Corn yields truth about summer drought

Corn yields truth about summer drought
September 1, 2000

The most impressive thing about this summer’s vaunted drought—called an “ultra-drought” by CBS icon Dan Rather—is that it wasn’t one. Whereas Rather called this a “summer to survive” in the Midwest, it actually looked more like a summer to grow.

Illinois experienced what is at least its third-wettest June (records go back to 1895). Toward the end of June, the entire state of Illinois, 90 percent of Missouri and Wisconsin, and half of Iowa were reporting unusually moist conditions. We think that qualifies as the “Midwest.”

But why should we be surprised by this spate of climate hyperbole? That kind of drought hype is about as repetitive as Vice President Al Gore saying “risky.” Last summer, for example, we were bombarded with the same story, even though less of the country than normal was experiencing a significant moisture shortage. Both the ostensible drought and forecasts of more of the same were based upon the appearance of La Niña (unusually cold) conditions in the tropical Pacific.

Going back just another year, recall the agricultural disasters predicted because of El Niño, the warm phase of this common Pacific oscillation. One major network featured brown cornstalks and a cloud of dust in August. That was in Texas, where corn is normally brown in August, given that it’s planted early in the year. As for the dust, it was kicked up by a harvester plucking fat ears.

The beating goes on and on. And what we find most interesting is that people continue to eat. Well and cheaply, we might add. What gives?

Let’s stipulate that supply and demand determine price. For food, the latter is increasing because there is a larger number of demanding mouths to feed. Everything else being equal, the price of food should increase slightly as a result of that. But adding in the effect of the 2000 drought, the 1999 drought, the 1998 drought, and so forth should be as calamitous as the Network News.

In an attempt to verify all these terrible stories, we plotted out the price of corn in dollars per bushel, allowing for inflation. What is immediately obvious is that the price of corn is lower than it has ever been. Despite all the weather gloom and doom, as well as the population increase, the relative supply of the most important crop produced by the most important agricultural nation in history must be increasing.

Our greener pals keep blaming us for the fact that Americans just don’t seem to care about global warming. But perhaps they ought to look in the mirror. Constantly hawking weather disasters has a way of losing its credibility in the face of agricultural abundance.

It is absurd to conflate warming with food shortages. The corn yield history was virtually steady for the first half of the twentieth century, followed by a dramatic rise in the second half. Today, one acre of land produces almost four times as much corn as it did 100 years ago.

During that same time, U.S. temperatures varied considerably from year to year and decade to decade. Obviously, there is little if any correspondence between the nation’s temperatures and its crop yields.

What warming the United States has seen in the last three decades has been primarily in winter and, within that season, largely confined to the coldest air masses—a prediction from greenhouse theory that the climate Cassandras rarely tout. A temperature change of this sort is beneficial for crops because it lengthens their growing season.

Another benefit for crop production is the ever-increasing atmospheric level of carbon dioxide. We can certainly assert with confidence that the presence of additional carbon dioxide is responsible for about 10 percent of this abundant harvest.

The evidence is in. Today’s climate is a boon to agriculture—no matter what you may hear on the evening news.


References

Michaels, P.J., et al., 2000. Observed warming in cold anticyclones. Climate Research, 14, 106.

National Agricultural Statistics Service, www.usda.gov/nass.