Renewable Farming

Wild weather calls for healthier soil to give you more yield resilience

Here in northeast Iowa, forecasters peg the low tonight, Jan. 30, 2019, at 29 degrees below zero. Last night’s wind chill was 40 below. Elsewhere around the Midwest, wind chills set records of 70 below. I’m a skeptic of human-caused global warming, and tempted to mutter a lame sarcasm like, “Where’s global warming when we need it?” But I’d prefer to share with you a more useful perspective while weather is on your mind. A perspective which could encourage you to build more yield resilience into your soils, so your farm generates more consistent yields whether warmer, cooler, wetter or drier climates prevail in coming seasons.

January 30, 2019    By Jerry Carlson —  Earth’s climate has constantly changed over the centuries. The rubble of civilizations which failed to cope with epochs of adverse climate litter every long-inhabited continent. When correlated, archeology and climatology reveal that warmer climates incubated healthier crops, civilizational advances, and peace between people groups. Cooling epochs imposed hunger, distress and brutal conflicts. For a thorough background on long-term climate change, buy a copy of the classic book, Climate and the affairs of men by Iben Browning and Nels Winkless III. Scientist Iben Browning, an early and expert climate-modeling mathematician, told me a couple of times: “We get our most accurate computer climate models when we ignore the presence of humans.”

Today’s environmental activists, media, and their UN enablers focus on constraining climate change by presuming to control emissions of carbon dioxide into the atmosphere. Billions upon billions of taxpayer money to battle carbon emissions diverts public investment from preparing agriculture and infrastructure for climate changes which are certain to occur, difficult to predict and impossible to control. Taxing, restricting and trading the right to emit carbon dioxide shows little possibility of meaningful control over climate. Independent climatologists and other observers remain skeptical of the UN climate-change mantra. Example: Tom Harris and Dr. Tim Ball, writing in the website PJ Media Jan. 29

A classic description of climatic impacts on previous civilizations emerged in 1953. You can download the PDF here: USDA soil scientist W. C. Lowdermilk’s classic Bulletin No. 99, Conquest of the Land Through 7,000 Years. He describes how soil degradation accelerated following climatic shifts toward cooling, which followed population growth in warmer epochs. Cooler, drier climates compelled ancient farmers to overgraze and over-till land. During benign decades, Rome’s Caesars could confiscate abundant grain imports from a fertile, well-watered North Africa. When cooling and expansion of the circumpolar vortex forced a dry climate into the Mediterranean and North Africa, Rome decayed internally and collapsed before the barbarian hordes. No bread, no circuses.

Factors other than “greenhouse gas” impact climate. These are more forceful, cyclical and provable than the slow rise of atmospheric carbon dioxide. Variations in solar energy are a significant driver. Why doesn’t this cyclical forcing attract more research attention? Is one reason that politicians can’t regulate, trade or tax the sun? Political forces and grant-seekers mostly rejected a conclusion of the U.S. National Academy of Sciences in 1975: “…we do not have a good quantitative understanding of our climate machine and what determines its course. Without the fundamental understanding, it does not seem possible to predict climate…” 

However, one Midwest agronomist discerned a link between sunspot cycles and corn crops in 1973: Iowa State’s Dr. Louis Thompson. He analyzed and published the statistical linkage between the double sunspot cycle and U.S. corn yields. Dr. Thompson appeared at many Pro Farmer seminars in the 1970s, when I was an editor there. Few USDA officials fully absorbed the significance of Dr. Thompson’s key observation: Extremely low and prolonged solar energy emissions, as signaled by vanishing sunspots (magnetic storms on the sun) raise the odds of mid-American drought at the end of every other sunspot cycle, or about every 22 years. If you farmed in the 1970s, you’re aware of how crop shortages sent crop prices rocketing after the 1976 double sunspot low. 

Even earlier, MIT professor of meteorology Hurd Willett pioneered forecasting driven by shifts in the circumpolar vortex. He studied solar cycles his entire career, which started at MIT in 1929. Willett found correlations between solar energy and variations in what we now call the jet stream — the polar vortex. These are high-altitude winds which flow around both poles along lines of high latitude. When the outer edge of high-altitude jetstream winds circling the North Pole bulge southward more persistently, this expansion of westerly winds imposes more dry and cool air on North America. In 1951 the American Meteorological Society honored Willett for Extraordinary Scientific Achievement. His work was fundamental to understanding long-term climatic change. The “polar vortex” is common jargon in forecasts such as the nearby map showing this week’s Midwest deep freeze.

Today’s Wall Street Journal carries a page-one feature by Douglas Belkin on the midweek deep freeze, titled Temperatures Plunge to Lowest Levels in Decades as Polar Vortex Hits Midwest. It includes the NOAA illustration nearby showing the circumpolar vortex. Deep loops in the outer rim of this vortex, which flare like a ballerina’s skirt, allow polar air to reach lower latitudes while warmer air pushes north. It’s Earth’s mechanism for maintaining balance between polar regions and lower latitudes. 

Climatologist Bob Henson also reasons that cycles in solar energy activity influence the vigor of the polar vortex. Since the carbon-driven theory of global warming — oops, climate change — rose to dominate climate dialogue, few climatic scientists have dared to research solar influences. For most climatologists, the sun is a deadly “third rail” that kills grant money flowing to carbon-emission prognostications. Here’s a link to Henson’s analysis posted on the Weather Underground website.

