One of the reasons I call myself a climate change agnostic — I’m not yet persuaded that man-made influences on the climate are pushing temperatures calamitously higher — is that there are alternative explanations for what has been driving long-term temperature fluctuations on the planet. One serious body of thought, largely overlooked by the climate establishment, posits that sun spots have a significant influence on the climate. That proposition is due to experience a major test.
As I understand it, sun spots are said to exercise an effect on climate through a complex chain of physical causation. According to this theory, sunspots indicate a heightened level of electro-magnetic activity on the surface of the sun. Electro-magnetic energy ejected from the sun interacts with the Earth’s magnetic field to reduce cosmic radiation penetrating to the atmosphere. Cosmic radiation interacts with chemicals in the atmosphere to seed certain types of cloud formations that reflect sunlight. The prediction arising from this series of conjectured linkages is that a dearth in sunspots will result in weaker electro-magnetic forces radiating from the sun, less blockage of cosmic rays, more cloud cover and lower temperatures.
Sun spots come and go in regular cycles, but the cycles vary in amplitude. As it happens, the sun is experiencing one of its weakest solar cycles in a century. (See this account at Vencore Weather.) Weak solar cycles — the so-called Maunder Minimum of 1645 to 1715 and the Dalton Minimum of 1790 to 1830 — coincided with the Little Ice Age. Some critics of the “consensus” climate-science view — that human-caused increases in carbon dioxide in the atmosphere is the critical variable driving climate change — suggest that the paucity of sun spots will induce a cooling of the Earth.
After reaching a new plateau of high temperatures in the 1990, the planet is in the 18th year of no meaningful temperature increases. That pause was not predicted by anyone hewing to the Global Warming “consensus,” and scientists are busily working to explain it within their own paradigm. But it’s also put-up or shut-up time for advocates of the sunspot hypothesis. If sunspots play a significant role in Earth’s climate, the weak solar cycle soon should be reflected soon in lower temperatures.
If global temperatures actually decline in the next few years, we could reasonably conclude that predictions of the Warmist camp to be refuted and the conjectures of the sunspot camp to be confirmed. On the other hand, if temperatures don’t decline, the sunspot people will have to go back to the drawing board and scribble some new equations. The one thing neither group is predicting is another two decades like the past two. It is entirely possible that both camps will be confounded. Wouldn’t that be something?