The environmental challenge has become over the last ten years more and more the main driver for future technologies and future aircraft architectures. The paper deals with the following topics: from local to global – anticipating the oil peak, another political and societal challenge – ACARE and environment – Clean Sky, a game-changing Public-Private Partnership – the numerous technical areas speeded up by the environmental challenge – Primes, Tiers One, Research Organisations, Universities, SMEs, are the Clean Sky Partners – the full set of demonstrators involving Clean sky Members and many Partners – Clean Sky will deliver main demonstrators from 2014 – the variety of means – Game-changing concepts will tackle further environmental challenges.