Mankind is just beginning to own up to our negative influence on the environment. A fierce debate will now likely arise on whether it is our right, as dominant species, to do as we will with the Earth. This paper is intended to preempt the argument that humans can act without regard for the environment by outlining some ways that we humans are still subject to the environment, namely to those occurrences termed natural disasters. When mankind disturbs nature’s balance, humans experience the repercussions along with the rest of Earth’s species.
One of the most obvious ways that humans have been affecting the environment is through the complete suppression of forest fires. Forest fires occur naturally and return the nutrients in plant debris to the soil. That fires are an essential element in the forest life cycle is evidenced by the existence of pyrogenic plants, which require fire to propagate. Suppression of forest fires is unique among human impacts because it is official policy intended to protect human lives and homes. However, if not allowed to burn off regularly, debris can accumulate and the next fire might have too much fuel to be suppressed. Such a fire would completely destroy forests (destroying even the fire-resistant pyrogenic trees) and efforts to save homes would prove futile because of the strength of the fire.
Other human influences with local impacts include landslides and mudslides. When forests are cleared or vegetation is disturbed in other ways, the underlying soils can become destabilized and prone to sliding because they are no longer bound by roots. Many practices can exacerbate sliding. Building roads across steep slopes places humans directly in the path of slides. Some of the deadliest slides in history have been linked to unsound mining practices. Impermeable surfaces, such as roofs, streets, and parking lots, concentrate rainwater runoff onto the remaining soils and increase slide risk.
Loss of forests may also be linked to increased severity of droughts. Trees transpire water vapor into the air. Rainforests get their name from the resulting increase in precipitation. When the trees are removed from the cycle, the fertility of the area, and the surrounding areas of human habituation, diminishes. On a larger scale, decreased photorespiration as a result of deforestation might lead to increased global warming through higher atmospheric CO2 levels. Warmer temperatures could worsen drought conditions worldwide, potentially resulting in a fresh water crisis and famine. However, increases global temperature will also decrease the amount of water stored in glacial or polar ice. This could cause a dramatic rise in ocean levels. While some areas are experiencing severe drought, others will become permanently inundated.
Nature’s most violent disaster, the hurricane, has also been linked to global warming. Hurricanes harness the energy of sun-heated tropical waters. Global warming increases the severity of hurricanes by increasing surface water temperatures (i.e. more energy goes into the system). It is important to remember that none of the systems on Earth work in isolation. Loss of forest leads to global warming which leads to hurricanes. Catastrophic forest fires result in a complete loss of vegetation which can lead to landslides. Relatively small disturbances can have far ranging and long term effects, meaning that lax environmental policies in one nation or state can potentially affect everyone on Earth. On this basis, many argue that an international organization should be given the power to police and regulate all activities which affect the environment. The main argument against such top-down regulation is that it is difficult, given the complex network of Earth systems, to predict the exact consequences of each action. However, because environmental impacts can irreversible, the burden of proof should lie on the party that may be harming the environment.
As the world’s population increases, unregulated expansion of human habitat will simultaneously increase our causative effect on natural disasters and place more people in close proximity of them. Take, for instance, a rapidly growing town in a third world country. Population pressure causes people to live on the slopes of the surrounding hills. All the local vegetation is consumed, either as firewood and building material or as fodder for livestock. When the rainy season hit, the community on the hill and much of the town below are lost in a mudslide. Such catastrophes have already occurred in Asia and South America and will likely become common occurrence if preventative measures are not pursued. Besides the loss of human live, the cost of relief efforts and humanitarian aid will cause people in the developed world to take notice. On a global scale, rising ocean levels would result in a considerable loss of land area, increasing the population pressure on the remaining area. This would also drive the effects of hurricanes further into landmasses than their previous range.
Those people who reject environmental protection simply for the sake of conservation should try thinking in terms of self-preservation instead. As the result of environmental mismanagement, the Earth could become at worst uninhabitable, at best an unpleasant place to live.
Send message to Swarthmore College Environmental Studies
last updated 1/25/06webmaster