What causes the seasons and climate zones of the earth and why?
The Earth revolves around the Sun in 365.25 days, giving rise to differences in the levels of Solar radiation reaching the Earth at any point. Proximity of the Earth to the Sun gives rise to the season we call Summer. Seasons are inverted in the Southern hemisphere.
The Earth is an oblate spheroid (sphere flattened at the Poles) and as we move away from the Equator, it gets progressively colder, giving rise to climatic zones, from the torrid at the Equator, to the frigid at the Poles.