Claude Lorius recalls his career, beginning with his first visit to the Antarctic in 1957, at the time of the International Geophysical Year. The air bubbles imprisoned in the ice make it possible to reconstruct the chemical composition of the atmosphere in previous centuries and to reveal the relationship between greenhouse gases and temperature. The researchers go back in time through the use of deeper and deeper core samples. At Dome C, a depth of 1000 m has been reached, which makes it possible to go back 30,000 years. At the Russian station Vostok, a complete climate cycle (150,000 years) has been described, and the EPICA program goes even further back (450,000 years).