In our emerging climate future, devastation will not land evenly. “Climate apartheid” names a world where the rich insulate themselves from its most catastrophic effects, while the global poor stand increasingly subject to rising seas, failing crops, intensifying weather events (floods, hurricanes, wildfires) and thus to the necessity of movement: some project a billion climate refugees by 2050. Yet analyses often fail to link climate apartheid to the existing systems mobilized to execute it—policing, prisons, borders—and so fail to connect climate (...) politics to enduring racialized projects of carceral control, as well as to Black, Native, and Latinx struggles against them. A key task is to develop capacious conceptual frameworks for understanding how religious actors are addressing the deep entanglements of political ecology and racial violence. This paper pursues that task in four parts. Part 1 introduces climate apartheid and proposes “cross-border solidarity” as an organizing concept for response, while underscoring that solidarity's chief virtue—its being already in use across diverse moral communities—is also what requires rigorous specification. What is the shape of “solidarity” amid climate futures? Parts 2 and 3 critique two frameworks ethicists might employ in facing that question: anthropocene discourse obscures race, while mestizaje discourse addresses race but risks reproducing its deepest logics. Part 4 proposes an alternative I will call cimarronaje. Of Taíno-Arawak and Spanish origin, the word refers to the historical experience, across slaveholding societies of the Americas, whereby enslaved African people fled plantations, escaped to surrounding hills and swamps, and reimagined forms of life with Indigenous communities, forged new ecologies together and, in the shadows of colonial empire, prefigured the theory and practices of cross-border solidarity we need today. (shrink)