[en] This contribution presents the IPCC, the Intergovernmental Panel on Climate Change. The author indicates the number of involved researchers, the work groups (climate changes, environmental and socio-economic consequences, adaptation and mitigation options), the number of published reports. The author addresses weather observations, their historical evolution, and the development of modelling studies (more than 40 3D models exist). He discusses information (sea temperature, average temperature, climate anomalies, sea level change, observed change in precipitation over land) which show that climate change is now unambiguous. Consequences are discussed in terms of temperature, of impact of CO₂ and greenhouse gases emissions, and the author discusses the issue of assessment of future risks related to temperature increase, sea level rise, evolution of precipitation, CO₂ emissions. Challenges concern housing location and construction, and researches on CO₂ capture and sequestration