Human Impact on Water Cycle

Fresh Water on Earth Is Limited Although 75% of the earth is covered in water, only 3% of the water is freshwater. Most of the freshwater is in glaciers and ice caps. Less than 1% of the freshwater on the earth is readily available.

Usable Water Is Valuable Think about how many ways you use clean freshwater every day. Did you wash your face? Brush your teeth? Take a drink? Cook food? Use the toilet? Eat fresh produce? Wash your clothes?

Greenhouse Gases Certain gases in the atmosphere help keep the earth warm. Without these greenhouse gases, the earth would be extremely cold. Many human activities increase the amounts of greenhouse gases in the atmosphere. This is believed to be causing global warming.

Global Warming Affects the Water Cycle Warmer air causes more evaporation and warm air holds more water. This intensifies the water cycle.

Intense Water Cycle In areas around water, there may be more clouds and precipitation. In areas that are away from bodies of water, there may be few clouds and less precipitation leading to dry soil, plants dying, wells drying up, etc.

Acid Rain Combustion of fossil fuels adds sulfur and nitrogen compounds to the air. These compounds mix with the water vapor in the atmosphere and make it more acidic.

Effects of Acid Rain Acid precipitation causes water on the earth’s surface to be more acidic. Many plants and animals cannot live in the more acidic conditions. They die and it affects everything in the food web. Acid rain deteriorates buildings, statues, etc.

What We Can Do: Cut down on production of greenhouse gases Use clean coal that does not contain as much sulfur Use scrubber technology when burning coal to remove sulfates before smoke enters the atmosphere Use less electricity Use alternative forms of energy to generate electricity (wind, solar)