A Free-Market Energy Blog

Judith Curry Interview (Part I: Climate Science)

By Robert Bradley Jr. -- February 3, 2021

“There’s a range of credible perspectives that I try to consider. It’s a very complex problem, and we don’t have the answers yet.”

“And now we have way too much confidence in some very dubious climate models and inadequate data sets. And we’re not really framing the problem broadly enough to … make credible projections about the range of things that we could possibly see in the 21st century.”

– Judith Curry, below

“One plus the truth equals a majority,” the saying goes. This certainly applies to Judith Curry, a distinguished academic and professional climate scientist now retired from Georgia Tech. (For previous posts at MasterResource on Dr. Curry, see here.)

The latest from this rare straight shooter comes from a taped interview with Christopher Balkaran at his Strong and Free Podcast, where, in his words, “my goal is to showcase multiple perspectives on the topics and ideas of our time, regardless of your politics and views.”


Judith Curry pulled back from the settled-science, alarmist mainstream when she saw bad science in the service of politics. As she explains it:

because I wasn’t actively advocating with the greens and I was critical of the behavior of some of the scientists involved in the climate gate episode. I got booted over to the denier side. And they tried to cancel me. I don’t have any allegiance to the extremes of either side of this, but the alarmists seem to be completely intolerant to disagreement and criticism.

See the 2010 Scientific American article, reproduced by Nature here, and summarized at MasterResource yesterday.

As for her own politics, Curry states:

I regard myself as sort of a centrist. I’m politically independent. I don’t have any allegiance to one side or the other. I understand the complexity of the problems, and I don’t really advocate for any solutions because I can’t think of any that I would want to advocate for that actually makes sense.

Moderator Introduction

“[H]ow often have you heard from scientists who are respected in their field that have openly questioned and been critical of the findings and the climate modeling put forward by the Intergovernmental Panel [on] Climate Change?,” asked Moderator Balkaran.

So I want to just sit down with professor Judith Curry…. Professor Curry openly accepts that climate change is real and it is happening, but the topic is so, so complex. And so determining what governments need to do is also complex.”


Professor Curry’s responses are edited and truncated below for brevity. (The full interview is transcribed here.) The subtitled sections below focus on the science and science-policy sides of the current debate; tomorrow’s post turns to her views on public policy.

Early Debate

“Climate change wasn’t a really big issue [in the 1970s and 1980s]. At the time, it was all about geophysical fluid dynamics, trying to understand the circulations of atmosphere and the ocean, radiative transfer, cloud physics. It was, it was very physics based.”

“I would hear in the media about people talking about, Oh, the ice age is coming , or doom and gloom from CO2 emissions, but nobody was really paying attention to all that very much in terms of what I would say was the mainstream field until the late 1980s, really.”

“[The big change came] from the UN Environmental Program. At the time, there was a push towards world government, socialistic kind of leanings, don’t like capitalism and big oil. …. And the UNEP was one of the sponsoring organizations for the IPCC. And so that really engaged more climate scientists and really brought it more into the mainstream.

But in the early days, a lot of scientists didn’t like this at all, they didn’t think that we should be going in this direction. And this was even the World Climate Research program and the World Meteorological Organization, they didn’t want to get involved in man-made climate change under the auspices of the IPCC. They said, ‘this is just a whole political thing. This is not what we do. We seek to understand all the processes and climate dynamics ….’

And that was really a pretty strong attitude, through, I would say the mid-nineties, say 1995. We had the UN Framework Convention on Climate Change at that point, they’re trying to get a big treaty going. And so defenders of the IPCC started pushing the idea that anybody who doubts us or challenges us, they are in the pay of big oil. After that, it became much more difficult to really challenge all that.

And certainly by the turn of the century, anybody who was questioning the hockey stick or any of these other things were slammed as deniers and ostracized.”

“And then after Climategate in 2010, the consensus enforcers became very militant. So it’s a combination of politics, and some mediocre scientists trying to protect their careers. And, they saw this whole thing as a way for career advancement, and it gives them a seat at the big table and political power.”

“All this reinforces pretty shoddy science and overconfidence in their expert judgment, which comprises the IPCC assessment reports. And then at some point you start to get second order belief. I mean, it’s such a big, complex problem. Individual scientists only look at a piece of it, and then they start accepting what the consensus says on the other topics.”