Sunspot activity has plunged the past few years, ending another cycle. We’ve cautioned that cooler northern hemisphere temperatures are a distinct possibility, despite the obvious rise in atmospheric CO2. Cooling was also a major concern of Dr. Reid Bryson, a world-class climatologist. I interviewed him at the University of Wisconsin before he and Thomas Murray published Climates of Hunger in 1979. He pointed to centuries of evidence that cool, dry epochs kill civilizations. One focus of his archeological research was Southwest Iowa. I grew up on a farm there, and found abundant arrowheads and other native American artifacts when rains exposed them. Drought around year 1200 drove most of these Southwest Iowa tribes into the region which is now Kansas and Oklahoma. 

The media keep presuming that every California wildfire, and even this week’s tragic Pacific Gas & Electric bankruptcy, is a direct consequence of atmospheric carbon dioxide. (This mantra was also the motive for painting asphalt streets in California a lighter color, to reflect those invasive rays of sunshine.)

To test this localized presumption by the mainstream media, I dug out data on average annual rainfall in Los Angeles from 1877 to 2018 (chart nearby). Shrinking annual rainfall from 1877 to 1928 probably can’t be attributed to carbon dioxide, because precipitation rose again into the 1980s despite rising atmospheric CO2. The rainfall decline since the mid-80s looks like the same downtrend rate as the 1877-1928 pattern of drier seasons. Because of the huge annual variations, such trends are only detectable by smoothing the data. Southern California is climatically a near-desert anyway, averaging only 15 inches of annual rain. More likely, such slight rising and falling trends in rainfall reflect forces other than the steady rise in atmospheric CO2. Could it be linked to the long-observed Pacific oscillations, La Niña and El Niño? Or solar variations? Few climatologists get tenure or climate-change grants to study those possibilities. Billions for blocking greenhouse gas; ignore all else.


Another inconvenient truth about the “correlation” between atmospheric CO2 and temperatures was cited by Al Gore — but misinterpreted — in his 2006 lectures and video, An inconvenient Truth. Gore’s analysts constructed a graph based on readings of Antarctic ice cores purported to indicate South Pole temperatures, precipitation and atmospheric carbon dioxide content dating back more than 400,000 years. Gore claimed a high correlation coefficient between CO2 and temperature. That part was correct.The Vostok data is graphed below.

Close analysis of the data shows that temperature peaks occurred hundreds of years before carbon dioxide levels peaked. Which was the cause, which was the effect? Example: Around 325,000 years ago, atmospheric CO2 spiked to 300 parts per million, approaching today’s 400 parts per million. The peak in annual temperatures occurred a few hundred years earlier. However, this inconvenient truth doesn’t reflect clearly in Gore’s PowerPoint chart. Gore’s roadshow then dramatically projected CO2’s parabolic rise into the future, with global temperatures in lockstep. This projection, based on the controversial “Hockey Stick” statistical model, is troubled by opposing mathematicians. But global-warming disciples fiercely defend it. (One of our friends, a professor of statistics and author of a book used to teach statistics, showed me that she can generate a hockey stick graph using random data.)

Through all these scientific climate clashes, the double sunspot cycle of about 22 years is largely ignored as mere climatic noise in spite of historic chilly, crop-cutting eras such as the “Maunder Minimum.” That was a 70-year gap of very low sunspots during 1645 to 1715. It occurred in close relationship with the ‘Little Ice Age’ in the Northern Hemisphere. Correlation is not causation, but other prolonged sunspot lows also associate with cooler climate periods.

Latest available NOAA record of sunspot numbers


We’re urging growers to apply the principle of “semper paratus” (“always prepared,” the motto of the U.S. Coast Guard) for raising crops, in view of the longer-term trend toward lower solar activity. This applies especially in the next several years, as Sunspot Cycle 24 is ending after a series of successively lower peaks in previous sunspot cycles. If what has happened to Northern Hemisphere crops does happen again, cooler and more erratic growing seasons would call for a resilient, biologically alive soil to help buffer weather extremes. In the 2018 season, farmers who’ve managed for a strong biological base with cover crops, reduced tillage, application of mycorrhizal and bacterial inoculants while avoiding microbe-destroying chemistry endured too-wet, too-dry stretches with more stable crops. 

Here are examples of post-harvest reports we’ve seen from growers who track biological principles we advocate at Renewable Farming:

1. Less firing of corn during N-starving dry stretches.

2. Corn stayed greener in late summer, when the final 40 bushels is pumped into kernels.

3. Very little stalk rot disease and thus less stalk breakage before harvest.

4. More uniform yields across soil variations within fields.

5. Higher average yields.

6. Greater utilization of nitrogen and other applied fertilizers, as they made several applications via in-furrow, 2×2 on both sides of the row, streaming with Y-drops and other later-season applications during peak N demand.


Update January 31: Heavy press coverage of the Midwestern “polar vortex” intrusion reminded me of the “Schoolchildren’s blizzard of 1888” in the Midwest. It started January 12, 1888 and grew in ferocity January 13. It killed 235 people. Many were children caught by surprise in one-room rural schools of Nebraska and the Dakotas. (I didn’t start attending my one-room country school, Franklin Grove in Page County, Iowa, until 1941, so I wasn’t involved in the storm.) The relevant point is that the stunning invasion of polar air was a bulge in the polar vortex which looked almost exactly like the one which occurred this week. See the official government map of barometer readings nearby.

This 1888 loop in the vortex also occurred at an extreme low of the sunspot cycle, with some months of 1986 and 1987 showing less than 10 sunspots. The highs of three previous cycles also star stepped down — another similarity with the long progressions of weaker solar activity.

The tragedy galvanized Congress to invest heavily in US Weather Service forecasting and warning capability. This link takes you to the History Channel, which has more details on the blizzard story.


Visit this report again through February for further updates. It’s a developing analysis!