INTRODUCTION
Concerns about environmental degradation stem from the fact that it is a global problem, even though the magnitude of the problem differs from region to region and from country to country. The effects of environmental degradation are also unevenly distributed across regions and across countries. In particular, in the Southern Africa sub-region, the effects of environmental degradation are quite pronounced. This is partly because the majority of the population depends on environmental resources for their survival, as is the case with other parts of Africa. This, of course, is not applicable to countries in the Northern Hemisphere. In addition, profound economic stagnation experienced by many countries in the sub-region, combined with weakening environmental governance, evidenced by the lack of environmentally sound policies, caused harm to sensitive ecosystems and resulted in degradation, lowered agricultural productivity and increase poverty
Little reliable data is available on the extent of land degradation in Africa. However, anyone who has travelled through the continent has observed that land degradation is widespread and serious. The presence of gullies and sand dunes, of degraded forests and grazing lands are obvious, although the effects of sheet erosion and declining soil fertility are less noticeable. The wealth of Africa depends on her ability to conserve and manage her land resources. It is a well known fact that soil degradation not only results in decreased food production but also in droughts, ecological imbalance and consequent degradation of the quality of life. In Africa, the most conspicuous symptoms of the negative impact of land degradation on food production are stagnating and declining yields and increasing levels of poverty.
One of the major threat the planet faces today, environmental degradation is bound to make life difficult for all the lifeforms, including us humans, sooner or later. Studies reveal that the deterioration of environment is occurring at an alarming rate. In fact, the High Level Threat Panel of the United Nations has enlisted it as one of the ten threats for humans. This issue shares space with problems like poverty, terrorism and civil war in the list, and this itself highlights the fact that we are heading for a certain disaster.
WHAT IS ENVIRONMENTAL DEGRADATION?
It is a process wherein the natural environment of the planet is degenerated to such an extent that the biodiversity and the general health of the planet is subjected to drastic reduction. In other words, this phenomenon can be defined as deterioration of the Earth's natural surroundings as a result of excessive exploitation of the available resources - these include water, air, flora, fauna, soil etc. The life on the planet is interwoven to such an extent that a decrease in a particular attribute triggers a domino effect on all the other attributes dependent on it.
Environmental degradation is the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems and the extinction of wildlife. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable.[1]
Environmental degradation is one of the Ten Threats officially cautioned by the High Level Threat Panel of the United Nations.
The United Nations International Strategy for Disaster Reduction defines environmental degradation as “The reduction of the capacity of the environment to meet social and ecological objectives, and needs”.[2]
Environmental degradation is of many types. When natural habitats are destroyed or natural resources are depleted, environment is degraded.
How is it Caused?
Environmental degradation can be attributed to various human activities and some natural processes, with the later having an insignificant share in the same. Most of the resources on the planet are vulnerable to depletion, and the rate at which we are exploiting them have already brought some of them to the brink of exhaustion. Exploitation of the fossil fuels is the best example of this phenomenon. Large-scale exploitation has depleted the fossil fuel reserves across the world, thus leaving us with no option but to find an alternate source of energy. Other human activities which have been contributing to this environmental issue include urbanization, overpopulation, deforestation, pollution, hunting, etc.
WHAT DOES IT AFFECT US?
Its effects are becoming more and more obvious in form of all those environmental issues affecting the planet. The hazardous waste let out by the industries tends to contaminate the water bodies in the vicinity, thus leaving the water unfit for drinking. Similarly, greenhouse gases, such as CFCs and carbon dioxide, let out in the atmosphere have a devastating effect on the environment, thus making the planet vulnerable to a range of problems, including global warming and climate change. On one hand, incessant agricultural activities have resulted in degradation of soil, while excessive deforestation to accumulate the growing population has resulted in degradation of air and water on the other hand. Humans have seldom sacrificed their necessities, but lately exploitation of resources to fulfill these necessities itself is taking a toll on the environment.
