Societies are turning to algorithmic and computational models to tackle multiplying and intensifying ecological crises, from climate change to resource depletion and waste. The turn toward modeling aims to produce actionable knowledge at the limits of conventional epistemologies, scientific standards, and ethics. This chapter analyzes models that either gauge the thresholds of unsustainability (i.e., climate models) or prescribe pathways to sustainability (i.e., logistical models in support of the green economy). Through a discussion of proxies informed by STS and media theory, I explore the interplay of certainty/uncertainty in the modeling of socio-ecological realities that are prohibitory complex, unstable, and undecidable. My question is what kinds of political possibilities this interplay, and its engagement through global relations, open up, considered in terms of cosmopolitan and cosmopolitical dilemmas. A cosmopolitan lens highlights that modeling ecological crisis requires global coverage and involves collaboration at global scale. In turn, models enable a seemingly “total view” in support of collective intervention, much needed to safeguard human and nonhuman life. A cosmopolitical approach, however, considers the assumption of a single and common cosmos underpinning cosmopolitanism more often than not the problem rather than the remedy, and it points to the multiplicity of worldings underlying uncertainty. This chapter assesses and rethinks models as well as the engagement with the interplay of certainty/uncertainty by exploring paradoxical intersections of the cosmopolitan and cosmopolitical.