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 sulfur1 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.
Consider two universes, the first in which climate models make accurate predictions and the second in which they don’t. In the latter situation, if climate models are wrong, there is no harm in continuing emissions (assuming the “direction of wrongness” wasn’t to underestimate the effects). However, if climate models correctly predict anthropogenic climate change as scientists believe they do, the models would also be expected to predict the effects of geo-engineering which suggest el-cheapo style “solutions” exist — at least in theory. But, as far as I know, there has been less research on the side effects (and/or the effects of increasing carbon dioxide emissions that are not countered) that would take place and there is less data to accurately predict the effects of other geo-engineering techniques. For example, the 19th century chemist Arrhenius predicted, rather simplistically, that an Earth warmed by higher carbon dioxide concentrations would be more pleasant, neglecting that the changes would not be uniform across the globe (let alone that some of the average increase in temperature would be from more extreme weather) and other phenomena such as flooding and hurricanes that would take place. But those issues aside, as long as our net carbon dioxide remains constant or grows, there can be almost no doubt that the build-up of carbon dioxide will lead to things such as ocean acidification. So, sure, we could probably maintain the Earth’s global mean temperature for pennies on the dollar2, but there would still be many nasty things we’d have to contend with. But the two universes we were dealing with were hypothetical; our models are either right or wrong. We have just one Earth. Why ruin a good thing?
“We could have saved the Earth but we were too damned cheap” — Kurt Vonnegut