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Showing posts with label deforestation. Show all posts
Showing posts with label deforestation. Show all posts

Tuesday, July 15, 2008

Deforestation for food and fuel – A devastating consequence of overpopulation - to be checked immediately:



Deforestation for food and fuel – A devastating consequence of overpopulation - to be checked immediately:

Tropical rainforests are incredibly rich ecosystems that play a fundamental role in the basic functioning of the planet. Rainforests are home to probably 50 percent of the world's species, making them an extensive library of biological and genetic resources. In addition, rainforests help maintain the climate by regulating atmospheric gases and stabilizing rainfall, protect against desertification, and provide numerous other ecological functions. These precious systems are among the most threatened on the planet because of unchecked population growth and rising demand.


As per the rough estimate, each day at least 80,000 acres (32,300 ha) of forest disappear from Earth.Rising demand for food, biofuels, wood for paper, building and industry made forest cover worldwide most vulnerable. The result of it is more deforestation, more conflict, more carbon emissions, more climate change and less prosperity for everyone. Growth in population, especially in developing countries, is the major culprit for irresponsible deforestation, degradation of global environment and climate change.


Demand for land worldwide to grow more food, fuel crops for future energy security and wood is set to outstrip supply, leading to the probable destruction of forests. Tropical forests in Asia, Africa and South America are at most vulnerable position as growth in population in developing countries in those continents is quite large.


Many reports suggests that, because of the rising demand for food and biofuel, by another two decades, more than 500 million hectares of extra land will be needed worldwide for growing crops and trees; but only 200 million hectares will be available without dipping into tropical forests. Thus, tropical forest areas are bound to be affected extensively in next couple of decades. Analysis of figures from the Food and Agriculture Organization of the United Nations (FAO) shows that tropical deforestation rates increased 8.5 percent from 2000-2005 when compared with the 1990s, while loss of primary forests may have expanded by 25 percent over the same period.


Some of the studies also suggest that, if the current level in agricultural yield continues, the amount of additional agricultural land required just to meet the world's projected food demand in 2050 would be about three billion hectares and nearly all would be required in developing countries. In such a scenario, tropical forest areas in developing countries would be destroyed, without repair, almost completely.


However, some academics place their hopes in agricultural technologies including genetic engineering to boost crop yields.


The main area of concern is, since the spectacular success of the expected green revolution is, so far, quite slow. In some areas, yields are falling - a trend, which is most likely to be, intensified by climate change due to global warming. Moreover, eating into tropical forests to create extra agricultural land would, in turn, deepen climate change. Further, greenhouse gases may also rise because of extensive deforestation. As these forests fall, more carbon is added to the atmosphere, climactic conditions are further altered, and more topsoil is lost to erosion.

Friday, May 2, 2008

The greatest adverse impact of Deforestation is Greenhouse effect:



The greatest adverse impact of Deforestation is Greenhouse effect:

As described earlier, an approximate area of more than thirty five football grounds of rainforest are deforested all over the world in every minute. The main area attacked for deforestation is the tropical rainforest – situated in on and around equator.

A. The main reason for deforestation is the demand for fuel, wood and paper products, cattle ranching, farming, mining and road construction.

a. Fuel: Half of all the trees cut down in the world are used for fuel. Burning wood is common in developing countries where there are often no readily-available alternatives. Most of the trees cut are not replaced, causing the problems.

b. Wood and Paper Products: The use of wood and paper is a huge factor driving deforestation all over the world. Hardwoods like mahogany are sought after for furniture and are consequently very valuable. Some time, for small number of mahogany, whole forest area is often cut down for those few trees.

c. Cattle-ranching: Areas of rainforest, generally in developing countries, are cleared by cutting down all the vegetation and then burning it. Pastures of grass are then grown and used for grazing cattle. As soon as the cattle are a certain age, they are slaughtered. Although some of the meat goes to the locals, a lot goes to the cheap meat industries in countries such as the UK, USA, and China etc. After a few years, all the nutrients have been removed from the already poor soil and the land is useless, so another area of rainforest has to be cleared.

d. Farming: Large areas of rainforest are cleared for farmland all over the world. In developing countries there are two main types of farming: (i) 'Slash and Burn' and (ii) 'Subsistence Farming'.

(i) Slash and Burn: Areas of forest are cleared to grow crops for a couple of years, then left for a few years for the rainforest to recover, then the process starts again. Slash and burn is the most sustainable of the farming methods, but only if the population in the area is low, because as soon as you get more people in an area, there is less land available for each person and areas of land don't have enough time to recover, so the soil is quickly exhausted. Slash and burn also increases air pollution.

