Human Environmental Impact
Published 20 Dec 2016
For the first several million years, the number of humans on earth was modest and their impact on the environment was local in scope. Hunting and gathering societies represent the earliest form of organized social life. As human civilization expanded and people started to congregate in cities, we prefer to construe the world in our own eyes reflecting our linguistic, cultural, inpidual, and even anthropological backdrops. Anthropology teaches us about the concept of beginning or commencement of every single thing, living or non-living, in this world as the first stage of development no matter how complicated human nature is (Erlandson and Rick, pp. 1227-1229, 2005).
But particularly since the industrial revolution in the eighteenth century, the exponential growth of the human population has been dramatic. Modern mechanized agricultural methods and improved medical care have contributed greatly to a growth rate that now adds 90 million per year. According to the United Nations, the human population size will reach 10 billion or more by the end of the twenty-first century (Diamond, pp. 98-99, 06).
The countries of the world fall into two groups. The so-called more-developed countries became industrialized first. These countries include the United States, Canada, Japan, Russia, Australia, New Zealand, and all the countries of Europe. Industrialization requires resource consumption: energy and minerals are needed to create the lifestyle enjoyed by the people of these industrialized countries (Hughes, pp. 101-105, 2001). The more-developed countries have 1.2 billion persons, which is only 22% of the world’s population, but they account for about 80% of the world’s energy and mineral resource consumption. The use of energy to transform raw materials into the goods that make a modern lifestyle possible results in heat and wastes, some of which, like carbon dioxide, alter the transfer rates of the biogeochemical cycles of the biosphere. There is no definite knowledge on how this will affect the workings of the biosphere, but certainly climate change will occur (Braje and Erlandson, pp. 12-15, 2005).
The earth’s climate has fluctuated in the past. We all know that ice ages have occurred in the history of the earth (Redman, pp. 18-21, 1999). Presently, we are enjoying a moderate temperature that the earth has not seen since about 130,000 years ago, but many are concerned that the global climate will continue to warm and at a rate ten times faster than anytime in the past (Hughes, pp. 37-39, 2001).
The oceans are currently taking up about one-half of the carbon dioxide emitted, or else the increase would be much higher than this stated amount. The emission of other gases due to human activities is also taking place. The amount of methane given off by the oil and gas wells, rice paddies, and all sorts of organisms including domesticated cows is increasing by about 1% a year (Braje and Erlandson, pp. 17-19, 2005).
Coal, petroleum or oil, and natural gas have been and still are the preferred sources of energy for home and industrial use. These are the fossil fuels, which were formed by partial decomposition of and pressure of the earth on the remains of plants and animals that lived millions of years ago. Petroleum is used as the starting material for gasoline and for many industrial products, such as plastic, synthetic fibers, and drugs (Erlandson and Rick, pp. 1229-1232, 2005).
In the present context, pollution can be defined as any environmental change that adversely affects the lives and health of living things. The burning of fossil fuels results in carbon oxides, hydrocarbons, nitrogen oxides, and particulates, which cause air pollution, along with other substances derived from other sources like photochemical oxidants, organic halogens, and aerosols. And some estimate that by 2025, there may be four times as many automobiles in the world as there are today. The release of industrially produced halogen compounds such as the chloroflourocarbons and the widespread use of nitrogen fertilizers, are also influencing the chemical composition of the atmosphere (Hughes, pp. 111-114, 2001).
Global warming is a phenomenon also referred to as greenhouse effect. It is brought about by the presence of some gases in the atmosphere which have the ability to absorb infrared radiation (heat); such gases are referred to as greenhouse gases (Diamond, pp. 28-31, 2006). The sun continuously radiates electromagnetic energy in space. Our planet, which is very small compared to the size of the sun and is about 150,000,000 kilometers away, intercepts a very small fraction (estimated to be one part in two billion) of that energy. Of that relatively small amount of energy intercepted by the earth, more than half (about 53 percent) does not even reach the earth’s surface; this is because part of it is absorbed by air molecules, part is reflected back into space by the earth’s surface, and part is reflected upward by air molecules, water droplets and particulates (Erlandson and Rick, pp. 1229-1230, 2005).
And so, less than half (about 47 percent of the small portion of solar radiation which the earth intercepts) actually reaches the earth’s surface. A very tiny fraction of this is utilized in photosynthesis. The rest is absorbed by the earth’s surface and objects on it, converted into energy of longer wavelength (longer than that of light); that is, infrared, and radiated back to the air above. This is mostly how the lower atmosphere is warmed (Erlandson and Rick, pp. 1233-1235, 2005).
Of the gases normally present in the air, two are greenhouse gases: carbon dioxide and water vapor. These gases have been in the atmosphere since the beginning of Earth’s history; yet rarely has its average annual temperature varied by more than one Celsius degree over the past 10,000 years. Probably it is because most of the carbon dioxide released into the air is readily dissolved by the oceans or used by forests in food-making. In other words, the oceans and forests are effective sinks of carbon dioxide (Braje and Erlandson, pp. 13-17, 2005).
Water vapor, carbon dioxide, and methane bin the atmosphere played a critical role in the history of the earth because their presence made the earth warm enough to allow living things to evolve. Data based on an analysis of gases trapped in the Arctic show that indeed the earth’s temperature has fluctuated in the past, according to atmospheric levels of carbon dioxide and methane. The greenhouse gases differ in their ability to absorb specific wavelengths of infrared radiation as it can. This means that adding a molecule of carbon dioxide. The greenhouse effectiveness of methane is now about 25 times that of carbon dioxide. Nitrous oxide is about 200 times more effective than carbon dioxide (Braje and Erlandson, pp. 18-19, 2005).
