Final answer:
Regulations were put in place to limit the release of sulfur and nitrogen oxides in the US, reducing the severity of acid damage. Cap-and-trade is an environmental policy that allows for the buying and selling of permits for pollutant emissions.
Step-by-step explanation:
In the United States, regulations were put in place to curtail acid rain, specifically limiting the amount of sulfur and nitrogen oxides that can be released into the atmosphere by industry and automobiles. These regulations have been effective in reducing the severity of acid damage to both natural and manmade environments in North America. Acid rain is still a growing problem in industrial areas of China and India.
Cap-and-trade is an environmental policy that allows for the buying and selling of permits for the emission of pollutants, such as sulfur and nitrogen oxides. It sets a limit, or a cap, on the total amount of pollutants that can be emitted. Companies that emit less than their allotted amount of pollutants can sell their permits to companies that emit more, encouraging companies to reduce their emissions.