Air pollution Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere. The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth’s ecosystems. Indoor air pollution and urban air quality are listed as two of the world’s worst pollution problems
Pollution also needs to be considered inside our homes, offices, and schools. Some of these pollutants can be created by indoor activities such as smoking and cooking. In the United States, we spend about 80-90% of our time inside buildings, and so our exposure to harmful indoor pollutants can be serious. It is therefore important to consider both indoor and outdoor air pollution. Outdoor Air Pollution Smog is a type of large-scale outdoor pollution. It is caused by chemical reactions between pollutants derived from different sources, primarily automobile exhaust and industrial emissions.
Cities are often centers of these types of activities, and many suffer from the effects of smog, especially during the warm months of the year. Another consequence of outdoor air pollution is acid rain. When a pollutant, such as sulfuric acid combines with droplets of water in the air, the water (or snow) can become acidified . The effects of acid rain on the environment can be very serious. It damages plants by destroying their leaves, it poisons the soil, and it changes the chemistry of lakes and streams. Damage due to acid rain kills trees and harms animals, fish, and other wildlife.
The U. S. Geological Survey (USGS), the Environmental Protection Agency (EPA), and Environment Canada are among the organizations that are actively studying the acid rain problem. The Greenhouse Effect, also referred to as global warming, is generally believed to come from the build up of carbon dioxide gas in the atmosphere. Carbon dioxide is produced when fuels are burned. Plants convert carbon dioxide back to oxygen, but the release of carbon dioxide from human activities is higher than the world’s plants can process.
The situation is made worse since many of the earth’s forests are being removed, and plant life is being damaged by acid rain. Thus, the amount of carbon dioxide in the air is continuing to increase. This buildup acts like a blanket and traps heat close to the surface of our earth. Changes of even a few degrees will affect us all through changes in the climate and even the possibility that the polar ice caps may melt. Ozone depletion is another result of pollution. Chemicals released by our activities affect the stratosphere , one of the atmospheric layers surrounding earth.
The ozone layer in the stratosphere protects the earth from harmful ultraviolet radiation from the sun. Release of chlorofluorocarbons (CFC’s) from aerosol cans, cooling systems and refrigerator equipment removes some of the ozone, causing “holes”; to open up in this layer and allowing the radiation to reach the earth. Ultraviolet radiation is known to cause skin cancer and has damaging effects on plants and wildlife. Indoor Air Pollution Many people spend large portion of time indoors – as much as 80-90% of their lives. We work, study, eat, drink and sleep in enclosed environments where air circulation may be restricted.
For these reasons, some experts feel that more people suffer from the effects of indoor air pollution than outdoor pollution. There are many sources of indoor air pollution. Tobacco smoke, cooking and heating appliances, and vapors from building materials, paints, furniture, etc. cause pollution inside buildings. Radon is a natural radioactive gas released from the earth, and it can be found concentrated in basements in some parts of the United States. Additional information about the radon problem is available from the USGS and the Minnesota Radon Project.
Pollution exposure at home and work is often greater than outdoors. The California Air Resources Board estimates that indoor air pollutant levels are 25-62% greater than outside levels and can pose serious health problems. Pollutants Pollutants can be classified as primary or secondary. Usually, primary pollutants are directly emitted from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact.
An important example of a secondary pollutant is ground level ozone — one of the many secondary pollutants that make up photochemical smog. Some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants. Major primary pollutants produced by human activity include: Sulfur oxides (SOx) – especially sulphur dioxide, a chemical compound with the formula SO2. SO2 is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulphur compounds, their combustion generates sulfur dioxide.
Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. Nitrogen oxides (NOx) – especially nitrogen dioxide are emitted from high temperature combustion. Can be seen as the brown haze dome above or plume downwind of cities. Nitrogen dioxide is the chemical compound with the formula NO2. Carbon monoxide – is a colourless, odorless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
Carbon dioxide (CO2) – a colourless, odorless, non-toxic greenhouse gas associated with ocean acidification, emitted from sources such as combustion, cement production, and respiration Volatile organic compounds – VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane (CH4) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming.. Particulate matter – Particulates, alternatively referred to as particulate matter (PM) or fine particles, are tiny particles of solid or liquid suspended in a gas.
