In the 21st Century, there is much debate about the extent to which human activity affects climate change. Current researchers call upon information gleaned from weather observations around the globe, from satellite data gathered by NASA, and from historical records. It might also be useful, as a way to get a mental picture of human-climate interaction, to collect some anecdotal evidence. No, we don't mean the kind where Grandpa says, 'In my day, the snowdrifts were five foot deep, and we walked barefoot 15 miles to school.' We need a more reliable primary source.
Primary sources contain first-hand accounts by eyewitnesses, or are artefacts contemporary to events they relate to. Can primary sources be inaccurate? Of course they can: they can be based on incomplete information, or they can consist of biased observations, propaganda, or outright lies1. What primary sources aren't is second-hand, hearsay accounts, or analyses based on review of the scholarly literature.
One way to gauge the effect of humans on the planet would be to look at the changes brought about in a given ecosystem that could be observed both before and after settlement. It's hard to do this in most cases, because humans have been wandering around the place for thousands of years. Most of the time, they didn't take notes, largely because they couldn't read or write and didn't own digital recording devices. But European humans started moving permanently to North America in the early 17th Century, and even in the late 18th Century, as the republican experiment called the United States was being born, there were still areas of eastern woodland that hadn't been settled by Europeans yet. We could watch this process if we had a reliable observer…oh, wait, we do.
Meet Joseph Doddridge
Joseph Doddridge (1769-1826) was born in Bedford, Pennsylvania, at that time a town on the edge of civilisation as European North Americans knew it. Which basically meant that beyond Bedford, there were no churches, schools, restaurants, or shops to be found (if you didn't count trading posts). What you needed, you'd better be able to find, catch, shoot, or make yourself, if you wanted to survive. As a child, Joseph and his siblings lived lives of hard work, hunger, and terror.
The hard work came from having to do everything from scratch. The hunger was mostly due to their high-protein diet: until their corn (maize) and squashes ripened, they had to subsist on game. The terror was provided by the people they called Indians. Throughout Joseph's childhood, there was almost perpetual war between the white settlers and Native Americans, who were competing for the same territory and who had very different ideas of how to share it. Although not all European and Native Americans were hostile to one another, some were, and atrocities were committed on both sides, as Joseph Doddridge points out in his memoir, Notes on the Settlement and Indian Wars of the Western Parts of Virginia and Pennsylvania from 1763 to 1783, published in 1824. Joseph Doddridge grew up to become the first Episcopal minister in trans-Allegheny Virginia2, as well as a physician. His observations on the rapidity of change in life around the time of the American War of Independence are unique. As Theodore Roosevelt notes, they are 'the most valuable book we have on old-time frontier ways and customs.' This book is our primary source, but in this case, we are only interested in evidence of human-induced ecological change.
What Was It Like?
One prominent feature of a wilderness is its solitude. Those who plunged into the bosom of this forest left behind them not only the busy hum of men, but domestic animal life generally. The departing rays of the setting sun did not receive the requiem of the feathered songsters of the grove, nor was the blushing aurora ushered in by the shrill clarion of the domestic fowls. The solitude of the night was interrupted only by the howl of the wolf, the melancholy moan of the ill-boding owl, or the shriek of the frightful panther. Even the faithful dog, the only steadfast companion of man among the brute creation, partook of the silence of the desert; the discipline of his master forbid him to bark, or move, but in obedience to his command, and his native sagacity soon taught him the propriety of obedience to this severe government. The day was, if possible, more solitary than the night. The noise of the wild turkey, the croaking of the raven, or "the woodpecker tapping the hollow beech tree," did not much enliven the dreary scene3.
Ignoring the judgement of the author, who finds this a 'dreary scene', what do we learn about the pre-settlement forest? It was quiet. The only noises come mostly from apex predators, such as wolves or panthers (mountain lions), because other animals are trying to avoid drawing attention to themselves. Doddridge makes an interesting observation about songbirds, which are mostly seed- and grain-eaters:
The various tribes of singing birds are not inhabitants of the desert; they are not carnivorous and therefore must be fed from the labors of man. At any rate they did not exist in this country at its first settlement.
