Long-term climate evolution based on ice core records

The observed climate variability at the time scales of glacial-interglacial cycles and at the millennial ones are here summarized using water isotope records obtained from deep ice cores drilled in the Antarctic continent. The use of oxygen (and/or hydrogen) isotopic composition as a temperature proxy, as well as the different climatic and postdepositional factors impacting on it, is briefly introduced. So far only two ice cores, EPICA Dome C and Dome F, extend back in time; Dome C for 800,000 years and Dome F for 720,000 years. Both isotopic records show a change in the glacial-interglacial amplitude around 450,000 years before present, the so-called Mid-Brunhes event, with a lower interglacial intensity before this event, also shown in the CO2 records. This shows a strong association between temperature and atmospheric CO2 content.