Regarding averting the 6th mass extinction event, which would be the first to be caused by another species, namely us, the work of Edward O. Wilson immediately comes to mind with his recent book entitled Half Earth which was published in 2016. One of the arguments put forward in the book is that if we managed to change our diet by reducing meat intake on a global scale we could potentially liberate enough land from agricultural production for ecosystem restoration to prevent the 6th mass extinction. Another argument put forward in the book is that if everyone put half of whatever land, roof-space, window box, allotment, balcony or garden into use for biodiversity conservation, there would be enough space for wildlife to continue to live alongside our species, in both rural and urban settings. In other words relevant to both sustainable diets and ecosystem services. The philosophical ideas of E.O. Wilson were first put forward in his book Biophilia which argues that all humans have an innate urge to identify with and to ultimately protect nature. He argues that therefore the door (to a sustainable society) is already half open, we only need to fully embrace this at philosophical, political, economic, and at local and international governance levels (e.g. through the education and planning systems). Another ecological philosopher you may be interested in looking up is Alan Rayner, an evolutionary mycological ecologist turned philosopher and (bio)artist. His idea of the philosophy of natural inclusion allows us to re-orientate our identities and relationships around and into symbiosis with nature. He has several books, one called Degrees of Freedom - living in Dynamic Boundaries is published by Imperial College Press. Chapter 8 of this book includes how human society, economically and politically, can learn from mycosophy so that a sustainable society might inevitably emerge. Another book of his is called Nature Scope - which develops Natural Inclusion into a formal body of philosophy and ethics around protecting nature. Another book called The Origins of Life Patterns, published by Springer develops these ideas further. A famous Canadian bio-ethicist is David Suzuki who has written many works including the book Genethics - the ethics of engineering life (relevant to the sustainable diets pathway). A further ethics for nature advocate is Joanna Macey in her many works including her book World As Lover, World as Self, published by Parallax Press, Berkeley, California. Another writer on these themes, particularly ethics regarding biodiversity conservation and agriculture is Vandana Shiva in her many works including the book Staying Alive - women, ecology and development, published by Zed books. There is also Stewart Brand's book Whole Earth Discipline - an eco-pragmatist manifesto, published by Atlantic Press, London. Of course, there is also the wonderful Lynn Margulis with her body of works on the endosymbiont theory, which embraces the symbiotic partnership of species as the main way in which evolution operates. Her works would fit well into thinking about ecosystem services, but could also link to sustainable food production regarding the design of agricultural systems that enhance the co-habitation (symbiosis) of species in benefitial partnerships such as is practiced in Permaculture (the agricultural system that uses ecological design principles to integrate biodiversity and food production). Permaculture uses 3 ethics that feed into its design principles; these being Earth Share, People Care and Fair Share. Lynn Margulis was married briefly to Carl Sagan who wrote the book Cosmos - the story of cosmic evolution, science and civilisation, published by Abacus. In the final chapter, like in the first book I mentioned above by Alan Rayner, he sets out how human society can emerge ethically to embrace a sustainable epoch. Happy reading!