Why is it so cold in winter?

The surface temperature of the earth is mainly the radiation of the sun. The strong radiation (sunlight) from the sun to the earth is hot, and the weak radiation is cold. The earth moves around the sun in an oval shape, and winter is the perihelion, that is, the sun gives the earth weak radiation at this time, so the temperature of the earth is low. Because of the revolution of the earth, one side of our earth is facing away from the sun in winter, that is to say, the other side of the earth is facing away from the sun in summer. Our backs are to the sun, so it will be very cold. Although we can see the sun every day, the sun is not directed at us. Who scatters sunlight?