Aeromobilities—socio-technical systems that lock in dependence on fossil fuel-based mobilities—contribute substantially to climate change and uneven geographies. They represent paradigmatic capitalism-driven forms of metabolism, permeated by logics of efficiency and growth. While existing literature has examined resistance to airport expansion, it has overlooked opposition to the metabolic dimensions of aeromobility. Using an urban political ecology (UPE) lens, this paper explores resistance to aeromobility through the case of the Stay Grounded movement against the expansion of Barcelona airport. We analyse airport resistance as a critique of capitalism-driven metabolization of nature, emphasizing the interplay of material flows, territorial subjectivities and degrowth-inspired imaginaries in opposing aeromobilities and constructing alternative visions. Using semi-structured interviews and a review of activist materials, we illustrate how the Stay Grounded movement forged discoursive and strategic alliances that reterritorialized opposition to airport expansion by integrating critiques of carbon emissions with broader struggles over livelihoods and ecological preservation. We highlight how degrowth principles, combined with territorial and metabolic analyses, enabled resistance to transcend localized NIMBYism and articulate transformative visions of mobility and urban-nature relations. This article contributes to UPE scholarship by providing a critical example of infrastructure politics in the context of climate emergencies and degrowth debates.