(ii) Subsistence Farming: Small areas of land that have been cleared are farmed. The produce is used to feed the family and provide a small surplus to buy other goods. The problem with this method is that the soil is quickly exhausted of its few nutrients and they are not replaced. This means that the farmers have to rely increasingly on fertilizers before eventually being forced to move.

e. Mining and Infrastructure: Minerals such as gold, bauxite (aluminium ore) and iron ore are often discovered in areas of rainforest. To mine them huge portions of rainforest are cleared, not just the area where the mine is, but also routes for roads and areas for storage of equipment and housing for men. In places where there are large rivers running through rainforest, deforestation often takes place in order to build hydroelectric power stations. The resulting dams cause enormous amounts of flooding behind the walls and large areas of drought downriver.

f. Population Increase: The world population is increasing day by day. With this explosion of population the amount of land needed for humans to live on also increases exponentially. More and more forest areas are being cleared to provide living space. This is known as ‘urbanization’.

B. The adverse effects of deforestation:

(i) Immediate effects of deforestation include the washing away of soil in the monsoon season. This is because trees are no longer anchoring and binding the soil and so mud slides take place. The earth is leached of minerals by the large amounts of water. The lack of vegetation also means that there will be very few animals in the area. The lack of decomposing vegetation and animals means that the nutrients are not replaced and the area quickly becomes infertile.

(ii) Rivers often silt up as soil is moved downriver and deposition takes place. Fish and plants relying on clear water die as the river becomes more and more clogged. This has a knock-on effect through the entire food chain.

(iii) If large areas of rainforest are cleared, the pattern of precipitation may change. This is because less evapotranspiration (evapotranspiration is a term used to describe the sum of evaporation and plant transpiration from the earth's land surface to atmosphere. Evaporation accounts for the movement of water to the air from sources such as the soil, canopy interception, and water bodies) takes place due to the lack of trees. Water is also not delayed before making its way through the ground because of the lack of trees, shrubs, and leaf litter.

(iv) Another very worrying effect of deforestation is global warming (please refer ‘description on global warming’ in the box below). The Earth is made habitable by a process called the greenhouse effect. Gases, mainly carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and water vapor (H2O), are found in the atmosphere. The effects of global warming are already showing themselves; the polar ice caps are melting and if this continues we are set for a significant rise in sea level, flooding many places.

C. How to help in mitigating the global warming:

(i) We should turn off the light when we do not require, and to use more energy-efficient bulbs. While energy-efficient bulbs are expensive, they do last longer. Not only will this save money, but it reduces the amount of electricity that needs to be generated and so less fossil fuels have to be burned.

(ii) Use public transport, walk, or cycle if possible. It is said that the bicycle is the most efficient form of transport known to man. Only travel in a car when necessary or share with some body to save petrol. This reduces CO2 emissions.

(iii) Try to buy paper or wood products that are certified by the Forestry Commission as being from sustainable, managed woodlands. Using recycled paper and its promotion help in reduction of destruction of forest.

(iv) Avoid excess printing of documents from the computer. Print non-presentation documents on the draft ink setting. If possible print on both sides of sheets of paper, thus saving both paper and money.

(v) Recycle as much as possible. This is not just limited to paper, but can include glass, plastic, metal, and a number of other things. Many councils run recycling collection services.

(vi) Encourage people you know to do any or all of the things above.

Description on Greenhouse Effect:

Consider a glasshouse in the open air - greenhouse works because of the glass panels that line the roof and walls. The glass is transparent to the visible light from the sun, so sunlight can shine in and warm things inside the greenhouse. Now a body at about 35°C emits mostly infrared radiation. (On the other hand our sun, with a surface temperature of about 5500°C, emits mostly visible light.) The glass panels are opaque to infrared light. The result is that the glass lets the energy of the sun in, but won't let it back out. This keeps the inside of a greenhouse warm.

Replace the greenhouse with Earth and glass panels with atmosphere in the above example, and that is how the Earth's greenhouse effect works.

Now to show why the greenhouse effect is a very good thing here are examples from our solar system.

(i) Mercury: Mercury is the closest planet to the sun, so you would expect it to be hot. It is, but only on the day side. During a Mercurian day temperatures reach 464°C, but because there is no atmosphere to cause a greenhouse effect, temperatures drop to -183°C at night. That's cold enough to warrant an investment in triple-paned windows.

