The earth is covered by a combination of gases which exist in a fixed proportion. These gases are intact with the help of Earth’s gravity and the covering is often referred to as the atmosphere. The existence of atmosphere saves us from the temperature Earth could receive from the Sun. The greenhouse effect is the phenomenon which is used by the Earth to manage its temperatures.
Talking about the Greenhouse effect (this concept is also used in nurseries now), the atmosphere absorbs the temperature from the rays received from the Sun. Harmful UV rays are left in the space while the useful heat and rays are allowed to penetrate to the surface of the Earth. The rays which are passed to the surface are constantly reused by the atmosphere to maintain a temperature within the covering. Extra heat is emitted outside the gaseous covering of the Earth.
Apart from above property, atmosphere helps us with few other things as well. The radiations which are received from the Sun are not good for the life on the planet. Atmosphere saves us from these radiations by scattering it into small parts are spreading it across the globe. This minimizes its impact on the living beings and we don’t feel the radiations.
When we think of the scenario where we are removing the atmosphere the first thing we would lose is the oxygen. Oxygen is the source of life for all the organisms on the planet and with no oxygen, the living cells would start to die (even plants need oxygen). Carbon dioxide is also essential for plants which when removed would bring an end to photosynthesis.
Without the atmosphere, the temperature levels would start to increase on Earth. The UV rays would travel directly and the water bodies would start to evaporate. We would experience heat strokes when we would try to walk under the sun. There would chances of losing eyesight due to Ultraviolet radiations. Deep oceans would be the only safe place to live and organisms would survive a bit longer in the ocean bed.
It is also believed that circulation of heat which is presently done by the atmosphere would stop as well. Areas would have extreme climates (some would be always hot while others would remain extremely cold). It would be difficult to survive in these kinds of climates.
For now, this is a hypothetical situation however if we don’t stop cutting down trees or stop polluting our surroundings; we would soon see that the atmosphere would come to an imbalance and life in that state would be really difficult. It would be like living without atmosphere.