In contrast, aerosol refers to particles and the gas togethe. Increased levels of fine particles in the air are linked to health hazards such as heart disease, altered lung function and lung cancer. Persistent free radicals connected to airborne fine particles could cause cardiopulmonary disease.  Toxic metals, such as lead, cadmium and copper. Chlorofluorocarbons (CFCs) – harmful to the ozone layer emitted from products currently banned from use. Ammonia (NH3) – emitted from agricultural processes. Ammonia is a compound with the formula NH3.
Although in wide use, ammonia is both caustic and hazardous. Odors — such as from garbage, sewage, and industrial processes Radioactive pollutants – produced by nuclear explosions, war explosives, and natural processes such as the radioactive decay of radon. Secondary pollutants include: Particulate matter formed from gaseous primary pollutants and compounds in photochemical smog. Smog is a kind of air pollution; the word “smog” is a portmanteau of smoke and fog. Classic smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide.
Modern smog does not usually come from coal but from vehicular and industrial emissions that are acted on in the atmosphere by ultraviolet light from the sun to form secondary pollutants that also combine with the primary emissions to form photochemical smog. Ground level ozone (O3) formed from NOx and VOCs. Ozone (O3) is a key constituent of the troposphere. It is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer Peroxyacetyl nitrate (PAN) – similarly formed from NOx and VOCs.
Minor air pollutants include: * A large number of minor hazardous air pollutants. Some of these are regulated in USA under the Clean Air Act and in Europe under the Air Framework Directive. * A variety of persistent organic pollutants, which can attach to particulate matter. How can air pollution hurt my health? Air pollution can affect our health in many ways with both short-term and long-term effects. Different groups of individuals are affected by air pollution in different ways. Some individuals are much more sensitive to pollutants than are others.
Young children and elderly people often suffer more from the effects of air pollution. People with health problems such as asthma, heart and lung disease may also suffer more when the air is polluted. The extent to which an individual is harmed by air pollution usually depends on the total exposure to the damaging chemicals, i. e. , the duration of exposure and the concentration of the chemicals must be taken into account. Examples of short-term effects include irritation to the eyes, nose and throat, and upper respiratory infections such as bronchitis and pneumonia.
Other symptoms can include headaches, nausea, and allergic reactions. Short-term air pollution can aggravate the medical conditions of individuals with asthma and emphysema. In the great “Smog Disaster” in London in 1952, four thousand people died in a few days due to the high concentrations of pollution. Long-term health effects can include chronic respiratory disease, lung cancer, heart disease, and even damage to the brain, nerves, liver, or kidneys. Continual exposure to air pollution affects the lungs of growing children and may aggravate or complicate medical conditions in the elderly.
It is estimated that half a million people die prematurely every year in the United States as a result of smoking cigarettes. Reduction efforts Air pollution has many disastrous effects that need to be curbed. In order to accomplish this, governments, scientists and environmentalists are using or testing a variety of methods aimed at reducing pollution. There are two main types of pollution control. Input control involves preventing a problem before it occurs, or at least limiting the effects the process will produce.
Five major input control methods exist. People may try to restrict population growth, use less energy, improve energy efficiency, reduce waste, and move to non-polluting renewable forms of energy production. Also, automobile-produced pollution can be decreased with highly beneficial results. Different Ways To Prevent Air Pollution Vehicle Care: Timely servicing of the car helps to keep it in a good condition and also minimizes fuel exhaust. Driving the car at an average speed and turning off in traffic is a key to save fuel.
Make sure to use unleaded petrol and opt for regular pollution checking of your car. Public Transport: Whenever possible, try to travel by public transports. This helps in two ways; prevents air pollution and increases public income. If you are going to a nearby place, go by walking or use bicycle, instead of using your vehicle. The objective is to minimize the use of fuels, as far as possible. Alternative Energy Source: Another effective way to prevent air pollution is to use alternative energy sources such as solar energy, hydroelectric energy and wind energy.
