Climate change through a different lens

We dig into the Today’s Farmer archives to bring historic perspective to our most recent drought.

The weather is discussed more frequently than any other topic which affords a subject for convenient conversation. It has been so since the dawn of civilization and doubtless for countless ages before. This is but natural, for the weather is not only our constant companion from the cradle to the grave, but it has a direct bearing on our individual and even national welfare.

To many city dwellers it may have but a passing interest, but to the farmer it is of vital concern, for upon the weather depends largely the returns from his labor. Crops are at the mercy of the weather from the time of planting until the harvest. It is the farmers’ working partner, so to speak, but this “silent partner” has a moody disposition. Instead of supplying temperatures, sunshine and rain in the right proportions, it may be damaging storms of wind and hail, untimely frosts, destructive floods or devastating drought. Agriculture is subject to greater risks than is any other major, legitimate industry of our country, yet it is basic—not only for our national welfare, but for our very existence as a nation.

While crops are subject to loss or destruction from various weather elements, the most important are temperature and rainfall—especially the matter of droughts. Drought has been man’s relentless enemy down through the ages.

The earliest historical reference to periodic deficiencies in rainfall is found in the Bible, where we are told of years of plenty followed by years of famine. Thus, at the outset, we see that recurring, disastrous droughts are not a product of recent years as some apparently think. They are of especial concern, however, in areas having normally scanty precipitation. Little is known of the agriculture of prehistoric man, but in that part of the world supposed to have been the cradle of the race, rainfall is insufficient for successful agriculture under natural conditions.

However, from the ruins of irrigation canals, to supplement the moisture supplied directly by nature, it appears that the dependence of crops upon rainfall was recognized at the very dawn of history. As early as 3000 BC, if not earlier, man was a tiller of the soil and garnered a harvest; and from that remote date up to the eighteenth century the history of agriculture and the weather is contemporary with that of civilization itself.

Many people think, because of the recent successive drought years, that our climate is permanently changing, either naturally or from some act of man. The popular fallacy that man can basically change climate or that it is changing from some other cause is not a product of the 20th century by any means. It is as old as historical America. In the log of one of Columbus’ voyages, the following is found:

JAMAICA, July 18,1494
In the western part of Jamaica there gathered every evening a storm of rain, which lasted about an hour, more or less, which the Admiral [Columbus] said he attributed to the great woods in those countries, for that he knew was usual, at first in the Canary Islands, and the Azores, whereas now the woods are cut down that shaded them, there are not such great and frequent storms of rain as there were formerly.

In Volney’s “Climate of the United States of America” (London, 1804), Thomas Jefferson’s weather diary is quoted as follows:
“A change in our climate is taking place very surely. Both heat and cold are becoming more moderate within the memory of even the middle-aged, and snows are less frequent and less deep.”
Volney says that Jefferson’s conclusions on this matter as to a marked change in climate was verified also by older residents with whom he discussed the matter in Kentucky, Ohio, Pennsylvania, New York and New England. Yet the records Volney gives as to average rainfall are about the same, in general, as those of recent years, more than a century and a quarter later. These impressions evidently were occasioned by the now well-known comparatively long-time trends in climate.

This brings us to the question, is our climate changing?
The answer depends on just what is meant by a change in climate—whether a temporary change or a permanent change. For a good many years up through 1936 there has been a tendency toward warmer and drier weather, the trends being especially marked during the past quarter of a century, notwithstanding an occasional bad flood or severely cold winter.

Take the winter season for example: With the exception of that for 1917-18 and 1935-36, the winters for the past 25 years or more, considering the country as a whole, have been uniformly warmer than normal.

Also, in the matter of rainfall, there has been an equally marked tendency to droughts in recent years. However, an examination of the longer weather records of the country, going back 100 years or more, indicates that this does not represent a permanent change of climate, but rather a warm, dry phase of our normal climate, to be followed, doubtless, by a cooler, wetter phase, when there will be more rain in summer and lower temperatures in winter.

The weather and the climate
Let us explain it this way: We have weather and we have climate. Weather refers to conditions for a day, a week or even a year. We say, for example, that the weather last month was so and so. Climate is the average weather (temperature, rainfall, etc.) over a very long period of years. For the purpose of comparison, let’s say 100 years.

Now we know that our weather from day to day and week to week frequently goes in a more or less cyclic movement, something like the waves of the ocean. That is, a few cool or cold days are succeeded by several days of warmer weather, and frequently a few days of rain are followed by fair, sunny weather for a short period.

