Posted by: shipbright | October 5, 2009

Water and feeding a hungry crowded planet

“There are people in the world so hungry that God cannot appear to them except in the form of bread”. Mahatma Gandhi

626px-Crops_Kansas_AST_20010624As we continue to orbit over the earth trying to get the “Big Picture” of freshwater on our planet we can literally see from the sky patches of farmland and grazing lands. As our global population continues to soar past 6 billion people and rapidly approaching 7 billion, the need for food marches right along. That food is made possible by water, soil and sun, but as Goethe said centuries ago, “all is born of water, all is sustained by water”.

We know from our previous discussion about the world population, the demand for water is not a 1-for-1 increase, or linear relationship. It is more of a 2-for-1 relationship, or exponential relationship. Irrigating land for the production of food and watering livestock is THE major factor in that demand. Globally, the withdrawal of water from rivers, lakes and aquifers for agriculture accounts for up to 70% of our freshwater use! In the American West NASA reports that 90% of the water withdrawn is for agricultural use.

An old saying from the American West was “Whiskey’s for drinking, water’s for fighting!” Urban populations [e.g. Los Angeles], agricultural producers [e.g. farmers and ranchers], and ecosystem demands [e.g. in-flow water needs for fish] are all competing for freshwater and it’s getting harder and harder to manage and balance all the needs.

This is such a big issue that no one blog could possibly touch on all its aspects. Universities, governments, business consortiums are devoted to this challenge. So my purpose here, as is the entire purpose of this blog, is to raise awareness of these issues so that an informed electorate can have the collective political will to address these issues before they become a Darfur or Cochabamba.

This issue is going to be divided up into two parts. This post will provide some big picture background and my next post on this will be looking at a specific example: the Ogallala Aquifer of the American West. Later on I would like to use another example from around the world so that you can see that no matter where you are and no matter how one may feel that their problems are unique to them, it’s actually the same story and just a different place. We can learn from each other and not make the same mistakes over and over again.

Here’s an edited quick background from the water encyclopedia:

irrigation-furrows…Various forms of agriculture, practiced on about half of Earth’s land surface, provide the vast majority of food that over 6 billion people eat. Agriculture also provides much of the fiber for cotton, wool, and linen clothing.

One of the primary ways in which humans use water is by planting important crops in places where they can capture natural rainfall as rain-fed agriculture. Some forms of agriculture, such as intensive rice and corn production, can be practiced only in rainy climates. Such agricultural forms are much more productive than others, such as cattle and sheep herding, which are usually relegated to semiarid climates.

One of the primary reasons rain-dependent forms of agriculture are more productive than dry-land forms is that they have sufficient water to allow plants to grow to their maximum potential. Therefore, the most agriculturally productive regions of the world are all regions where natural rainfall is sufficient to allow rain-fed agriculture to flourish: for example, the eastern and central United States; the Pampas of Argentina; central Europe; northern and eastern India and Bangladesh; eastern China; and the valleys and volcanic islands of southeast Asia.

Because agricultural crops are so dependent on water, purposely adding water, beyond what naturally falls as rain, is widely practiced to increase agricultural production. This critical practice is known as irrigation.irrigation

Irrigation is an ancient practice that originated along the Tigris and Euphrates Rivers in what is now Iraq, and spread in ancient times to the desert valley of the Nile River in Egypt, the Indus River in Pakistan, and all the way to China. Native Americans also practiced irrigation long ago, especially in the areas now called Mexico and the southwestern United States.

It is estimated that 40 percent of all crops grown in the world today are grown using irrigation. The practice of irrigation can increase the productivity of crops on what would otherwise be rain-fed agriculture. It can also expand agriculture into areas where it would not otherwise be practiced due to aridity.

In the twentieth century, the practice of irrigation was greatly increased to provide food for the world’s growing population. Globally, irrigation now accounts for 69 percent of the 3,240 cubic kilometers (772 cubic miles) of water withdrawn for human use, and 87 percent of all water consumed. Proportions in the United States are 42 percent of all withdrawals and 87 percent of all consumption.

Asia, with the majority of Earth’s population, remains the world’s most irrigated region. The three most populous countries—China, India, and the United States—are also the leading countries in irrigated area and in water used in irrigation. Pakistan and especially Egypt remain the countries most dependent on irrigation, although other countries of dry southwestern and central Asia (e.g., Saudi Arabia, Iran, Iraq, and Uzbekistan) greatly depend on irrigation for their food and fiber supplies.

water and ag2In every irrigated region, water supplies are a limitation on further expansion of irrigated agriculture. In many regions, renewable supplies have already been exceeded, resulting in falling groundwater levels and greatly reduced river flow. In some regions, the depletion of water resources due to irrigation has reached crisis proportions. Today the Colorado River rarely reaches the Sea of Cortez (often called the Gulf of California), and even the Yellow River of China is sometimes drained completely. The Aral Sea in central Asia has lost half its surface area, most of its volume, and all of its once-enormous fishing industry. These are all examples of the depletion of regional water resources by irrigated agriculture.

Irrigation efficiency is improving with drip irrigation systems such as those pioneered in water-short Israel. In the southern Great Plains, some farmers are simply reverting back to dry-land agriculture as groundwater levels fall so low that they cannot afford to pump the water to the surface.

Agriculture uses vast quantities of water and also causes extensive pollution, primarily by introducing nonpoint-source contaminants. Runoff from agricultural fields often contains eroded soil, fertilizers, animal manure, or pesticides that together form a major source of water pollution.

Commentary: Those in the agricultural world face a huge and complex challenge in their efforts to meet the global food demand at a time of increasing and competing demands for water. Benjamin Franklin said that “necessity is the Mother of invention” and for centuries we have been irrigating our crops and watering our livestock in most of the same ways we always did. But with agriculture claiming about 70% of all the water withdrawals from rivers, lakes and groundwater something had to give.

water drop and treeAnd it has….farmers, ranchers, and aquaculturists have been seriously looking at how to improve water efficiencies for decades now. Around the world human ingenuity has allowed deserts to bloom [e.g. Israel], arid lands to become fertile [e.g. Cyprus], and croplands to become more productive with less water [e.g. American western plains].

The demands for water continue to grow though. Those with historical rights to water jealously guard those rights while those for whom the need for more water has increased are demanding access to that water. These conflicts take place all over the world and we saw the conflict between grazers and farmers play out in Darfur. People need freshwater for their own hydration and to produce food. If they don’t have it then it doesn’t take long for the situation to trigger our natural survival instincts and animal spirits and kill for it.

No water…no civility…no civilization.


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