Nowadays, sophisticated technologies such as wind turbine, solar water heaters are introduced to generate electricity and other energy forms for the household use. Saving Energy: Saving energy will, of course, help to prevent air pollution. Switch off the lights, fans, air conditioners, televisions, and other appliances, when not in use. You can also share a room with others when the air conditioner or fan is on, instead of switching them on in every room. Minimize Air Pollutants: Always try to minimize smoke emission, as it can contribute to air pollution.
One way is to compost dried leaves and kitchen waste, instead of burning them. Composting will also give you organic fertilizer for your garden. While buying the products, always choose air-friendly and recyclable products that will minimize the emission of pollutants. Floods There are few places on Earth where people need not be concerned about flooding. Any place where rain falls is vulnerable, although rain is not the only impetus for flood. A flood occurs when water overflows or inundates land that’s normally dry. This can happen in a multitude of ways. Most common is when rivers or streams overflow their banks.
Excessive rain, a ruptured dam or levee, rapid ice melting in the mountains, or even an unfortunately placed beaver dam can overwhelm a river and send it spreading over the adjacent land, called a floodplain. Coastal flooding occurs when a large storm or tsunami causes the sea to surge inland. Most floods take hours or even days to develop, giving residents ample time to prepare or evacuate. Others generate quickly and with little warning. These flash floods can be extremely dangerous, instantly turning a babbling brook into a thundering wall of water and sweeping everything in its path downstream.
Types of Floods Riverine * Slow kinds: Runoff from sustained rainfall or rapid snow melt exceeding the capacity of a river’s channel. Causes include heavy rains from monsoons, hurricanes and tropical depressions, foreign winds and warm rain affecting snow pack. Unexpected drainage obstructions such as landslides, ice, or debris can cause slow flooding upstream of the obstruction. * Fast kinds: include flash floods resulting from convective precipitation (intense thunderstorms) or sudden release from an upstream impoundment created behind a dam, landslide, or glacier.
Estuarine * Commonly caused by a combination of sea tidal surges caused by storm-force winds. A storm surge, from either a tropical cyclone or an extratropical cyclone, falls within this category. Coastal * Caused by severe sea storms, or as a result of another hazard (e. g. tsunami or hurricane). A storm surge, from either a tropical cyclone or an extratropical cyclone, falls within this category. Catastrophic * Caused by a significant and unexpected event e. g. dam breakage, or as a result of another hazard (e. g. earthquake or volcanic eruption). Human-induced Accidental damage by workmen to tunnels or pipes. Muddy * A muddy flood is produced by an accumulation of runoff generated on cropland. Sediments are then detached by runoff and carried as suspended matter or bed load. Muddy runoff is more likely detected when it reaches inhabited areas. Muddy floods are therefore a hill slope process, and confusion with mudflows produced by mass movements should be avoided. Other * Floods can occur if water accumulates across an impermeable surface (e. g. from rainfall) and cannot rapidly dissipate (i. e. gentle orientation or low evaporation). A series of storms moving over the same area. * Dam-building beavers can flood low-lying urban and rural areas, often causing significant damage. Effects of Floods Primary effects * Physical damage – Can damage any type of structure, including bridges, cars, buildings, sewerage systems, roadways, and canals. Secondary effects * Water supplies – Contamination of water. Clean drinking water becomes scarce. * Diseases – Unhygienic conditions. Spread of water-borne diseases. * Crops and food supplies – Shortage of food crops can be caused due to loss of entire harvest. 4] However, lowlands near rivers depend upon river silt deposited by floods in order to add nutrients to the local soil. * Trees – Non-tolerant species can die from suffocation.  * Transport – Transport links destroyed, so hard to get emergency aid to those who need it. Tertiary/long-term effects Economic – Economic hardship, due to: temporary decline in tourism, rebuilding costs, food shortage leading to price increase, etc. Control In many countries across the world, rivers prone to floods are often carefully managed. Defenses such as levees, bunds, reservoirs, and weirs are used to prevent rivers from bursting their banks.
