Waste Gases

• Sulfur dioxide and various oxides of nitrogen are emitted as waste products from car exhausts, power plants and factories. The gases react with water and other elements in the air to form acidic compounds. The acidic compounds reach the earth as rain or snow.
  
  

Acid Rain

• The acid rain falls into rivers, lakes and streams and changes their pH balance, causing them to become acidified. Acidification has detrimental effects on the plants and animals that live and grow in the water. Acid rain also damages trees such as spruce and other trees that grow at high altitudes.
  
  

Ocean Acidification

• Human activities have led to an increase in the amount of carbon dioxide in the atmosphere. Much of this carbon dioxide is absorbed by the oceans. The increased carbon dioxide has lowered the pH of seawater and is detrimental to both the biology and chemistry of the oceans.