The main idea of the International Research Training School NUPUS is to bring togetherresearchers and students from various disciplines in a common effort to study nonlinearities and scale issues related to porous media flow. The research efforts are do ne in projects directly funded by NUPUS or funded sperately, like the projects MatMoRA, VAMP, IGEMS, and SUCCESS on the Norwegian side. The International Research Training School NUPUS aims to improve "the qualification ofdoctoral researchers within th e framework of a focused research program and a structuredtraining strategy''. The Norwegian side of NUPUS, funded by this project, will facilitate exchanges, regular meetings, short courses, and conferences for students and researchers associated with N UPUS. As part of this the project group will organize the "2nd International Conference on Non-linearities and Upscaling in Porous Media''.The central research topics of the International Research Training School NUPUS arenon-linearities and upscaling of flow and transport processes in porousmedia. Non-linearities are particularly important for multiphase flow systems because ofthe strongly non-linear constitutive relations for basic hydraulic properties thatcharacterize the interaction between poro us media and fluids. Upscaling, on the otherhand, is a problem inherent to any modeling approach for porous media. Non-linearities and the need for effective upscaling methods are particulary evident in modeling and simulation of CO2-storage in the und erground, which is a main application area of the research in the NUPUS-program. This application area will also be a main focus of "2nd International Conference on Non-linearities and Upscaling in Porous Media''.