In this article we build on recent ‘geo-’ themed work in human geography to move beyond the Earth and consider what our own planet shares with other astronomical bodies. Mobilising ideas from the planetary sciences, we sketch a speculative philosophy of planetary evolution in three steps. First, we develop an idea of ‘the planetary’ that sees planets as ongoing processes and sets of relations stretched over space and time. We then consider ‘the intraplanetary’: how planets develop internal self-difference and evolve their own unique identities. From there, we turn to ‘the multiplanetary’, exploring in the broadest way how planets might come to forge new kinds of interplanetary relations. We conclude by asking how the idea of a planetary becoming ‘without return’ might help us think more expansively about human interactions with other astronomical bodies – and with our home planet.

The cultural politics of climate change has always relied on images, most notably the "hockey stick" graphs of changing global temperature over the last thousand years (Schneider and Nocke 2014). Geoengineering—the proposed, deliberate, large-scale technological intervention into climate processes to counteract global warming—has also developed its own visual aesthetic. Geoengineering is climate promise, hope, absolution; but it is also the weirdest of technologies: one that takes the whole planet as its object, that is impossible to really test before deployment, and that would be wielded not from without but from within (Macnaghten and Szerszynski 2013). It is thus perhaps not surprising that proponents deploy schematic and cutaway graphics that in their very visual style seem to promise objectivity and feasibility (Schrickel 2014).But now we have this book from Design Earth, an architectural research practice founded in 2010 by Rania Ghosn and El Hadi Jazairy, associate professors of architecture at the Massachusetts Institute of Technology and the University of Michigan respectively. The Planet after Geoengineering was their contribution to the 2021 Venice Architecture Biennale How Will We Live Together, in the section called "As One Planet." The exhibited version took the form of a five-by-five array, in which each of five geoengineering scenarios was represented vertically in a column of five strata leading from the subterranean to outer space, with an accompanying animated version.This graphic novel version combines the familiar aesthetic of geoengineering diagrams with other visual styles, such as early modern engravings, to present their five imagined futures, each of which takes one present-day geoengineering proposal and leads it into often hallucinatory territory. The first, "Petrified Carbon," focuses on plans to extract carbon dioxide from the free atmosphere and sequester it in the deep ocean or in rock. By the end, Design Earth has led us into a fantastic underground city where the extracted carbon is used to make artificial diamonds, which become progressively brighter as atmospheric carbon dioxide rises and nitrogen impurities fall."Arctic Albedo" sees the arctic sown with glass seeds to reflect back sunlight and slow warming. But the thawing arctic becomes home to strange sights: giant globular artificial glaciers capture released methane and use it as a material for biotech; the tundra is rewilded as grassland, grazed by horses, bison, and biotechnologically resurrected mammoths; Indigenous peoples carry out controlled burning; and released methane powers a transmitter that creates a continuous shower of diamonds.In "Sky River," geoengineering is used to counter growing drought. Snow is melted and evaporated to create an aerial river of moist air, which is then tracked and seeded with silver iodide to fall as rain—but then the ensuing silver pollution kills fish. Conflicts over water proliferate—as do new religious myths and rituals to try to understand and control the changing patterns of rainfall."Sulfur Storm" explores a future in which dust is artificially injected into the atmosphere to reflect back sunlight. Atom bombs are used to trigger volcanic explosions; balloons, kites, drones, aircraft, and artillery are deployed to continuously emit sulfur dust into the air, with disastrous effects on the ozone layer and ground-level air quality. Those who can afford it live under domes, and excess sulfur dioxide is extracted from the air for industrial purposes.Finally, "Dust Cloud" imagines an artificial orbiting shell of ground asteroids and smashed artificial satellites; a space-based solar power plant also directs a beam onto the earth. The atmosphere is once again filled with dust, suffocating humans and other animals, and obscuring a starry sky now filled with new constellations depicting extinct animals.Then come three short but powerful pieces of commentary. Kathryn Yusoff situates the contemporary geoengineering imaginary in a longer historical context and rightly praises Design Earth for their contribution to stimulating a broader conversation about geoengineering, in which wider groups of people—and the arts and humanities—can engage in problem definition and the imagining of alternative futures. Importantly, she also suggests that geoengineering can play a useful role as a "provocation at the edges of political possibility."Holly Jean Buck also situates the geoengineering imaginary in the longer cultural politics of the twentieth century, suggesting that we need stories like those offered by Design Earth to make it tractable to the mind. Like Yusoff, she sees their five scenarios as usefully resisting the premature defaulting to conventional questions about feasibility and decision-making processes. She nicely glosses them as stories of caution, myth, conspiracy (and ambiguity), psychology, and terror—and suggests that perhaps the most dangerous thing about geoengineering is the way it is presented as a technical fix separable from the wider "everything-transformation" that the climate crisis demands.In his own essay, Benjamin Bratton contextualizes geoengineering in an even broader way, as a synecdoche for human intelligence in general. This "planetary sapience," he suggests, capable not just of remaking but also of comprehending the planet that gave rise to it, is of cosmic significance—but also ineradicably associated with risk, destructiveness, and the possibility of error, and thus capable of bringing about its own destruction. He takes the standpoint (familiar to sociologists of geoengineering cultures) of the "reluctant geoengineer," one who presents geoengineering as a possibly necessary lesser evil compared with unchecked climate change—but gives this a cosmic twist: if human civilization collapses, or humans even go extinct, planetary sapience is snuffed out, and it may never return. His bottom-line hope—and partial defense of geoengineering—is that if the future really is extinction, better that someone or something will know and remember it.Taken together, Design Earth, Yusoff, Buck, and Bratton present us with a rich set of narrative framings of geoengineering as a possible future—far richer than those control-based narratives favored by most proponents of the technologies (and, it might be argued, than those offered by most opponents). Design Earth has done something very valuable by producing stories "before geoengineering" that provoke such thoughts—five stories that might be told "after geoengineering," by distant-future beings we can only faintly imagine, about the crucial choices made by humanity in the midst of the climate chaos of the twenty-first century.

