On August 8 the second edition of the book 'The Three Levels of Sustainability' that I co-authored with George Curiel has been published by Routledge. 
In the book we cover how the concept of sustainability evolved at the level of societies and organisations from the 1970s until now. We also claim that to these two levels a third should be added: the level of individual human beings with their capacity to care for themselves, others, and the earth as a whole.
It might seem contra-intuitive to insist about the capacity of people to care for others and the earth when we are confronted with brute wars and the effect of climate change. 
Yet, as we show in the book, it is thanks to this capacity that people can take the lead and help developing a more sustainable society and organisations.
Curious? have a look at the book at https://www.routledge.com/The-Three-Levels-of-Sustainability/Cavagnaro-Curiel/p/book/9780367726256

Elena Cavagnaro