Time evolutions of the greenhouse effect gases concentration and the climate from the Vostok core

Polar ice and air bubbles trapped in it, attest climate history and the atmospheric composition of the Earth. The Vostok drill at the Russian station of Vostok on the Antarctic Plateau provides a more 400 000-year long record of these conditions. Through this time, climate in Antarctica oscillated between 4 glacials, for which surface temperatures were about 10 degreesC below modern ones, and 5 interglacial periods as the modern one. It is shown that greenhouse gases (CO2 and CH4) concentrations are higher during warm periods than cold ones. Scrutinising glacial to interglacial transitions shows that southern Hemisphere processes lead northern ones. Furthermore, sea level rise appears to lag variations of other variables. Finally, these records give evidence that CO2 and CH4 levels measured at present time, have never been reached during the late 420 000 years.