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by John Spritzler

July 15, 2023

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Global warming (a.k.a. "climate change") alarmists tell us that if we don't stop C02 emissions (from burning fossil fuel), then there will soon be a climate CATASTROPHE so horrible that we need to do whatever it takes, and make whatever sacrifices are required, to prevent it from happening.

But what EXACTLY is this 'worst case' prediction? Let's see what the only Nobel Memorial Prize in Economics winner who has focused on climate change says; this is William Nordhaus. Nordhaus has used ultra-sophisticated methods to make estimates of how much the world's economic production ("the world's economy," or world GDP) will be reduced by global warming of a given number of degrees Celcius compared to what it would be if there was not this global warming.

Before looking at Nordhaus's estimates of the effect of global warming on world GDP, we need to see what the current predictions are for GDP growth. I am going to present the findings of an organization called PwC, which you can read about here. This is a huge organization that employs more than 100,000 people and has gross revenues of more than $50 Billion from providing services to 84% of Global Fortune 500 companies, including projections of GDP.

PwC reports:

"The world economy could more than double in size by 2050, far outstripping population growth, due to continued technology-driven productivity improvements"

[from ]

The key point here is simply that the world's GDP isn't slated to remain the same, or even to just increase a little bit; it is expected to grow a LOT!

Keep in mind now that the warning "Global warming/climate change is causing an imminent CATASTROPHE" doesn't conjure up an image of the world's economy ALMOST but not actually doubling by 2050, does it? No! This warning conjures up an image of the world's economy drastically SHRINKING with people dying in large numbers, right?

So now let's see what the UN's famous Intergovernmental Panel on Climate Change (IPCC) predicts the global warming will be under the "business as usual" scenario, i.e., if we don't do anything to reduce C02 emissions. Here's what the IPCC says:

"Based on current model results, we predict: under the IPC C Business-as-Usual (Scenario A ) emissions of greenhouse gases, a rate of increase of global-mean temperature during the next century of about 0.3°C per decade (with an uncertainty range of 0.2°C to 0.5°C per decade); this is greater than that seen over the past 10,000 years. This will result in a likely increase in global-mean temperature of about 1°C above the present value by 2025 and 3°C before the end of the next century. The rise will not be steady because of the influence of other factors; "

[from ; note that this quotation ends with a semi-colon because this is a bullet point followed in the report by further bullet point predictions based on different assumptions that there is some amount of reduction in C02 emissions]

A report in 2019 by The Breakthrough Institute reported this "business as normal" prediction for the year 2100:

There is a strong case to be made that transitions in the global energy system over the past decade mean that a conservative business-as-usual projection of current trends in the energy system continuing is now likely to lead to warming of around 3C by 2100. 

[from,of%20around%203C%20by%202100. ]

Combining these economic GDP and climate (°C increase) projections, based on the "business as usual" no-reduction-in-C02-emissions assumption, together, what do we have?

We have the expectation of a LOT of GDP increase (doubling by 2050, i.e., increasing by 100%) despite an increase of 3 °C global temperature by 2100.


With this in mind, let's see what the economist Nordhaus estimates the economic impact of rising global temperature will be. Here are his words:


"The present study has two objectives. The first is a review of studies that estimate the global economic impacts of climate change using a systematic research synthesis (SRS). In this review, we attempt to replicate the impact estimates provided by Tol (2009, 2014) and find a large number of errors and estimates that could not be replicated. The study provides revised estimates for a total of 36 usable estimates from 27 studies. A second part of the study performs a statistical analysis. While the different specifications provide alternative estimates of the damage function, there were no large discrepancies among specifications. The preferred regression is the median, quadratic, weighted regression. The data here omit several important potential damages, which we estimate to add 25% to the quantified damages. With this addition, the estimated impact is -2.04 (± 2.21) % of income at 3 °C warming and -8.06 (± 2.43) % of income at 6 °C warming. We also considered the likelihood of thresholds or sharp convexities in the damage function and found no evidence from the damage estimates of a sharp discontinuity or high convexity."