When these defenses fail, emergency measures such as sandbags or portable inflatable tubes are used. Coastal flooding has been addressed in Europe and the Americas with coastal defences, such as sea walls, beach nourishment, and barrier islands. Many governments mandate that residents of flood-prone areas purchase flood insurance and build flood-resistant structures. Massive efforts to mitigate and redirect inevitable floods have resulted in some of the most ambitious engineering efforts ever seen, including New Orleans’s extensive levee system and massive dikes and dams in the Netherlands.
And highly advanced computer modeling now lets disaster authorities predict with amazing accuracy where floods will occur and how severe they’re likely to be. Drought Drought is a period or condition of unusually dry weather within a geographic area where rainfall is normally present. During a drought there is a lack of precipitation. Droughts occur in all climatic zones. However, its characteristics vary significantly from one region to another. Drought usually results in a water shortage that seriously interferes with human activity.
Water-supply reservoirs empty, wells dry up, and crop damage ensues. Its seriousness depends on the degree of the water shortage, size of area affected, and the duration and warmth of the dry period. In many underdeveloped countries, such as India, people place a great demand on water supply. During a drought period there is a lack of water, and thus many of the poor die. Most precipitation depends on water vapor carried by winds from an ocean or other source of moisture. If these moisture-carrying winds are replaced by inds from a dry region, or if they are modified by downward motion, as in the center of an anticyclone, the weather is abnormally dry and often persistently cloudless. If the drought period is short, it is known as a dry spell. A dry spell is usually more than 14 days without precipitation, whereas a severe drought may last for years. Impacts of Drought Drought produces a large number of impacts that affects the social, enviornmental, and economical standard of living. Its affects spread far beyond the physical effects of drought itself. Water is integral to produce goods and provide certain services.
Some direct impacts of drought are reduced crop, rangeland, and forest productivity; reduced water leves; increased fire hazard; increased livestock and wildlife death rates; and damage to wildlife and fish habitat. A reduction in crop productivity usually results in less income for farmers, increased prices for food, unemployment, and migration. The many effects of drought can be listed as economic, environmental, or social. Effects of Drought Economic – Loss of national economic growth, slowing down of economic development – Damage to crop quality, less food production – Increase in food prices Increased importation of food (higher costs) – Insect infestation – Plant disease – Unavailability of water and feed for livestock which leads to high livestock mortality rates – Disruption of reproduction cycles (breeding delays or unfilled pregnancies) Environmental – Increased desertification – Damage to animal species – Reduction and degradation of fish and wildlife habitat – Lack of feed and drinking water – Disease – Increased predation. Social – Food shortages – Loss of human life from food shortages, heat, suicides, violence – Mental and physical stress – Water user conflicts – Political conflicts – Increased poverty
Types of Drought Meteorological, Hydrological, Agricultural and Socioeconomic Meteorological Drought Meteorological drought is the amount of dryness and the duration of the dry period. Atmospheric conditions that result in deficiencies of precipitation change from area to area. Agricultural Drought Agricultural drought mainly effects food production and farming. Agricultural drought and precipitation shortages bring soil water deficits, reduced ground water or reservoir levels, and so on. More of these effects can be listed by clicking here. Deficient topsoil moisture at planting may stop germination, leading to low plant populations.
Hydrological Drought Hydrological drought is associated with the effects of periods of precipitation shortages on water supply. Water in hydrologic storage systems such as reservoirs and rivers are often used for multiple purposes such as flood control, irrigation, recreation, navigation, hydropower, and wildlife habitat. Competition for water in these storage systems escalates during drought and conflicts between water users increase significantly. Socioeconomic Drought Socioeconomic drought occurs when the demand for an economic good exceeds supply as a result of a weather-related shortfall in water supply.
