The World Water Problem
Water is one of the world’s growing problems- in agriculture, access to clean-drinking water in developing countries, and within the contexts of climate change.
In The World Food Problem: Toward Ending Nutrition in the Third World, by Howard D. Leathers and Phillips Foster, the authors said, “…water use in agriculture is a major source of environmental concern related to agricultural production. Increased irrigation carries the threat of increased soil erosion, increased chemical runoff, and results in water pollution, and increased threat of global warming …” (Leathers & Foster, 179).
Large-scale agricultural systems with extensive monoculture and row cropping practices often result in harsh soil erosion, runoff, and associated loss in nutrients in crop species. Fertilizers, pesticides, and herbicides contain over 1600 different chemicals. Shockingly, only 1% of these chemicals actually reach their intended target, while the other 99.9% of chemicals fall into the ground and evaporate into the air. Chemical pesticides and fertilizers affect wildlife (and tend to reduce biodiversity), and contaminate ground/surface water. Sediment from erosion is the greatest pollutant of ground/surface water in the United States and is a major carrier of agrochemicals into the water system. Pollution of ground/surface water from runoff and associated fertilizer/pesticide/herbicide use present a serious hazard to the ground/surface water and cause irreversible erosion of agricultural land.* Overuse and erosion have damaged much of the world’s cropland. Erosion from agricultural lands and overpopulation has left “…one third of the world’s cropland (1.5 billion hectares), … abandoned during the past 40 years because erosion has made it unproductive” (Leathers & Foster, 177). Land can lose productivity or be retired from production completely due to overproduction and improper drainage practices that contribute to soil erosion and salination.
In the context of drainage, sewage from unlined canals and heavy watering of fields in areas with inadequate drainage can raise the underlying water table. Since all water contains some salt, high water tables concentrate the salt in the root zones of plants and starve the plants for oxygen; resulting in, inhibited growth and lower crop yields**. A typical irrigation rate leaves behind about 2 to 5 tons of salt per hectare annually, if the salt is not flushed out, salt can accumulate into enormous quantities in only a couple of decades. When rivers fill up with settlement, flooding then occurs during rainy seasons.
Pollution of ground/surface water, soil erosion, and salination are rapidly contributing to the world’s “water problem”.
Pollution of ground/surface waters are of major concern, not only in agriculture, but also in the context of the world’s drinking water. Due to irrigation and chemical runoff, many third world developing countries do not have an adequate source for clean drinking water. “… Because people drink water, of course, reduced water quality can directly harm public health. Of special concern here is the possibility that water can become contaminated with pesticides [because,] chemicals are deliberately developed to be toxic… This affects not only humans, but also birds, fish, and other wildlife” (Leathers & Foster, 84). Contaminated drinking water contributes to secondary malnutrition- caused by inadequate absorption of nutrients. With secondary malnutrition, nutrients are not absorbed in the body for a number of reasons, especially due to parasites and diarrhea caused by unsanitary drinking water. “Public health measures such as providing sanitary human waste disposal and clean water are especially important in reducing secondary malnutrition… A worldwide effort has increased the number of people with access to safe drinking water by 1.6 million people since 1990. In 2006, 84% of the population of all developing countries [have been deemed to] have access to an improved drinking water source ( United Nations 2008 :42)” (Leathers & Foster, 24). In contrast, “The World Health Organization (WHO 2003b) estimates 1.1 billion people do not have access to improved water supplies” (Leathers & Foster, 244). Clean drinking water can also be a delivery issue. “Providing an ample supply of clean water to a Third World city can be a political as well as an engineering problem. Port-au-Prince, Haiti, provides an extreme example. During 1976, shortage of water outlets promoted a sustainable and profitable private marker for what was, ostensibly, a publicly provided city service… The issue whether water should be provided by public utilities or by private companies continues to be a subject of heated debate (World Food Bank 2001)” (Leathers & Foster, 244).The effort to provide clean drinking water to all countries is ongoing.