[from ]

Notice that Nordhaus is bending over backwards here to avoid being too optimistic. That's what it means when he writes, "The data here omit several important potential damages, which we estimate to add 25% to the quantified damages." Potential damages are damages we have no particular reason to expect, but "who knows what might happen?"

The UN's IPCC says that under the 'business as usual' scenario it expects a 3°C increase in global warming by the "end of the next century," i.e., by 2200 (not 2100). Nordhaus says that such a 3°C increase would lead to a "-2.04 (± 2.21) % of income," meaning, because of the minus sign, a loss of this much income.

But keep in mind that this handful of percentage points loss of income is relative to what the income would otherwise be; it means that instead of the GDP rising a LOT (a doubling,  i.e., a 100% increase, as soon as 2050, not to mention 2200) it will rise, but a little bit less than a LOT (a mere handful of percentage points less.)

Even if the global temperature rises double what the IPCC expects under the 'business as usual' assumption, i.e., 6°C instead of 3°C, the Nordhaus estimate of a -8.06 (± 2.43) % loss of economic productivity STILL means economic production will rise, but a little bit less than a LOT, and not shrink the way the "catastrophic global warming" alarmists would have the public believe.

Think about how different the IPCC's message would be if instead of telling us "We're all going to die!" it told us "We're going to be wealthier, but a little bit less than a LOT wealthier."


The dinosaurs lived in the Mesozoic Era, between about 245 and 66 million years ago. At this time, the average global temperature was about 22 °C. Today (see the plot of historic C02 and global mean temperature online here, and while you're at it see if it suggests that higher temperature is caused by higher C02--it does not!) the average global temperature is only about 12 °C. If the temperature rises even 6 °C, which is twice what the IPCC expects it to do by the year 2022 if we do nothing to reduce C02 emissions, then the global mean temperature would still only be 18 °C, which is substantially LESS than what it was when the dinosaurs--and all the rest of the enormously varied life during the Mesozoic Era, including our mammal ancestors who excelled when the comet wiped out the dinosaurs--THRIVED! I hardly think this higher temperature would lead to "We're all going to die!"

C02 is plant food. More C02 in the atmosphere means larger crops, which is why greenhouse owners pump C02 into their greenhouses. In our current economy, food is a relatively small part of the GDP, and so the benefit of C02 for food production doesn't get noticed that much in Nordhause's estimate of the effect of rising temperature due to higher C02 concentration on GDP. But nonetheless, bigger crops is hardly bad news for us human beings, right?


To learn why the alarmists are trying to alarm us, please read my article, "WHY DOES THE ROCKEFELLER FAMILY FUND WANT YOU TO REDUCE YOUR CARBON FOOTPRINT?" at .


First, I suggest you read "THE RIGHT AND THE WRONG WAY TO JUDGE EXPERTS" before you decide not to look at the data they present and their analyses of them just because you don't like their employer.

#1. But in case you DO judge experts only according to who employs them, here's a video of a top-notch climate expert, Dr Judith Curry, Professor Emeritus and former chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, who is now SELF-EMPLOYED, after having left her position as a tenured professor because of the absurd bias in climate research funding.

#2. Another top-notch climate scientist wrote a book that I urge people to read with the following introduction:

A good book I suggest you read is Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters by Steven E. Koonin. Below are some extracts from it starting with Koonin's distinguished bio and then dealing with 1) the "97% consensus", 2) the way the "climate denier" accusation is based on wrong-headed "science," and 3) how the best course of action today is to adapt to climate change rather than trying to stop it.

First, who is the author? Here's his bio, excerpted from the book:

“Dr. Steven E. Koonin is one of America’s most distinguished scientists, a member of the National Academy of Sciences, and a leader in United States science policy. Currently a professor at New York University, Dr. Koonin holds appointments in the Stern School of Business, the Tandon School of Engineering, and the Department of Physics.

