When Ernest Gellner began writing on nationalism, anthropogenic climate change had not yet been fully identified as a major global crisis and a threat to human survival. But by 1983, when his most famous and highly cited book ‘Nations and Nationalism’ appeared in print, the prospect of climate change was already being considered across a variety of scientific disciplines. This chapter begins with an observation: while Gellner emphasized industrialization and industrialism as the matrix of nationalism, he also fully identified the former with the beginning of the modern age—the industrial society that slowly replaced agricultural society as the inaugurator and hallmark of modernity. In Gellner’s theory industrialization and industrialism led to the expansion of nationalism. Yet, industrialization eventually brought about something more drastically life-changing than industrialism itself: an increasing reliance on fossil fuel consumption for economic growth, inaugurating what Andreas Malm defines as ‘fossil capitalism’. While for Gellner the rise of industrial society propelled the entrance into modernity, it simultaneously paved the way for a precipitous exit from it—even though we are only just beginning to be aware of the trend today after decades of interdisciplinary scientific research. The notion of the Anthropocene signals this radical historical shift, a highly traumatic transition that may be incomprehensible within the classical modernist Weltanschauung. This chapter seeks to answer two core existential questions. First, if the effects of the passage from agricultural to industrial society were so all- pervasive, which consequences can be envisaged in a forced exit from modernity due to its own short-circuit? Second, if industrial expansion has led to both nationalism and climate change, and their pairing has become particularly pernicious, how could a Gellnerian perspective enlighten us as we are being pushed arbitrarily towards a new time- frame, which might well turn out to be the shortest historical age ever. We have now entered an era of extreme uncertainty in which revolutionary, rather than radical, solutions are required. This chapter speculates on how Gellner might have responded to such an existential question, as we begin envisaging the utmost fringes of a self- destructive modernity devoid of all eschatological meanings. I will focus on two aspects of Gellner’s thought: the role of industrialism (and industrialization) and the critique of postmodernism. Of the two, the first is the most consequential in terms of creating a possible new theoretical approach for the upcoming times. —————————————————————————————————– CITE AS : Conversi, D., 2022. ‘Gellner in the Anthropocene: Modernity, Nationalism and Climate Change’. In P. Skalník (eds) Ernest Gellner’s Legacy and Social Theory Today. Cham: Springer International Publishing, 155-184.