I’ve heard some people say they don’t understand how people can hold the view that climate change is not anthropogenic yet claim that climate change can be countered cheaply using geo-engineering, e.g., by injecting sulfur ((Why, IUPAC, why?)) into the atmosphere. The reason for their concern is that they think it’s logically inconsistent since the effects of geo-engineering techniques and anthropogenic climate change are predicted by the same computer models. However, (anthropogenic) climate change deniers are being perfectly reasonable as far as thinking about temperature goes. Let me explain.