In this article, You will read Global and Regional Ecological changes and Imbalances – for UPSC (Environmental Geography).
Global and Regional Ecological changes and Imbalances:
We live in a world where humans are having profound impacts on the global environment. Climate is warming, the populations of many species are in decline, pollution is affecting ecosystems and human health, and human societies now face new risks in terms of sea-level changes, disease, food security, and climate extremes.
Scientists who study global environmental change are interested in learning how drivers of environmental change (including human population growth and consumption, energy use, land-use changes, and pollution) impact biological systems across many scales — from the level of
the individual organism to populations, communities, and ecosystems (Vitousek 1994).
Global environmental change science is therefore a highly multidisciplinary effort, involving physical scientists who study climate, the oceans, the atmosphere, and geology, as well as biologists investigating physiology, evolution, and ecology.
Drivers of Global Change
Human Population and Consumption
Almost 7 billion people now live on Earth. The rapid growth of the human population, especially over the last 300 years, is one of the most remarkable trends in population change ever observed. Demographers project that the world population will rise to 9 billion by 2050 and level off somewhere between 9–12 billion people by the end of the century.
In many modern societies, more people require more resources, such as crops, seafood, forest products, energy, and minerals, and increasingly larger economies to support economic development and rising standards of living.
Population growth and the increased demand for natural resources is therefore a major factor driving global environmental change.
The population story is more complex, however, because there is not a simple relationship between the number of people and the amount of resources consumed. Affluence, or the wealth per person, and the social norms of consumption are also important. For example, the populations of China and India are roughly 1.32 and 1.14 billion people, respectively — about four times that of the US. However, the energy consumption per person in the US is six times larger than that of a person in China, and 15 times that of a person in India. Because the demand for resources like energy is often greater in wealthy, developed nations like the US, this means that countries with smaller populations can actually have a greater overall environmental impact.
Over much of the past century, the US was the largest greenhouse gas emitter because of high levels of affluence and energy consumption. In 2007, China overtook the US in terms of overall CO2 emissions as a result of economic development, increasing personal wealth, and the demand for consumer goods, including automobiles.
Energy Use/Climate Change
Worldwide, fossil fuels (oil, coal, and natural gas) dominate our energy consumption, accounting for 85% of all energy used. As mentioned previously, the rapid rise of fossil fuels is a relatively recent phenomenon, developing in the nineteenth century with the discovery of oil and the industrialization of economies, and expanding rapidly in the twentieth century with increased economic development and rising populations and affluence.
From 1860–1991, energy use per person rose more than 93 fold compared to a world population increase of four-fold, indicating that rising affluence and consumption are driving energy demand (Cohen 1995).
Burning fossil fuels releases about 8.5 billion tons of carbon (as CO2) into the atmosphere each year, causing its concentration to increase and Earth‘s greenhouse warming to strengthen, which leads to rising global air temperatures. Since 1880, the average global air temperature has risen approximately 0.9°C. The top five CO2-emitting countries/regions are China, the US, the EU, Russia, and India, which together account for two-thirds of global emissions.
Global change scientists use climate models to determine how added greenhouse gases affect changes in air temperature and precipitation. If fossil fuel burning continues at current rates, global temperatures may rise by as much as 4°C by the year 2100 (IPCC 2007). Precipitation changes are expected to lead to increased rainfall in mid-to-high latitude regions, but increased droughts are projected for subtropical regions (IPCC 2007).
Land Use Changes
Landscapes are changing worldwide, as natural land covers like forests, grasslands, and deserts are being converted to human-dominated ecosystems, including cities, agriculture, and forestry (Figure 2). Between 2000– 2010, approximately 13 million hectares of land (an area the size of Greece) were converted each year to other land cover types (FAO 2010).
Developed regions like the US and Europe experienced significant losses of forest and grassland cover over the past few centuries during phases of economic growth and expansion. More recently, developing nations have experienced similar losses over the past 60 years, with significant forest losses in biologically diverse regions like Southeast Asia, South America, and Western Africa.
Land use changes affect the biosphere in several ways. They often reduce native habitat, making it increasingly difficult for species to survive. Some land use changes, such as deforestation and agriculture, remove native vegetation and diminish carbon uptake by photosynthesis as well as hasten soil decomposition, leading to additional greenhouse gas release. Almost 20% of the global CO2 released to the atmosphere (1.5–2 billion tons of carbon) is thought to come from deforestation.
One of the by-products of economic development has been the production of pollution — products and waste materials that are harmful to human and ecological health.