“A scientist working on some aspect of the climate problem may know very little about carbon dioxide, the carbon budget, radiative transfer, all that fundamental science, but they will accept the climate consensus because it’s easy and good for their career. And so it just becomes a self-fulfilling prophecy.

“And now we have way too much confidence in some very dubious climate models and inadequate data sets. And we’re not really framing the problem broadly enough to really understand what’s going on with the climate and to make credible projections about the range of things that we could possibly see in the 21st century.”

Climate Sensitivity

“Well, there is almost certainly a signal of manmade emissions affecting the earth climate. All other things being equal, it’s warmer than it would otherwise be.

The real issue is the magnitude of man-made warming relative to the whole host of other things that go on in the natural climate system. And then the bigger issue is really whether this warming is dangerous. You know, a certain amount of warming is generally regarded by people as a good thing. But a whole lot of warming, isn’t especially a good thing, especially if it’s melting ice sheets and causing sea level rise.

Sea level rise operates on very long timescales. And the manmade warming that we’ve seen so far, I don’t think is really contributing much to the sea level rise that we’ve observed so far. I mean, that’s just a much longer term process. And even if we stopped emitting carbon dioxide today, the sea level rise would keep rising. So, the climate system is way more complex than just something that you can tune, with a CO2 control knob. That just isn’t how it works.”

Climate Models

“The climate models originated from weather forecast models, and then they added an ocean, then land surface biosphere, and then chemical processes, and now ice sheets. They keep adding all these modules and increasing complexity of the models,  but the basic dynamics are driven by the same kind of models that model the weather.

We’ve learned a lot from climate models, by running experiments, turning things off, turning things on, adjusting parameters, taking clouds out, taking sea ice out, holding the sea surface temperature constant in the tropical central Pacific and see what happens, you know, we learn how the climate works by using climate models in that way.

However, the most consequential applications of climate models are to tell us what caused the 20th century climate change, how much the climate change is going to change in the 21st century and what’s causing extreme weather events.

I mean, those are the more consequential applications and climate models aren’t fit for any of those purposes. And that’s pretty much acknowledged even in the IPCC report. Well, they, they do claim that they can attribute the global warming, but this can’t be easily separated from the natural variability associated with large-scale ocean circulations.

And the way they’ve used climate models to do that involves circular reasoning, where they throw out climate simulations that really don’t match what was observed. So you, you end up, even if you’re not explicitly tuning to the climate record, you’re implicitly tuning.

And then the thing with extreme events, weather events, is beyond silly because these climate models can’t resolve the extreme events and they can’t simulate the ocean circulation patterns that really determine the locations of these extreme events.

And then when you start talking about 21st century, the only thing they’re looking at is the manmade human emissions forcing, they’re not predicting solar variability. They’re not not predicting volcanic eruptions. They can’t even predict the timing of these multidecadal to millennial ocean oscillation.

So all they’re looking at is this one little piece. Okay. So, what are you supposed to do with all that? Not sure we know much more than the sign of the change from more CO2 in the atmosphere, which is more warming.

And then there’s another thing. The most recent round of global climate model simulations, the so-called CMIP5 for the IPCC 6th assessment report. All of a sudden the sensitivity to CO2 the range has substantially increased in a lot of the models, way outside the bounds on the high side of what we thought was plausible, even five years ago.

So what are we to make of that? And how did that happen? Well, it’s a rather arcane issue related to how clouds cloud particles interact with aerosol particles.

By adding some extra degrees of freedom into the model related to clouds, then it becomes all of a sudden way more sensitive to increases in CO2. What are we supposed to make of that? I mean, we do not have a convergent situation with these climate models.

And this is not mention that the 21st century projections from the climate models, don’t include solar variations. They don’t include volcanoes or the ocean circulation, all of these things that they don’t include.

So what are we left with? And then there are these precise targets, such as we will exceed our carbon budget in 2038. This is way too much precision that is derived from these very inadequate climate models.”

Regional Climate Predictions

” … climate model taxonomy … look[s] at the outputs of climate models mostly regionally, and then over interpret them, relating the output to some really bad impact act. But it’s scientifically completely meaningless.

First, the climate models don’t have any skill on regional spatial scales. And second, when climate scientists start making these linkages with wine growing or whatever, they forget a whole lot of other ancillary factors like land use and, all sorts of other things that can contribute to whatever they might be looking at.