Water deterioration
One major component of environmental degradation is the depletion of the resource of fresh water on Earth. Approximately only 2.5% of all of the water on Earth is fresh water, with the rest being salt water. 70% of the fresh water is frozen in ice caps located on Antarctica and Greenland, so only 30% of the 2.5% of fresh water is available for consumption.[3] Fresh water is an exceptionally important resource, since life on Earth is ultimately dependent on it. Water transports nutrients and chemicals within the biosphere to all forms of life, sustains both plants and animals, and molds the surface of the Earth with transportation and deposition of materials.[4]
The current top three uses of fresh water account for 95% of its consumption; approximately 85% is used for irrigation of farmland, golf courses, and parks, 6% is used for domestic purposes such as indoor bathing uses and outdoor garden and lawn use, and 4% is used for industrial purposes such as processing, washing, and cooling in manufacturing centers.[5] It is estimated that one in three people over the entire globe are already facing water shortages, almost one-fifth of the world’s population live in areas of physical water scarcity, and almost one quarter of the world’s population live in a developing country that lacks the necessary infrastructure to use water from available rivers and aquifers. Water scarcity is an increasing problem due to many foreseen issues in the future, including population growth, increased urbanization, higher standards of living, and climate change.[3]
Climate change and temperature
Climate change affects the Earth’s water supply in a large number of ways. It is predicted that the mean global temperature will rise in the coming years due to a number of forces affecting the climate, the amount of atmospheric CO2 will rise, and both of these will influence water resources; evaporation depends strongly on temperature and moisture availability, which can ultimately affect the amount of water available to replenish groundwater supplies.
Transpiration from plants can be affected by a rise in atmospheric CO2, which can decrease their use of water, but can also raise their use of water from possible increases of leaf area. Temperature increase can decrease the length of the snow season in the winter and increase the intensity of snowmelt in warmer seasons, leading to peak runoff of snowmelt earlier in the season, affecting soil moisture, flood and drought risks, and storage capacities depending on the area.[6]
Warmer winter temperatures cause a decrease in snowpack, which can result in diminished water resources during the summer. This is especially important at mid-latitudes and in mountain regions that depend on glacial runoff to replenish their river systems and groundwater supplies, making these areas increasingly vulnerable to water shortages over time; an increase in temperature will initially result in a rapid rise in water melting from glaciers in the summer, followed by a retreat in glaciers and a decrease in the melt and consequently the water supply every year as the size of these glaciers get smaller and smaller.[3]
Thermal expansion of water and increased melting of oceanic glaciers from an increase in temperature gives way to a rise in sea level, which can affect the fresh water supply of coastal areas as well; as river mouths and deltas with higher salinity get pushed further inland, an intrusion of saltwater results in an increase of salinity in reservoirs and aquifers.[5] Sea-level rise may also consequently be caused by a depletion of groundwater,[7] as climate change can affect the hydrologic cycle in a number of ways. Uneven distributions of increased temperatures and increased precipitation around the globe results in water surpluses and deficits,[6] but a global decrease in groundwater suggests a rise in sea level, even after meltwater and thermal expansion were accounted for,[7] which can provide a positive feedback to the problems sea-level rise causes to fresh-water supply.
A rise in air temperature results in a rise in water temperature, which is also very significant in water degradation, as the water would become more susceptible to bacterial growth. An increase in water temperature can also affect ecosystems greatly because of a species’ sensitivity to temperature, and also by inducing changes in a body of water’s self-purification system from decreased amounts of dissolved oxygen in the water due to rises in temperature.[3]
Climate change and precipitation
A rise in global temperatures is also predicted to correlate with an increase in global precipitation, but because of increased runoff, floods, increased rates of soil erosion, and mass movement of land, a decline in water quality is probable, while water will carry more nutrients, it will also carry more contaminants.[3] While most of the attention about climate change is directed towards global warming and greenhouse effect, some of the most severe effects of climate change are likely to be from changes in precipitation, evapotranspiration, runoff, and soil moisture. It is generally expected that, on average, global precipitation will increase, with some areas receiving increases and some decreases.
Climate models show that while some regions should expect an increase in precipitation,[6] such as in the tropics and higher latitudes, other areas are expected to see a decrease, such as in the subtropics; this will ultimately cause a latitudinal variation in water distribution.[3] The areas receiving more precipitation are also expected to receive this increase during their winter and actually become drier during their summer,[6] creating even more of a variation of precipitation distribution. Naturally, the distribution of precipitation across the planet is very uneven, causing constant variations in water availability in respective locations.
Changes in precipitation affect the timing and magnitude of floods and droughts, shift runoff processes, and alter groundwater recharge rates. Vegetation patterns and growth rates will be directly affected by shifts in precipitation amount and distribution, which will in turn affect agriculture as well as natural ecosystems. Decreased precipitation will deprive areas of water, causing water tables to fall and reservoirs and wetlands, rivers, and lakes to empty,[6] and possibly an increase in evaporation and evapotranspiration, depending on the accompanied rise in temperature.[5] Groundwater reserves will be depleted, and the remaining water has a greater chance of being of poor quality from saline or contaminants on the land surface.[3]
Population growth
The available fresh water being affected by climate is also being stretched across an ever-increasing global population. It is estimated that almost a quarter of the global population is living in an area that is using more than 20% of their renewable water supply; water use will rise with population while the water is also being aggravated by decreases in streamflow and groundwater caused by climate change. Even though some areas may see an increase in freshwater supply from an uneven distribution of precipitation increase, an increased use of water supply is expected.[8]
An increased population means increased withdrawals from the water supply for domestic, agricultural, and industrial uses, the largest of these being agriculture,[9] believed to be the major non-climate driver of environmental change and water deterioration. The next 50 years will likely be the last period of rapid agricultural expansion, but the larger and wealthier population over this time will demand more agriculture.[10]
Population increase over the last two decades, at least in the United States, has also been accompanied by a shift to an increase in urban areas from rural areas,[11] which concentrates the demand for water into certain areas, and puts stress on the fresh water supply from industrial and human contaminants.[3] Urbanization causes overcrowding and increasingly unsanitary living conditions, especially in developing countries, which in turn exposes an increasingly number of people to disease. About 79% of the world’s population is in developing countries, which lack access to sanitary water and sewer systems, giving rises to disease and deaths from contaminated water and increased numbers of disease-carrying insects.[12]
Agriculture
Agriculture is dependent on available soil moisture, which is directly affected by climate dynamics, with precipitation being the input in this system and various processes being the output, such as evapotranspiration, surface runoff, drainage, and percolation into groundwater. Changes in climate, especially the changes in precipitation and evapotranspiration predicted by climate models, will directly affect soil moisture, surface runoff, and groundwater recharge.
In areas with decreasing precipitation as predicted by the climate models, soil moisture may be substantially reduced.[6] With this in mind, agriculture in most areas needs irrigation already, which depletes fresh water supplies both by the physical use of the water and the degradation agriculture causes to the water. Irrigation increases salt and nutrient content in areas that wouldn’t normally be affected, and damages streams and rivers from damming and removal of water. Fertilizer enters both human and livestock waste streams that eventually enter groundwater, while nitrogen, phosphorus, and other chemicals from fertilizer can acidify both soils and water. Certain agricultural demands may increase more than others with an increasingly wealthier global population, and meat is one commodity expected to double global food demand by 2050,[10] which directly affects the global supply of fresh water. Cows need water to drink, more if the temperature is high and humidity is low, and more if the production system the cow is in is extensive, since finding food takes more effort. Water is needed in processing of the meat, and also in the production of feed for the livestock. Manure can contaminate bodies of freshwater, and slaughterhouses, depending on how well they are managed, contribute waste such as blood, fat, hair, and other bodily contents to supplies of fresh water.[13]
