Bill Nye explains that thermohaline currents are created by warm and salty water sinking and rising in the ocean. Water with a higher concentration of salt is more dense and thus sinks into the ocean.
This clip illustrates ocean currents and the factors that affect them. It mentions that there are both surface currents and deep sea currents, which make up 90% of the ocean's water. It also explains how the Earth's rotation causes phenomena such as the Coriolis Effect.
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 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.