International audienceSolar spectral irradiance is an important driver for the Earth's atmosphere. The irradiance spectrum received by the Earth varies at all time scale and the amplitude of the (relative or absolute) depends strongly on the considered wavelengths. We will make a review of our current knowledge of solar irradiance variability based on observations, models and solar proxy, trying to identify points where no general agreement exists in the community. In more details, we will focus on the cycle and longer-term variations of the spectrum, based on the past and present observations and their agreement with models. We will also discuss the assumption behind the models and how proxy are used to estimate solar irradiance variations in the past. The research leading to these results has received funding from the European Community's Seventh Framework Program (FP7 2012) under grant agreement n • 313188 (SOLID