A New Apex Predator
Agriculture changes an ecosystem in different ways: not only by felling trees and ploughing up land, but by creating different niche opportunities for wildlife. Settlers often came into conflict with apex predators, as well. One of the dangers of life in the backcountry was encountering bears. Bears were numerous at the time. They were also formidable.
It is said, that for some time after Braddock's defeat4, the bears, having feasted on the slain, thought that they had a right to kill and eat every human being with whom they met. An uncle of mine, of the name of Teter, had like to have lost his life by one of them. It was in the summer time, when bears were poor, and not worth killing; being in the woods, he saw an old male bear winding along after him; with a view to have the sport of seeing the bear run, he hid himself behind a tree; when the bear approached him. he sprang out and hallooed at him; but cuffee5, instead of running off as he expected, jumped at him with mouth wide open; my uncle stopped him by applying the muzzle of his gun to his neck, and firing it off; this killed him in an instant. If his gun had snapped, the hunter would have been torn to pieces on the spot. After this, he says he never undertook to play with a bear.
Early settlers conducted a sort of war with the bears, in which both sides ate the losers. Hunters like Tennessee's Davy Crockett supplied homesteaders with bear meat. Wolves, also a threat, were largely indigestible, and very much harder to kill. According to Doddridge, they were too cunning to shoot, and very difficult to trap. His speculation, based on observation, was that the sharp decline in the wolf population in the decades after settlement was mainly due to the accidental introduction of rabies – which was also a threat to humans, as it was incurable at that time6.
By displacing larger fauna, humans installed themselves as a new form of apex predator. Scavengers were also affected. Doddridge notes:
The buzzards, or vultures, grey and bald eagles, ravens, or as they were generally called corbies, were very numerous here in former times. It was no uncommon thing to see from fifty to one hundred of them perched on the trees over a single carcase of carrion. All these large carnivorous birds have nearly disappeared from our settlements.
Other Wildlife Changes
Doddridge points out that habitat loss was not the only result of increased human presence in the North American wilderness.
Our mornings and evenings are now enlivened with the matins and vespers of a great variety of singing birds, which have slowly followed the emigration from the other side of the mountain.
The honey bees are not natives of this country; but they always keep a little in advance of the white population. We formerly had some professed bee hunters; but the amount of honey obtained from the woods was never considerable, owing to the want of a sufficient quantity of flowers to furnish it.
In addition to bees and insects, rodents followed human migration – and even one marsupial.
Rats, which were not known here for several years after the settlement of the country, took possession of it, in its whole extent, in one winter season. Children of twelve years old, and under, having never heard their name, were much surprised at finding a new kind of mice, as they called them, with smooth tails.
Opossums were late comers into the country. Fox-squirrels have but a very few years ago made their appearance on this side of the mountains.
Rats, squirrels, and opossums were unwelcome visitors, as they ate grain, and spoiled crops and stored foodstuffs. It was a good thing for the settlers that they also brought cats and dogs with them for vermin control.
Doddridge sums up the shift in animal populations this way:
Thus our country has exchanged its thinly scattered population of savages for a dense population of civilized inhabitants, and its wild beasts and large, carnivorous fowls, for domesticated animals and fowls, and others which although wild are inoffensive in their habits, and live at least partially on the labors of man. This has been effected here perhaps in less time than such important changes were ever effected in any other region of the earth.
Human occupation and the shift to agriculture had altered the flora and fauna of the region. In addition to providing more grains to attract both rodents and songbirds, clearing away the dense undergrowth had reduced the number of insects, such as the sandflies that gave Punxsutawney, Pennsylvania its name. The songbirds may have helped fight the insects, too, as did the smoky fires the humans lit around their forts to chase away the biting insects from their cattle. Humans had attracted new pollinators, as well. But did these changes affect climate and weather? Let's see what Doddridge has to say.
