The Downside of Human Travel

Kristen Traband

Thousands of years ago, the average human being led a life in which he or she only traveled within a small area. These humans, who were hunter-gatherers, traveled only as much as was necessary for survival – they left land that was exhausted of resources in search of land that could provide them with the food and shelter they needed, and often returned to previously occupied land when the resources there had been restored. Human travel at this time was motivated solely by survival. In modern times, conversely, it is not uncommon for the average human to travel great distances for the purposes of business, entertainment, or other forms of pleasure. On a much smaller scale, the average human in today’s society must travel short distances many times in just one day, commuting to work, school, or to run errands such as grocery shopping. Travel has become an intrinsic part of modern human lifestyle, and has led to increases in human wealth and happiness. Not all aspects of human travel have been positive, however; on the contrary, human travel has had numerous negative effects on the environment, including the altering of ecosystems and the unnatural spread of disease, as well as increased levels of pollution and the depletion of vital natural resources. While man has mastered the technology of travel for purposes of human advancement, this progress has had many negative corollaries.

When human beings began their first ventures into travel and eventually into colonialism, they were met with the challenge of adapting to new landscapes, climates, and organisms. While most humans were able to acclimatize to their new surroundings, the environments into which they entered were sometimes unable to adapt to their new inhabitants. For example, in the famous case of Easter Island, located in the southeastern Pacific Ocean, human inhabitation of the island eventually caused the ecosystem there to fail. The Polynesian colonists who came to Easter Island were responsible for massive deforestation of the island, both directly and indirectly. In a direct way, the Polynesians who came to Easter Island cut down trees for the purposes of creating and moving moai, stone statues that were part of the religious traditions of the settlers (Ponting 4). The human inhabitants of the island cut down lumber at such a rate that the population of trees on the island was unable to replace itself. In addition to physically cutting down trees, the settlers were also responsible for deforestation in that they had brought rats with them when they had first came to the island, and the island quickly became infested with these rats. Whether the colonists meant to bring the rats with them as a source of food or whether the rats happened to be on the boats they used to travel to Easter Island, the rat population that came to inhabit Easter Island quickly became out of control due to the lack of predators and abundant resources on the island (Hunt 6). Anthropologists have uncovered gnawed seeds that date back the early days of human inhabitation of Easter Island, evidence that rats prevented the already dwindling tree population from regenerating. Deforestation crippled the ecosystem of Eastern Island, eventually leading to the extinction of many plant and animal species on the island. The human population on the island dwindled because of the resulting famine, disintegrating into a highly uncivilized and sometimes cannibalistic society. Human travel to Easter Island upset the balance of the island’s fragile ecosystem, leading to catastrophic consequences.

Human travel during colonial times also had an impact on disease transmission. One of the most devastating consequences of Europeans traveling across the Atlantic and settling in the New World in the sixteenth and seventeenth centuries was the widespread death that occurred amongst Native American populations due to the native’s susceptibility to European diseases. Because colonial Europeans had evolved from a culture that lived closely with domesticated animals, they had been exposed to many animal diseases and had developed a general immunity to the various forms of sickness over the course of thousands of years; humans living in the Americas had no such prolonged exposure and therefore were unable to build up biological defenses against them. Diseases such as smallpox, measles, typhus, and influenza ravaged populations in both Central and North America (Ponting 231). In Mexico, the great Aztec empire, which once boasted a population of approximately 25 million at the time Spanish conquistadors first arrived in 1518, saw their numbers dwindle to just six million in the mid-sixteenth century and to just one million by the year 1600 (Ponting 230). Diseases such as yellow fever and malaria also were brought to the New World by Europeans, causing catastrophic loss of life. While some diseases such as syphilis were transmitted in the other direction, from Americans to Europeans, the majority of the damage was incurred by the people living in America. By traveling from Europe to America and bringing with them a host of deadly illnesses that wiped out native populations, European settlers were able to take control of the Americas.

In more modern times, human travel has impacted the environment in that the crisis of global warming can mainly be attributed to pollutants found in engine exhaust. Increasing carbon dioxide as well as methane emissions have become a major problem, causing the ozone layer to deplete and therefore allowing more of the sun’s rays to penetrate the Earth’s atmosphere, leading to a trend of warmer temperatures across the globe (Blunier 2). Rising temperatures means that glaciers are receding and ice is melting in both the North and South Pole, causing the ocean level to rise. Scientists have predicted that the Earth’s ocean level could rise at a rate as great as one meter per century (Rincon), which would have disastrous consequences for the planet, including loss of land, increased flooding in costal areas, more severe storm systems, deserts expanding into forested regions, and extinction of many types of plants and animals, among others (Kerr 188). While some of the pollutants that are responsible for the depletion of the ozone layer are the byproduct of manufacturing and industrial production, a large part of the emissions can be attributed to the exhaust of automobiles, airplanes, and other gasoline-powered vehicles that aid human travel. As human culture has evolved to a mobile society, more and more people own and use personal vehicles, contributing to the exponential growth in carbon emissions over the last few decades. The average human uses their automobile to travel to work, to the hardware store, to the movie theater, and virtually anywhere else they desire to go. With so many people utilizing the convenience of personal vehicles to travel to various places, the atmosphere has become increasingly inundated with pollutants. The effects of global warming are already being felt across the globe, and if human beings remain a mobile society and continue to use forms of travel that pollute the world, the Earth’s ecosystem will surely suffer cataclysmic damage.

Over the course of a few thousand years, human beings have shifted from a virtually stationary culture to one of extreme mobility. The effect of this transformation on the environment has been decidedly negative – on a microcosmic scale, many ecosystems have suffered from human beings entering a previously uninhabited environment. Humans have continued to take advantage of the Earth’s resources throughout the course of history, and while the Earth has been able to adapt in many senses, humanity has done irreversible damage to the Earth, the effect of which will more than likely be strongly felt in the coming decades.

The film that won the Academy Award for Best Picture in 2007, The Departed, opens with a quote that epitomizes modern human machismo: “I don’t want to be a product of my environment; I want my environment to be a product of me.” Humans have seemingly lived by this mantra since the first man walked the Earth, and have by most means achieved the stated goal of impacting, rather than being impacted by, their environment. Only time will tell if humanity will be able to retain the upper hand in the fragile relationship between human life and the environment.



Blunier, Thomas "PALEOCLIMATE:"Frozen" Methane Escapes from the Sea Floor" Science 2000, vol. 288, pp. 68-69.

Hunt, Terry L. “Rethinking the Fall of Easter Island.”

Kerr, Richard A., "Global Warming is Changing the World." Science 13 April 2007, Vol. 316, No. 5822, pp. 188-190.

Ponting, Clive. A Green History of the World: The Environment and the Collapse of Great Civilizations. St. Martin's Press, New York, 1991.

Rincon, Paul. “Sea Rise Could be Catastrophic.”

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last updated 03/26/08