> Around 1979 Dyson worked with the Institute for Energy Analysis on climate studies. This group, under Alvin Weinberg's direction, pioneered multidisciplinary climate studies, including a strong biology group. Also during the 1970s, Dyson worked on climate studies conducted by the JASON defense advisory group.
There have been lots of advances in modelling complex systems, but it’s notoriously difficult to find models that work beyond a short timeframe. Dumb simple models often work better than cutting edge, complicated, much more realistic ones simply because there are less variables to get wrong. And every time you make an advance, the assumed accuracy of the model’s long term predictions needs to be reset: if model A predicted 1 year accurately, and you improved it so model A.1 predicted the next year accurately, you don’t have a model that accurately predicted 2 years; there is still only 1 unknown year that was predicted, and A.1 was just as accurate/inaccurate as model A at predicting that unknown year whether or not it took that past year into account.
We’ve seen how easy it is for sophisticated and complex models of chaotic systems like the stock market to fail despite people’s faith in them. His point seems as prudent now as back then; I think some systems are a lot more complicated than we’d like, and that we should have enough hubris to acknowledge that and be constantly testing our assumptions against empirical data.
He didn’t dismiss the value of models in helping understand chaotic systems, he was just wary about their long term predictions. And that doesn’t necessarily mean they’re wrong, only that they should not be taken as Gospel for anything beyond a fairly short time frame.
I’ve watched a number of relatively lengthy interviews and presentations he’s given that have been about or have touched on the topic of climate change, and he consistently references measurements of carbon’s effects and emphasizes the importance of real world measurements. His criticism is of abstract models of climate that attempt to make long term predictions.
If you’re most familiar with his positions through quotes and third hand reporting, I encourage you to listen to videos of him. I found him quite enjoyable to listen to. He was not the partisan he was sometimes painted as, although he was interviewed by people that were, but rather seemed genuinely curious and interested in truth and exploration.
Here are a few videos.
https://youtu.be/-mmI6DorL_Y?t=3m07s
His core claims appear to be that A) Increased CO2 has measurable, beneficial effects B) CO2 is one of many factors contributing to a complex system effecting climate that we don’t fully comprehend C) The positive or negative effects of climate change we’re observing depend on the region D) It is better to create a wide range of practical engineering solutions to deal with the effects of a changing climate than to think we can fully control it or know what effect our interventions or lack thereof will do in the future.
Some of those claims might be wrong, but I think it’s inaccurate to say they weren’t scientifically based.
There is also something of the motte-and-bailey fallacy when he claims that the modeling is not accurate enough to be trusted, while also telling us how things are going to work out.