Today data collected around the world show a steady rise in the concentration of the various greenhouse gases. These data are used to generate computer models that predict the earth may warm to temperatures never before experienced by living things. The global climate has already warmed about 0.6oC since the industrial revolution. Computer models are unable to consider all possible variables, but the earth’s temperature may rise from 1.5oC-4.5oC by 2060 if greenhouse emissions continue at the current rates (Hughes, pp. 155-157, 2001). But aside from carbon dioxide and water vapor, another group of greenhouse gases has surfaced. These are the so-called CFCs which are used mostly in refrigerators and air-conditioners and lately as propelling agent of ladies’ hair spray and paints, among others (Hughes, pp. 121-122, 2001).
Expanded use of CFCs and a rise in the carbon dioxide level in the air resulting from an increase in consumption of energy derived from fossil fuels can result global warming. Incidentally, CFCs are also responsible for destruction of ozone in the upper atmosphere (Hughes, pp. 169-170, 2001).
What might be some harmful effects of such a change in the earth’s climate? Three possible consequences are:
Thermal expansion of ocean waters and melting of glaciers may bring about a gradual rise in sea level. This in turn will cause flooding of coastal areas, something which will greatly affect every continent because archipelagic nature and abundant waters surrounding the landmasses (Hughes, pp. 169-170, 2001).
Receding coastlines may include marginal lands devoted to agriculture, in which case the flooding of coastal areas may also mean less food production (Hughes, pp. 169-170, 2001).
Higher temperature of the air will cause greater evaporation from the earth’s surface. This will mean drier soils and lower productivity (Hughes, pp. 169-170, 2001).
Certainly, global warming has started to bring about climate changes, which computer models attempt to forecast. It is predicted that as the oceans warm, temperatures in the polar regions will rise to a greater degree than other regions. Glaciers would melt and sea levels will rise, not only due to this melting but also because water expand as it warms. Water evaporation will increase, and most likely there will be increased precipitation along the coasts and dryer conditions inland. The occurrence of droughts will reduce agricultural yields and also cause trees to die off. Expansion of forests into Arctic areas will most likely not offset the loss of forests in the temperate zones. Coastal agricultural lands such as the Bangladesh, India, and China would be inundated, and billions will have to be spent to keep coastal cities like New York, Boston, Miami, and Galveston in the United States, from disappearing into the sea (Redman, pp. 49-51, 1999).
Today, the industry’s marketing formulations are required to meet varying federal and state environmental laws. The Clean Air Act specifically requires refiners to produce reformulated gasoline, and the requirement to provide a specific blend for a specific area can present challenges to refiners and other suppliers if there are supply disruptions. While most of the United States depends on the industrial sector as a source of energy, there are sources of energy that are relatively non-polluting and should have been utilized a long time ago (Kline, pp. 17-20, 2000).
Certainly, our world is characterized by constant, major, simultaneous changes, and these changes touch us all. Peoples may have clustered in different and separate means but we all recognize our oneness as global citizens. Over the past decades, sociologists have correctly identified and analyzed major trends that have transformed our world: the globalization of the economy, the staggering impact of technology on our lives and our cultures, etc. They have gone further, providing profound insights into the universal future so that we could understand and put order to the chaos that seems to loom just over millennium’s horizon. As history moves forward, humanity continues to discover and invent new technologies to improve life on earth. Whereas before, many of these inventions dwelt only in the imagination, today, the things that were once only imagined have been turned into useful gadgets (Redman, pp. 92-96, 1999).
Most would agree, however, that such stupendous modernization does not come without a price. In particular, modern warfare is a very bad example of modernized technologies. Sophisticated weapons technology has provided the means for mass destruction of life and property; instantaneous communication and wide dissemination of information of all kinds may have bound intercontinental peoples together but at one fell swoop, have also brought with them less privacy; the great use and abuse of natural resources has wrought severe threats to the environment which supposedly nourishes the society; and the comparatively frenetic pace of human existence may ultimately call into question many of the benefits of modern technology (Diamond, pp. 6-8, 2006).
Changing social mores, altered demographics, economic ills, the aging of society, changing political boundaries, international drug wars, new, lethal viruses and worldwide environmental concerns; these realities present new and special problem-solving challenges brought about by humankind’s immense impact on their environment. With chilling clairvoyance, futurists prophesied decades ago that adaptation and inpidualism were a personal survival necessity, which we all draw from the practical resources of Mother Nature.
- Braje, T. J. and Erlandson, J. M. (2005). “Reassessing Human Settlement on the South Coast of San Miguel Island, California: the use of 14C Dating as Reconnaissance Tool.” Radiocarbon, pp. 11-19.
- Diamond, J. (2006). Collapse: Why Societies Choose to Fail or Succeed. New York: Viking.
- Erlandson, J. M. and Rick, T. C. (2005). “A Geoarchaeological Chronology of Holocene Dune Building on San Miguel Island, California.” The Holocene, pp. 1227-1235.
- Hughes, J. D. (2001). An Environmental History of the World. Routledge: New York.
- Kline, B. (2000). First Along the River: A Brief History of the US Environmental Movement. Acada ooks: Oxford.
- Redman, C. (1999). Human Impact on Ancient Environments. University of Arizona: Tucson.