Steven Koonin on Climate Science

Steven Koonin is one of America’s most distinguished scientists, with decades of experience, including a stint as undersecretary of science at the Department of Energy in the Obama administration. In this wide-ranging discussion, based in part on his 2021 book, Unsettled: What Climate Science Tells Us, What It Doesn’t, and Why It Matters, Koonin gives a more refined look at the science behind the climate issue than the media typically offers, guiding us through the evidence and its implications. As Koonin explains in this interview, he was “shaken by the realization that climate science was far less mature than I had supposed” and that the “overwhelming evidence” of catastrophic implications of anthropogenic global warming wasn’t so overwhelming after all.

The Captain
does not deny climate change. He just doesn’t like the politics of climate change


When I have an issue with my heart, I talk to a cardiologist, not a urologist (even if they’re both very smart).

When I have an issue with global climate change, I talk to a climatologist, not a theoretical physicist (even if they’re both very smart).


When I have an issue with global climate change, I talk to a politically savvy professional well tutored in the field of energy and climate.

Complex systems, by definition, need a wider field of knowledge than just one science, specially one funded by governments.

The Captain


Well, if we’re in a war, I’d tend to follow the strategies of our military, who are 100% funded by the government, as opposed to military advisors working for private companies.

Following experts does not guarantee 100% success, but it sure does lean the odds in your favor.

Just for the record, most climatologists with advanced degrees are trained in geography, environmental sciences, chemistry, physics, mathematics, meteorology, oceanography, and statistics.


Did you by any chance watch the Koonin interview I linked? If you did you would have been in for a surprise. Koonin said that the UN Intergovernmental Panel on Climate Change (IPCC) gets it mostly right! So where is the problem?

Koonin explain how through a bureaucratic telephone game the message the politicians get is far removed from what the science is saying. Like I said in my previous reply, the issue is not so much science but politics. But if you shut out the opposition views you miss half the picture.

Did you read the IPCC reports? Neither did the politicians, they get

Summary for Policymakers

What does the press report?

Scary soundbites.

The Captain


No, I did not watch the interview. However, I’ve read Koonin’s book Unsettled. It didn’t impress me, so I did not watch.

My take on climate change is:

  1. We listen to the vast majority of climate change scientists and sink a lot of resources into trying to mitigate it. If they’re right, it was a wise investment. If they’re wrong, we needlessly wasted a lot of resources but kept a bunch of people employed with nice paying jobs.

  2. Or, we listen to the minority of climate change scientists who don’t think it’s a big deal or that it’s just a political maneuver. If they’re right, we’ve avoided wasting a lot of resources. Whew! If they’re wrong, it’s lights out for most, if not all, of humanity.

  3. We all go to Mars. I’ve always wanted to go to Mars. I’m very jealous of Matt Damon.

  4. The middle ground. There’s just enough climate change to sink Florida.

Monty, I’ll take door #1.

Although #4 might not be so bad.


I am very glad to read this. You agree that human emitted CO2 is the main driver of the recent warming. You agree that future CO2 emissions expose us to significant risk.

I am with you completely, how we respond to the current impact and future threat of climate change is politics. It is unfortunate that more people aren’t following your lead and grounding political choices in science.

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Haven’t even thought about it.

A volcano, an earthquake, a tsunami, or an asteroid can wipe out humanity and you worry about CO2?

The Captain


CO2 is something we can control. The others we cannot. Pretty simple really.

Nearly all the scientists are saying humans are the main driver of climate change. Big Oil admitted this internally 30+ years ago. That is not politics. Yet you still aren’t convinced?


Get rid of humans!

The Captain


A volcano or earthquake could wipe out humanity? Well, although not entirely outside the realm of the possible (yes, something like the volcanic era that created the Deccan Traps 66 million years ago would be very difficult to deal with), I say hyperbole. As for asteroids, we actually are making very rapid progress to erasing that as a possibility, primarily by finding and tracking most of the pesky things in our neighborhood, but also by figuring out real tactics for dealing with one before it collides with Earth.

You left out the danger of extremely dangerous epidemics, and again, we are getting close on closing that door too. War?! and all the other forms of human created human executed misery and death? Well, making certain that Putin’s war on Ukraine fails and that there are nasty consequences for his circle will help a lot to lessen that danger. Further developing a world concensus and alliance system regarding such wasteful and deadly forms of national expressiveness would be good and seems possible.

CO2 is a nice gas within the levels of recent eons. However, our current clear case of GCC IS an extreme peril to human systems of life, and methane and CO2 clearly are the main causes.

I am puzzled by the quasi religious sentiment that nothing major can nor should be done to reverse the needless and now ever clearer deadly risk. And the risk is not so much the oncoming heat and changes in the “norm” of the last few thousand years of human existence (as deadly as that would be), but the very high probability of all manner of complex human systems (economics, social civility, governance) being incapable of the shocking systemic changes now coming down on us…

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Seems as if that’s the path we’re on.

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I don’t believe any of those things can wipe out humanity. Heating the planet to temperatures above the ability of biologic processes to actually work will ‘wipe out humanity, and every living thing’!



As you may know, the earth has been generally cooling for the last 50 million years and during the last 3-5 million years. Overall, there are three basic states for climate – hothouse, icehouse and in between.

The icehouse state is characterized by ice at the poles, so you know where we find ourselves now. In fact, the Little Ice Age period which ended a couple of centuries ago was the coldest in several hundred million years.

Here’s a graph:



Too many humans is a real problem, but nobody wants to talk about it!


The DrBob graph shows 50F (or 10C) swings in average global temperature over the past 500 million years. Human civilization can be thought to begin with the advent of agriculture about 10,000 years ago, which is basically a dot on the far right end of the graph.

The climate over those 10,000 years turns out to have been relatively stable, with mean global temperature swings within 1C.


That probably isn’t a coincidence. The development and maintenance of complex human societies probably benefitted from stable global temperatures. If so, then messing with that stability by dumping a ton of greenhouse gases into the atmosphere probably isn’t a good idea.


The above paragraph includes ‘probably’ three times. On a scale of 1 to 10, is that ‘probably’ 1, 5, or 9?

The Captain

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Actually, you can just remove the ‘probablies’ and the comment is perfectly accurate.



That’s a nice graph with up-to-date data and was designed for a museum exhibit at the Smithsonian. With deep time, it’s interesting to not just look at a linear timescale like this graph uses. The linear timescale emphasizes deep time and deemphasizes more recent data. I like this graph with multiple timescales. Together, they paint a more complete picture of Earth’s global temperature history.