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Greenhouse gases are the gases that absorb the infrared radiations and create a greenhouse effect. For eg., carbondioxide and chlorofluorocarbons.”

Causes are:-

Global Warming

It is the phenomenon of a gradual increase in the average temperature of the Earth’s atmosphere. The main cause for this environmental issue is the increased volumes of greenhouse gases such as carbon dioxide and methane released by the burning of fossil fuels, emissions from the vehicles, industries and other human activities.

Depletion of Ozone Layer

Ozone Layer protects the earth from harmful ultraviolet rays from the sun. It is found in the upper regions of the stratosphere. The depletion of the ozone layer results in the entry of the harmful UV rays to the earth’s surface that might lead to skin cancer and can also change the climate drastically.

The major cause of this phenomenon is the accumulation of natural greenhouse gases including chlorofluorocarbons, carbon dioxide, methane, etc.

Smog and Air Pollution

Smog is formed by the combination of smoke and fog. It can be caused both by natural means and man-made activities.

In general, smog is generally formed by the accumulation of more greenhouse gases including nitrogen and sulfur oxides. The major contributors to the formation of smog are automobile and industrial emissions, agricultural fires, natural forest fires and the reaction of these chemicals among themselves.

Acidification of Water Bodies

Increase in the total amount of greenhouse gases in the air has turned most of the world’s water bodies acidic. The greenhouse gases mix with the rainwater and fall as acid rain. This leads to the acidification of water bodies.

Also, the rainwater carries the contaminants along with it and falls into the river, streams and lakes thereby causing their acidification.

Runaway Greenhouse Effect

This phenomenon occurs when the planet absorbs more radiation than it can radiate back. Thus, the heat lost from the earth’s surface is less and the temperature of the planet keeps rising. Scientists believe that this phenomenon took place on the surface of Venus billions of years ago.

This phenomenon is believed to have occurred in the following manner:

A runaway greenhouse effect arises when the temperature of a planet rises to a level of the boiling point of water. As a result, all the water from the oceans converts into water vapour, which traps more heat coming from the sun and further increases the planet’s temperature. This eventually accelerates the greenhouse effect. This is also called the “positive feedback loop”.

There is another scenario giving way to the runaway greenhouse effect. Suppose the temperature rise due to the above causes reaches such a high level that the chemical reactions begin to occur. These chemical reactions drive carbon dioxide from the rocks into the atmosphere. This would heat the surface of the planet which would further accelerate the transfer of carbon dioxide from the rocks to the atmosphere, giving rise to the runaway greenhouse effect.

In simple words, increasing the greenhouse effect gives rise to a runaway greenhouse effect which would increase the temperature of the earth to such an extent that no life will exist in the near future.

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It is a battle fought between the East India Company force headed by Robert Clive and Siraj-Ud-Daulah (Nawab of Bengal). The rampant misuse by EIC officials of trade privileges infuriated Siraj. The continuing misconduct by EIC against Siraj-Ud-Daulah led to the battle of Plassey in 1757.

Causes are:-

• The rampant misuse of the trade privileges given to the British by the Nawab of Bengal
• Non-payment of tax and duty by the workers of the British East India Company

Other reasons that supported the coming of this battle were:

• Fortification of Calcutta by the British without the Nawab’s permission
• Misleading Nawab on various fronts by British
• An asylum was provided to Nawab’s enemy Krishna Das