Scholars recently called for increased analysis of opportunity structures that produce white-collar crimes in legitimate business systems. In the current research, we use mental models, a tool from cognitive psychology, to describe opportunity structures for white-collar crime in the European Emissions Trading System, the largest carbon market in the world. Specifically, we use routine activities theory to describe the convergence of motivated offenders and suitable targets in the absence of capable guardians in different parts of the system. Implications for utilizing routine activities theory to understand and address crime in carbon markets are discussed.