Sunday, September 9, 2007

GloBaL WarMinG!

GLOBAL WARMING?




Global warming refers to the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation.There is an increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in greenhouse gas via the greenhouse effect.


HoW ComE?




The greenhouse effect is the process in which the emission of infrared radiation by the atmosphere warms a planet's surface.the warming of air inside a greenhouse compared to the air outside the greenhouse. The Earth's average surface temperature is about 33°C warmer than it would be without the greenhouse effect.Basically,it traps heat.....SIMPLE?



The earth receives energy from the Sun in the form of radiation. The Earth reflects about 30% of the incoming solar radiation. The remaining 70% is absorbed, warming the land, atmosphere and oceans. For the Earth's temperature to be in steady state so that the Earth does not rapidly heat or cool, this absorbed solar radiation must be very nearly balanced by energy radiated back to space in the infrared wavelengths.When greenhouse effect becomes stronger, it could make the Earth warmer and may cause problems for humans, plants, and animals.






PrOBleMS.....



Weather:-



1.Increased evaporation-As the climate grows warmer and the causes of global dimming are reduced, evaporation will increase due to warmer oceans. Because the world is a closed system this will cause heavier rainfall and more erosion and may lead to desertification due to deforestation.



2.Destabilization of local climates-the southern part of the Arctic region has experienced a temperature rise 1 °C to 3 °C (1.8 °F to 5.4 °F) over the last 50 years. Canada, Alaska and Russia are experiencing initial melting of permafrost. This may disrupt ecosystems and by increasing bacterial activity in the soil lead to these areas becoming carbon sources instead of carbon sinks.



Oceans:-



1.Sea level rise-With increasing average global temperature, the water in the oceans expands in volume, and additional water enters them which had previously been locked up on land in glaciers, for example, the Greenland and the Antarctic ice sheets. An increase of 1.5 to 4.5 °C is estimated to lead to an increase of 15 to 95 cm.



2.Temperature rise-The temperature of the Antarctic Southern Ocean rose by 0.17 °C between the 1950s and the 1980s, nearly twice the rate for the world's oceans as a whole. As well as effects on ecosystems (e.g. by melting sea ice, affecting algae that grow on its underside), warming could reduce the ocean's ability to absorb CO2.



Ecosystem:-



1.Forests-Forests in some regions potentially face an increased risk of forest fires. When there is more forest fires,the quantity of CO2 produced by fossil fuel combustion will increase.



2.Food Supply -The increase of temperature will cause a severe climate change whereby places that we use to grow crops will see a severe drought and cause a decrease in food supply. In some parts of the world, people may not have enough to eat because they cannot grow the food that they need.

RefLEct...

Therefore we should do something to make a difference even a single thing like recycling paper,switching off the lights.....and so on...

We hope that everyone will do their part and ANSWER THE CALL!