This talk analyzes Japanese “Metabolist” architects’ use of plastics as building materials in relation to current debates on anthropogenic climate change. I take their architectural design of prefabricated “capsules” as a point of departure to analyze how their vision of recyclable capsules echoes the mid-century ecosystem analogy of “Spaceship Earth” that gained traction among economists, and scientists in Japan and North America in the late 1960s. Once imagined as the gigantic space capsule covered with its atmospheric shell, the Earth also emerged as an object of technological intervention, namely geoengineering. This imagination of the planetary capsule has recently returned with vigor amidst contemporary debates on the Anthropocene. In order to clarify the relevance of Metabolism to the current discourse on climate engineering, this chapter zooms in on the central metaphor of metabolism that Metabolist architects used as their group’s namesake, a metaphor which they borrowed from the work of Marx and Engels in order to highlight their ecological vision of capsules and megastructures as living organisms. Read alongside the recent Marxist ecological theory of the “metabolic rift” and debates on the Anthropocene, the ecological undertone of Metabolist architecture presents a dilemma of sustainability: they aspire to produce sustainable architecture, and yet their reliance on plastics and their petro-economic financing betray their aspiration at the material level. It is this paradox and its implications for the current discourse on geoengineering that this talk will explore. About the speaker Furuhata Yuriko is an Associate Professor at McGill University, Montreal, and has published widely in the field of Japanese film and media, and is author of Cinema of Actuality: Japanese Avant-Garde Filmmaking in the Season of Image Politics (Duke University Press, 2013) and the forthcoming Atmospheric Control: A Transpacific Genealogy of Climatic Media (2022).