Abstract
The extent and mass of snow and ice (continental ice caps, sea ice, snow, mountain glaciers, frozen ground) is one of the main indicators of the state of the global climate system. The reason is obvious : their extent and mass are strongly dependent on climate. But because of their particular properties - notably their white color, which reflects most of the sun's rays - they also have a major influence on climate. Do they have the potential to amplify future climate change ? What's more, we often talk about their potential for abrupt and irreversible changes (" climate shifts "). What is really ? This seminar aims to clarify these issues.