The transfer of water from agricultural to urban and suburban use raises concerns about agricultural sustainability, rural socioeconomic decline, food security, an increased carbon footprint from imported food, and decreased foreign trade balance.[9] The depletion of fresh water, as applied to more specific and populated areas, increases fresh water scarcity among the population and also makes populations susceptible to economic, social, and political conflict in a number of ways; rising sea levels forces migration[disambiguation needed] from coastal areas to other areas farther inland, pushing populations closer together breaching borders and other geographical patterns, and agricultural surpluses and deficits from the availability of water induce trade problems and economies of certain areas.[8]
Water management
The issue of the depletion of fresh water can be met by increased efforts in water management.[4] While water management systems are often flexible, adaptation to new hydrologic conditions may be very costly.[6] Preventative approaches are necessary to avoid high costs of inefficiency and the need for rehabilitation of water supplies,[4] and innovations to decrease overall demand may be important in planning water sustainability.[9]
Water supply systems, as they exist now, were based on the assumptions of the current climate, and built to accommodate existing river flows and flood frequencies. Reservoirs are operated based on past hydrologic records, and irrigation systems on historical temperature, water availability, and crop water requirements; these may not be a reliable guide to the future. Re-examining engineering designs, operations, optimizations, and planning, as well as re-evaluating legal, technical, and economic approaches to manage water resources are very important for the future of water management in response to water degradation. Another approach is water privatization; despite its economic and cultural impacts, service quality and overall quality of the water can be more easily controlled and distributed. Rationality and sustainability is appropriate, and requires limits to overexploitation and pollution, and efforts in conservation.[4]
How Can we Deal With it?
At one point of time, the damage reaches a stage wherein the environment can't attain the required balance on its own. In such a situation, we humans need to step in, and ensure that the damage is curbed and balance is attained. Simple measures, such as conservation of electricity, use of alternative energy sources, avoiding the use of things that pollute the environment, soil conservation, etc., can help in saving the environment from the threat of degradation. Environmentalists, the world over, are trying their best to save our environment, and we need to do our bit to make sure that they succeed. The need of the hour is to identify the causes of environmental degradation, and eliminate them one by one.
We need to understand the fact that we are a part of the interwoven life system on the planet, and any problems, like environmental degradation and environmental pollution, are bound to affect us directly or indirectly. Though the disaster is not expected to happen tomorrow or a hundred years from now, that doesn't mean it will never happen at all. That being said, the onus is on us - the most intelligent species on the planet, to make sure that such problems are kept at bay.
Little reliable data is available on the extent of land degradation in Africa. However, anyone who has travelled through the continent has observed that land degradation is widespread and serious. The presence of gullies and sand dunes, of degraded forests and grazing lands are obvious, although the effects of sheet erosion and declining soil fertility are less noticeable.
The wealth of Africa depends on her ability to conserve and manage her land resources. It is a well known fact that soil degradation not only results in decreased food production but also in droughts, ecological imbalance and consequent degradation of the quality of life. In Africa, the most conspicuous symptoms of the negative impact of land degradation on food production are stagnating and declining yields and increasing levels of poverty.
Throughout the continent, regardless of the climatic zone, meteorological records show that unpredictability of rains is a common feature. In the Sahel, variations in total annual rainfall can be up to 30 or 40 per cent. Even, the humid and sub-humid zones are subject to rainfall fluctuations of 15 to 20 per cent. In most cases, the rainfall is rarely gentle and even. It usually comes as torrential downpours, which are destructive to soils and harmful to plants.
Central Africa will face no land shortage even if it is still using low inputs. With intermediate inputs, Zaire alone can feed 1,280 million people, 95 per cent of the projected total for the whole of sub-Saharan Africa in the year 2025. But this enormous surplus capacity is based on clearing most of the rain forest for agriculture. Even if this were to be done, it would not solve the food problems of the Sahel or East Africa any more than North America's present surplus could. The only way this huge potential can alleviate population pressure elsewhere is the occurrence of massive migrations into Central Africa from the surrounding areas, a solution which is fraught with political and environmental problems.
The belt of land running through the West African Sahel region and the Sudan to northeast Ethiopia and Kenya is particularly vulnerable. Around 90 percent of rangelands and 80 per cent of rain-fed farmlands in the area are affected by degradation - including soil erosion, deforestation, and loss of woody vegetation which makes them less able to bear crops and pasture.
