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)