b. Emissions from the widespread burning of fossil fuels since the start of the Industrial Revolution have increased the concentration of greenhouse gases in the atmosphere. Because these gases can remain in the atmosphere for hundreds of years before being removed by natural processes, their warming influence is projected to persist into the next century.

Bell Telephone Science Hour produced this video in 1958, explaining how the production of CO2 from factories and automobiles is causing the atmosphere to warm, melting the polar ice caps, and causing the sea level to rise.

This animated visualization represents a time history of atmospheric carbon dioxide in parts per million (ppm) from 1979 to 2011, and then back in time to 800,000 years before the present.

This short cartoon video uses a simple baseball analogy (steroid use increases probability of hitting home runs) to explain how small increases in greenhouse gases can cause global temperature changes and increase the probability of extreme weather events.

In this activity, students explore the increase in atmospheric carbon dioxide over the past 40 years with an interactive online model. They use the model and observations to estimate present emission rates and emission growth rates. The model is then used to estimate future levels of carbon dioxide using different future emission scenarios. These different scenarios are then linked by students to climate model predictions also used by the Intergovernmental Panel on Climate Change.