It is Time to Bury the Grand Solar Minimum Myth

From Watts Up With That?

By Javier Vinós

Fourteen years ago, a new climate myth was born. A grand solar minimum (GSM) was in the making that would not only reverse global warming but plunge the planet into a new Little Ice Age, surprising the warming alarmists and causing undue suffering. The time has come to bury that myth.

1. The origin of the myth

The deep solar minimum of 2008-2009 was a complete surprise to solar physicists. They did not know that solar activity could become so low because it had not occurred during the time of solar observations with modern instrumentation. In 2009, a solar scientist named Habibullo Abdussamatov published a paper in Russian in which he argued that the following years would see a major cooling based on the onset of a new GSM. His evidence was

  • The low solar activity of the then ongoing solar cycle (SC) minimum 23-24.
  • A bicentennial cycle in solar activity that supposedly decreased solar activity after 1600 and after 1800
  • The pause in global warming since 1998

Figure 1. From Abdussamatov 2009. “The Sun defines the climate”. Nauka i Zhizn, N1, pp. 34-42.

This prediction reached the West and became very popular, like any catastrophic prediction, actually. Articles about the arrival of a GSM proliferated on climate blogs, such as the one on WUWT: The ‘Baby Grand’ has arrived.

Other scientists, such as Livingston & Penn and de Jager & Duhau, joined Abdussamatov in 2009 in proposing the arrival of a GSM, though being more cautious about its climatic effects. It went so far as to threaten the global warming narrative at a time under assault from the Pause and Climategate. Thus, none other than Stefan Rahmstorf came to their defense saying that according to the models

“a new Maunder-type solar activity minimum cannot compensate for global warming caused by human greenhouse gas emissions.”(Feulner & Rahmstorf 2010)

2. 2012-2015, the myth’s golden years

After 2009 solar activity was slowly increasing, and it was clear that SC24 was a cycle the likes of which had not been seen in nearly a century. Many scientists were writing papers on an SGM, which had gone from hypothesis to serious possibility. Abdussamatov published new papers in English in 2012 and 2013.

In 2011, Swedish sea level expert Nils-Axel Mörner published an article in one of the few journals still accepting skeptical contributions, Energy & Environment. He began with a bold statement:

“Around 2040-2050 we will be at a new major Solar Minimum. A new ‘Little Ice Age’ in the Arctic and northwestern Europe can be expected then,”Nils-Axel Mörner, 2011

a claim for which he provided no evidence other than an extension of solar activity based on the sunspot record.

Two years later, Nils-Axel got 18 other researchers to participate in the first issue of a newly created journal, Pattern Recognition in Physics. It was a special issue on how the orbits of the planets might cause solar variations. It included a letter signed by the 19 researchers that constituted a frontal attack on the IPCC conclusions. Among the signatories were well-known researchers such as Willie Soon, Nicola Scafetta, Ole Humlum, David Archibald, Harald Yndestad, and Don Easterbrook, as well as some people active on the Internet, such as Tallbloke. The predictable result was the cancellation of the magazine by its publishers. The letter ended with a conclusion and two implications agreed upon by the signatories. The second implication is relevant here:

“Obviously, we are on the way to a new grand solar minimum. This casts serious doubt on the question of continued, even accelerated, warming as claimed by the IPCC project.”

By then, lots of articles were being published about the coming GSM and its possible effect on climate (de Jager & Duhau 2012; Solheim et al. 2012; Anet et al. 2013; Steinhilber & Beer 2013). Multiple articles on the Internet made the myth very popular among climate skeptics and alarmists, attracted by the catastrophic nature of a new ice age.

3. Valentina Zharkova’s stardom.

It was in July 2015 when the myth jumped into newspapers around the world. A Northumbria University researcher, Valentina Zharkova, presented her solar model at a meeting, and the news release highlighted that it predicted a “60% drop in solar activity in the 2030s, to ‘mini ice age’ levels.”

The climate connection was not made by her, it was made by those who wrote the press release. Her paper (Zharkova et al. 2015), published that same year, included nothing about climate. She herself said:

“In the press release, we didn’t say anything about climate change. My guess is that when they heard about the Maunder minimum, they used Wikipedia or something like that to find out more about it.”Valentina Zharkova

Her research was linked to climate change and the Little Ice Age only after the media coverage. However, she said that it made sense to her once the connection was made. She liked the attention. To this day, she continues to link her research on solar activity to climate effects. In a 2020 editorial for the journal Temperature (Zharkova 2020), she writes:

“This, in turn, can result in a decrease in Earth temperature of up to 1.0°C relative to the current temperature over the next three cycles (25-27) of grand minimum 1. The largest temperature drops will [occur] during the local minima between cycles 25-26 and 26-27.”Zharkova, 2020

Irina Kitiashvili, a NASA researcher, also has a model that predicts SC25 will have about half the activity of SC24 (Kitiashvili 2020). The problem with the Kitiashvili and Zharkova models is that they are a complex linear extrapolation of the decreasing solar activity since SC21 in 1980.

