The challenge from ice cores: understanding the climate and atmospheric composition of the late Quaternary

The Quaternary period is a critical one for understanding the working of the Earth System because it shows a wide range of climates under a geography similar to the present. Ice cores are an important palaeorecord because they record aspects of the atmosphere (including trace gas concentrations) rather directly. This paper takes advantage of recently published results from ice cores completed since an earlier ERCA chapter was published. These extend the ice core record from Antarctica back towards 800,000 years, confirming the close relationship between different parameters (particularly CO 2 and Antarctic temperature), but showing a different behaviour (with cooler interglacials) in the period preceding 450,000 years before present compared to the later period. New records of the last glacial cycle have documented the entire suite of rapid climate warmings (Dansgaard-Oeschger events) in this period, shown the behaviour of Antarctica during these events, and given us a first clear view of Greenland climate in the later parts of the last interglacial. Taken together these results present a compilation of the behaviour of the Earth that challenges palaeoclimatologists and Earth System modellers towards better understanding of the system.