The same thing happens in climates—the only difference being that we count the time in periods of years instead of days. It is important to remember that these climatic cycles vary in length, just as do the weather cycles, resulting in some periods of light rainfall, or droughts, lasting longer than others.

Droughts in the United States may be divided into two general classes. In one class are those of a transitory nature, affecting usually a relatively small area and of comparatively short duration—frequently lasting only a single year. In the other are those general droughty conditions that have a tendency to persist for comparatively long periods of time. When a minimum phase of precipitation obtains, such as recently experienced, there occur at short intervals what may be called families of droughts, in contradistinction to the transitory, or short-period ones that fall in the first group.

Short-period droughts, in general, are characteristic of sections having comparatively heavy rainfall, such as east of the Mississippi River, and long-period droughts in areas of relatively light rainfall, such as the western Great Plains.

Prior to the minimum phase of precipitation responsible for the recent family of droughts, so to speak, the last general condition of this kind occurred in the latter part of the 80s and the early 90s of the last century. At that time, following a series of years with rather abundant rainfall, widespread deficiencies in moisture began in 1886 extending up to 1895, culminating in severe droughts in 1894 and 1895, the driest years of that minimum phase.

Following this there was a series of years with rainfall ranging generally above normal. In the period between the 1886-95 extensive drought and that beginning about 1930, there were several belonging to the transitory class (short-lived and often affecting seriously only comparatively small areas). Among these may be mentioned that of 1901 in the interior valleys and the Southwest. The following year, 1902, had plenty of moisture in most states.

Another transitory drought occurred in 1910, principally in the central and northern states and the South, but this again was largely a one-year affair. Another one in 1917 affected mostly the Southwest and northern Plains, and still another, in 1925, was severe in the South and Southeast.

Thus, for some 60 years up to 1930, there were a number of short-period droughts, but only one persistent and markedly dry phase of United States climate—that of 1886 to 1895, lasting, in general, about 10 years. Some years, of course, were better than others.

Three extremely dry years
The more recent dry phase began in 1930 and continued, with a few interspersions of fairly good years, such as 1935, up through the summer of 1936. There have been in this period three extremely dry years: 1930, 1934 and 1936. The few available precipitation records, covering 100 years or more, indicate that a general dry phase, somewhat comparable to that of 1886 to 1895, and the more recent one of 1930 to date, obtained in the 30s of the last century, or approximately 100 years ago.

The outstanding wet phase of the United States climate in the last century was from about 1865 to 1885, with a secondary maximum during the first two decades of the present century, though several transitory droughts were interspersed.

This summary refers specifically to that part of the country east of the Rocky Mountains. Some tree-ring records of the far Northwest indicate that there probably was a major precipitation phase at least in that area, soon after the middIe of the 18th century within period of 1755 to 1780, with a succeeding maximum phase culminating about beginning of the 19th century.

While study of long weather records has not as yet disclosed a law to justify a forecast of future droughts, such study does give historical background, which warns us that droughts in the future may be expected to be just as severe as those of the past. For example, the records show that in the early nineties, or some 40 years ago, there was a drought in the so-called “dust bowl” of the Great Plains about as severe as that recently experienced. Doubtless, when the present drought definitely comes to an end, there will be a period of years with comparatively heavy rainfall, just as before, and little will be heard about dust storms and the like.

But, in planning a permanent farm program for such areas, the basic considerations should include the practical certainty that dry climatic phases, at least as severe as the past, will recur.

There is much loose talk these days about changes in climate due to human activity, and various suggestions that man should do this, that, or the other thing to prevent droughts. Such talk is utter nonsense. But here we must distinguish between preventing droughts as such and doing certain things to modify unfavorable conditions when the droughts do occur. These two things are separate and non-related. Many theories are advanced as to the cause of the recent droughts. Those most frequently heard are extensive radio broadcasting and the drainage of small lakes, ponds, marshes and the like. Most of the others are too silly even to mention. The broadcasting theory may be disposed of quickly. It is definitely known that radio waves have no influence whatever on atmospheric pressure conditions nor on the temperature. Consequently, they could not affect condensation, the major factor in precipitation. Furthermore, some long records show that quite similar, or even more severe, droughts occurred many years before the radio was even thought of. If broadcasting is responsible for recent conditions, what was the sinister influence that caused the drought centering around 1850 and that in the early nineties of last century?