(ii) Earth: Our greenhouse effect keeps our night side almost as warm as our day side, allowing life to flourish and keeping the world's collective heating bill manageable.

(iii) Venus: Venus is an example of having a greenhouse that is too good at trapping in the heat.

Even though Venus is twice as far away from the Sun as Mercury, Venus is the planet with the hottest surface temperature day or night. At about 484°C, lead melts on the surface at any time of the day.

The reason why this doesn't happen to Earth is due to the fact that Venus has a much thicker atmosphere with many different kinds of gases. Earth's atmosphere is full of gases that trap infrared radiation (so-called greenhouse gases), but they only trap certain wavelengths at a certain efficiency. In other words, a lot escapes. Venus's atmosphere is more diverse as well as denser, so it traps more wavelengths of infrared radiation at a greater efficiency, making the surface hellishly hot.

That is where the greenhouse effect gets its bad reputation. We do not have a lot of carbon dioxide in our atmosphere right now, and if more is released into the atmosphere, more of the infrared radiation that it traps will be held in, making the world warmer than it is. This kind of global warming is a bad thing.

Sunday, March 16, 2008

Soil erosion and its prevention:




Soil erosion and its prevention:

Soil erosion by water, wind and tillage affects both agriculture and the natural environment. Soil loss, and its associated impacts, is one of the most important (yet probably the least well-known) of today's environmental problems. It is mostly due to poor land use practices, which include deforestation, overgrazing, unmanaged construction activity and road or trail building.

Soil is a complex mixture of living and non-living materials. It provides anchorage and sustenance to plants. Natural agents like water and wind, constantly tend to remove the top soil and cause erosion. Rain falling upon the unprotected top soil, washes it down into the streams. Due to the absence of plant covering, eroded soil cannot hold water. Water rushes into the rivers and overflows as flood. Dust storm also causes soil erosion. The particles of top soil are picked up in such quantities that they form clouds of dust. Human beings also cause soil erosion. The growing human habitation and expansion of urban areas lead to removal of vegetation. Once vegetation is removed, the naked soil gets exposed to wind and water. Improper tillage is another cause of soil erosion. Farmers often loosen the top soil for removing weeds and preparing seed beds. They also leave agricultural fields lying fallow for long time. These practices expose the top soil to the wind and cause erosion.

Soil erosion is always a result of mankind's unwise actions, such as overgrazing or unsuitable cultivation practices. These leave the land unprotected and vulnerable. Accelerated soil erosion by water or wind may affect both agricultural areas and the natural environment, and is one of the most widespread of today's environmental problems. Soil erosion is just one form of soil degradation. Other kinds of soil degradation include salinisation, nutrient loss, and compaction.

Prevention of soil erosion: Plants provide protective cover on the land and prevent soil erosion for the reasons: (a) plants slow down water as it flows over the land (runoff) and this allows much of the rain to soak into the ground; (b) plant roots hold the soil in position and prevent it from being washed away; (c) plants break the impact of a raindrop before it hits the soil, thus reducing its ability to erode; (d) plants in wetlands and on the banks of rivers are of particular importance as they slow down the flow of the water and their roots bind the soil, thus preventing erosion.

Preventing soil erosion requires technical changes to adopt. Aspects of technical changes include: (i) use of contour ploughing and wind breaks; (ii) leaving unploughed grass strips between ploughed land; (iii) making sure that there are always plants growing on the soil, and that the soil is rich in humus (decaying plant and animal remains). This organic matter is the "glue" that binds the soil particles together and plays an important part in preventing erosion; (iv) avoiding overgrazing and the over-use of crop lands; (v) allowing indigenous plants to grow along the river banks instead of ploughing and planting crops right up to the water's edge; (vi) encouraging biological diversity by planting several different types of plants together; (vii) conservation of wetlands (see Enviro Facts "Wetlands" and "River Catchments").

We can check soil erosion by adopting the following additional practices:

