Summary

Precipitation—a major control of fresh water availability—is unevenly distributed around the globe. More precipitation falls near the equator, and landmasses there are characterized by a tropical rainforest climate. Less precipitation tends to fall near 2030 north and south latitude, where the world’s largest deserts are located. The water crisis refers to a global situation where people in many areas lack access to sufficient water or clean water or both. The current and future water crisis requires multiple approaches to extending our fresh water supply and moving towards sustainability. Some of the longstanding traditional approaches include dams and aqueducts. Water pollution is the contamination of water by an excess amount of a substance that can cause harm to human beings and the ecosystem. The level of water pollution depends on the abundance of the pollutant, the ecological impact of the pollutant, and the use of the water. The most deadly form of water pollution, pathogenic microorganisms that cause waterborne diseases, kills almost 2 million people in underdeveloped countries every year. Resolution of the global water pollution crisis requires multiple approaches to improve the quality of fresh water. The best strategy for addressing this problem is proper sewage treatment. Untreated sewage is not only a major cause of pathogenic diseases, but also a major source of other pollutants, including oxygen-demanding waste, plant nutrients, and toxic heavy metals.

Review Questions

1. What is the water cycle and why is it important to fresh water resources?
2. What should society learn from the case history of the Aral Sea?
3. Why is society facing a crisis involving water supply and how can we solve it?
4. What are the major kinds of water pollutants and how do they degrade water quality?
5. How would you rank the water pollution problems described in this chapter? Why?
6. Why is untreated sewage such an important water pollutant to remediate?
7. Why are people facing a crisis involving water pollution and how can we solve it?

Attributions

Theis, T. & Tomkin, J. (Eds.). (2015). Sustainability: A comprehensive foundation. Retrieved from http://cnx.org/contents/1741effd-9cda-4b2b-a91e-003e6f587263@43.5. Available under Creative Commons Attribution 4.0 International License. (CC BY 4.0). Modified from original.

Essentials of Environmental Science by Kamala Doršner is licensed under CC BY 4.0. Modified from the original.