4. 2018 turns the tables

A paper by Zharkova’s group in 2018 (Popova et al. 2018) pushed their model back 800 years and was harshly criticized by prominent Finnish solar researcher Ilya Usoskin (Usoskin 2018). He was a reviewer for the paper but his review was lost through the publisher’s system and subsequently published as a commentary. Usoskin stated with good reason that:

“it is impossible to make harmonic predictions for thousands of years based on only 35 years of data,”Usoskin, 2018

and that the model output was contradicted by observations.

Figure 2 is a figure from Zharkova et al. 2015 with my annotations in red.

While the Maunder Minimum is where it should be, the Spörer Minimum, the largest GSM in thousands of years is missing in action, instead, she misleadingly labeled the period 1350-1500 as the Medieval Warm Period which took place at least 300 years earlier. Zharkova had joined the ranks of climate scientists willing to misrepresent the data to further their careers. Zharkova’s model is not worth the computer time it consumes. This is a sad reality for so many models today.

In 2018 the new solar minimum was arriving, and climate blogs published numerous articles about a coming GSM. A solar minimum is also the time when the solar polar fields reach their 11-year maximum values, which allows us to predict the strength of the coming cycle using the polar field precursor method. At a meeting in 2018, Leif Svalgaard made public his prediction that SC25 should have slightly more activity than SC24, not less.

5. January 2023 already has as much activity as February 2014.

February 2014 was the most active month in SC24, with 146.1 sunspots, and 166.2 solar flux units (sfu) in the 10.7 cm radio band, the other way to measure solar activity. January 2023 had 143.6 sunspots and 176.6 sfu, matching the activity of the most active month in SC24 (Figure 3).

Figure 3. Solar activity as measured by monthly sunspot number (left, black) and 10.7 cm solar flux (right, red), between 1975 and January 2023.

The smoothed sunspot number used by SILSO to determine solar cycle onset, solar cycle end, and solar cycle maximum is delayed by 6 months due to smoothing. However, it consistently shows that SC25 is slightly more active than SC24 at the same distance from the minimum.

Figure 4. Using SILSO’s smoothed sunspot number SC25 shows slightly more activity than SC24. Source: Jan Alvestad

There is a long time left until SC25 ends, predictably around 2031-32, but it is no longer defensible to claim that SC25 will be much less active than SC24. Therefore, fears that a GSM will develop during the next solar cycles should end.

6. Solar spectral analysis knew it since 2006

Before this whole story started, before the polar field precursor method had a prediction for SC24, before anyone knew that a decline in solar activity was coming, in 2006 Mark Clilverd, along with other British and Finnish researchers, published a paper entitled “Predicting solar cycle 24 and beyond” (Clilverd et al. 2006). In this remarkable paper, they used a spectral method based on secular cycles in sunspot numbers to predict that cycles SC24 and 25 would have much lower activity than previous cycles, but would be followed by SC26 when activity would begin to recover (Figure 5).

Figure 5. Clilverd’s model predicted two cycles of low activity long before they happened.

Recall that in 2006 NASA scientists predicted a large solar cycle 24, larger than SC23.

Being the first to predict the current extended solar minimum as the expansion of only two cycles and giving the correct dates, it is only fair that this extended solar minimum is called the Clilverd Minimum.

I also did a simple spectral model of past and future solar activity in 2016, which I posted in a commentary on WUWT. The model was refined in 2018 for my book and appears in Chapter 13 (21st Century Climate Change). The variable modeled is the total number of monthly spots in a cycle from start to finish, since the maximum activity is a less reliable variable. It cannot predict the length of a cycle, so it assumes 11-year cycles (Figure 6). If a solar cycle is not precisely 11 years long, the shape of the cycle will be affected, but the overall solar activity should not be affected.

Figure 6. Spectral model of solar activity showing the centennial Feynman cycle (F1-F4) and predicting solar activity until 2130. Figure from Vinós 2022.

This model also predicted in 2016 that no GSMs should occur in the 21st century. In fact, it may be two to three centuries before humans experience a GSM again. Not a bad outcome if it turns out to be correct, as GSM have a very strong negative climatic effect (Vinós 2022).

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