1. Intensive cropping and use of proper drainage canals.

2. Terracing on the sloping fields. This retards the speed of the flowing water.

3. Planting trees and sowing grasses.

4. Extensive aforestation practices to be carried out.

Tuesday, February 12, 2008

Importance of Urban green cover in improving environmental standard










In the last decade many of the developing countries in Asia, East Europe and Africa have seen rapid growth of industrialization, due to which many of the countries have emerged as economic power house. This rapid growth in industrialization has lead to unplanned development of urban areas by large scale cutting of trees, converting agricultural land into human habitation and deforestation. This has affected adversely on general environment and maintaining ecological balance. Rapid migration and increase in population in the urban areas has also lead to large scale spreading of air & water pollution, garbage etc., and also impairing aesthetic value of area / land. Traffic congestion, water shortages, solid waste, and air, water and noise pollution are common noticeable problems in almost all the urban areas since last few years. The escalated urbanization, associated with environmental degradation, has generated a debate on how much urban green space has been lost due to the urbanization process. Integrated means of addressing the ecological and environmental, economic and social concerns are still neglected in the framework of development. As a result, large areas of urban green space are declining rapidly, and causing numerous environmental problems. However, both environmental awareness and environmental legislation (setting of standards etc.) have advanced considerably in recent years, but enforcement is lagging almost everywhere.

Now, it is well recognized that urban green space plays an important role in the social and natural sustainability of a city. An increase of vegetated surfaces in the urban landscape, provide ecological diversity etc. - can help mitigate several negative effects of urbanization on climate, air pollution, since they contribute to the reduction of the structural differences between the urban area and its rural surrounding. The mitigation processes operated by the vegetation take place both through biophysical and microclimatological properties. Urban green cover form essential structural and functional elements that make cities and urban regions more livable places for their citizens. It is thus, key role of improving the quality of urban life as well as environment. Their imperceptible role in arresting pollution, acting as dust-busters, reducing noise pollution by muffling the sounds of urban living, their cooling effect on the city's temperatures, and how all of this can help keep climate change at bay, are well-known.

Good quality green space enhances the quality of urban life and contributes to wider Government objectives such as improved health, more sustainable neighbourhood renewal and better community cohesion, especially in more deprived communities. Neglected parks attract anti-social behaviour and have the potential to undermine regeneration of deprived neighbourhoods.

Urban green spaces provide a wide range of outputs, however, due to their multi-functional characteristics, the development and management of parks and green spaces is becoming a more and more complex planning issue that needs careful consideration, if green spaces are to be successful places, accepted and appreciated by citizens.

Importance of Forests:


Importance of Forests:

A forest is an area with a high density of all types of trees, shrubs, vegetations. Forests cover considerable areas of woodland. The word forest eventually came to mean wooded land more generally. Forests can be found in all regions capable of sustaining tree growth. Forests sometimes contain many tree species within a small area (as in tropical rain and temperate deciduous areas), or relatively few species over large areas (e.g., arid region). Forests are often home to many animal and plant species, and other vegetations. This emphasis on trees reflects their ecological, biological, and cultural importance. Also, trees are critical to the classification of forests. Trees represent some of the oldest living organisms on the planet. Trees are instrumental in the development and support of civilizations. They form important links in the earth's geological, chemical, and hydrological cycles by:

  • Taking in CO2 and releasing oxygen;
  • Releasing carbon and mineral elements such as nitrogen and phosphorus (important in plant growth) as they decay;
  • Absorbing moisture for growth and releasing it as vapor through transpiration;
  • Preventing erosion by reducing the force of rainfall at the soil surface and by intercepting and absorbing water, rather than allowing it to run off directly;
  • Harboring a diversity of wildlife;
  • Acting as windbreaks;
  • Providing us with shade and beauty on a largely agricultural and urban landscape.

At present unfortunately, the forest environment has been impaired heavily by natural processes or by human activities resulting large scale deforestations. Deforestation is the conversion of forested areas to non-forest land by cutting of trees for urban use. Deforestation results from removal of trees without sufficient reforestation.

Impact on the environment by deforestation:

  • Generally, the removal or destruction of significant areas of forest cover has resulted in a degraded environment with reduced biodiversity. In many countries, massive deforestation is ongoing and is shaping climate and geography.
  • ·Deforestation, to be precise, responsible for Global warming.
  • · Deforestation affects the amount of water in the soil and groundwater and the moisture in the atmosphere. Forests support considerable biodiversity, providing valuable habitat for wildlife.
  • Moreover, forests foster medicinal conservation and the recharge of aquifers.
  • ·Deforested areas become sources of surface water runoff, which moves much faster than subsurface flows. That quicker transport of surface water can translate into flash flooding and more localized floods than would occur with the forest cover.
  • ·Long-term gains can be obtained by managing forest lands sustainable to maintain both forest cover and provide a biodegradable renewable resource.
  • ·Forests are important stores of organic carbon, and forests can extract carbon dioxide and pollutants from the air, thus contributing to biosphere stability and probably relevant to the greenhouse effect.
  • Forests are also valued for their aesthetic beauty and as a cultural resource and tourist attraction.