On average, would Earth be warmer or cooler without the atmosphere? Explain your answer.

The atmosphere is responsible for maintaining the temperature of the Earth. There are some gases present in the atmosphere known as greenhouse gases. These gases are transparent to solar radiation. So, the radiation from the sun will reach the earth.

When the earth gets heated by this radiation, it will emit infrared radiation. The greenhouse gases will trap this radiation and it will re-emit this to the earth. As a result, it contributes to global warming.

In the absence of an atmosphere, the radiation reaching the earth will heat up the ground and then get back into space. Heat will be transferred into the space. Because the radiation is not trapped anywhere. So, the temperature of the earth will decrease, and the earth will become cooler.

As a result of the absence of greenhouse gases, the earth becomes cooler without the atmosphere.