pose lower risk to human health and the environment
Today, the United States has almost eliminated production and import of all ODS and will successfully complete the phaseout by 2030.
The ozone layer is expected to recover by mid-century. By restoring the ozone layer, we reduce incidences of skin cancer and cataracts.
Click on items in Strat City, USA to explore how ozone layer protection affects many aspects of everyday life.