Plan B 3.0: Mobilizing to Save Civilization


Lester R. Brown

Chapter 4. Emerging Water Shortages: Introduction

Africa’s Lake Chad, once a landmark for astronauts circling the earth, is now difficult for them to locate. Surrounded by Cameroon, Chad, Niger, and Nigeria—all countries with fast-growing populations—the lake has shrunk 96 percent in 40 years. The region’s soaring demand for irrigation water coupled with declining rainfall is draining dry the rivers and streams that feed the lake. As a result, Lake Chad may soon disappear entirely, its whereabouts a mystery to future generations. 1


The shrinkage of Lake Chad is not unique. The world is incurring a vast water deficit—one that is largely invisible, historically recent, and growing fast. Because the deficit comes largely from aquifer overpumping, it is often discovered only when wells go dry.


This global water deficit is the result of demand tripling over the last half-century. The drilling of millions of irrigation wells has pushed water withdrawals beyond recharge rates, in effect leading to groundwater mining. The failure of governments to limit pumping to the sustainable yield of aquifers means that water tables are now falling in countries that contain more than half the world’s people, including the big three grain producers—China, India, and the United States. 2


Beyond these traditional sources of water insecurity, climate change is now affecting water supplies. Rising temperatures are boosting evaporation rates, altering rainfall patterns, and melting the glaciers that feed rivers during the dry season. As the glaciers melt, they are threatening to convert perennial rivers such as the Ganges in India and the Yellow in China into seasonal rivers, increasing both water and food insecurity. With the earth’s climate system and its hydrological cycle so intertwined, any changes in climate will alter the hydrological cycle. 3


Among the more visible manifestations of water scarcity are rivers running dry and lakes disappearing. A politics of water scarcity is emerging between upstream and downstream claimants both within and among countries. Water scarcity is now crossing borders via the international grain trade. Countries that are pressing against the limits of their water supply typically satisfy the growing need of cities and industry by diverting irrigation water from agriculture and then importing grain to offset the loss of productive capacity.


The link between water and food is strong. We each drink on average nearly 4 liters of water per day in one form or another, while the water required to produce our daily food totals at least 2,000 liters—500 times as much. This helps explain why 70 percent of all water use is for irrigation. Another 20 percent is used by industry, and 10 percent goes for residential purposes. With the demand for water growing in all three categories, competition among sectors is intensifying, with agriculture almost always losing. While most people recognize that the world is facing a future of water shortages, not everyone has connected the dots to see that this also means a future of food shortages. 4


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