Acid rain is a widespread problem and can travel long distances. This map shows the affect it has had on forests in northern Europe.
Acid rain acidifies lakes and streams and contributes to damage of trees and many sensitive forest soils. Acid rain increases the corrosion of building materials and paints, including statues and sculptures that cannot be rebuilt. SO2 and NOx gases and their products can also damage visibility and harm peoples health.
Solutions to the Problem
The best way to combat acid rain is to reduce the amount of NOx and SO2 being released into the atmosphere. Catalytic converters in cars can reduce the emissions of NOx by up to 90 percent, but although they are standard in new cars, they cause more carbon dioxide to be released, which contributes to the greenhouse effect.
SO2 emissions from power stations can be reduced before, during, or after combustion.
If a fuel with low sulphur content, such as coal, is burned, not much sulphur dioxide will be formed. However, low sulphur fuels are expensive because they are in increasing demand, and although high sulphur fuels can be treated to reduce their sulphur content, this is also expensive. The SO2 created during burning a fuel can be absorbed if an appropriate chemical, like limestone, is there as the fuel burns. Once the fuel has been burned, the SO2 can be removed from the gases. Most methods spray a mixture of limestone and water onto the gases. This reacts with the SO2 to form gypsum, a useful building material. Another option is not to burn fossil fuels, but to use alternative energy sources. Alternative energy sources such as solar or hydroelectric power can be used to produce “clean” electricity, but are still expensive.
All of these methods for reducing acid gases are costly, and have disadvantages, but laws have been passed to force businesses to use them. This may seem like a drastic step to take, but acid rain is a very big problem.
