Question

Greenhouse effect is due to
A. accumulation of O3 and depletion of CO2.
B. accumulation of both O3 and CO2.
C. accumulation of CO2 and depletion of O3.
D. presence of green plants on the earth.

Answer 1

The increase in the temperature of the earth from an optimum range to a level where it is dangerous for the environment is called the greenhouse effect.

Complete answer:
In simplest terms, greenhouse is the effect of warming of the earth due to rise in the environmental temperature. The water vapour, gases such as carbon dioxide, methane and certain other gases present in the air cause the solar energy to trap the earth and does not allow it to reflect back towards outer space. In normal sense, the sunlight which heats up the earth's surface is reflected back towards the space as infrared radiation. This process helps to protect the earth’s surface from overheating. The greenhouse effect occurs when the sun energy cannot be radiated back due to the water vapour and other gases that are present in the atmosphere and instead the sun energy causes to heat up the temperature of earth.

The most common types of greenhouse gases are carbon dioxide, methane, ozone and water vapours.

Ozone appears as a layer in the atmosphere which helps to prevent and absorb the harmful ultraviolet radiations from the sun and prevents it from reaching the surface of earth. Ozone is a molecular variation of the regular oxygen molecule. The ozone molecules have three oxygen atoms instead of 2. It is naturally present in the atmosphere. Due to various activities, ozone acts as a greenhouse gas near the surface of the earth as it is a constituent gas to cause smog. Due to the effect of the automobile emission, free ozone molecules can be created which can absorb the heat. It is also a chemical irritant. Ozone contributes to about 10% of the greenhouse gases causing warming of the atmosphere.

Carbon dioxide is one of the major types of greenhouse gases and it accounts for about 55% of all the greenhouse gases. Carbon dioxide is released during exhalation by living organisms as a waste product and it is taken up by the plants to perform photosynthesis. It is released into the atmosphere due to burning of fuels especially fossil fuels like coal and natural gases. It is the largest contributor to the greenhouse effect resulting in climatic changes.
Hence, the option(B) is the correct and appropriate answer.

Note: Greenhouse effect is the warming or increase in the temperature of the atmosphere of the earth and is caused due to absorption or trapping of the solar radiation. Many different types of gases are known to contribute to the greenhouse effect.