One of the world’s most eminent physicists, Freeman Dyson, died Friday at age 96.

Dyson, who spent much of his career at Princeton, was a groundbreaking pioneer who made enduring  contributions in the fields of physics and mathematics.

Among is most famous contributions was his work partnering with physicist Richard Feynman on quantum electrodynamics.  He worked with many of the creators of modern nuclear energy.

Dyson also postulated famous broad thought experiments such as the “Dyson sphere.”  Those of us who grew up watching Carl Sagan’s Cosmos, will recall Sagan’s devotion to Dyson’s “project Orion” which theorized that interstellar travel can be obtained using today’s nuclear technology.  Sagan expressed frustration that America is not building one of Dyson’s Orion spacecraft, “right now.”

Dyson was famously counted among the world’s most respected skeptical scientists on climate change.

He strongly disapproved of the demonization of CO2 and thought it wrong that the global warming movement refuses to factor the benefits of increased atmospheric CO2 into its climate assessments, particularly the role of CO2 in promoting plant growth.

Dyson was equally perturbed by the proliferation of climate computer simulations that consistently run warmer than measured temperature observations.  He told the Yale environment magazine:

They are models, but they don’t pretend to be the real world. They are purely fluid dynamics. You can learn a lot from them, but you cannot learn what’s going to happen 10 years from now…

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.

It’s a fact that they don’t know how to model it. And the question is, how does it happen that they end up believing their models? But I have seen that happen in many fields. You sit in front of a computer screen for 10 years and you start to think of your model as being real. It is also true that the whole livelihood of all these people depends on people being scared. Really, just psychologically, it would be very difficult for them to come out and say, “Don’t worry, there isn’t a problem.” It’s sort of natural, since their whole life depends on it being a problem. I don’t say that they’re dishonest. But I think it’s just a normal human reaction. It’s true of the military also. They always magnify the threat. Not because they are dishonest; they really believe that there is a threat and it is their job to take care of it. I think it’s the same as the climate community, that they do in a way have a tremendous vested interest in the problem being taken more seriously than it is.

Dyson was a committed Democrat who supported President Obama. “I’m 100% Democrat and I like Obama,” he said, but he took the wrong side on the climate issue and the Republicans took the right side.”

Freeman Dyson was brilliant and fearless.  As Shakespeare wrote, “when comes such another?”