The Effect

This is some effects if trees getting lesser :


GLOBAL WARMING



What is global warming, and how is it affecting the earth and its inhabitants ? Global warming is sometimes referred to as the greenhouse effect. The greenhouse effect is the absorption of energy radiated from the earth's surface by carbon dioxide and other gases in the atmosphere , causing the atmosphere to become warmer. The greenhouse effect is what is causing the temperature on the earth to rise , and creating many problems that will begin to occur in the coming decades. For the last 10,000 years, the earth's climate has been extraordinary beneficial to mankind and we have prospered tremendously well under a benign atmosphere.

Today , however , major changes are taking place. We are destroying the ozone layer which allows life to exist on the earth's surface.If we do not slow down our use of fossil fuels and stop destroying the forest , the world could become hotter than it has been in the past one million years. Atmospheric disturbance brought on by the additional warming will produce more violent storms and larger death tolls. Changes in temperature and rainfall brought on by global warming will in turn change the composition of the forest.

Evaporation rates will also increase and circulation patterns will change. Decreased rainfall in some areas will result in increased rainfall in others. In some regions , river flow will be reduced or stopped all together completely. Other areas will experience sudden downpours that create massive floods. The central portions of the continents , which normally experienced occasionally droughts , might become permanently dry wastelands. Coastal regions, where half the human population lives , will feel the adverse effects of rising sea levels as the ice caps melt under rising temperatures of the ocean.

If the present melting continues , the sea could rise as much as 6 feet by the middle of the next century. Large tracks of the coastal lang would disappear , as would shallow barrier islands and coral reefs. Low lying fertile deltas that support millions of people would vanish. Delicate wet lands , where many marine life hatch their young , would be reclaimed by the sea. Vulnerable coastal cities would have to move farther inland to against the angry sea , where the larger number of extremely dangerous hurricanes would prowl the ocean stretches.




FIGHT GLOBAL WARMING  !!!

SAVE THE EARTH ...
SAVE OUR LIFE ...



GREEN HOUSE EFFECT



The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases.
Solar radiation at the frequencies of visible light largely passes through the atmosphere to warm the planetary surface, which then emits this energy at the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection.
The existence of the greenhouse effect was argued for by Joseph Fourier in 1824. The argument and the evidence was further strengthened by Claude Pouillet in 1827 and 1838, and reasoned from experimental observations by John Tyndall in 1859, and more fully quantified by Svante Arrhenius in 1896.
If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth is, it would have a temperature of about 5.3 °C. However, since the Earth reflects about 30%  of the incoming sunlight, the planet's effective temperature (the temperature of a blackbody that would emit the same amount of radiation) is about −18 °C, about 33°C below the actual surface temperature of about 14 °C.The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect.
Earth’s natural greenhouse effect makes life as we know it possible. However, human activities, primarily the burning of fossil fuels and clearing of forests, have intensified the natural greenhouse effect, causing global warming.

Greenhouse Gases
Main article: Greenhouse gas
By their percentage contribution to the greenhouse effect on Earth the four major gases are:
The major non-gas contributor to the Earth's greenhouse effect, clouds, also absorb and emit infrared radiation and thus have an effect on radiative properties of the atmosphere.





SOIL EROSSION




Erosion is the process by which materials are removed from the surface and transported to another location. It works by hydraulic or aeolian actions and transport of solids (sediment, soil, rock and other particles) in the natural environment, and leads to the deposition of these materials elsewhere. It usually occurs due to transport by wind, water, or ice; by down-slope creep of soil and other material under the force of gravity; or by living organisms, such as burrowing animals, in the case of bioerosion.
Although erosion is a natural process, human land use policies also have had an effect on erosion, especially industrial agriculture, deforestation, andurban sprawl. Land that is used for industrial agriculture generally experiences a significantly greater rate of erosion than that of land under natural vegetation, or land used for sustainable agricultural practices. This is true if tillage is used, which reduces vegetation cover on the surface of the soil and disturbs both soil structure and plant roots that would otherwise hold the soil in place. However, improved land use practices can limit erosion, using techniques such as terrace-building, no-till, and tree planting.
A certain amount of erosion is natural and, in fact, healthy for the ecosystem. For example, gravels continuously move downstream in watercourses. Excessive erosion, however, causes serious problems, such as receiving water sedimentation, ecosystem damage and outright loss of soil. Erosion is distinguished from weathering, which is the process of chemical or physical breakdown of the minerals in the rocks. The two processes may occur concurrently, however.