Concerns have been raised that a focus on greenhouse gas removals (GGR) in climate models, scientific literature and other media might deter measures to mitigate climate change through reduction of emissions at source – the phenomenon of ‘mitigation deterrence’. Given the urgent need for climate action, any delay in emissions reduction would be worrying. We convened nine deliberative workshops to expose stakeholders to futures scenarios involving mitigation deterrence. The workshops examined ways in which deterrence might arise, and how it could be minimized. The deliberation exposed social and cultural interactions that might otherwise remain hidden. The paper describes narratives and ideas discussed in the workshops regarding political and economic mechanisms through which mitigation deterrence might occur, the plausibility of such pathways, and measures recommended to reduce the risk of such occurrence. Mitigation deterrence is interpreted as an important example of the ‘attraction of delay’ in a setting in which there are many incentives for procrastination. While our stakeholders accepted the historic persistence of delay in mitigation, some struggled to accept that similar processes, involving GGRs, may be happening now. The paper therefore also reviews the claims made by participants about mitigation deterrence, identifying discursive strategies that advocates of carbon removal might deploy to deflect concerns about mitigation deterrence. We conclude that the problem of mitigation deterrence is significant, needs to be recognized in climate policy, and its mechanisms better understood. Based on stakeholder proposals we suggest ways of governing GGR which would maximize both GGR and carbon reduction through other means.

Over the last fifty to sixty years, a series of developments in the Earth sciences laid the groundwork for the theory of abrupt, planet-wide climate change and the more general idea of an Earth system capable of shifting between different operating states. In this context, from the 1960s onwards, a nascent 'planetary thinking' emerged in the work of certain late twentieth-century continental philosophers – including Serres, Morin, Lefebvre and Deleuze and Guattari. However, with its focus on mutual, co-constitutive relations between human and nonhuman actors, post-1980s more-than-human social thought tended to turn away from the larger geologic or planetary scales. After reviewing this 'retreat from the Earth', this chapter explores some new ways of negotiating between the idea of a dynamic, self-organising Earth and more intimate, place-based conceptions of the human. In particular, we look at the resonances and connections between the self-differentiating powers of our home planet and the difference and diversity characteristic of our own species. This brings us to a consideration of what thinking with and through the excessive forces of the Earth might mean for addressing questions of social injustice and epistemic violence.

