In order to highlight the urgent need for action, this memory first of all states: that of a planet on the brink of asphyxiation, whose annual resources were exhausted in 2016 as early as 8 August; whose biodiversity is so seriously threatened that experts speak of a “sixth extinction”; where human activity has, for the first time from the dawn of humanity, changed the climate to threaten its own survival. The causes stem from the shift made by our western societies between the 17th and 19th centuries with the emergence of scientific thinking as the only legitimate one, that of materialism and the adoption of the paradigm of growth as a universal economic recipe. The financialisation of the economy and its global deregulation have accelerated the process in recent decades and have led, beyond environmental damage, to serious human inequalities leading to famines, exodes and wars. Metropolitan areas, the anchors of globalisation, are generally presented as the framed future of the majority of humanity. The massive migration to these major cities has caused, and continues to cause in developing countries, the de-structuring of the territory, the loss of autonomy, the widening of inequalities and social exclusion. While the “urban entrepreneurship” policy currently pursued by cities, which is meant to be “sustainable, excellent, green and smart”, has a rather virtuous profile, it remains ineffective in terms of local development and “sustainable development”. Moreover, it is rather a source of social inequality. Many thinkers, philosophers, urban planners, journalists, scientists, etc., but also citizens, are taking action to implement the transition, whether through their research, their thoughts or the active example of concrete solutions. The avenues they open show that there is a need to prepare for shocks in an emergency, with the difficulty of a huge denial of the situation, but that this remains possible. A major campaign for global and global awareness of the issues at stake, “conscientialisation”, can thus positively change the vision of the future and give everyone the opportunity to act; developing a positive vision based on successful initiatives will stimulate the actions that can save us. A new model of cities is emerging: for metropolitan areas, the only response is the decay, size and power, and at the same time, the restocking of rural areas and small towns that have been emptied of their populations. The truly smart city is the one that is already preparing to transform itself into one or more self-managed organic regions (according to Alberto Magnaghi’s vision), based on ecology, food and energy autonomy, with the development of a collaborative and alternative economy decoupled from profit.