The supply of many economic goods, such as water, forage, food grains, fish, and hydroelectric power, depends on weather. Due to variability of climate, water supply is sufficient in some years but not satisfactory to meet human and environmental needs in other years. The demand for economic goods is increasing as a result of increasing population. Supply may also increase because of improved production efficiency and technology. Drought protection and relief Strategies for drought protection, mitigation or relief include: * Dams – many dams and their associated reservoirs supply additional water in times of drought. Cloud seeding – an artificial technique to induce rainfall.  * Desalination of sea water for irrigation or consumption. * Drought monitoring – Continuous observation of rainfall levels and comparisons with current usage levels can help prevent man-made drought. For instance, analysis of water usage in Yemen has revealed that their water table (underground water level) is put at grave risk by over-use to fertilize their Khat crop.  Careful monitoring of moisture levels can also help predict increased risk for wildfires, using such metrics as the Keetch-Byram Drought Index or Palmer Drought Index. Land use – Carefully planned crop rotation can help to minimize erosion and allow farmers to plant less water-dependent crops in drier years. * Outdoor water-use restriction – Regulating the use of sprinklers, hoses or buckets on outdoor plants, filling pools, and other water-intensive home maintenance tasks. * Rainwater harvesting – Collection and storage of rainwater from roofs or other suitable catchments. * Recycled water – Former wastewater (sewage) that has been treated and purified for reuse. * Transvasement – Building canals or redirecting rivers as massive attempts at irrigation in drought-prone areas.
Afforestation Afforestation is the establishment of a forest or stand of trees in an area where there was no forest.  Reforestation is the reestablishment of forest cover, either naturally (by natural seeding, coppice, or root suckers) or artificially (by direct seeding or planting).  Many governments and non-governmental organizations directly engage in programs of afforestation to create forests, increase carbon capture and sequestration, and help to anthropogenically improve biodiversity. Commerce and Afforestation
Commercially, wood is required for various purposes such as timber, paper pulp, wood pulp, charcoal, fuel, etc. Afforestation for commercial purposes has led to the growth of plantation forests, where trees are grown primarily as agricultural plantation crops and harvested accordingly. This, in turn, has helped prevent further exploitation and destruction of natural forests. According to a report published by the Australian National University, the area under plantation forests globally had increased to 135 million hectares by 1997, with annual plantation afforestation and reforestation rates nearing 10 per cent of the total area.
About 75 per cent of these plantation forests were established in temperate regions as the rate of expansion has been the highest in tropical areas. Successful Afforestation The scope of afforestation should extend from simple planting of trees to planting the right types of trees at the right places. Many communities and countries have already taken steps towards setting standards for planning, designing and executing afforestation projects. The Climate Community and Biodiversity Alliance (CCBA) is one such example. The CCBA is working towards creating standards in this field.
Britain offers an example of successful, sustainable and standardised afforestation and reforestation management. According to Forest Research, a research organisation under Britain’s Forestry Commission, at the start of the 20th century the forest reserves in Britain were less than 5 per cent due to centuries of deforestation. Since 1919, there has been a sustained expansion of forest cover in many areas of the country. As a result, at the beginning of the 21st century, forests cover nearly 12 per cent of Britain, with the figure in parts of Scotland nearing 25 per cent.
In other words, areas of the country have moved from being ‘forest poor’ to becoming ‘forest rich’. The achievements represented by this expansion of forest cover have been internationally recognised as the opportunities for diversifying the forests to meet the multiple criteria of sustainable forest management. The new forests that have been created provide the opportunity for developing modern wood processing industries that are internationally competitive yet help support a diversified and vibrant rural economy. Another great example of successful afforestation is Israel.
