Issue Pollution II Water Water Pollution Water is

Issue: Pollution, II Water

Water Pollution Ø Water is an essential part of our life- support system—indeed, it covers 71% of the surface of the globe

Water Pollution Ø It serves many, many functions in our lives, including: Ø Modifying the climate Ø 90% of photosynthesis occurs in water Ø Most organisms are 90% water Ø It carries nutrients to cells, helps build cells and carries away waste Ø Helps dilute pollutants and carry them away

Water: Basis of Life Ø Consider the excitement of the Mars Rover

Water Pollution Ø We have discussed already the Hydrological Cycle by which water is purified, approximately taking 10 days

Water Pollution Ø The amount of water remains the same, about 80 trillion gallons Ø Of this 0. 003% is available to us, and the supply is far from evenly distributed Ø Salt water is about 97% of the total Ø Of the remaining 3% much is tied up in ice, the atmosphere, in plants and in us Ø The rest is in groundwater

Where does the Water Go? Ø Around the world, three-quarters is used for agriculture, and this has increased 400% since 1940. Ø What about here in the USA?

Water in the USA Ø We use highly-purified water for: flushing toilets, washing cars, sprinkling lawns etc. Ø Our water efficiency is very low Ø We use about 90 gallons/day/person, which is three times domestic consumption worldwide, 20 x that in LDCs Ø The public wants drinking water, factories want to flush away waster, and farmers’ fields pour tons of nitrogen into rivers.

We have tried to expand resources by… Ø Building dams Ø Drilling into deeper and deeper groundwater Ø Desalinating seawater Ø Some people have suggested towing icebergs from the Polar regions.

Waste Ø By conservation alone we could save 50% of the water we use Ø By decreasing evaporation and seepage loss Ø Redesigning industry to be water efficient Ø Adjusting water price to reflect value

Water efficiency campaigns

Pollutants

What is the situation in the USA

What have we done about it?