More on the statistical dispute between Scafetta and Schmidt

By Andy May

The argument about the proper way to estimate error in the European Centre for Medium-Range Weather Forecast (ECMWF) ERA5 weather reanalysis dataset between Nicola Scafetta and Gavin Schmidt has finally been published by Geophysical Research Letters. Schmidt, Jones, and Kennedy’s comment is here (Schmidt, Jones, & Kennedy, 2023), and Scafetta’s response is here (Scafetta N., 2023a).

I first wrote about this dispute earlier in the year here. Nothing much has changed in the final versions.

Schmidt, Jones, and Kennedy’s assessment of the error in the ERA5 surface temperature dataset average still (incorrectly) assumes that, during such a period, the global surface temperature was constant from 2011-2021 and that its yearly variability is due to random noise. This is clearly a nonphysical interpretation of Earth’s climate, since there are real systematic changes in the climate from year to year, whether one assumes they are due to natural or man-made forces, or both.

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Wall Street Journal Article on Exxon’s “beliefs”

By Andy May

Open letter to the authors of the Wall Street Journal article: “Inside Exxon’s Strategy to Downplay Climate Change,” by Christopher M. Matthews and Collin Eaton.

Dear Mr. Matthews and Mr. Eaton,

I was quite surprised to see your article in the news section of the September 14, 2023 issue of the Wall Street Journal and not in the opinion section. It is quite misleading, and along the lines of the fully debunked Supran and Oreskes article in Environmental Research Letters (2017, v. 12, no. 8). As I discuss in a blog post this idea was thoroughly destroyed by Kimberly Neuendorf in court.

Like Supran and Oreskes, you assume that Exxon is one being with one mind, which is very far from the truth, as I research in detail in this blog post. The causes of climate change are not known, and as a result, the spectrum of opinions within Exxon is as large as that in the general public.

Some people are under the illusion that climate change is fully understood, that humans somehow control it, and it is dangerous. All these ideas are conjecture and without foundation, as explained in this post.

You can believe what you like, but conjecture is not fact, and Exxon is not a person. Your news article is based on faulty assumptions and too much conjecture, it belongs in the opinion section.


Andy May

Andy May Petrophysicist – Climate Change and Photography

The Buzz about The Frozen Climate Views of the IPCC

By Andy May

Our new book, The Frozen Climate Views of the IPCC: An Analysis of AR6, is creating a lot of attention and excitement around the world. It is the first authoritative critique of the new IPCC (Intergovernmental Panel on Climate Change) climate change report, “AR6.” AR6 ignores all climate change research that goes against their narrative and agenda, we show you what they are hiding in this book.

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How the 2015 Major El Niño Was Predicted Years in Advance using a Lunar Cycle

By Javier Vinós

The Earth’s oceans contain a vast mass of cold water beneath a thin layer of warm water, and the limited amount of mixing between them plays a crucial role in our existence. Tides, primarily influenced by changes in the moon’s orbit, are the main force behind this mixing, which has the potential to cool the climate. Keeling, who pioneered CO2 measurements, believed this theory and predicted a cooling trend for the next decade. The impact of the 18.6-year lunar cycle on climate has been known for some time, but more recent research has revealed its influence on the El Niño Southern Oscillation (ENSO). In 2007, two Canadian scientists studying the effects of this cycle on the Pacific coast of North America successfully predicted the occurrence of a major El Niño event in 2015 based on lunar orbital data. Remarkably, their prediction proved accurate.

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Understanding the role of the sun in climate change

By Nicola Scafetta

Although the sun provides nearly all the energy needed to warm the planet, its contribution to climate change remains widely questioned. Many empirically based studies claim that it has a significant effect on climate, while others (often based on computer global climate simulations) claim that it has a small effect.

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My CO2 Presentation to Clintel

The presentation was given to the public at the beautiful Hotel Villa Flora in Hillegom, Netherlands, on June 20, 2023. It was organized by Marcel Crok, director of Clintel.

You can watch the whole presentation on “Are fossil-fuel CO2 emissions good or bad?” here.

I discussed the 2016 debate between Professor David Karoly, Professor of Atmospheric Science in the school of Earth Sciences at the University of Melbourne (now retired) and Professor William Happer, Cyrus Fogg Brackett Professor of Physics at Princeton University (now retired). This illuminating and wide-ranging debate, hosted by James Barham of, thoroughly explains the issues surrounding climate change.

The talk is mostly taken from my book: The Great Climate Change Debate: Karoly vs. Happer. Most of the text and illustrations in an earlier version of the talk, presented to the American Association of Petroleum Geologists (AAPG) in 2022, can be viewed here.

Solar Activity: Cycle 25 Surpasses Cycle 24

By Javier Vinós

Over the past two decades, solar activity has been characterized by an extended solar minimum spanning two solar cycles, known as the Clilverd Minimum. This phenomenon is currently affecting the climate, but before we can understand its impact, we must address the significant discrepancy between the solar effects observed in paleoclimate proxy records and modern observations. The relationship between solar signals and climate response is complex and not fully understood. However, there is substantial evidence from models and reanalyses that the relationship exists. A recent hypothesis is that the solar signal modulates heat and moisture transport to the Arctic, which explains its relatively small effect during a single solar cycle. However, when an anomaly in solar activity persists over several cycles, as it did during the 70-year modern solar maximum, its effect accumulates and has a large impact on the planet’s energy budget. Understanding this mechanism is critical to understanding the overall impact of solar activity on our climate.

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A Twitter Debate on Clintel’s IPCC AR6 Critique

By Andy May

In May 2023, Clintel published a book (see figure 1) criticizing AR6 (IPCC, 2021), a publication that was supposed to summarize climate science research to date. We found that AR6 was biased in its reporting of recent developments in climate science, and they ignored published research contrary to their narrative that humans have caused all the warming since the Little Ice Age (the so called “preindustrial”), and that recent warming is somehow dangerous. Comments and reviews of the Clintel volume can be seen here and on Judith Curry’s website here.

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Figure 1. The Clintel critique of the IPCC AR6 report. More details here or click on the image.

This post discusses a twitter debate about possible mistakes in the Clintel volume, specifically the Chapter 6 (written by Nicola Scafetta and Fritz Vahrenholt) discussion of the evidence that changes in the Sun affect Earth’s climate. We argue that recent evidence supports a role for the Sun in modern climate change, and the IPCC argues that the Sun has not contributed to recent (since 1750, see AR6, page 959, figure 7.6) warming or recent climate change.

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A Critique of AR6

By Andy May

Read in German here, courtesy of Christian Freuer.

After more than two years of hard work, Marcel Crok, I, and 11 other scientists have finally published our critique of the Intergovernmental Panel on Climate Change (IPCC) sixth report (AR6). The entire book has been extensively peer reviewed and a low-resolution pdf of a nearly final draft of the book has been available for weeks at All comments received on this draft have been carefully considered and incorporated, if approved by the team, in the final book. We are a bit hard on AR6, but our criticisms are well deserved. Only the eBook is out now, the print edition should be along in a week or two. The Kindle edition is text-to-speech enabled. Available at Amazon and Kobo.

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The Holocene CO2 Dilemma

Guest Post By Renee Hannon

This post evaluates the relationship of global CO2 with regional temperature trends during the Holocene interglacial period. Ice core records show that CO2 is strongly coupled with local Antarctic temperature and slightly lags temperature over the past 800,000 years (Luthi, 2008). Whereas the emphasis has been on CO2 and temperature lags/leads, this study focuses on Holocene millennium trends in different latitude-bounded regions.

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