About 70 per cent of Israel’s forests are man-made. They have managed to successfully execute afforestation in harsh desert conditions and have consequently prevented the desert from expanding. The Yatri Forest in Israel, which was planted by the Jewish National Fund in 1964, is a healthy mix of vegetation and forest animals today. In the years to come, continuous and sincere efforts in this sphere would be of vital importance. Afforestation could be the answer if amalgamation of commerce and environment on a sustainable basis is to be achieved globally. Environment and afforestation
The effects of an increasing population, growing pollution and the consequent decrease in forest area on the environment are well known. Afforestation is the answer to some extent, but needs to be carried out in a structured way with thorough knowledge of local environment, vegetation, soil type and socio-economic issues; not knowing or ignoring local conditions can prove extremely dangerous to the ecosystem. A sustainable and well-planned afforestation project helps improve soil conservation, catchment management and water quality. Such a project can also act as a wind barricade, as in the case of the The Great Green Wall Project in China.
A very ambitious afforestation project that has spanned 70 years and 4,480km, it involves the building of a tree wall skirting the Gobi Desert. The tree wall is being built with the sole aim of fighting and acting as a barricade to ferocious sandstorms originating from the desert. Afforestation projects undertaken without a complete understanding of the surroundings can cause additional environmental damages. For instance, fast-growing trees commonly used in timber plantations consume huge amounts of water, hence depleting water resources around the area. There are also concerns about irreversible changes in the soil caused by exotic species.
For example, pine trees are known to turn the soil acidic. The water from the soil eventually trickles down to local streams and water bodies, which, in turn, causes harm to both the water and land ecosystems. The concern mainly arises with large-scale monoculture tree plantations in Third World countries. Such plantations are usually set up for the purposes of abundant and cheap supply of raw materials to industrialised countries. A number of non-government organisations have joined hands to form a global network in order to share information and implement joint action against such plantations.
Deforestation Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use.  Examples of deforestation include conversion of forestland to farms, ranches, or urban use. Deforestation occurs for many reasons: trees or derived charcoal are used as, or sold, for fuel or as timber, while cleared land is used as pasture for livestock, plantations of commodities, and settlements. The removal of trees without sufficient reforestation has resulted in damage to habitat, biodiversity loss and aridity.
It has adverse impacts on biosequestration of atmospheric carbon dioxide. Deforestation has also been used in war to deprive an enemy of cover for its forces and also vital resources. A modern example of this, for example, was the use of Agent orange in Vietnam. Deforested regions typically incur significant adverse soil erosion and frequently degrade into wasteland. Disregard or ignorance of intrinsic value, lack of ascribed value, lax forest management and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale.
In many countries, deforestation, both naturally occurring and human induced, is an ongoing issue. Deforestation causes extinction, changes to climatic conditions, desertification, and displacement of populations as observed by current conditions and in the past through the fossil record Causes There are many causes of contemporary deforestation, including corruption of government institutions, the inequitable distribution of wealth and power, population growth and overpopulation, and urbanization. 14] Globalization is often viewed as another root cause of deforestation, though there are cases in which the impacts of globalization (new ? ows of labor, capital, commodities, and ideas) have promoted localized forest recovery.  The degradation of forest ecosystems has also been traced to economic incentives that make forest conversion appear more profitable than forest conservation.  Many important forest functions have no markets, and hence, no economic value that is readily apparent to the forests’ owners or the communities that rely on forests for their well-being. 19] From the perspective of the developing world, the benefits of forest as carbon sinks or biodiversity reserves go primarily to richer developed nations and there is insufficient compensation for these services. Developing countries feel that some countries in the developed world, such as the United States of America, cut down their forests centuries ago and benefited greatly from this deforestation, and that it is hypocritical to deny developing countries the same opportunities: that the poor shouldn’t have to bear the cost of preservation when the rich created the problem. 20] Effects of Deforestation Deforestation is the “permanent removal of standing forests,” as the U. S. Environmental Protection Agency defines it. Although suburban sprawl, industry and agriculture still pose major threats, U. S. deforestation has somewhat stabilized, in part due to a wave of forest management and environmental protection laws enacted in the later decades of the 20th century. Location Deforestation, current and past, is a serious problem around the world, particularly in tropical areas.