Drawing on the work of Andrew Feenberg, Gilbert Simondon, Yuk Hui, Mary Helms and others, we develop a critical account of human 'technics'—understood broadly as the 'bringing forth' of the properties and potentialities of physical reality—as an enfolding of planetary and cosmic powers into the social world. We use the contemporary examples of synthetic chemicals and mineral extraction to explore how such a framing illuminates the dangers of modern technology in a new way. We then turn to the longer history of magico-mythical and ritualised ways in which human involvement in potentially dangerous technical activities has been understood and regulated. In the final section, we step back and consider the prospects for a new, 'spiritualised' or cosmological reimagining of technology in the contemporary world that draws on the insights of both western science and a-modern knowledge formations.

In our discussions around the theme of solid fluids, we often resort to everyday words, many of them of ancient derivation and rich in association. We have decided to make a list of some of the words that come up most often – barring those that already figure as the principal characters of individual contributions – and to distribute among ourselves the task of writing a sort of mini-biography for each. The resulting lexicon with 19 entries, ranging from ‘cloud’ and ‘concrete’ to ‘wave’ and ‘wood’, serves as a conclusion to the collection as a whole.

In this article we make a case for an understanding of human difference that attends to the way that social collectives engage with the Earth’s own capacity for self-differentiation. This draws us into conversation with recent interpretations of Hegel that see at the heart of his philosophy not a self-aggrandizing human agent set against a passive nature but an inherently fractured subject confronting a no-less intrinsically sundered outer reality. We use the example of traditional open-field cultural burning to show how skilled operators can painstakingly develop responses to ecoclimatic variability, putting this into dialogue with Hegel’s reflections on the ‘incendiarism’ of political revolution as a human expression of the wider self-antagonism of nature. We go on to make connections between Hegel’s account of the way that subjects can anticipate their own futurity and Indigenous conceptions of non-linear time, suggesting that the emergence of new earth-oriented practices can be seen as a complex interrelation of past, present and future. We close by suggesting that ‘progress’ for Hegel is not about the collective subject achieving omniscience and omnipotence, but involves the onerous and harrowing coming to terms with both its own divided identity and its exposure to a discordant external reality.

In this paper I try to identify a minimal definition of culture that might be applicable in the much-more-than-human realm that extends beyond organic matter and human involvement. I speculate that culture conceived in this broad way might be a metapattern or ‘machinic solution’ available to matter of diverse kinds, organic and inorganic. I explore how this idea might apply this to colloids – hybrid forms of matter such as sols, foams and gels that are mixtures of matter in different phase states, some continuous and some discontinuous, and which can behave in complex ways that mix features of solid and fluid behaviour. I conclude by suggesting that attending to both the similarities and differences between ‘culture’ in the organic and in the inorganic realms might force us to rethink our understanding of both.

Negative emissions techniques (NETs) promise to capture greenhouse gases from the atmosphere and sequester them. Since decarbonisation efforts have been slow, and the climate crisis is intensifying, it is increasingly likely that removing greenhouse gases from the atmosphere will be necessary to meet internationally-agreed targets. Yet there are fears that pursuing NETs might undermine other mitigation efforts, primarily the reduction (rather than removal) of greenhouse gas emissions. This paper discusses the risk of this phenomenon, named ‘mitigation deterrence’. Some of us have previously argued that a cultural political economy framework is needed for analysing NETs. Such a framework explains how promises of future NETs deployment, understood as defensive spatio-temporal fixes, are depoliticised and help defend an existing neoliberal political regime, and its inadequate climate policy. Thus they risk deterring necessary emissions reductions. Here we build on that framework, arguing that to understand such risks, we need to understand them as the result of historically situated, evolving, lived practices. We identify key contributing practices, focussing in particular but not exclusively on climate modelling, and discuss how they have been reproduced and co-evolved, here likened to having dug a hole for ourselves as a society. We argue that understanding and reducing deterrence risks requires phronetic knowledge practices, involving not just disembodied, dispassionate technoeconomic knowledge-making, but also strategic attention to political and normative issues, as well as emotional labour. Reflecting on life in the hole hurts.

This paper argues that an exploration of colloids can help us situate human social life within a wider understanding of the sociality and animacy of matter. Colloids are substances such as sols, foams, powders, gels, doughs and pastes that exhibit complex and shifting macroscale physical properties that do not conform to standard conceptions of solids, liquids or gases. Colloids can behave in complex and creative ways because of their topological enfolding of dispersed and continuous matter, in different phases, at a ‘mesoscale’ intermediate between the scale of molecules and that of the macroscale substance. I relate colloids, with their twin phenomena of ‘repetition’ and ‘mediation’, to an understanding of social life as reducible neither to the interaction between separate individuals nor to a transindividual whole. I suggest that human social life participates in a colloidal ‘metapattern’ of repetition and mediation that is manifest across diverse material substrates and spatial scales.

