Answer:
the Earth is tilted on its axis
the Earth is a sphere
different materials on Earth's surface absorb heat at different rates
Explanation:
The heating and cooling rates of land and water differ. This effects the heating of the earth according to these substances. Since the planet Earth is spherical in shape, the equator heats up more as compared to that of the polar regions. The differences in the seasons is because of the axis on which the Earth is tilted. Because of rotation, the heating and cooling of the Earth's surface differ. These are the reasons that are the reason for the uneven heating of the sun.