Agricultural production interacts with the environment on a global scale, especially in terms of climate change. “Global warming refers to the phenomenon by which water vapor, carbon dioxide, methane, and other trace gases in the atmosphere trap heat on the surface of the planet. As the quantities of these gases in the atmosphere increase, the amount of heat trapped will increase, and the average temp of the planet will increase” (Leathers & Foster, 188).
Agriculture is the largest contributor to climate change. Since the 1950’s and the Industrial Revolution, the average global temperature has risen 1°F every 2 decades. If humans continue at this rate, the average global temperature will rise at an alarming rate of 1°F every decade.
Climate change is associated with changing rainfall patterns that make some areas dryer and some wetter. This results in “… severe weather, making some areas more prone to hurricanes, tornadoes, and droughts” (Leathers & Foster, 189). Rainfall patterns have begun to change dramatically in recent years, and “…according to the EPA (EPA 2008), precipitation will increase in areas close to the polls, and decreases much as 20% in tropical areas”; which, can be devastating to crops and agricultural production (Leathers & Foster, 191).
Droughts can change a crops growing cycle, causing death of the crop species or lower yields. These changes can also alter disease prevalence in insect and plant species, and can harm other select species because their ecosystem may shift while the property line/boundaries of their preserves do not. Deeper and more prolonged droughts have recently been recorded in the Midwestern areas of the U.S. (and as a result- loss of agricultural land due to soil erosion), along with the contrasting flooding of coastal regions due to an increase in the global average temperature.
In coastal areas, sea levels rise and massive flooding occurs. The “…average sea level is likely to rise 4 to 20 inches by the mid-21st century…[which, can make]… some areas inhabitable because of floods…. The risk from rising sea levels is not only that land will be flooded, but also drainage problems will increase and seawater intrusion to freshwater sources will occur. The IPCC (2007a), considers salination of irrigation water to be the most likely impact of rising sea levels on agriculture” (Leathers & Foster, 190). Floods have also become more frequent in recent years due to the effects of climate change and agricultural production. “Because of this weird weather, 37 countries were facing flood emergencies in early 1998” (Leathers & Foster, 192, box 12.3).
Climate change directly affects the rise in the global average temperature; which, produces more variability in weather patterns. Irregular rainfall patterns caused by the increase of the global average temperature, result in deeper and more prolonged droughts and promote the expansion of populations of pests and diseases, or coastal flooding, resulting in displacement of individuals and reduced agricultural productivity, due to water logging of crops, salination, and a reduction of freshwater due to seawater contamination.
Water is one of the world’s growing problems. In agriculture, runoff, soil erosion, salination, and drainage, cause major damage to agricultural lands/productivity, and contaminate ground and surface water. Access to clean-drinking water in developing countries is improving, but still needs much work, and is considered an urgent problem, and finally, the world’s water problem directly effects climate change and weather patterns, producing negative externalities in multiple various contexts.
* The toxic runoff gets into drinking water, and streams that open into the golf of Mexico, causing a dead zone i.e. hypoxia, which, gives way to the loss of Marine life causing a loss in biodiversity. In 1998 the US use 20,000,000 tons of chemical fertilizers on croplands, nitrogen and ran off into streams resulted in hypoxia, the death of dissolved oxygen speeds up algae’s growth and decay cycle, which kills imitable bottom dwellers and scares off other marine life. In 1999 the Gulf dead zone grew 20,000 km² the largest in recorded history. ECO 190 Lecture Notes- Spring course at University of Maine, 2012.
** “Irrigation systems from underground pumping also decreases the water tables below the ground. In box 11.2 titled Irrigation in China, page 177, an example is provided describing this in North China plain, where the water tables have dropped 5 feet per year over a five-year period studied in the mid-1990s (Leathers & Foster, 177).
Foster, Phillips & Howard D. Leathers. The World Food Problem: Toward Ending Nutrition in the Third World. Lynne Rienner Publishers, Inc. 2009. Print.