Electro magnetic radiation has a supreme control over the the earth's atmosphere system. Ozone layer protects our atmosphere from getting affected by the UV rays which is very harmful for living beings and environment. Reflection of light from object that is known as albedo is also a vital thing in controlling environmental heating phenomena.
Absorption and radiating back of sun's energy is also a phenomena that control earth's climatic pattern. Earht's climatic zone is divided on the basis of its receiving and absorption capacity of light, role of UV rays etc.