<p>Clear limits for cumulative effects are needed to safeguard the ecological structures, functions, and processes on which society depends in a rapidly changing world. However, ecological thresholds are difficult to discern and even more challenging to integrate meaningfully into cumulative effects assessments (CEA). It has been suggested that establishing a safe operating space for cumulative effects could move the dial forward in this respect. Yet, there remains little guidance on how to achieve this. Here, we propose a schema for measuring cumulative effects relative to a safe operating space grounded in ecological resilience. We then explore practical considerations for implementing this schema in CEA based on six attributes of a resilient ecosystem: diversity, connectivity, modularity, memory, openness, and feedbacks. We posit that a safe operating space may serve as a powerful tool to understand how our collective footprint may be undermining the ability of ecosystems to adapt and respond to future disturbances. By assessing cumulative effects against a safe operating space, society can better understand when systems are pushed to the edge of their safe zone and manage our interactions so as to avoid a catastrophic shift in the conditions needed for ecological and societal prosperity.</p>