Question

If there was no atmosphere, the average temperature on earth surface would be: A) lower B) higher C) same D) ${0^ \circ }C$

Answer 1

Hint: The Greenhouse effect is defined as the process in which the gases surrounding the Earth’s atmosphere trap the sun’s heat.

Complete step-by-step answer:
Our atmosphere contains various greenhouse gases such as Carbon Dioxide, Methane, Water vapour, Ozone and Nitrous oxide. They trap the heat from escaping the surface of the Earth producing a Greenhouse effect. This keeps the Earth warm.
The greenhouse gases do this, by absorbing the radiation and emitting it back to the Earth’s surface in the infrared range of the spectrum.
In the absence of this atmosphere, there will be no mechanism to keep the heat trapped within and the temperature of the surface of the Earth will drop very drastically, and the Earth will, literally, freeze to a lump of ice.

So, the correct answer is option A

Note:
1) The proportion of the emission remaining in the atmosphere after a specific period of time is called "airborne fraction" . The annual airborne fraction is the ratio of the atmospheric increase in a given year to that year's total emissions.
2) The contribution of the greenhouse gases are not equal. Different greenhouse gases have different contributions to the combined effect. It is mainly dependent on the characteristic of the gas and its abundance in the atmosphere. For example, methane radiates 84 times more than that same volume of carbon dioxide can emit and since, the concentration of methane is very less in our atmosphere, so its contribution is very low. The highest contributors are Water Vapour and Carbon Dioxide.