The Earth Observatory needs your help to understand how climate may change as more and more carbon dioxide is added to the atmosphere. We’re concerned that as fossil fuel use and deforestation increase, regions around the world may experience severe changes in climate. Begin your investigation by viewing the first two movies: Radiation from Sun and Earth and Earth’s Energy Balance. Try practice questions 1 and 2 to see how much you know.
Name three differences between radiation from the Sun and radiation from the Earth.
Why doesn’t the Earth indefinitely heat up as it absorbs shortwave radiation from the Sun?
As you have just learned, the temperature of Earth has been relatively constant over time. You have also learned that this is possible because as the planet absorbs solar radiation, it also emits longwave radiation into space. Despite this radiative equilibrium, some longwave radiation remains trapped beneath the atmosphere of the Earth and warms the surface of the Earth. Watch the Greenhouse Effect movie to find out what causes this phenomenon.
How do carbon dioxide and water vapor prevent longwave radiation emitted by the surface of the Earth from escaping to space?
If all the molecules of carbon dioxide and water vapor were removed from the atmosphere, what do you think would happen to Earth’s surface temperature? Why?
If more molecules of carbon dioxide were added to the atmosphere, what do you think would happen to Earth’s surface temperature? Why?
You’ve now learned how shortwave radiation emitted by the sun and longwave radiation emitted by carbon dioxide and water vapor contribute to the heating of the Earth’s surface. Over the past 120 years, scientists have observed that the Earth’s average global surface temperature has increased. At the same time, the atmospheric concentration of carbon dioxide has also increased. Take a closer look at how these changes may have occurred by watching Human Activities and Carbon Dioxide, Modern Atmospheric Concentrations of Carbon Dioxide, and Modern Global Temperature.
Explain why the amount of carbon dioxide in the atmosphere has increased since the late 1800’s.
Describe how the global average temperature of Earth’s surface has changed over the past 100 years.
Scientists use computer climate models to help them understand how temperature in different regions of the world may change as carbon dioxide increases. Learn more about these tools by viewing the next movie, Computer Climate Models.
Describe how computer climate models help scientists understand how climate may change in the future.
Are computer models able to predict exact temperature values for the future? Why or why not?
Print out this page and answer these questions, or write your answers in complete sentences on your own sheet of paper.