In the early 2000s, as a result of the thinking of Jean-Pierre Dupuy, we were surprised to not believe what we knew. The third and then fourth IPCC reports then enabled us to realize the existence of a major climate risk and thus the need to reduce our greenhouse gas emissions upstream. We didn't do anything about it. Based on solid knowledge, produced and evaluated on an international scale, we refused to take any fundamental steps. We didn't believe what we knew. We had the opportunity to foresee, we didn't foresee anything. Global emissions continued to rise yesterday and today. In defense of the past, we can argue that these findings were abstract, that nothing or very few things indicated to our senses the climate disruption that scientists pointed out. After twenty years, the situation has changed. Since 2018, climate change has been forcing itself on our senses and becoming obvious. Have we decided to act? No, or very little. Worse, the refusal to believe what we knew has been replaced by a refusal to recognize what we feel, denial, or a stated desire to do nothing! According to a study of perceptions of climate change in 30 countries published by Obs'COP in 2023, the proportion of the population that acknowledges anthropogenic causality is decreasing (just under two-thirds), while that which denies it is increasing. disruptions (slightly less than 10 %) and that which denies any human responsibility (less than a third). (Dominique Bourg, philosopher, honorary professor at the University of Lausanne)