And it ends up with climate change being the dominant narrative for everything that’s going on. And that’s just simply not the case. With the over-reliance on climate models, climate dynamics is really becomes sort of a dying field.

You know, I was old school at the university of Chicago with geophysical fluid dynamics and all this really hard stuff. Okay. Now people do statistical analyses on climate model output, and we’ve lost our sense of understanding of how the atmosphere and the ocean interact to produce our climate.

There’s very few universities that have good programs in climate dynamics at this point. And you don’t see a lot of students in those research groups, they rather do the sexier, easier climate model taxonomy studies.

Climate dynamics is still there, but it’s far from dominant. I mean that you geophysical fluid dynamics, climate dynamics that ruled in the sixties, seventies, eighties, and even into the nineties, but in the 21st century, we’ve seen that really become like a renascent sub-field, with climate model taxonomy ruling the roost.”

Government Funding

“[The problem of] government funding is not that they just reject those kinds of proposals. They make it hard for you to even submit them because their announcement of opportunity for proposals already implicitly or explicitly assume … impacts of manmade, global warming, regional impacts on whatever.

So there’s already either an implicit or explicit assumptions about all this. As a result, it’s really the independent scientists, retired people, people in the private sector, independently wealthy people who are doing [the more questioning] work.”

Current Research

“[Atmospheric Dynamics is] so low on the totem pole of what people high in higher university administration worry about. I mean, you still have like meteorology undergraduates learn about atmospheric dynamics. There aren’t too many oceanography undergraduate programs, but when you go to graduate school in oceanography, you get a lot of fluid dynamics.

But there are all these new degree programs spinning up in climate, that are far away from the geo-physical roots . These new programs combine policy with a little bit of science and economics and whatever. And then the science part of it basically gets minimized.

And that’s where all the students are running to these environmental science, climate policy kinds of programs, leaving a talent dearth of people with the good mathematical physical mindset and wanting to enter into the more challenging fields. So, these more difficult fields are not especially thriving.”

“[Atmospheric dynamics doesn’t] bring in the big bucks in terms of research centers and whatever. It’s hard to maintain them. A couple of years ago, I visited University of Chicago, my old Alma mater, and they still maintained their very strong focus on the dynamics. There was nobody there running climate models and doing this silly stuff, and they didn’t have a lot of students and they didn’t have hardly any funding, but they were carrying the torch and doing fantastic work.”

“Unfortunately, that’s not where the that’s not where the center of mass is – its in these new climate policy degree programs or environmental studies kind of programs. As a result we’ve lost a lot of our infusion from physics.

There still is an infusion from chemistry, more on the atmospheric chemistry. Part of this seems to be thriving, relatively relating to air quality and complex chemical reactions in the atmosphere. That seems to be thriving. But I would say the more physics based side of all this is really dwindling.”


Part II tomorrow on the Curry Interview with Christopher Balkaran at Strong and Free Podcast will turn to public policy issues regarding the climate change debate.


  1. Alan Lowey  

    It’s not necessarily *global* warming. A new physics tidal forcing hypothesis predicts that the equatorial ocean regions are cooling, whilst mid-high latitudes are warming.

    A new study of 153 galaxies has shown a Modified Newtonian gravity theory will plausibly replace Einstein’s GR if the results are robustly confirmed.

    Gravity theory isn’t settled therefore climate science isn’t settled.


  2. Russell Seitz  

    “[ A couple of years ago, I visited University of Chicago, my old Alma mater, and they still maintained their very strong focus on the dynamics. There was nobody there running climate models and doing this silly stuff, and they didn’t have a lot of students and they didn’t have hardly any funding, but they were carrying the torch and doing fantastic work.”

    “Unfortunately, that’s not where the that’s not where the center of mass is – its in these new climate policy degree programs or environmental studies kind of programs. As a result we’ve lost a lot of our infusion from physics.”

    That could be because pontificating about future policy is a lot less demanding than bleeding edge hydrodynamic modeling in complexly linked and chaotic systems like the hydrospherer an atmosphere.

    The cold truth is that we are still don’t know the limits of the outliers that may be provoked by anthropogenic radiative forcing , so it’s no safer to underestimate outcomes than overstate them.


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