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Tuesday, March 8, 2011

Global Warming...

What is Global warming...???


Global warming is nothing but increase in the average temperature of Earth's near surface air and oceans.
According to the 2007 fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 20th century.
Most of the observed temperature increase since the middle of the 20th century has been caused by increasing concentrations of greenhouse gases, which result from human activity such as the burning of fossil fuel and deforestation. Global dimming, a phenomenon of increasing concentrations of man-made atmospheric aerosols, which affect cloud properties and block sunlight from reaching the surface, has partially countered the effects of warming induced by greenhouse gases.

Global Warming Causes...

As said, the major cause of global warming is the emission of green house gases like carbon dioxide, methane, nitrous oxide etc into the atmosphere.
The major source of carbon dioxide is the power plants. These power plants emit large amounts of carbon dioxide produced from burning of fossil fuels for the purpose of electricity generation. About twenty percent of carbon dioxide emitted in the atmosphere comes from burning of gasoline in the engines of the vehicles. This is true for most of the developed countries. Buildings, both commercial and residential represent a larger source of global warming pollution than cars and trucks.
Building of these structures require a lot of fuel to be burnt which emits a large amount of carbon dioxide in the atmosphere. Methane is more than 20 times as effectual as CO2 at entrapping heat in the atmosphere.
Methane is obtained from resources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel manufacture. When fields are flooded, anaerobic situation build up and the organic matter in the soil decays, releasing methane to the atmosphere.
The main sources of nitrous oxide include nylon and nitric acid production, cars with catalytic converters, the use of fertilizers in agriculture and the burning of organic matter.
Another cause of global warming is deforestation that is caused by cutting and burning of forests for the purpose of residence and industrialization.
Anual Green House Gas Emissions By Sector...



What is 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, energy is transferred to the surface and the lower atmosphere. As a result, the temperature there is higher than it would be if direct heating by solar radiation were the only warming mechanism.
The greenhouse effect was discovered by Joseph Fourier in 1824, first reliably experimented on by John Tyndall in 1858, and first reported quantitatively by Svante Arrhenius in 1896


Basic Mechanism.:
The Earth receives energy from the Sun in the form UV, visible, and near IR radiation, most of which passes through the atmosphere without being absorbed.
Of the total amount of energy available at the top of the atmosphere (TOA), about 50% is absorbed at the Earth's surface. Because it is warm, the surface radiates far IR thermal radiation that consists of wavelengths that are predominantly much longer than the wavelengths that were absorbed.
 
Most of this thermal radiation is absorbed by the atmosphere and re-radiated both upwards and downwards; that radiated downwards is absorbed by the Earth's surface. This trapping of long-wavelength thermal radiation leads to a higher equilibrium temperature than if the atmosphere were absent.
 
Greenhouse gases:
 
By their percentage contribution to the greenhouse effect on Earth the four major gases are
 
water vapor 36–70%
carbon dioxide 9–26%
methane 4–9%
ozone 3–7%
 
Our Contribution To Reduce Global Warming...:
 
Educate yourself about global warming:
Recycle more by using recycling bins, composting, etc.
Buy locally made and locally grown products:
Buy minimally packaged goods:
Insulate anything that uses energy to stay a different temperature from its environment.
Replace old appliances and reduce reliance on them.
Unplug unused electronics.
Grow fast growing plants.
Use public transportation.
Ride a bicycle.
Use Refills.

What You Can Do To Prevent Global Warming:

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