- What is the origin of California’s fresh water sources?
Vocabulary
consumptive Water use where water is ’lost’ to evaporation.
drip irrigation Pipes & tubes that deliver small amounts of water directly to the soil at
the roots.
incentive A financial benefit for taking a particular action.
non-consumptive Water use that does not ’use up’ the water supply.
Points to Consider
- How could fresh water be more valuable than gold or a diamond?
- Which human activity uses more water than all other activities combined?
- Why don’t all farmers use drip irrigation and other water efficient irrigation methods?
21.2 Problems with Water Distribution
Learning Objectives
- Explain why water shortages are increasingly frequent throughout the world.
- Discuss why 1.1 billion people (one fifth of the people on Earth) do not have access to
safe drinking water. - Explain why humans can use less than one percent of all water on Earth.
- Discuss the ways in which human water demands are unsustainable.
Introduction
Humans are facing a worldwide water crisis according to the United Nations. The crisis
includes worldwide shortages of fresh water that humans can access, scarcity of safe drinking
water supplies and water pollution.
World Water Supply and Distribution
Water is everywhere. More than 70% of the Earth’s surface is covered by water. The Earth
has a limited supply of water that we can use. There are supplies of freshwater in lakes,