This paper examines various aspects of moving from high carbon economies and societies to a cluster of low carbon systems. First, some historical material is considered from the Second World War and the 1970s, periods with some lessons for the contemporary 'powering down' of whole societies. Second, analysis is provided of some green shoots of a powering down of existing systems identifiable in the contemporary developed world. Third, analysis is provided of the array of systems, social practices and innovations that would have to develop in order to effect powering down on a sufficient scale and within an appropriate time period. Most examples are drawn from transport and mobility. Finally, the paper demonstrates just why developing new systems is so hard, especially as this must involve a transformed cluster of systems. The forces that make a new cluster unlikely are exceptionally powerful and make this a very difficult but not impossible outcome.