The world of oils is becoming increasingly complex. Compared to a decade ago when there were very few types of oils, new technologies such as fracking have allowed around 300 new oils to come on-stream. Figuring out which oils are the most carbon intensive—depending also on how they are refined and used—has become very complex but also very important for investors and regulatory agencies. The Carnegie Endowment for International Peace, in conjunction with Stanford University and the University of Calgary, has developed a first-of-its-kind Oil-Climate Index (OCI) to compare these resources. Tom Carver sat down with Deborah Gordon, the head of Carnegie’s Energy and Climate program, to discuss the ways the OCI describes the new world of unconventional oils.