The heating that occurs when gases such as carbon dioxide trap heat escaping from the Earth and radiate it back to the surface; so-called because the gases are transparent to sunlight but not to heat and thus act like the glass in a greenhouse.
The overall warming of the earth’s lower atmosphere primarily due to carbon dioxide and water vapour which permit the sun’s rays to heat the earth, but then restrict some heat-energy from escaping back into space.
i) Carbon dioxide CO2
iii) Water Vapour
iv) Chloro Fluoro-Carbon (CFC)
v) Nitrous oxide
Mechanism OF Greenhouse Effects:
Our Earth receives most of its energy, called radiation, from the Sun.
This energy is electromagnetic radiation in the form of Visible light, with small amounts of Infrared (IR) and Ultraviolet (UV).
The incoming Visible solar energy has a very short wavelength and passes right through the atmosphere.
The Earth’s surface absorbs the solar energy and releases it back to the atmosphere as Infrared (IR) radiation, some of which goes right back into space.
But some of the IR radiation emitted by the Earth is absorbed by greenhouse gases in the atmosphere and sent back towards the Earth’s surface.
That warms the Earth’s surface. Three main gases in our atmosphere that contribute to the greenhouse effect are carbon dioxide, methane, and water.
These gases absorb the infrared radiation emitted by the Earth and re-radiate the energy as heat back towards the Earth, causing a warming known as the greenhouse effect.
The warming due to greenhouse gases is expected to increase as humans add more greenhouse gases to the atmosphere.
Sources Of Greenhouse Gases:
Carbon dioxide (CO2) is a colourless gas that’s a by-product of the combustion of organic matter. Today human activities are pumping huge amounts of CO2 into the atmosphere, resulting in an overall increase in carbon dioxide concentrations.
Methane occurs naturally when organic material decomposes. Man-made processes produce methane in several ways:
By extracting it from coal
From large herds of livestock (i.e., digestive gases)
From the bacteria in rice paddies
Decomposition of garbage in landfills
Importance Of Greenhouse Effect:
Following is the importance of greenhouse effect.
i) Without greenhouse effect, the Earth would not be warm enough for humans to live.
ii) Without greenhouse gases, heat would escape back into space and Earth’s average temperature would be about 600 F colder.
A gradual increase in the overall temperature of the earth’s atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants
Causes Of Global Warming:
The main causes of global warming, in order of the magnitude of their impact, are:
1. Carbon Dioxide from:
A. Fossil Fuel
C. Failing Sinks
2. Methane from:
A. Cattle and Rice Paddies
B. the Arctic Tundra
3. Nitrogen Oxides from Farming
4. Other Gases
Effects OF Global Warming:
When it comes to global warming, harmful effects like melting polar ice caps, weather changes, and an increase in diseases are changing the world and will ultimately affect your life. Below is the list of effects that global warming is having on environment, climate and human kind.
1. Melting of glaciers:
The melting of glaciers will create plethora of problems for human kind and the animals living in the earth. Due to increased global warming, the level of the sea will rise which will lead to flooding and this will in turn create havoc in human life. Apart from raising the sea levels, it will also endanger several species of animals and thus will hamper the balance of the ecosystem. Moreover these large glaciers reflect light back into the space and with meltdown of these glaciers, earth will be further warmed.
2. Climate Change:
Irregular weather patterns have already started showing results. Increased precipitation in the form of rain has already been noticed in polar and sub Polar Regions. More global warming will lead to more evaporation which will cause more rains. Animals and plants cannot easily adapt to increase rainfall. Plants may die due to it and animals may migrate to other areas, which can cause entire ecosystem out of balance.
Large scale evaporation will be the major cause of droughts in many places particularly Africa. Although, it is reeling under the huge pressure of water crisis, increased global warming would further make the situation worse and will cause malnutrition.
As the temperature becomes warmer, it will have an effect on the health of humans and the diseases they are exposed to. With the increase in the rainfall, water borne diseases are likely to spread specially malaria. The earth will become warmer and as a result heat waves are likely to increase that will cause a major blow to the people particularly in Europe.
5. Hurricanes frequency:
As the temperature of the oceans rises, hurricanes and other storms are likely to become stronger. With the increase in the global warming the water in the ocean warms up and it heats up the surrounding air, creating hurricanes. More water evaporation means more hurricanes.
Global warming will affect agriculture. Although the results are not visible yet, but it may show its colours in years to come. As the global temperature will increase plants will find it harder to survive and will die. Plants are the major source of food for human beings and as a result food shortage will occur. The shortage of the food may lead to war and conflicts in some countries.
Steps To Control Global Warming:
i) Use Public Transport:
ii) Use Renewable Energy Like Wind Power:
iii) Burn Methane:
iv) Use Smart Cooler, Heater & Air Conditioner
v) Tune up and maintain vehicles properly
vi) Reduce electricity usage to the maximum
vii) Prefer recycling
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