Explanation : 

The Earth’s atmosphere plays a crucial role in regulating the planet’s temperature, making it hospitable for life. This regulation is primarily achieved through the natural greenhouse effect.

I. Without the atmosphere, temperature would be well below freezing point everywhere on the Earth’s surface.

This statement is true. Scientific calculations indicate that without the Earth’s atmosphere and the natural greenhouse effect, the planet’s average surface temperature would be significantly colder, approximately -18°C to -20°C. This temperature is well below the freezing point of water (0°C), implying that water on Earth would largely exist in a frozen state.

II. Heat absorbed and trapped by the atmosphere maintains our planet’s average temperature.

This statement is also correct. The atmosphere, through the greenhouse effect, absorbs and traps heat, preventing it from escaping directly into space. This process maintains Earth’s average surface temperature at approximately 15°C, which is conducive to life. The atmosphere acts as an insulating layer, akin to a “cozy blanket,” regulating the planet’s thermal balance.

III. Atmosphere’s gases, like carbon dioxide, are particularly good at absorbing and trapping radiation.

This statement is correct. Certain gases in the atmosphere, known as greenhouse gases, are highly effective at absorbing and re-emitting longwave (infrared) radiation that is radiated from the Earth’s surface. Carbon dioxide (CO2) is a prominent example of such a gas, known for its ability to absorb infrared energy at specific wavelengths, thereby contributing significantly to the trapping of heat within the atmosphere. Other greenhouse gases include water vapor, methane, and nitrous oxide.

All three statements are correct. So, the final answer is I, II and III