We explore the combined effects of a climate threshold (a potential ocean thermohaline circulation collapse), parameter uncertainty, and learning in an optimal economic growth model. Our analysis shows that significantly reducing carbon dioxide ðCO2Þ emissions may be justified to avoid or delay even small (and arguably realistic) damages from an uncertain and irreversible climate change—even wh...

Most accounts of thresholds between alternate regimes involve a single, dominant shift defined by one, often slowly changing variable in an ecosystem. This paper expands the focus to include similar dynamics in social and economic systems, in which multiple variables may act together in ways that produce interacting regime shifts in social-ecological systems. We use four different regions in th...