The concept of 'environmental carrying capacity' has long been central to ecological studies, yet its application to human societies remains contentious. While biologists define carrying capacity as the maximum population size an ecosystem can sustain indefinitely, human systems introduce complexities such as technological innovation, trade, and cultural values. A recent study by Zhang et al. (2023) argues that static models of carrying capacity fail to account for adaptive behaviors, suggesting that societies can temporarily exceed ecological limits through resource substitution. However, critics contend that such flexibility undermines long-term sustainability, as it masks cumulative environmental degradation. This debate highlights a fundamental tension between optimistic views of human ingenuity and pessimistic assessments of ecological limits.