Monday, April 02, 2007

The Global Water Crisis

Growing up in Southeast Asia and having gone through seasonal water rationing, I still wonder whether I appreciate how precious water is. Having lived in the U.S. for years I take for granted that water is available on demand. But in large regions of the world, water is increasingly becoming a precious commodity. Political scientists and environmentalists have been warning that wars and crises might erupt over water in the near future.

In this post, I will use time-series and geographic data to highlight the serious challenges that lie ahead. Water availability is measured, in terms of cubic meters per capita (annually), during three periods: 1975, 2000, 2025. I use the following definitions which appeared in a recent issue of Plenty Magazine:
  • Scarcity = less than 1000 cubic meters per capita
  • Stress = 1000 to 1700 cubic meters per capita
  • Vulnerable = 1700 to 2500 cubic meters per capita

(To enlarge a particular image, click on it.) In 1975, Scarcity and Stress was centered primarily in North Africa.

By the year 2000, three large countries (China, India, Iran) were classified as vulnerable. East African nations were experiencing Stress or Scarcity.

To forecast water supply per capita in the year 2025, we need to make some assumptions regarding population growth (low, medium, or high growth rates). In the map below, I elected to use medium population growth rates. Looking towards the year 2025, current forecasts paint a bleak picture:

By 2025, the impact of drier climate translates to well over 2 Billion people experiencing water Scarcity or Stress. If we include Vulnerable countries, we are looking at over 3 Billion people! Besides North and East Africa, the Middle East and South Asia will be struggling to meet their water needs. The humanitarian, geopolitical, and security implications are quite scary. (The more optimistic forecast, using low population growth rates, paints essentially the same picure.)

The coming water crisis is a global problem -- the number of people and the regions affected means that the industrialized countries cannot ignore this issue. Can regions and adjacent nations work together peacefully to meet their water needs? Will desalination overcome its current economic and environmental deficiencies? Just as energy conservation and efficiency are important components of any sound energy policy, water conservation and efficiency need to be emphasized.

Green architects in industrialized countries are already designing buildings which incorporate design features like reusing gray water and low-flow toilets. Suitable water capture and efficiency solutions need to be funded for developing and poor countries. Poor nations can use funding and expertise from the industrialized nations, particularly the OECD members. Unfortunately, Western leaders are not acting fast enough. When was the last time you heard a politician talk about this issue?

UPDATE: Newsweek has a short article on China's water crisis.

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