Thomas Stocker first reviewed the pioneering role of Hans Oeschger and his group. Oeschger made major contributions to the understanding of climate processes. Stocker also pointed out the high international respect and quality of Swiss research. In the second part of the presentation Stocker focussed on the progress in understanding the abrupt climate changes of the past, the «Dansgaard-Oeschger events». He emphasized that changes in climate are not necessary incremental, but may well show abrupt and irreversible changes. Climate policy must consider these additional facts when taking precautionary measures. Chair of the meeting was G.-R. Plattner.