Question

write the main three causes of global warming .

Answer 1

11. Ozone Depletion

ozone depletion

Increase in ozone levels in the stratosphere over Antarctica, are the result of complex chemical processes. The return of the Sun at the end of winter triggers photochemical reactions that lead to the destruction of ozone in the stratosphere. As reported Over the Arctic the gradual development of an annual decline during the 1990s, has been observed. The Protection of the Ozone Layer amendments has been issued to eliminate certain CFCs from industrial production, the substantial destruction of ozone in the stratosphere over Antarctica, has not seen any improvement till date.

10. Deforestation

deforestation

The use of forests for fuel (both wood, for charcoal and other necessary lifestyle products) is one cause of deforestation. In order satiate ourselves, for wood and other products, mainly habitat and to build farms we are chopping forests which is not a good sign and has also leads to decrease in rainfalls. Forests are very human friendly, they clean the air as they act as natural filters remove and store carbon dioxide from the atmosphere, and this deforestation releases large amounts of carbon, as well as reducing the amount of carbon gas capture on the earth.

9. Methane and Nitrous oxide emissions from agriculture, Arctic sea beds and factories

methane gas

Methane is one of the greenhouse gases, which causes global warming. When organic matter is broken down by bacteria under oxygen-starved conditions as in agricultural fields, methane is produced. The process also takes place in the intestines of herbivorous animals, and with the increase in the amount of concentrated livestock production, the levels of methane released into the atmosphere is increasing. Another source of methane is methane clathrate, a compound in large amounts of methane trapped in the crystal structure of ice. As methane escapes from the Arctic seabed, the rate of global warming increases, accordingly.

8. Aerosols present in the Atmosphere

aerosols

Atmospheric aerosols is able to alter the climate in two important ways.

They scatter and absorb solar and infra-red radiation

They may change the micro-physical and chemical properties of clouds and possibly their lifetime and extent.

This can be explained as, scattering of solar radiation acts to cool the planet, while the absorption of solar radiation by aerosols warms the air directly instead of absorption of sunlight from the surface of the Earth.

The human contribution to the amount of aerosols in the atmosphere takes many forms, such as:

Biomass burning produces a combination of organic droplets.

Exhaust emissions from transport generate pollutants that are either aerosols from the outset, or are converted by chemical reactions in the atmosphere to form aerosols.

The concentrations of condensation nuclei are about three times higher in the Northern Hemisphere than in the Southern Hemisphere. This higher concentration is estimated to result in radiation forcing that is only about 50 percent higher in the Northern Hemisphere as reported.

Answer 2

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Three causes of global warming are :

1. It is caused by burning fossil fuels.As the vehicles which move on road burn fossil fuels , it produces pollution and hence lead to global warming.

2. Deforestation : It is one of the most important points to be noted . Deforestation means cutting down of trees excessively . And it reduces the oxygen in our surroundings and leads to global warming

3 Farming : Using pesticides and fertilizers lead to global warming