Earth's climate is dominated by its shape (approximately a sphere), its orbit around the Sun, its albedo, and its rotation.
Since it's a rotating sphere with an axis inclined by about 23 degrees relative to its orbital path, it experiences a cycle of seasons with each orbit of the Sun.
The rotation allows relatively even heating by the Sun (alternating between day and night), permitting the existence of liquid water year-round. It also causes Coriolis forces to act on the wind, which dominate global weather patterns.
The Earth's albedo (the fraction of the Sun's light reflected back into space) controls its mean temperature. Increased levels of carbon dioxide in the atmosphere traps infrared radiation, raising the temperature. Increased levels of soot high in the atmosphere stop sunlight from hitting the ground, lowering the temperature.
