Bill Nye is obssessed with erosion and explains that rocks change over time. He explains what causes weathering (although he calls it erosion): water, ice, wind, sand, and chemicals. He illustrates the process of erosion in his lab.
Bill explains how the ocean affects climates in different parts of the world. He mentions the Gulf Stream and how it keeps Britain much warmer it would be otherwise. He also explains El Nino and how it affects the climate of the Americas.
Bill explains how we measure time and mentions some of the tools we use to measure it. He notes that time measurements, such as days, months, and years, are based on astronomical events and uses a motion machine to illustrate the Earth's revolution around the Sun and the Moon's revolution around the Earth.
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.