Human Actions and Earth's Waters

Humans and the Water Supply

• Human water use can be lumped into five categories. The uses are arranged in order of greatest to the least amounts of total water use on Earth:
  • Agriculture (sixty-nine percent)
  • Industry uses (fifteen percent of global water use)
  • Home and Personal use (fifteen percent)
  • Recreation uses (less than one percent)
  • Environmental use (less than one percent)
• Despite California's abundant water supply from surface streams and groundwater, the state has a number of water rights issues that will be important long into the future.

Problems with Water Distribution

• Water is a renewable resource, but it is not unlimited. Humans are limited to less than one percent of the water on Earth. Also, water is not evenly distributed across the globe.
• Water is so valuable that countries have fought each other over water rights throughout history. Water shortages and water pollution have become so serious across the world, that some organizations call our water status a "water crisis". The crisis is blamed on overpopulation, overuse of water, pollution, and global warming.
• Undeveloped countries are rarely able to afford water treatment and purification facilities, unless other countries and international organizations help.

Water Pollution

• Industrial, agricultural, and municipal sources produce harmful water pollutants such as toxic chemicals, radiological agents, and animal wastes. Thousands of people die from waterborne diseases every year.

Protecting the Water Supply

• Many technologies are available to conserve water as well as to prevent and treat water pollution. Yet, most undeveloped countries cannot afford the technology they need to collect, treat and distribute water to their people.
• Developing countries may be able to afford water treatment systems, but people still need incentives to use conservation steps.