Movie courtesy of the Changing Climates project at Colorado State University.

Greenhouse Effect Movie - Scott Denning

In this movie, Professor Scott Denning of the Atmospheric Science Department at Colorado State University explains how greenhouse gases in Earth's atmosphere warm our planet. In this lively, animated presentation, Professor Denning first explains how visible light (a form of electromagnetic radiation) from the Sun delivers energy to Earth. Next, he describes how some of this energy is trapped in Earth's atmosphere by the greenhouse effect, which warms our planet. Molecules of greenhouse gases, especially water vapor and carbon dioxide, "recycle" some of the heat energy which would otherwise escape from Earth in the form of infrared radiation.

Most of the gas molecules in our atmosphere are nitrogen (N2) and oxygen (O2). Each of these types of molecules has just two atoms. This means these molecules can only vibrate in one way, and therefore aren't very good at absorbing energy. Carbon dioxide (CO2) and water vapor (H2O) molecules, on the other hand, have three atoms per molecule... so they can vibrate in various different ways. This makes them better at absorbing energy from infrared radiation... which is why they are such effective greenhouse gases.

Adding extra carbon dioxide to Earth's atmosphere increases the temperature of the atmosphere. Humans have added lots of CO2 to the atmosphere, mostly by burning fossil fuels such as oil, coal, and natural gas. This extra CO2 enhances the greenhouse effect and is the main cause of global warming.

Right-click (Windows) or Option-click (Mac) here to download a copy of this video in QuickTime format.

Last modified January 29, 2010 by Randy Russell.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Earth's Greenhouse Gases

Less than 1% of the gases in Earth's atmosphere are called greenhouse gases. Even though they are not very abundant, these greenhouse gases have a major effect. Carbon dioxide (CO2), water vapor (H2O),...more

Earth's Greenhouse Effect

Energy from the Sun can enter the atmosphere, but not all of it can easily find its way out again. This is a natural process called the greenhouse effect. Without any greenhouse effect, Earth’s temperature...more

Electromagnetic Radiation

Electromagnetic radiation is the result of oscillating electric and magnetic fields. The wave of energy generated by such vibrations moves through space at the speed of light. And well it should... for...more

What Controls the Climate?

A factor that has an affect on climate is called a “forcing.” Some forcings, like volcanic eruptions and changes in the amount of solar energy, are natural. Others, like the addition of greenhouse gases...more

Carbon Dioxide - CO2

Carbon dioxide is a colorless and non-flammable gas at normal temperature and pressure. Although much less abundant than nitrogen and oxygen in Earth's atmosphere, carbon dioxide is an important constituent...more


Nitrogen is a chemical element with an atomic number of 7 (it has seven protons in its nucleus). Molecular nitrogen (N2) is a very common chemical compound in which two nitrogen atoms are tightly bound...more


Oxygen is a chemical element with an atomic number of 8 (it has eight protons in its nucleus). Oxygen forms a chemical compound (O2) of two atoms which is a colorless gas at normal temperatures and pressures....more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA