This paper is a synthesis of the key messages from the individual papers written by the Blue Planet Laureates, and discusses the current and projected state of the global and regional environment, and the implications for environmental, social and economic sustainability. It addresses the drivers for change, the implications for inaction, and what is needed to achieve economic development and growth among the poor, coupled with environmental and social sustainability, and the imperative of action now. The paper does not claim to comprehensively address all environment and development issues, but a sub-set that are deemed to be of particular importance.