Water Resources in the World

With climate changes and increasing use of water in agriculture, fresh water shortage becomes an increasing problem. As elsewhere, in Chapter 5, Sachs describes the symptoms and provides some suggestions for solutions.

1. Global warming and water:

Global warming's direct impact on water is the quicker and greater water evaporation in hot weather, leading to heavy downpours in rainstorms that cannot be properly absorbed by the ground, causing soil erosion and runaway water, and droughts as water is excessively absorbed into the air (vapor extracted from one place does not translate into rain for the same place but often becomes rain elsewhere).

2. Urbanization and water:

As the world becomes more urbanized, i.e. with concrete buildings and concrete paved streets, water becomes less easily absorbed into the ground, causing floods (as as the September 2008 one in NW Indiana) because sewages could not contain them, and runs away elsewhere. Ground water is not sufficiently replenished, causing water shortages in regions, and even the gradual sinking of the whole city because of the lower water levels underground.

3. Agriculture and water use:

Extensive agricultural use of water, especially with electric pumps, tends to over-pump water from the underground without giving enough time for underground water replenishment, causing the gradual drying up of regions. Irrigation has led to the slowing down or decrease of water flow in many parts of the world, including the Aral Sea, the Yellow River, and the Rio Grande, among countless others.

4. Dams and reservoirs and water use:

To industrialize and for agricultural irrigation, dams and reservoirs are built all over the world, causing much ecological damage. Dams slow down river flows, causing greater sedimentation, and eventually lose their effectiveness as hydro-electric power sites. They and reservoirs also may cause earthquakes. Dams also cause the extinction of many river species. Example, the Three Gorges Dam in China.

5. Water scarcity is closely connected to political instability. Of the regions of high water scarcity identified in Sachs, the Sahel (the Saharan desert), the Horn of Africa (East Africa), Israel-Palestine, the Middle East, and the Indo-Gangetic Plains, are all problem areas where war and conflict rage to different extents. Example: recent pirate activities in Somalia: U.S. targets Somali pirates. Water scarcity precipitates the weakening or downfall of governments, and promotes warfare or piracy as an alternative form of politics, or economic livelihood.

6. Solutions to water shortage:

7. For different regions of the world: using local solutions and free market incentives in their conservation campaigns: India: building backyard dams, and in Africa: making better use of seasonal wetlands (both from Fresh Water: National Geographic).