He founded NYU’s Center for Urban Science and Progress, which focuses research and education on the acquisition, integration, and analysis of big data for big cities.

Dr. Koonin served as Undersecretary for Science in the US Department of Energy under President Obama, where his portfolio included the climate research program and energy technology strategy.

He was the lead author of the US Department of Energy’s Strategic Plan (2011) and the inaugural Department of Energy Quadrennial Technology Review (2011).

Before joining the government, Dr. Koonin spent five years as chief scientist for BP, researching renewable energy options to move the company “beyond petroleum.”

For almost thirty years, Dr. Koonin was a professor of theoretical physics at Caltech. He also served for nine years as Caltech’s vice president and provost, facilitating the research of more than three hundred science and engineering faculty and catalyzing the development of the world’s largest optical telescope, as well as research initiatives in computational science, bioengineering, and the biological sciences.

In addition to the National Academy of Sciences, Dr. Koonin’s memberships include the American Academy of Arts and Sciences, the Council on Foreign Relations, and JASON, the group of scientists who solve technical problems for the US government; he served as JASON’s chair for six years. He chaired the National Academies’ Divisional Committee for Engineering and Physical Sciences from 2014 to 2019, and since 2014 he has been a trustee of the Institute for Defense Analyses.

He is currently an independent governor of the Lawrence Livermore National Laboratory and has served in similar roles for the Los Alamos, Sandia, Brookhaven, and Argonne National Laboratories.

He is a member of Governor Cuomo’s Blue Ribbon Commission to Reimagine New York in the post-COVID-19 era. Dr. Koonin has a BS in physics from Caltech and a PhD in theoretical physics from MIT. He is an award-winning classroom teacher and his public lectures are noted for their clarity in conveying complex subjects.

He is the author of the classic 1985 textbook Computational Physics, which introduced methodology for building computer models of complex physical systems.

He has published some two hundred peer-reviewed papers in the fields of physics and astrophysics, scientific computation, energy technology and policy, and climate science, and has been the lead author on multiple book-length reports, including two National Academies studies.


Through a series of articles and lectures that began in 2014, Dr. Koonin has advocated for a more accurate, complete, and transparent public representation of climate and energy matters.”

— Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters by Steven E. Koonin

So, he's obviously just a fringe science-hating "climate denier" and probably a flat-earther as well, right?

Here's an excerpt from his book about the "97 percent consensus":

Any appeal to the alleged “97 percent consensus” among scientists is another red flag. The study that produced that number has been convincingly debunked. 8 And in any event, nobody has ever specified exactly what those 97 percent of scientists are supposed to be agreed upon. That the climate is changing? Sure, count me in! That humans are influencing the climate? Absolutely, I’m there! That we’re already seeing disastrous weather impacts and face an even more catastrophic future? Not at all obvious (for reasons I hope you understand, having read this far).

— Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters by Steven E. Koonin

Here's another excerpt from his book dealing with the way even academies of science fail to distinguish between non-human-caused versus human-caused climate change; this lays the basis for the media accusations of "climate denier" against those who DO distinguish between these two causes:

Academies reports undergo an extensive authoring and review process. I know that process well, having led two Academies studies and reviewed the reports of several others, along with for six years overseeing all the Academies’ report activities in Engineering and the Physical Sciences (including several in Energy, but none in Climate Science). This process does indeed result in reports that are almost always objective and of the highest quality. Unfortunately, as we’ve seen, their reviews of the National Climate Assessments (they don’t write the assessments themselves) in 2014 and 2017/ 18 didn’t quite meet that standard.

