1. When the Earth is closer to the sun it receives more heat than when it is further from the sun. But this orbital shape changes over time, affecting the Earth's overall climate situation. This variation is known as eccentricity and it changes over a period of about 100,000 years
2. The movement of the Earth around the Sun combined with the tilt of the Earth's axis causes weather, seasons and climate. The Sun causes weather patterns and the long-term average of weather patterns creates climatic zones around the world. The combined average regional climates create the Earth's climate.