Renewable Farming

Another climate watcher warns: Sunspot lows point to potential climate cooling

One of the most instructive websites for tracking solar cycles is This link takes you to a page showing historic solar cycles. The general guideline is that Earth’s global temperatures often turn cooler in prolonged periods of low sunspot activity, an index of solar magnetic storms. Less incoming geomagnetic energy wraps around our planet during those cycles. Low solar activity historically associates with cooler temperatures in our main crop-growing latitudes.

November 17, 2018 — The chart at right below is a screen shot of the “long wave” of the sunspot cycle, lifted from the free educational site

When you open their live website, you can zero in on any part of the long cycle by dragging your cursor across the years you want to zoom in on. To return to the full chart, you click on the “Reset zoom” button on the upper right of the chart. The main point of this long cycle series is that the three most recent cycle peaks have proven successively lower. The June 1989 top had a 13-month average of 284 daily sunspots. The July 2001 top had a 13-month average of 174 daily sunspots. And the third top, in June 2014, had a 13-month average of only 116 daily sunspots. So for about 30 years, the overall chart trend of sunspot peaks sloped downward. 

That’s the pattern which worries climate watchers who’ve measured relationships between solar activity and Earth’s temperatures. Several are pondering the possibility of a stretch something akin to the “Maunder Minimum” of very low sunspot activity from 1645 to 1715. The term was coined by researcher John A. Eddy in a 1976 paper in the journal Science

English meteorologist John Dalton also tracked another sunspot quiet period from 1790 to 1830, and this period became known as the Dalton Minimum. Both of these quiet periods on the sun correspond to a cooler climate on Planet Earth.

In 1972-73, Iowa State University agronomist Dr. Louis Thompson pioneered the study of solar cycles in relation to U.S. crops, and warned USDA officials that the unusually low peak in sunspot activity in 1969, plus a rapid decline thereafter, raised odds of more cool, less productive corn and soybean yields. Officials mostly shrugged off Dr. Thompson’s caution, as U.S. average corn yields hit 97 bu. per acre in 1972 and dipped only slightly to 91 bu. in 1973. But in 1974, drought dragged average yields below 72 bu. per acre, nearly tripling corn prices to $3 a bushel. That ignited a land-buying boom, which ended with the infamous land price bust of the early 1980s.

The current sunspot cycle is approaching a low of 3 to 14 sunspot regions on a daily basis. Solar prognosticators vary widely in their expectations. Writer and activist Michael Snyder, whose forté is warning his blog readers to be “preppers” — prepare for the worst — just posted this analysis cautioning folks about global cooling ahead. 

Michael’s dramatic commentary extracts some scientific foundations from the sources he cites in his essay. We’re far more cautious in warning of climate calamities, but for several years we’ve encouraged farmers to manage toward cropping systems with resilience — the ability to smooth out yields through climate extremes. Essentially that means a soil base rich with humus and biological activity. Soils like that can support crops through dry stretches, absorb extreme rainstorms more readily, and recycle natural nutrients more quickly and completely. 

The ingredients for crop resilience: Sparing use of salt-based fertilizers. Very limited herbicide/pesticide application. Aggressive cover crop programs. Strip-till or no-till. Crop diversity, and livestock if you can make it fit.

Update Nov. 25, 2018A Warming Climate Brings New Crops to Frigid zones. That’s the headline of a lead feature in today’s Wall Street Journal. Reporter Jacob Bunge, one of the best WSJ writers to cover the ag beat in years, documents how Canadian farmers are expanding acreages of corn and soybeans in Alberta and elsewhere across Canada. They’re encouraged by annual average temperatures 3.6 degrees warmer than in 1950, extending the average growing season two weeks.

The presumption behind the WSJ analysis is that long-range global warming will persist indefinitely, fueled by man-made carbon dioxide buildup in the atmosphere. 

Climates have always changed throughout history — sometimes warming, sometimes cooling. The northern Sahara Desert was once Rome’s breadbasket. In America, the 1910-1930 decades saw a series of more abundant rainfall seasons in the High Plains of Kansas, Oklahoma and western Nebraska. That rain, plus higher wheat prices, led to plowing as much as 200 million acres of permanent prairie for crops — primarily wheat. Then climate shifted again. “Normal” drought years returned, and the Dust Bowl became part of America’s farming legend.

Iowa State University Extension Climatologist Elwynn Taylor documents that since the 1950s, southwest Iowa has gained about two inches of growing-season rainfall. But in its longer history, this region became cool and dry, driving native tribes farther south into today’s Missouri and Kansas. 

We need to keep such changes in perspective, and use all the technical tools available to build production resilience into our management systems.

Yesterday the Heartland Institute released an extensive critique of the latest United Nations climate change report, based on studies by climate experts outside the subsidized loop of the UN climate industry.