Climate Change in Groundhog Country
Great changes have taken place in our system of weather…. At the first settlement of the country the summers were much cooler than they are at present. …The coldness of the nights was owing to the deep shade of the lofty forest trees, which everywhere covered the ground. In addition to this, the surface of the earth was still further shaded by large crops of wild grass and weeds, which prevented it from becoming heated by the rays of the sun during the day.
In other words, the change in ground cover had an immediate effect on mean temperatures. Summers were mostly dry, and frost set in as early as September.
Hunting snows usually commenced about the middle of October. November was regarded as a winter month, as the winter frequently set in with severity during that month…
For a long time after the settlement of the country we had an abundance of snow, in comparison to the amount we usually have now. It was no unusual thing to have snows from one to three feet in depth, and of long continuance.
Doddridge claims to have noticed great changes in the Ohio Valley region's weather patterns in his lifetime.
From this history of the system of the weather of our early times, it appears that our seasons have already undergone great and important changes. Our summers are much warmer, our falls much milder and longer, and our winters shorter by at least one month, and accompanied with much less snow and cold than formerly. What causes have effected these changes in our system of weather, and what may we reasonably suppose will be the ultimate extent of this revolution, already so apparent, in our system of weather?
Doddridge believes that agriculture will lead to warming.
Every acre of cultivated land must increase the heat of our summers, by augmenting the extent of the surface of the ground denuded of its timber, so as to be acted upon and heated by the rays of the sun.
The future prospect of the weather throughout the whole extent of the western country is not very flattering. The thermometer in the hottest parts of our summer months already ranges from ninety to one hundred degrees. A frightful degree of heat for a country as yet not half cleared of its native timber! When we consider the great extent of the valley of the Mississippi, so remote from any sea to furnish its cooling breezes, without mountains to collect the vapors, augment and diversify the winds, and watered only by a few rivers, which in the summer time are diminished to a small amount of water, we have every data for the unpleasant conclusion that the climate of the western regions will ultimately become intensely hot and subject to distressing calms and droughts of long continuance.
Meteorology was not a well-developed science in North America in the late 18th Century, but weather deeply concerned all European Americans from the beginning. After all, at the first census in 1790, 97% listed their profession as 'farmer'. The Farmer's Almanac began publication in 1818 and has been continuous since then.
Was Doddridge deeply concerned about human-induced climate change? Yes and no. On the one hand, as a physician, he worried about climate-related human health issues:
Already we begin to feel the effects of the increase of the heat of summer in the noxious effluvia of the stagnant water of the ponds and low grounds along our rivers. These fruitful sources of pestilential exhalations have converted large tracts of our country into regions of sickness and death, while the excessive heat and dryness of our settlements, remote from the large water courses, have been visited by endemic dysenteries in their most mortal states.
On the other hand, Doddridge seems to have thought that these sorts of changes were inevitable. In addition to noticing that Virgil, the 1st-century-BCE Roman poet, had already noticed the connection between agriculture and climate change, Doddridge is also aware of the interconnectedness of various ecosystems on the North American continent.
The conflict for equilibrium between the rarified air of the south and the dense atmosphere of the north will continue forever the changeable state of weather in this country, as there is no mountainous barrier between us and the northern regions of our continent.
Doddridge himself lived through one unusual weather event which he doesn't mention in his book: the 'Year Without a Summer' of 1816. Lowering of the planet's temperature by .4-.7°C worldwide resulted in severe food shortages in North America. Doddridge may not have known it, but the disastrous year of Eighteen-Hundred-and-Froze-to-Death was probably caused by the 1815 eruption of Mount Tambora in the Dutch East Indies (Indonesia), the largest volcanic eruption in recorded history.
Weather on this planet is, indeed, interconnected. Both geological and man-made events affect it. Few, if any, could have foreseen the monumental changes brought about by the Industrial Age. Doddridge may not have envisioned the far-reaching effects of massive shifts in land use. If he had, he might have been more worried about human activity than he was about bears.
For Follow-Up Reading
Would you like to read more from Dr Doddridge? He has a lot of fascinating stories, and he's free to enjoy on archive.org.