Skip main navigation

New offer! Get 30% off one whole year of Unlimited learning. Subscribe for just £249.99 £174.99. New subscribers only. T&Cs apply

Find out more

Earth’s water

With so much water on Earth, how is water scarcity a problem? In this article Dr. Glenn Patterson discusses reasons water scarcity can be an issue.
Ocean in Antarctica with snowy mountains in the back
Earth is a water planet. Seventy percent of its surface is covered by water. Water seems to be everywhere, in the oceans, lakes, streams, glaciers, and even in people. Our bodies contain about 65 to 75 percent water by weight.

With so much water around and in us, it would seem that water scarcity would seldom be a problem, and we could just take the abundance of water for granted. Indeed, many of us tend to do just that, assuming that inexpensive water will magically appear when we turn on the tap. But for several reasons, water scarcity is likely to be one of the world’s significant issues of the 21st century.

First, the amount of freshwater easily available for human use is extremely limited in comparison to the amount of water on earth. 97.5 percent of earth’s water is in the oceans or other salty water bodies, and is too salty to drink without expensive desalination.

Second, water is very unevenly distributed over the earth’s land surface. Some areas have plenty of water, but some have hardly any.

Third, water is also unevenly distributed in time. Rains generally come in dependable patterns, but at any given time large areas of the earth are affected by droughts that may last from a few weeks to several years.

© Colorado State University
This article is from the free online

Water Scarcity: Crisis and Response

Created by
FutureLearn - Learning For Life

Reach your personal and professional goals

Unlock access to hundreds of expert online courses and degrees from top universities and educators to gain accredited qualifications and professional CV-building certificates.

Join over 18 million learners to launch, switch or build upon your career, all at your own pace, across a wide range of topic areas.

Start Learning now