ABSTRACT
From the descriptions given in the previous chapter, it is clear that the Earth’s climate system must have behaved differently during the last glacial episode (and for that matter during all previous glacials) to how it behaves during the interglacial conditions we enjoy today. The fact that both interglacial and glacial conditions persisted for thousands of years suggests not only that the climate system can exist in at least two equilibrium states, but also that one or more factors may have caused it to change states. That it did not experience runaway cooling or warming indicates that feedback mechanisms must operate to limit the amount of change.