The Effect
Approximately 40% of the world's agricultural land is seriously degraded. According to the UN, an area of fertile soil the size of Ukraine is lost every year because of drought, deforestation andclimate change. In Africa, if current trends of soil degradation continue, the continent might be able to feed just 25% of its population by 2025, according to UNU's Ghana-based Institute for Natural Resources in Africa.

In the case of human use, the effects are also generally linked to overpopulation . When large number of hikers use trails or extensive off-road vehicle use occurs, erosive effects often follow, arising from vegetation removal and furrowing of foot traffic and off-road vehicle tires. These effects can also accumulate from a variety of outdoor human activities, again simply arising from too many people using a finite land resource.]When land is overused by animal activities (including humans), there can be mechanical erosion and also removal of vegetation leading to erosion. In the case of the animal kingdom, this effect would become material primarily with very large animal herds stampeding such as the Blue Wildbeest on the Serengeti plain. Even in this case there are broader material benefits to the ecosystem, such as continuing the survival of grasslands that are indigenous to this region. This effect may be viewed as anomalous or a problem only when there is a significant imbalance or overpopulation of one species.
One of the most serious and long-running water erosion problems worldwide is in the People's Republic of China , on the middle reaches of the Yellow River and the upper reaches of the Yangtze River. From the Yellow River, over 1.6 billion tons of sediment flows into the ocean each year. The sediment originates primarily from water erosion in the Loess Plateau region of the northwest.

SOIL EROSSION ? PUT AT THE SIDE ! WE DON'T WANT THAT !




LANDSLIDE



A landslide  is a geological phenomenon which includes a wide range of ground movement, such as rockfalls ,deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments. Although the action of gravity is the primary driving force for a landslide to occur, there are other contributing factors affecting the original slope stability. Typically, pre-conditional factors build up specific sub-surface conditions that make the area/slope prone to failure, whereas the actual landslide often requires a trigger before being released.

Landslides occur when the stability of slope changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of factors, acting together or alone. Natural causes of landslides include:
  • groundwater (porewater) pressure acting to destabilize the slope
  • loss or absence of vertical vegetative structure, soil nutrients, and soil structure.
  • erosion of the toe of a slope by rivers or ocean waves.
  • weakening of a slope through saturation by snow melt, glaciers melting, or heavy rains
  • earthquakes adding loads to barely stable slope
  • earthquake-caused liquefaction destabilizing slopes
  • volcanis eruptions

Landslides are aggravated by human activities, Human causes include:  
  • vibrations from machinery or traffic.
  • blasting earthwork which alters the shape of a slope, or which imposes new loads on an existing slope
  • in shallow soils, the removal of deep-rooted vegetation that binds colluvium to bedrock
  • Construction, agricultural or forestry activities (logging) which change the amount of water which infiltrates the soil.




FLASH FLOOD



A flash flood is a rapid flooding of geomorphic low-lying areas—washes, rivers, dry lakes and basins. It may be caused by heavy rain associated with a storm , hurricane , or tropical storm or melt water from ice or snow flowing over ice sheets or snowfields. Flash floods may occur after the collapse of a natural ice or debris dam , or a human structure such as a man-made dam , as occurred before the Johnstown of 1889. Flash floods are distinguished from a regular flood by a timescale less than six hours. The temporary availability of water is often utilized by foliage with rapid germination and short growth cycle, and by specially adapted animal life. 


Flash flooding occurs when precipitation falls too quickly on saturated soil or dry soil that has poor absorption ability. The runoff collects in low-lying areas and rapidly flows downhill. Flash floods most often occur in normally dry areas that have recently received precipitation, but may be seen anywhere downstream from the source of the precipitation, even many miles from the source. In areas on or near volcanoes , flash floods have also occurred after eruptions, when glaciers have been melted by the intense heat. 


Flash floods are known to occur in the highest mountain ranges of the United States and are also common in the arid plains of southwestern United States. Flash flooding can also be caused by extensive rainfall released by hurricanes and other tropical storms , as well as the sudden thawing effect of ice dams. Human activities can also cause flash floods to occur. When dams, constructed for hydro-electricity, have failed, large quantities of water can be released and can destroy everything within its path.







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