Acid Rain
When the levels of Sulphur Dioxide or Nitrogen Oxide rise in the atmosphere, the result is rain and precipitation that is high in these gases, which are harmful to the soil and delicate ecosystems on which they settle. In fact, acid rain can kill freshwater fish as well as the plants and animals that depend on neutral or alkaline conditions in which to live. When an area is subject to ongoing acid rain, the natural pH (acidity level) of its soil and water changes, which limits the plants and animals that can thrive there.