Countries with significant deforestation include Thailand, Brazil, the Congo and Indonesia, as well as parts of Eastern Europe, according to GRID-Arendal, a UN Environment Programme collaborating center. (See References 4) Environment Deforestation affects the earth’s physical environment by causing soil erosion, poor water quality, reduced food security and impaired flood protection, according to a report from the World Resources Institute. Because forests are the source of employment and food for many people, their destruction can cause mass migration to cities.
With the influence that tropical forests have on weather, particularly rain, deforestation can cause altered weather patterns. (See References 3) Biological Diversity When massive swaths of forest are destroyed, species loss follows. Tropical areas, like Brazil’s rain forests, have the world’s highest concentrations of biologically diverse species. When the habitat for plants and animals is cut down or burned, species that may not be present anywhere else on Earth disappear. In addition, deforestation of tropical forests leaves many species of migrating birds without a winter home. See References 3) Climate Change Deforestation is a main cause of the higher concentrations of greenhouse gases in the atmosphere. In particular, deforestation causes high levels of carbon dioxide: it is released when forests are burned or when they decompose, and when trees that used to take in this carbon dioxide are cut down, levels rise. Greenhouse gases are trapped in the atmosphere and act as a barrier for heat that would normally be released into space; as a result, temperatures across the globe rise and change rainfall patterns, ice cover and sea levels.
Control Measures Reducing emissions Major international organizations, including the United Nations and the World Bank, have begun to develop programs aimed at curbing deforestation. The blanket term Reducing Emissions from Deforestation and Forest Degradation (REDD) describes these sorts of programs, which use direct monetary or other incentives to encourage developing countries to limit and/or roll back deforestation. Farming New methods are being developed to farm more intensively, such as high-yield hybrid crops, greenhouse, autonomous building gardens, and hydroponics.
These methods are often dependent on chemical inputs to maintain necessary yields. In cyclic agriculture, cattle are grazed on farm land that is resting and rejuvenating. These systems have low dependence on fossil fuels and agro-chemicals, are highly self-maintaining, highly productive, and with strong positive impact on soil and water quality, and biodiversity. Monitoring Deforestation Reducing and monitoring deforestation is a new chapter of this dense keywords lifetime.
There are multiple methods that are appropriate and reliable for monitoring deforestation. One method is the “visual interpretation of aerial photos or satellite imagery that is labor-intensive but does not require high-level training in computer image processing or extensive computational resources”.  Another method includes hot-spot analysis (that is, locations of rapid change) using expert opinion or coarse resolution satellite data to identify locations for detailed digital analysis with high resolution satellite images.
Forest management Efforts to stop or slow deforestation have been attempted for many centuries because it has long been known that deforestation can cause environmental damage sufficient in some cases to cause societies to collapse. Reforestation In many parts of the world, especially in East Asian countries, reforestation and afforestation are increasing the area of forested lands.  The amount of woodland has increased in 22 of the world’s 50 most forested nations. Asia as a whole gained 1 million hectares of forest between 2000 and 2005.
Tropical forest in El Salvador expanded more than 20% between 1992 and 2001. Based on these trends, one study projects that global forest will increase by 10%—an area the size of India—by 2050.  Forest plantations To meet the world’s demand for wood, it has been suggested that high-yielding forest plantations are suitable. It has been calculated that plantations yielding 10 cubic meters per hectare annually could supply all the timber required for international trade on 5% of the world’s existing forestland.
By contrast, natural forests produce about 1–2 cubic meters per hectare; therefore, 5–10 times more forestland would be required to meet demand. Biodiversity Biodiversity refers to all the different kinds of living organisms within a given area. Biodiversity includes plants, animals, fungi, and other living things. Biodiversity can include everything from towering redwood trees to tiny, single-cell algae that are impossible to see without a microscope. Kinds of Biodiversity A common way to measure biodiversity is to count the total number of species living within a particular area.