The rise of pollution corresponds to the increased use of petroleum in the twentieth century, as new synthetic products such as plastics, pesticides, solvents, and other chemicals, were developed and became central to our lives.
Many air pollutants, including nitrogen and sulphur oxides, fine particulates, lead, carbon monoxide, and ground-level ozone come from coal and oil consumption by power plants and automobiles. Heavy metals, such as mercury, lead, cadmium, and arsenic, are produced from mining, the burning of fossil fuels, and the manufacture of certain products like metals, paints, and batteries.
Aquatic ecosystems such as rivers, lakes, and coastal oceans have traditionally been used for pollution disposal from industry and sewage treatment plants, but they have also been subject to unintentional runoff from upland watersheds, such as nitrogen and phosphorus loss from agricultural soils and home septic systems as well as plastics washed into rivers and oceans from storm sewer systems.
We often don‘t think of nutrients like nitrogen and phosphorus as pollutants. However, humans now add more nitrogen to the biosphere through fertilizers than is added naturally each year by all of the nitrogen-fixing bacteria on the planet (Vitousek 1994). The Pacific and Atlantic oceans now have garbage patches full of plastic that are possibly as large as the continental US. These are strong indicators of global change — humanity now dominates the global movement of nitrogen and other materials on Earth.
Environmental degradation affects mankind at a global scale regardless of any particular country, region or race. Few examples of environmental issues of global significance are: Ozone layer depletion, Global warming and Loss of biodiversity. During last three decades man‘s physical and biological environment, is witnessing rapid changes. Lack of proper judgment in massive use and misuse of technology has created global environmental problems.
Ozone layer depletion:
Earth’s atmosphere is divided into three regions, namely troposphere; stratosphere, and mesosphere. The ozone layer, in the stratosphere, acts as an efficient filter for harmful solar Ultraviolet rays. In recent years, scientists have measured a seasonal thinning of the ozone layer primarily at the South Pole. This phenomenon is being called the ozone hole. Increased penetration of solar UV-B radiation is likely to have a high impact on human health, forests, and grasslands, etc. The ozone layer, therefore, is highly beneficial to plant and animal life on earth filtering out the dangerous part of the sun’s radiation and allowing only the beneficial part to reach earth. Any disturbance or depletion of this layer would result in an increase of harmful radiation reaching the earth’s surface leading to dangerous consequences.
Causes of ozone layer depletion Ozone (O3) layer can be destroyed both bynatural and man-made causes-
i. Natural causes: A number of naturally occurring substances destroy stratospheric ozone. Most important of these compounds are: Hydrogen oxide (HOx), Methane (CH4), Hydrogen gas (H2), Nitrogen oxides (NOx). Chlorine monoxide (ClO); during volcanic eruptions, significant amount of chlorine may be released in the stratosphere. Tiny particulate matter in the stratosphere, known as stratospheric aerosols, may also lead to ozone destruction.
ii. Human activity-related causes: Any event, which releases chlorine atoms into the atmosphere, can cause severe ozone destruction because chlorine atoms in the stratosphere can destroy ozone very efficiently. Most damaging among such agents are human-made chlorofluorocarbons (CFCs), which is widely used as refrigerants and to pressurize sprays cans. In the stratosphere, chlorine atoms from CFCs react with ozone to form chlorine monoxide and oxygen molecules.
Effect of O3-layer depletion
Measures to prevent ozone (O3) layer depletion
Global awareness and action on the part of the world community in the form of Helsinki (1989), Montreal (1990‘s) conventions and protocol have had some important success on this front. A complete ban on the use of CFCs and other ozone-destroying chemicals is recommended. Further, the use of HCFCs (Hydrochloric fluorocarbons) as a substitute for CFCs is being recommended on a temporary basis because HCFCs are relatively less damaging to the ozone layer as compared to CFCs, but they are not completely ozone-safe.
Over the years, it was found out that the earth is relatively getting warmer and warmer. The key greenhouse gas (GHG) causing global warming is carbon dioxide. Chlorofluorocarbons (CFCs), even though they exist in very small quantities, too contribute to global warming, significantly.
Effect on living beings:
- Increased CO 2 concentration in the atmosphere may increase photosynthetic productivity of plants. This in turn produces more organic matter. It may seem a positive effect. But, then-
- Weeds may proliferate rapidly and that too at the expense of useful plants.
- Insects and other pests that feed on plants may also increase in number.
- Survival of other organisms gets affected
Strategies to cope with greenhouse effect
We must take immediate steps to minimize global warming by reducing the emission of greenhouse gases especially carbon dioxides.
