Abstract

The polar ice sheets hold one of Earth’s great sedimentary records. By drilling ice cores from Greenland and Antarctica, we can obtain ice that fell as snow, extending back so far 800,000 years in Antarctica and over 120,000 years in Greenland. Ice cores contain information about climate and numerous other environmental parameters; crucially the air bubbles trapped in the ice give access to the past composition of the atmosphere, including the greenhouse gas concentrations. In this talk I will first discuss the strengths and weaknesses of ice cores, and then demonstrate how ice cores are collected. I will then present a few examples of the knowledge we have gained from ice cores – about greenhouse gases, about glacial/interglacial cycles, and about rapid climate changes most likely induced by changes in ocean heat transport. A particular focus of the talk will be on interglacials: warm periods within the later part of the Quaternary. Are there rules that govern the timing of glacial terminations and inceptions, and the strength of interglacials such as the present one? Finally I will discuss prospects for obtaining even older ice in the future.