Tropical regions, areas that are warm year-round, have the most biodiversity. Temperate regions, which have warm summers and cold winters, have less biodiversity. Regions with cold or dry conditions, such as mountaintops and deserts, have even less. Importance of Biodiversity All species are interconnected. They depend on one another. Forests provide homes for animals. Animals eat plants. The plants need healthy soil to grow. Fungi help decompose organisms to fertilize the soil. Bees and other insects carry pollen from one plant to another, which enables the plants to reproduce.
With less biodiversity, these connections weaken and sometimes break, harming all the species in the ecosystem. Ecosystems with a lot of biodiversity are generally stronger and more resistant to disaster than those with fewer species. For instance, some diseases kill only one kind of tree. In the early 1900s, American chestnut blight killed most of the chestnut trees in the eastern forests of North America. The forest ecosystem survived because other kinds of trees also grew there. Uses and Values of Biodiversity Biodiversity is important to people in many ways. Plants, for instance, help humans by giving off oxygen.
They also provide food, shade, construction material, medicines, and fiber for clothing and paper. The root system of plants helps prevent flooding. Plants, fungi, and animals such as worms keep soil fertile and water clean. As biodiversity decreases, these systems break down. Hundreds of industries rely on plant biodiversity. Agriculture, construction, medical and pharmaceutical, fashion, tourism, and hospitality all depend on plants for their success. When the biodiversity of an ecosystem is interrupted or destroyed, the economic impact on the local community could be enormous.
Biodiversity is especially important to the medical and pharmaceutical industries. Scientists have discovered many chemicals in rain forest plants that are now used in helpful drugs. One of the most popular and safe pain relievers, aspirin, was originally made from the bark of willow trees. Scientists have studied only a small percentage of rain forest species in their search for cures. But every year, thousands of species go extinct, or die out entirely, before scientists can determine whether they might be useful in medicines. Uses of Biodiversity In Plants – Plants provide – Food, medicines and raw materials * Plant extracts used in – Glue, soaps, cosmetics, dyes etc. In Animals – * provide food and material for clothes * sources of medicines * for transportation * in agriculture * animals helps in pollination and dispersal of seeds * animal waste is used as fuel as well as fertilizer Decreasing Biodiversity In the past hundred years, biodiversity around the world has decreased dramatically. Many species have gone extinct. Extinction is a natural process; some species naturally die out while new species evolve.
But human activity has changed the natural processes of extinction and evolution. Scientists estimate that species are dying out at hundreds of times the natural rate. A major reason for the loss of biodiversity is that natural habitats are being destroyed. The fields, forests, and wetlands where wild plants and animals live are disappearing. Land is cleared to plant crops or build houses and factories. Forests are cut for lumber and firewood. Between 1990 and 2005, the amount of forested land in Honduras, for instance, dropped 37 percent.
As habitats shrink, fewer individuals can live there. The creatures that survive have fewer breeding partners, so genetic diversity declines. Pollution, overfishing, and overhunting have also caused a drop in biodiversity. Global climate change—the latest rise in the average temperature around the globe, linked to human activity—is also a factor. Protecting Biodiversity People all over the world are working to maintain the planet’s biodiversity. In the United States, the Endangered Species Act protects about 2,000 organisms that are in danger of becoming extinct.
Animals and plants are the most familiar types of endangered species, but a fungus, such as the white ferula mushroom can also be threatened. The white ferula mushroom, a delicacy that only grows on the Italian island of Sicily, helps decompose organic compounds such as plants. Some environmental groups are working to create a sustainable mushroom population to satisfy consumers as well as the local ecosystem. Around the globe, thousands of wilderness areas have been set up to conserve plants, animals, and ecosystems.
Local, national, and international organizations are cooperating to preserve the biodiversity of regions threatened by development or natural disasters. UNESCO’s World Heritage Site program recognizes areas of global importance, such as the enormous wetland region of the Pantanal in South America. Many national parks, such as Glacier National Park in the U. S. state of Montana, protect biodiversity within the park by restricting extractive activities, such as mining and drilling. As ecosystems become healthier, their biodiversity increases