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 video features a number of different climate scientists describing the effects of the increasing amount of carbon dioxide on global climate and proposing a series of solutions to mitigate these effects. Video addresses health problems and other costs to humans associated with climate change.

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.