This chapter argues that to practise social work in the Anthropocene it is crucial to decentre the human. This decentring does not involve devaluing the human but embedding their experience in the non-human world. We begin with a discussion of the Anthropocene along with the ecological crises and the growth in population, production and consumption as issues that underpin it. We highlight the importance of moving from anthropocentrism to Gaia in the way we understand the relationship between the human and the non-human world. This shift will enable social workers to rethink the social, the community and human rights in more ecocentric ways and will have implications in the ways social workers engage in activism and practice to affect social change.

The discovery of dark matter in galaxies marks a turning point in astrophysics

especially because of its conceptual relevance to cosmology. After a brief introduction to the dynamics of collisionless stellar systems, a short account is given of the study of dark halos in ellipticals. Then it is shown that the dark matter contained in galaxies does not change the value of the key cosmological parameters significantly. The text continues with an outline of some modern simulations of structure formation, a vast and fast-evolving field of research that ultimately focuses on the issues that define the formation and the evolution of galaxies and on the structure of dark halos. Then, at the forefront of current research, for the nearby and present universe the potential of modern telescopes such as Gaia is briefly recalled; for the distant and early universe, a short summary is given of the role of gravitational lensing as diagnostics of dark matter for galaxies, clusters of galaxies, and structure formation. Finally, the main steps are outlined of an attempt (MOND), started in the early 1980s and still continuing with some success, which explores the possibility that the law of gravitation requires a modification on the scales of galaxies and beyond and that dark matter does not exist.

As I indicated in the Introduction, I will begin my tour of four select security referents at the macro level and work my way down. I will do so for four reasons. The first is to help shake off any lingering anthropocentric biases that might skew the analysis were we to work in the opposite direction. Human security, of course, naturally invites an anthropocentric treatment; culture as I shall be discussing it is also largely a human concern; and the state is a human creation. Were we to get into the habit of putting people at the centre of our analysis, we might do so too readily precisely where it would be least appropriate. The second is that ecospheric security will be the least familiar concept of the four and for that reason might risk coming across as an afterthought if I were to treat it last. Third, and relatedly, given the unfamiliar style of analysis to which I aim to subject these referents, I see advantages in giving it its first rigorous test in a context in which it is least likely to grate, hoping thereby to cultivate a degree of comfort with it once I turn to referents that we are used to analyzing in less unconventional ways. Fourth, and most importantly, I will argue that the ecosphere must take priority as a security referent, and accordingly must condition our understanding of the others. This argument would be more difficult to make were I to put various carts before the horse.

The correspondence commences in the summer of 1970, when a still untenured Margulis sends Lovelock a request for information along with offprints of her own work. The scientific collaboration of Lovelock and Margulis launched in earnest in January 1972, a year and a half after their first exchange of letters. The opening chapters of their correspondence document Margulis’s importance for both the construction and the communication of Gaian ideas. Their collaboration develops precisely as a writing partnership, with Margulis in the de facto role of in-house editor as well as co-author of their early papers. The letters exchanged in 1972 show them meticulously working through the host of technical matters intrinsic to their bold project until an initial manuscript is ready for submission. These early letters are also the most minutely specialized, as they are both still teaching the other what they need to learn in order to bring their respective specializations together.

The introduction offers an original discussion of the emergence of Gaia, informed by the extant literature while centered on the letters exchanged in their working relationship, drawing new connections and insights from these previously unpublished materials. It highlights a range of themes that animate their conversations and the history of Gaia as a scientific and philosophical idea. The introduction treats the first encounter of Lovelock and Margulis; their individual careers and professional personae; material and social aspects of their collaboration; questions of authorship; the range of scientific disciplines necessary to Gaia's elaboration; matters of geography and institutions; the significance of the occasional disagreements between Lovelock and Margulis over how best to characterize Gaia; Gaia's reception within different disciplinary and social contexts, including evolutionary biology, Earth sciences, systems sciences, exo- and astrobiology, and a range of political and environmental cultures. The introduction concludes with a chronological outline of the correspondence.

This piece takes the reader on a virtual trip through the Earth System, using visualisations as a key tool to understand our home planet and our evolving knowledge about it. It begins and ends with trips between the Earth’s surface and space, experiencing the Earth System from above. In between, however, we take an historical tour of the planet, tracking the evolution of humanity’s growing understanding of the Earth and how it functions as a system. The tour wanders through the evolving scientific landscape, beginning with the famous ‘Blue Marble’ image of Earth taken by the Apollo 11spacecraft in 1972, continuing with James Lovelock’s Gaia hypothesis and John Schellnhuber’s second Copernican revolution, and finishing with Paul Crutzen’s confronting assertion that the Earth System is now in the Anthropocene, leaving humanity’s comfort zone of the Holocene as a receding memory.

Busy with our own world, we often think that animals are just a part of it, minor players in the large, smart, progressive lives of humans. But if we flip the point of view, things change. What are the animals’ worlds that remain inaccessible to us? Be they wild or domestic, animals hold for themselves seething multitudes of points of view that work below the surface of our own ways of understanding them. An encounter with an animal is a moment in which we come to recognize that animals have lives beyond us. In this look from myriad nonhumans, we realize there are more points of view than our own, and that there are other ways of dwelling on earth that are just as important to these animals as ours are to us. This allows us to better consider the ecosystems of which they and we are a part and to change the narrative about how we live with other animals on this shared earth.

This overview of the book introduces the Human System as an open, historical, and adaptive system, formed 70,000 years ago by a founding human community as its members created syntactic language. The system grew to the point where it is now in trouble because of excessive growth and painful social inequality. Analysis relies on Darwinian assumptions of evolutionary growth – biological, cultural, and social – as these processes coevolve with each other and with Gaia, a model of the natural world of living things. The discipline of world history is introduced to provide the framework for the narrative and the underlying analysis: world history combines concepts, data, and perspectives from multiple disciplines in natural and social sciences. It gives special attention to behavior of human groups as well as individuals. The chapter concludes by reviewing the book’s argument, presenting two or three historical and analytical hypotheses for each chapter: these hypotheses are to be documented, tested, and debated in the details of each chapter.