In the current climate crisis, young people are portrayed paradoxically: victims and stakeholders, political protagonists and school truants. Based on ethnographic research with the climate movement, this article explores how youths manage their activism as it interfaces with their socialisation contexts, tracing prevalent adult antagonisms: radicalism, condescension and individualism. Drawing on sociological conceptualisations of climate precariousness and on an educational theorisation of subjectification, I argue that activists construct margins of resistance in their everyday political practices by incorporating processes that interrupt adult structures while reframing educational imagination. This highlights how the individual present is colonised by the risks posed to a collective future, leading adult power to be contested at a collective-public level (through performative reconfigurations of existing orders) and subverted at an individual-private level (by repurposing privileges towards climate struggle). Resistances to adultism uncover competing notions of future and education as integral to politicisation processes within the climate movement.