The regular increase in greenhouse gases due to anthropogenic emissions in the atmosphere may have a major impact on the Earth's climate in the forthcoming decades. In order to reduce the uncertainties in forecasting climatic changes, it is necessary to better understand the processes involved in interactions between aerosols, clouds, radiation and atmospheric circulation. Such interactions are poorly represented by current numerical models and there is a need to quantify their role in phenomena involved in the evolution of the climate system.

Carbon dioxide uptake by the upper ocean and continental biosphere also constitutes a large element of uncertainty in climate models. Spaceborne sensors will play a key role in climate research by providing global, long term observations of parameters describing the state of the atmosphere and Earth surfaces.

POLDER acquired data will be processed in order to:

determine the physical and optical properties of aerosols so as to classify them and study their variability and cycle,
improve the climatological description of certain physical, optical and radiative properties of clouds,
precisely determine the influence of aerosols and clouds on the Earth's radiation budget,
quantify the role of photosynthesis from the continental biosphere and oceans in the global carbon cycle.