Key Series: To What Degree?

What is science telling us about climate change? Leading climate change experts discuss one of the most complex scientific puzzles to ever confront mankind.

The series contains over 70 videos in eight playlists covering issues including the history of climate change research, how we know about anthropogenic climate change, the carbon cycle, how climate modeling works, Earth's heat balance, the water cycle, the report of the Intergovernmental Panel on Climate Change, and what Americans believe about climate change. (For an introduction to the science of climate change, start with the "How Do We Know?" playlist.)

Each of these videos can be viewed individually, or in a playlist, from the links below.

Playlists: