An interactive simulation of Earth's seasonal dynamics that includes the axial tilt and other aspects of Earth's annual cycle.

This is part of a larger lab from the University of Nebraska at Lincoln: http://astro.unl.edu/naap/motion1/motion1.html

This video succinctly explains the mechanism of the natural greenhouse effect and the cause of global climate change (anthropogenic global warming). It is short, basic, and to the point. It's also available in 12 languages!