Carter retired from James Cook University in 2002, maintaining the status of "adjunct professor" until January 2013, when Carter's position of adjunct professor was not renewed. He maintained an association with several think tanks that disagree with some aspects of the scientific consensus on climate change. He was a founding member of the New Zealand Climate Science Coalition, an emeritus fellow and science policy advisor at the Institute of Public Affairs, a science advisor at the Science and Public Policy Institute, and the chief science advisor for the International Climate Science Coalition (ICSC).