Answer:
Earth's axis is tilted relative to its orbital plane.
Earth orbits around the Sun, completing one orbit each year
Explanation:
The earth tilt at an angle causes the sun rays to hit the earth surface around the globe differently. Due to the oblique angle that the rays hit the subtropics and poles, there is less heat intensity compared to the equator where the sun rays hit the earth's surface at a more or less right angle.
The earth rotation around the sun also causes seasons coupled with the earth’s tilts. As the earth rotates, in one point in the orbit, the northern or southern hemispheres will be tilted towards the sun. The phenomenon varies the local temperatures of particular regions of the earth hence driving seasonal climatic changes.
