Global warming is the increase in temperature of earth due to greenhouse gases like carbon dioxide CO2 which causes nine to 26 percent of greenhouse effect, water vapors has 36 to 70 percent and methane CH4 has four to nine percent. These gases are useful up to a limit to make planet habitable but excess of these gases cause harm to ozone layer and earth.
There are many causes of global warming
A huge amount of carbon dioxide is released from these power plants by the burning of fossil fuels to generate electricity. Coal is the major fuel used for this purpose and it produces eight percent of more carbon per unit of energy than the natural gas.
Nearly 20 percent of the carbon dioxide gets accumulated in the atmosphere by the burning of gasoline in the engine of vehicles. Some vehicles which are made for rough terrain gives out more carbon dioxide if it is used on the simple roads. So it is better to drive simple vehicles on the city roads.
Industrial revolution has increased the concentration of carbon dioxide, methane, tropospheric ozone, CFCâ€™s and nitrous oxide. 31% of carbon dioxide and 149 % of methane has increased after the industrial revolution started in mid of 1700â€™s
After the carbon dioxide methane is the second gas responsible for global warming and it is 20 times more active for trapping heat than CO2. It is released from bovine flatulence, rice paddies, fossil fuel manufacture etc. rice is grown in flooded fields and they destroy organic matter of the soil giving out methane.
Formation of nitrous oxide is mainly from the production of nylon and nitric acid which is used in fertilizers, production of cars with catalytic converters. It has been estimated that nitrous oxide contributing much in global warming in the recent decades.
Trees absorb carbon dioxide that we exhale and released from various other sources. So if we cut more trees more carbon dioxide will accumulate in the atmosphere. Deforestation is causing 25% of more carbon in the air because trees are cutting at 34 million acres per year.
Most common feedback is evaporation of water. Excess of CO2 in the atmosphere cause more water to evaporate. And vapors are also greenhouse gas. This cycle goes on. As a result more greenhouse effect than of the alone CO2. This can be reversed very slowly because CO2 can remain in the air for long time.
Another feedback effect is clouds. When we see it from below it gives out infrared radiation to the surface and when seen from above reflects sunlight and infrared radiation. So sometimes it gives cooling and sometimes warming effect depending on the altitude of cloud.
One more feedback process is ice-albedo feedback. With the increase in temperature ice on the Polar Regions melt and takes the form of water but water is not good reflective as that of ice. So much heat is captured in the planet.