This short video, is the fifth in the National Academies Climate Change, Lines of Evidence series. It focuses on greenhouse gases, climate forcing (natural and human-caused), and global energy balance.

This simulation allows the user to project CO2 sources and sinks by adjusting the points on a graph and then running the simulation to see projections for the impact on atmospheric CO2 and global temperatures.

For this lesson, the guiding Concept Question is: What is climate change and how does climate relate to greenhouse gas concentrations over time? This activity is the second lesson in a nine-lesson module 'Visualizing and Understanding the Science of Climate Change' produced by the International Year of Chemistry project (2011).

This video is narrated by climate scientist Richard Alley. It examines studies US Air Force conducted over 50 years ago on the warming effects of CO2 in the atmosphere and how that could impact missile warfare. The video then focuses on the Franz Josef glacier in New Zealand; the glacier is used to demonstrate a glacier's formation, depth of snow fall in the past, and understand atmospheric gases and composition during the last Ice Age. Supplemental resources are available through the website.