Solar Activity and Sunspot Numbers

In general, low sunspot numbers are associated with colder periods in our history. The Little Ice Age (LIA) lasted for several centuries (early 1600’s to the late 1800’s). The Maunder Minimum represented the depths of the LIA. The Thames River in England routinely froze over during this period (as evidenced by the winter fairs). The Dalton Minimum was another cold period across the entire Northern Hemisphere. Crop shortages, mass starvation and civil strife were common during these cold periods.  More recently, those old enough will remember the cold and winter storms we experienced during the 1960’s and 1970’s. Those lower temperatures correspond to Solar Cycle 20 (a dip in both sunspot numbers and solar activity). And despite media reports of continued “Global Warming”, four of the last six winter years in North America have been colder and snowier than average (2013/14, 2014/15, 2015/16 and 2017/2018). The story is similar in Europe with several colder and snowier winters than normal since the new millennium (2002/03, 2005/06, 2009/10, 2011/12 and 2017/2018).

However, the sunspot numbers are very qualitative and therefore only loosely associated with climate changes. Solar activity (as measured by Total Solar Irradiance (TSI)) ties much better to climatic changes. Solar activity has increased significantly since the depths of the Little Ice Age. A significant portion of the increased temperature over the last 150 years is due to that increased solar activity. Solar activity peaked around 1950 and has remained relatively stable since then. As a result, I believe the temperature increase since 1950 has been strongly influenced by the increasing CO₂ levels in the atmosphere, but that future influence will be negligible over the next two decades.

Future solar activity is forecasted to decline quickly over the next few years/decades. If those declines take us back to the Dalton and Maunder Minimum TSI levels, we are going to experience the same hardships associated with every historical “Grand Solar Minimum” humankind has experienced. The moderate warming effects of CO₂ will not prevent the cooling effects associated with the decline of our sun’s activity.

Cycles 23 and 24 are detailed in the above chart, with sunspots in blue and TSI in red. Cycle 24 has a sunspot number count that is reminiscent of the Dalton Minimum. However, TSI is higher than the Dalton Minimum. As a result, temperatures have not yet begun to fall (although they have stagnated for the last 20 years). A couple of quick notes. Cycle 24’s duration (9 years) is noticeably shorter than the typical 11 year cycle. Sunspot activity is very low right now with 106 out of 199 days in 2018 showing zero sunspots. Sunspots were only present for 4 days in July 2018 with no sunspots over the last 10 days.

Cycles 25 and 26 are forecasted to have both lower sunspot numbers and TSI. Colder temperatures and extended winters are very likely to soon become the norm.

The chart included below compares the solar activity over the last 200 years with the solar activity of the previous 200 years.

The two tracks are remarkably similar. The solar activity magnitude is different for each of the periods, but the general trends are consistent. The Total Solar Irradiance (TSI) has been declining rapidly since the yearly 2014 peak. That decline is not yet showing up in the 10 year MA (moving average) but the decline will become noticeable as we move further into the upcoming Grand Solar Minimum. As mentioned on the previous page, Abdussamatov’s forecast suggests solar activity levels will drop back down into a range equivalent to the Dalton or Maunder Minimums.

The solar activity levels over the most recent 200 years is noticeably higher than previous 200 years. The previous 200 years corresponds directly to the Little Ice Age (LIA) and includes both the Maunder Minimum and the Dalton Minimum. Low solar activity and cold temperatures began right after the Medieval Warm Period as shown in Figures 12 and 13 from the main text and also included the Sporer Minimums. The LIA corresponded closely with the lowest solar activity in the last 7,500 years. The Modern Maximum corresponds closely with the highest solar activity over the last 7,500 years.

Solar and astrophysics are not my area of expertise so I’m not going to go into detail on the science. I’ll stick to looking at the data and the correlations. I have however included a quick summary below from a colleague scientist that highlights the bigger solar picture and is in line with my own views.

“Connections between variations in earth climate and changes in solar radiation have been known by historic observers, but measured in more detail only since the last century.

• The glacial stages of the Pleistocene and the behaviour of the interglacials were tied to the eccentricity of the earth’ orbit around the sun by Milankovitch’ painstaking manual calculations. 
• Detailed isotope work and paleobotanic research ascribed variations in solar radiation as the cause of distinct cyclic climate changes occurring in the (interglacial) Holocene as well.
• Svensmark’s cloud chamber experiments and those with the CERN reactor showed how the galactic cosmic ray stream could be influenced by changes in solar radiation and so eventually affect cloud cover on earth.

The cyclic patterns of changing climate can range from tens of years (the historic ones) to thousands of years (100,000 years In the case of the ice ages). That should be no surprise because these patterns are astronomic and find their origin in the conjunctions and oppositions of our fellow planets circling the sun.  The large “inner planets” (Jupiter, Venus, Saturn) are able to affect the circular pattern that the sun follows around the gravitational centre of our solar system.

The interior solar convection and the sun’s dual dynamo are apparently affected by the process, because the inner orbital behaviour of the sun shows a cyclicity with elements similar to that of the magnetic output.

It is not per se the solar radiation which directly affects climate on earth. But the solar variations can be found in cyclic patterns of temperature, oceanic oscillations, cloud cover and precipitation. Atmosphere and oceans are the transmitters, and all with various amounts of time delay.” The IPCC’s mandate is to assess human influence on climate, and though it does include some review of natural forces, many solar physicists say the review is cursory and typically confined to changes in Total Solar Irradiance (TSI), which is only one element of solar activity. As has been noted, one IPCC report contained reference to only one solar physicist who cited their own single research paper as evidence that the sun’s role was minimal. It is unusual to draw a scientific conclusion from a single reference.