The following steps would be useful in reducing emission/release of greenhouse gases into the atmosphere:
- Increased fuel efficiency of power plants and vehicles;
- Development/implementation of solar energy/non-fossil fuel alternatives;
- Halting deforestation;
- Supporting and undertaking tree-planting (afforestation);
- Reduce air-pollution.
Loss of biodiversity:
Biodiversity refers to the variety of life on earth, and its biological diversity. It actually boosts ecosystem productivity where each species, no matter how small, all have an important role to play and that it is in this combination that enables the ecosystem to possess the ability to prevent and recover from a variety of disasters. But nowadays human activity is changing biodiversity and causing massive extinctions. Rapid global warming can affect ecosystem‘s chances to adapt naturally.
The reasons for ecological imbalance are associated with the increasing industrialization, irrational waste of natural resources, deforestation, water pollution — all this because of what ecological disaster is happening. Harming nature, man jeopardizes its existence. This also creates a lot of trouble for mankind: a demographic crisis, hunger, lack of natural resources, and destruction of the environment. Unjustified deforestation leads to the disappearance of animals and birds. This leads to changes in the ecological balance.
Impact of Eco-imbalance
Some important impacts of polluted environment and imbalanced ecosystems are as follows:
Effects on Human Health
Polluted air, water, and land generate many harmful chemical and biological agents that have a negative impact on human health. A wide range of communicable diseases can be spread through the elements of the environment polluted by human and animal waste products.
This is clearly evidenced by the plagues of the middle ages when the disease spread through rats that were fed on contaminated human waste.
Although major diseases transmitted via the environment have been almost eliminated in developed countries through immunization and sanitation programs, no country is totally immune from outbreaks of environmentally transmitted diseases, as the outbreak of SARS (Severe Acute Respiratory Syndrome) in 2003 in many countries clearly proved.
The protection of soil against the hazards of degradation is essential if the productivity of soil has to be sustained. Soil degradation has many causes, but the immediate concerns are improper land use, soil erosion, and acidification, and salinisation, water-logging and chemical degradation.
Soil erosion is the washing or blowing away of the surface soil. Erosion may take place under natural conditions, but it is greatly increased when human activities cause the disappearance of the protective cover of natural vegetation. Acidification and salinization directly reduce soil fertility.
They may be caused by acid rain and the accumulation of water-soluble salts in the soil. Chemical degradation of soil may occur if the nutrients in the soil are leached out or harmful chemicals like DDT and radioactive substances. Soil erosion is a global problem.
The term “desert” encompasses a wide range of environmental complexes:
1. Rainless deserts, where rainfall is not an annually recurring event.
2. Run-off deserts, where the annual rainfall is low (less than 100 mm) and variable.
3. Rainfall deserts, where the rainfall is insufficient for crop production (100-200 mm).
4. Man-made deserts, parts of the semi-arid areas (rainfall 200-350 mm) that have been transformed into deserts due to man’s overexploitation of the land.
Desertification results from the combined effect of two factors; severe recurrent droughts and human over-exploitation of drylands. The cures for desertification have been known for a long time. They consist of the reverse processes, i.e., biological recovery of environmental conditions, naturally or artificially induced. Considerable experience in combating desertification has been acquired by the US, Australia, and Israel but corrective measures are expensive though net benefits would certainly exceed the costs.
Genetic Resource Depletion
The genetic material contained in the domesticated varieties of crop plants, trees, livestock, aquatic animals, and microorganisms is essential for the breeding programs in which continued improvements in yields, nutritional quality, flavour, durability, pest and disease resistance, responsiveness to different soils and many other qualities are achieved. Because of intensive selection for high performance and uniformity, the genetic base of much food production in modern times has grown dangerously narrow.
Contamination of Food
Chemical contaminants reach food and livestock feed from many sources. Pesticides used in farming often find their way into crops. In addition, veterinary drugs and animal growth-promoting chemicals may pass into meat and dairy products like milk and butter. Some food preservatives like sodium nitrite, chemicals, and materials contained in food packaging may also enter the packaged food. Crops may be chemically contaminated by the airborne deposition of industrial emissions or by industrial effluents. The current trend to centralize food processing, handling, and distribution of food and the greater reliance on large storage facilities may aggravate some of the above problems.
The whole world is the stakeholder in creating awareness for the protection of the environment and combating environmental degradation. Environmental degradation is a social problem and considering its impact on society, law courts need to take pro-active action in regard to environmental protection by implementing the laws that have come up to combat environmental degradation. More so, as environmental degradation has social implications because it impacts the socio-economic progress of the nation. Failure on the part of the governmental agencies to effectively enforce environmental laws and non-compliance with statutory norms by polluters resulted in accelerated degradation of the environment.
