Beakman explains that the seasons are created by the Earth's axis being tilted. He brings Capernicus in to explain more and then uses a model to show how depending on Earth's orbit and axis the amount of sun on a given portion will affect seasons.
Scrat places a nut on the ground, causing the Earth to split in half. He travels down the layers of the Earth and chases the nut on the Earth's core. This clip comically shows how the different continents and many of Earth's iconic structures formed.
Bill Nye explains why it gets colder as one travels up through the atmosphere. He uses miniature replicas of a city and a mountain to support his explanation. Bill also briefly touches upon the lapse rate.
Bill Nye explains what volcanoes are, how they're formed, and what causes an eruption. He then explains the impact of volcanoes on the earth's geography.