Rapid Climate Variability: Description and Mechanisms

The previous chapters focused on climate variations stemming from factors external to the climate system: tectonics, orogeny, variations in insolation. Yet the study of glacial records and marine sediments over the past three decades has revealed major changes within the climate system over much shorter time scales than previously envisaged. These abrupt reorganisations of the climate system, which cannot be explained by forcings external to the system, are true climate ‘surprises’. In this chapter, we describe the expression of these events on a global scale and give examples of modelling studies which have helped understanding these events and their impacts.