Environmental problems are not confined only to a particular nation but have become the problems of the international community.
It has been realized by mankind that living and non-living elements in the environment keep interacting with one another to maintain a mutual balance called ―ecological balance‖. But regrettably, the man in his journey to civilization started polluting his own environment. And it has, of late, dawned upon him to resort to ―sustainable development‖ as a part of distributive justice- think of future generations too and make the planet earth fit for the coming generations.
Ecological Imbalance in India
The following points highlight the five main factors responsible for ecological imbalance in India. The factors are:
- Degradation of Land and Soil Erosion
- Faulty Utilisation of Water Resources
- Environmental Problems from Faulty Mining Practices
- Industrial and Atmospheric Pollution
Degradation of Land and Soil Erosion:
The Ministry of Agriculture, Government of India has reported about the serious problem of land degradation and soil erosion as given in Table.
The table reveals that about 174 million hectares (i.e., 53 percent of the total land area) of land in India is facing the serious problem of land degradation out of which 144 million hectares is subjected to soil erosion through water and wind and the rest 30 million hectares is subjected to other problems. Moreover, heavy population pressure has led to the conversion of forest and permanent pastures into croplands leading to indiscriminate grazing.
Large scale deforestation has been continuing since independence due to over- exploitation and mismanagement of forest resources. During the first two decades of planning (i.e., from 1951 to 1972) India lost about 3.4 million hectares of forestland out of which about 70 per cent of that area was lost to river valley projects, roads and communications and industries. Deforestation is still continuing at a rapid scale and the problem has reached to such a proportion that it has totally disturbed the ecological balance of the country.
The National Committee on Environmental Planning has remarked that total land surface having adequate tree cover is not more than 12 per cent of the total geographical area of the country, although the official statistics show it as 22 per cent of the total geographical area.
The degree of deforestation in Himalayan ranges from Kashmir to North-East India is very high. All these have led to an ecological collapse in the country.
Faulty Utilisation of Water Resources:
Being one of the wettest countries of the world India is still suffering from floods and droughts due to faulty utilization of water resources. Since independence, too much importance was laid on the development of big dams.
But these gigantic dams have displaced crores of tribal people, drowned a million hectares of rich forest areas, failed to prevent and control floods, and often created destructive flash floods in the downstream valley. As per one recent estimate, it is found that area affected by floods in India has increased from 20 million hectares in 1971 to 40 million hectares at present. Moreover, these huge dams and multi-purpose projects have created an environmental impact in the form of degradation of soil in the command areas due to continuous waterlogging and increasing soil salinity.
The major portion of increasing salinity affected areas lies in the Indo-Gangetic plains of U.P., Punjab and Haryana.
Environmental Problems from Faulty Mining Practices:
In India large-scale extraction of minerals are creating serious environmental problems, ruining the country‘s land, water, forest, and air. Large-scale mining has resulted in the conversion of agricultural and forest land into stockyards townships, roads, railway lines, etc., and removed vegetation and topsoil.
The disposal of mining waste, mineral dust from mines are constantly polluting the air and also reducing agricultural productivity. Underground mines are often creating subsidence of land due to it‘s overexploitation. Mining activity is also polluting water resources as the rain waters, passing through mineral wastes, are flowing into rivers and streams.
The mining operation has also resulted in large-scale deforestation, soil erosion and is also responsible for various health hazards to human beings in the form of respiratory problems and other illnesses. Thus in the new Mineral Policy, 1993, attempts have been made to check this environmental pollution arising out of mining operations and to follow some reclamation measures.
Industrial and Atmospheric Pollution:
In India, unplanned and uncontrolled growth of industries and ill-maintained automobiles are creating huge atmospheric pollution regularly leading to huge environmental problems. The main atmospheric pollutants include carbon dioxide, carbon monoxide, oxides of nitrogen, sulfur dioxide, hydrocarbon, and metallic traces.
Besides some specific pollutants are also being mixed with the atmosphere which includes lead from automobile emission, urea dust from fertilizer factory, cement and lime dust from cement factories, increasing radiation of nuclear power stations, etc.
Moreover, industrial wastes coming out of fertilizer factories, paper mills, leather factories are constantly being discharged in rivers, lakes, and seas, creating huge health hazards for the population of the country.
Thus under this present situation, environmental problems of India are being added in increasing proportion. Thus it is high time that planners and policymakers of the country should take necessary steps to reduce the degree of environmental pollution in the country and should
preserve the proper environment at any cost.