The old appeal to authority. Nice. Well, Dyson is a physicist and mathematician, so his opinion on this matters exactly the same as yours - not a jot.
You're doing a great job of discrediting yourself - no one else needs to even bother.
You are grossly overstepping in your zeal to disprove your opponent. Unless of course you really do think physics and math aren't relevant to computer modelling of... statistical estimates for changes in radiation absorption based on multiple variables. You know, the very heart and soul most important component of the greenhouse effect.
Dyson's opinions as portrayed in the linked article include:
He had his agenda. Obviously he wanted to write a piece about global warming and I was just the instrument for that, and I am not so much interested in global warming. He portrayed me as sort of obsessed with the subject, which I am definitely not. To me it is a very small part of my life. I don’t claim to be an expert. I never did.
Later he makes his position on various items known:
I was involved in climate studies seriously about 30 years ago. That’s how I got interested. There was an outfit called the Institute for Energy Analysis at Oak Ridge. I visited Oak Ridge many times, and worked with those people, and I thought they were excellent. And the beauty of it was that it was multi-disciplinary. There were experts not just on hydrodynamics of the atmosphere, which of course is important, but also experts on vegetation, on soil, on trees, and so it was sort of half biological and half physics. And I felt that was a very good balance.
After describing the work at Oak Ridge and a general assessment by everyone about the interconnectedness of the climate across disciplines:
It’s a problem of very complicated ecology, and to isolate the atmosphere and the ocean just as a hydrodynamics problem makes no sense.
Thirty years ago, there was a sort of a political split between the Oak Ridge community, which included biology, and people who were doing these fluid dynamics models, which don’t include biology. They got the lion’s share of money and attention. And since then, this group of pure modeling experts has become dominant. I got out of the field then. I didn’t like the way it was going. It left me with a bad taste.
What’s wrong with the models. I mean, I haven’t examined them in detail, (but) I know roughly what’s in them. And the basic problem is that in the case of climate, very small structures, like clouds, dominate. And you cannot model them in any realistic way. They are far too small and too diverse.
So they say, ‘We represent cloudiness by a parameter,’ but I call it a fudge factor. So then you have a formula, which tells you if you have so much cloudiness and so much humidity, and so much temperature, and so much pressure, what will be the result... But if you are using it for a different climate, when you have twice as much carbon dioxide, there is no guarantee that that’s right. There is no way to test it.
Dyson doesn't seem particularly overstepping his knowledge. He doesn't seem to be 'denying' things. He's just putting forward some pretty reasonable skepticism. Notably, the IPCC repeatedly observes as well that the impact of clouds is the single biggest unknown in current modelling, largely because it's so very, very hard to model accurately.