<p>Over the last several decades, complex systems have become the central scientific metaphor for multidisciplinary investigations of planetary processes. Though complex systems thinking offers useful affordances for modeling and understanding select dimensions of social-environmental change, its theoretical closure and totalizing ontology limit its ability to address the qualitatively distinct transformations occasioned by the Anthropocene or their meaning for more-than-human political communities. This paper examines the increasingly troubled scientific assumptions inherent to a complex systems approach to dynamic change, its distinct political and economic affordances for actionable knowledge, and the social validity of systems-based projections under conditions of accelerating uncertainty. What are the explanatory and predictive limits of the complex systems paradigm and are its affordances adequate for understanding unprecedented kinds of change? How does the nature of the complex systems paradigm itself limit and hinder the intellectual pursuit of complexity? Seeking an inclusive path forward, I resituate complex systems and their extended technoscientific networks within the more capacious framework of assemblage thinking, whose attention to the structuration of both matter and knowledge can help repurpose the products of Western technoscience towards emancipatory ends. Such an approach eschews reductionism, dualism, and instrumentality in favor of engaging planetary complexity on its own, more-than-human terms, with implications for how Western science can be employed towards socionatural adaptation.</p>