In this short response, we engage with four generous and stimulating commentaries on our Planetary Social Thought (2021). We endorse Cecilia Åsberg's suggestion that the boundary between the environmental humanities and social sciences is dissolving – but also call for more inventive relations between these disciplines and the natural sciences. We discuss László Cseke's account of the rise of factory-farmed ‘broiler’ chickens as a reversal of many of the achievements of the Earth over the last half-billion years. We agree with Franklin Ginn's suggestion that vegetality is a crucial vector of planetary self-exploration and invention – and one that can give us clues as to what life might become on other worlds. We reflect on Simon Dalby's observations about the lack of reference to planetary governance in the book, suggesting that we need a way of thinking about the politics of the Earth that goes beyond conflict and agonism – in Åsberg's words, that we need to learn not just to survive but to thrive.

Building on recent work identifying how the infrastructures of human social and economic life themselves depend on the "natural infrastructure" of biogeochemical systems, I explore the idea that infrastructuring - involving causal relations between subsystems operating at different timescales - might be a strategy widely adopted by matter undergoing self-organization under planetary conditions. I analyze the concept of infrastructure as it is used to describe features of the human "technosphere" and identify the importance of a difference in timescales between supporting and supported structures and processes. I explore some examples of how the wider planet might be said to engage in timescale-distancing and infrastructuring, focusing in particular on examples from the hydrosphere and biosphere. I then turn to the question of how to explain infrastructuring, developing a neocybernetic account of infrastructuring as involving the separation of a system into subsystems at different timescales in mutual but asymmetrical causal relations. I conclude by exploring the implications of this approach for the way we think about planets in general and the human technosphere.

In a reply to ‘Speculative Listening’ by Kaya Barry, Michele Lobo and Michelle Duffy, I defend representation as a resource for experimental and speculative practice, arguing that the loss of total immersion in the flux and becoming of the world that the representational engenders is a precondition for experimentation and speculation.

In this paper I make a case for a philosophy of continuous matter, in dialogue with object-oriented ontology. A continuous-matter philosophy is one that focuses not on the identity, properties, and relations of discrete, countable objects, but on the nature of extended substances, both in relation to human experience and in terms of their own “inner life.” I explore why and under what conditions humans might perceive the world as objects or as continuous substances, and the language that humans use for talking about both. I argue that approaching the world as continua requires the foregrounding of concepts that emphasize the immanent (internal to a region of space), the inclusive (with contrasting properties coexisting in the same substance), the gradual (manifesting differentially at different points), and the generative or virtual (involving the constant production of form and new gradients). I suggest that starting philosophy from continuous matter rather than objects also has wider implications for speculative thought

In this article I discuss three “Warnings to Humanity” about the state of the global environment, signed by global networks of scientists and published in 1992, 2017 and 2019. I place these in the context of the long practice in human culture of separating and relating different registers of time: the human time of communication and recollection, and ‘inhuman’ times such as the time of the gods, culture heroes, or latterly Earth history. I suggest that in the Anthropocene the ability of geological and meteorological tropes to control the semiotic relations between lived human time and deep, planetary time is being disrupted. I then use speech act theory to analyze how the language of the three “Warnings” works to position the scientist signatories as accredited “watchmen” monitoring the changing relations between human and Earth time, and wider humanity as exposed to knowing culpability in ongoing global environmental deterioration. I conclude by suggesting that the meshing of human and Earth time is stretching the representational capabilities of the natural sciences to breaking point, and that the environmental humanities should also play an important role.

In this chapter, as a demonstration of planetary mobilities as method, I take a paradigmatic transport vehicle – the bus – and ask seven geophilosophical questions about it as a mobile entity. I show how this exercise can help us to situate the bus in the long story of the Earth, and reveal our debt to the Earth as a storehouse of accumulated potentialities. I then show how dismantling the bus – removing the bodywork, the seats, the chassis and wheels, the fuel tank and engine – can suggest ways of moving together that are more generous to moving things and less damaging to the planetary commons.