The field is vibrant, the use of the models in policymaking has been rapid and influential, and the development and use of the models under the scrutiny of critics is strong and on-going. As it becomes clearer that carbon pricing must be a large part of the solution to reducing greenhouse gas emissions, the importance and influence of IAMs can only continue to increase. IAMs are the best tools we have for honestly translating the current knowledge about climate change, including its profound uncertainty, into policy advice. There are three prominent IAMs of climate change. The Dynamic Integrated Climate-Economy (DICE) model developed by Bill Nordhaus at Yale University, USA. The Policy Analysis of the Greenhouse Effect (PAGE) model, developed by me, Chris Hope, at the University of Cambridge, UK. The Climate Framework for Uncertainty, Negotiation and Distribution (FUND) model, developed by Richard Tol, now of Sussex University, UK. The vast majority of the independent impact and SCCO2 estimates that appear in the peer-reviewed literature are derived from these three models. Their origins, influence, and shortcomings are discussed.