Abstract
Atmospheric water vapour is the first greenhouse gas and plays a major role in our climate and its changes. Indeed, because of the link between temperature and the capacity of air to contain water vapor, this gas amplifies by a factor of 2 to 3 the warming caused by greenhouse gases emitted by human activities. The seminar will describe the water cycle and its impact on the climate, and the importance of measurements and numerical modelling in improving our knowledge, weather forecasts and climate projections.
