The word “Anthropocene” appeared for the first time in printed form in 2000. It was introduced by the Dutch chemist Paul Crutzen and the U.S. limnologist Eugene Stoermer in a two-page paper jointly published in the issue number 41 of the IGBP Newsletter. They coined the neologism to express the idea shared by both that we have already entered a new unprecedented age in which our species has become a major geological agent.
 Since then, a veritable explosion in the number of publications dedicated to the concept has occurred. Taking in consideration only the data provided by Web of Science, until 2010 around 100 books and papers were published about the Anthropocene, in 2015 that number increased eightfold, and in the last three years again this number has doubled, making a total that goes beyond 2000 publications in less than two decades.
 Another thing to be noticed is the broadening of the discussion of the concept from the Geosciences (aiming at its explanation, i.e., at finding out if there is enough reliable evidence available for its formal incorporation in the scientific discourse) to the Social Sciences (seeking its understanding, that is, the uncovering of the historical reasons that led to its emergence and what political, economic, social and cultural consequences derive from it) and to the Humanities (attempting at a critique of its theoretical and practical implications). This is giving rise to the formation of the multidisciplinary field of the Anthropocene studies.
 The Anthropocene did not go unnoticed to the philosophers too, leading them to inquire its ontological, epistemological, moral and aesthetic assumptions and implications. Moreover, because it seems to be provoking a deep transformation of Philosophy itself, a sense of urgency to think it through is now arising in the wider philosophical community.
 With the purpose of producing a relevant contribution to the ongoing debate on the theme, within the 9th Braga Meetings on Ethics and Political Philosophy (BMEPP 9), between June 11 and 12, a special session with the title “Philosophical challenges of the Anthropocene” was organized. This dossier includes a selection of the best papers, from more than two dozen, delivered during that event.
 The first is authored by one of the keynote speakers of the BMEPP 9, Professor Darrel Moellendorf (Goethe-Universität Frankfurt), and has the title “Three Interpretations of the Anthropocene: Hope and Anxiety at the End of Nature”. We are very grateful to Professor Moellendorf for having had the generosity to offer us his text for publication in this dossier.
 In his paper he argues that there are three plausible interpretations, or attempts to make sense of the Anthropocene as an ongoing process: the Promethean, generating great expectations about our capacities to manage the planet; the destructive, provoking considerable anxiety regarding our environmental-civilizational destiny; and the inegalitarian, raising growing concern about our collective coexistence. According to him, any of them is equally plausible, and it is quite difficult to predict which trajectory the Anthropocene will take in the future.
 The second contribution, from Cláudia Toriz Ramos (Fernando Pessoa University), entitled “Ecopolitics and global security: from discourse to policies”, shows, with great clarity, how the ecopolitical discourse has been crafted, assimilated to public policies, and ultimately contributed to the development of international and global security policies that pay increasing attention to environmental sustainability and security in contemporary times.
 Bernhard Sylla (University of Minho) in “Anti-dualism in the discourse on the Anthropocene” carried out a thorough analysis and criticism of the more or less widely adopted claim among scholars of the “three cultures”, Natural Sciences, Social Sciences and Humanities, that the recognition of the Anthropocene implies the obsolescence of philosophically entrenched dualisms, such as nature vs. culture, social system vs. ecological system, or subject vs. object, and the resulting need to overcome that way of thinking that is incapable of coping with the environmental challenges of today. Focusing on the criticism that Andrew Feenberg and Gernot Böhme addressed at Donna Haraway and Bruno Latour`s purported forms of anti-dualism, he argues that although valuable it is not sufficiently convincing.
 The last piece, “The cosmopolitan and environmental challenges of the idea of Europe in the age of the Antropocene”, penned by Bruno Rego (University of Minho), attempts a reassessment of the principles of classical contractualism and sketches a revamp of the idea of Europe for the 21st century in response to the problems triggered by the anthropogenic global environmental crisis. He also proposes that cities in the EU space can be thought of as cosmopolitan political agents and foster an effective socioecological contribution to the Anthropocene challenges.
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