On June 28, 2019, the presidents of the National Academies of Science, Engineering, and Medicine issued a statement affirming “the Scientific Evidence of Climate Change.” The sole paragraph dealing with the science itself read:

"Scientists have known for some time, from multiple lines of evidence, that humans are changing Earth’s climate, primarily through greenhouse gas emissions. The evidence on the impacts of climate change is also clear and growing. The atmosphere and the Earth’s oceans are warming, the magnitude and frequency of certain extreme events are increasing, and sea level is rising along our coasts. 10"

Even given the need for brevity, this is a misleadingly incomplete and imprecise accounting of the state of climate science. It conflates human-caused warming with the changing climate in general, erroneously implying that human influences are solely responsible for these changes. It invokes “certain extreme events” while omitting the fact that most types (including those that pop most readily to mind when one reads the phrase “extreme events,” like hurricanes) show no significant trend at all. And it states that “sea level is rising” in a way that not only suggests that this, too, is solely attributable to human-caused warming, but elides the fact that the rise is nothing new.

I’m quite sure that this personal statement issued by the presidents in a news release was not reviewed by the usual Academies procedures; if it had been, its deficiencies would have been corrected. The statement therefore carries the weight of the Academies’ name without being subject to its customary rigor.

Ironically, the statement goes on to say the Academies “need to more clearly communicate what we know.” Which in this case they didn’t.

When communication of climate science is corrupted like this, it undermines the confidence people have in what the scientific establishment says about other crucial societal issues (COVID-19 being the outstanding recent example).

As Philip Handler, a prior president of the National Academy of Sciences, wrote in the 1980 editorial I mentioned in the Introduction: It is time to return to the ethics and norms of science so that the political process may go on with greater confidence. The public may wonder why we do not already know that which appears vital to decision—but science will retain its place in public esteem only if we steadfastly admit the magnitude of our uncertainties and then assert the need for further research. And we shall lose that place if we dissemble or if we argue as if all necessary information and understanding were in hand. Scientists best serve public policy by living within the ethics of science, not those of politics. 11

— Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters by Steven E. Koonin

Here is an excerpt from the end of Koonin's book in which he says that what makes the most sense today is for us to ADAPT to climate change rather that try (based on insufficient scientific knowledge) to stop it:

I’m less bullish on “forced and urgent” decarbonization, either through a price on carbon or by way of regulation. The impact of human influences on the climate is too uncertain (and very likely too small) compared to the daunting amount of change required to actually achieve the goal of eliminating net global emissions by, say, 2075. And for me, the many certain downsides of mitigation outweigh the uncertain benefits: the world’s poor need growing amounts of reliable and affordable energy, and widespread renewables or fission are currently too expensive, unreliable, or both.

I would wait until the science becomes more settled—that is, until the climate’s response to human influences is better determined, or, failing that, until a values consensus emerges or zero-emissions technologies become more feasible—before embarking on a program to tax or regulate greenhouse gas emissions out of existence or to capture and store massive amounts of carbon dioxide from the atmosphere. I believe the socio-technical obstacles to reducing CO2 emissions make it likely that human influences on the climate will not be stabilized, let alone reduced, in this century. If the effects of those influences become more evident and more severe than they have been to date, of course, the balance of costs and benefits might shift, and society might well shift along with it. But I’d be surprised if this happened anytime soon.

Advocating that we make only low-risk changes until we have a better understanding of why the climate is changing, and how it might change in the future, is a stance some might call “waffling,” but I’d prefer the terms “realistic” and “prudent.” I can respect the opinions of others who might come to different conclusions, as I hope they would respect mine. Those differences can only be resolved if we realize that they’re ultimately about values, not about the science.

Another prudent step would be to pursue adaptation strategies more vigorously. Adaptation can be effective. As mentioned in the previous chapter, humans today live in climates ranging from the Tropics to the Arctic and have adapted through many climate changes, including the relatively recent Little Ice Age about four hundred years ago. Effective adaptation would combine credible regional projections of climate change with a framework for assessing the costs and benefits of various adaptation strategies. As we’ve seen, we’re a long way from having either of those. So the best strategy is to promote economic development and strong institutions in developing countries in order to improve their ability to adapt (and their ability to do many other positive things as well).

— Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters by Steven E. Koonin

#3. "Challenging 'Net-Zero' with Science" (40 page document) at  . The first author, Richard Lindzen, is a member of the National Academy of Sciences; one doesn't get any more top-notch than that!


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