Tol and Fankhauser (1998) reviewed the modelling of impacts in 18 IAMs that participated in the Stanford Energy Modeling Forum 14, discussing the level of spatial detail, the damage categories considered, the impact metrics, the climatic and non-climatic drivers of impacts, the functional specification and benchmarks of monetized damage functions, the feedback of impacts on other model variables and the representation of adaptation. Yohe (1999) briefly reviewed the representation of impacts in 20 IAMs, including most of the models considered by Tol and Fankhauser (1998). Stanton, Ackerman and Kartha (2009) review 30 climate-economy models, focusing on the treatment of four critical issues.