These grim prospects are all based on the assumption that past trends continue. They are entirely realistic and they point towards disaster. Africa is the world's nightmare, a continent of recurrent drought, famine and bloody tribal, ethnic conflicts and civil warfare, perpetually dependent on food aid handouts with spreading deserts and shrinking forests.
The facile response to these prospects is to point out that many developed countries are not self-sufficient in food or energy and that they pay for their imports with exports of manufactured goods or services. Could not Africa's food-deficit countries do the same ? The problem here is that the prospects of industrialization in Africa are dimmer than those in any other region of the world. The developed countries are price-takers and competitors among themselves in protected markets for their exported agricultural products. Apart from the oil-rich countries and a few city-states deluged with foreign investment, no country has industrialized without a reasonably healthy agricultural base. Africa seems to be caught in a trap; industrialization could solve her food problems, but with agriculture stagnant, the chances of industrialization are slim. In addition, with the level of income of the 80 % of population living in the rural sector very low, chances of having a market for industrialization are further very slim.
In countries with limited cultivable land and high population-growth rates - such as Kenya, Ethiopia, Malawi, Burundi, and Rwanda - fallow periods are no longer sufficient to allow soil fertility to be restored, so that crop yields have fallen. In response, farmers have been forced either to bring increasingly marginal lands into cultivation, or to migrate into tropical forest areas, exacerbating problems of land degradation and deforestation.
Nowhere is the lethal interaction of poverty and environmental degradation more evident than in Ethiopia. About half of the country's highland area is significantly eroded, reducing yields by between 2 per cent and 3 per cent a year. According to a 1986 study by the UN Food and Agricultural Organization, over 1,900 million tons of soil are lost from the highlands annually. If the trend continues, some 38,000 square kilometres will be eroded down to bare rock by the year 2010, and a further 60,000 square kilometres will have a soil depth of 10 centimetres, below which the soil would be too shallow to support cropping. About 2 million hectares of farmland are already estimated to be beyond recovery.
References
1. ^ Johnson, D.L., S.H. Ambrose, T.J. Bassett, M.L. Bowen, D.E. Crummey, J.S. Isaacson, D.N. Johnson, P. Lamb, M. Saul, and A.E. Winter-Nelson. 1997. Meanings of environmental terms. Journal of Environmental Quality 26: 581-589.
2. ^ "ISDR : Terminology". The International Strategy for Disaster Reduction. 2004-03-31. Retrieved 2010-06-09.
3. ^ a b c d e f g h ”Water.” Climate Institute. Web. Retrieved 2011-11-03.
4. ^ a b c d Young, Gordon J., James Dooge, and John C. Rodda. Global Water Resource Issues. Cambridge UP, 2004.
5. ^ a b c Frederick, Kenneth D., and David C. Major. “Climate Change and Water Resources.” Climatic Change 37.1 (1997): p 7-23.
6. ^ a b c d e f g Ragab, Ragab, and Christel Prudhomme. “Soil and Water: Climate Change and Water Resources Management in Arid and Semi-Arid Regions: Prospective Challenges for the 21st Century.” Biosystems Engineering 81.1 (2002): p 3-34.
7. ^ a b Konikow, Leonard F. “Contribution of Global Groundwater Depletion since 1990 to Sea-level Rise.” Geophysical Research Letters 38.17 (2011).
8. ^ a b Raleigh, Clionadh, and Henrik Urdal. “Climate Change, Environmental Degradation, and Armed Conflict.” Political Geography 26.6 (2007): 674-94.
9. ^ a b c MacDonald, Glen M. “Water, Climate Change, and Sustainability in the Southwest.” PNAS 107.50 (2010): p 56-62.
10. ^ a b Tilman, David, Joseph Fargione, Brian Wolff, Carla D’Antonio, Andrew Dobson, Robert Howarth, David Scindler, William Schlesinger, Danielle Simberloff, and Deborah Swackhamer. “Forecasting Agriculturally Driven Global Environmental Change.” Science 292.5515 (2011): p 281-84.
