Without the greenhouse effect, the average temperature at the surface of the Earth would have been $ -18 \, ^\circ C $ rather than the present average of $ 15 \, ^\circ C $.

Which gases are commonly known as greenhouse gases?

What are the correct proportions of the two gases responsible for the greenhouse effect?

The given diagram represents the greenhouse effect.
$I.$ Greenhouse gases absorb infrared radiation from the earth. The absorbed radiations are again emitted towards the earth's surface,heating it up.
$II.$ $CO_{2}, CH_{4}, CFCs$ and $N_{2}O$ are the gases responsible for the greenhouse effect.
$III.$ An increase in the level of greenhouse gases results in considerable heating of the earth,leading to global warming.
Which of the statements given above are correct?

Which one of the following is $NOT$ caused by global warming?

Which gases are responsible for increasing the temperature of the atmosphere?