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Our earth is our home, so if we want to protect our home we should protect our environment from harmful effects of human activity. Some of these activities cause pollution. Pollution now is a very important problem. Some of these problem are: the ozone holes, global warming (or green-house effect), acid rain … The ozone layer is a layer of gases which stop harmful radiation from the sun protecting the earth. Recent research shows that there is a hole in part of the ozone layer which is caused by smoke from factories, car exhaust fumes, aerosol cans.
Global warming is an increase in world temperature caused by an increase in carbon dioxide. Acid rain is rain that contains dangerous chemicals, this is caused by smoke from factories. Another problem is poisons in food. Farmer soften spray chemicals in crops to safe them from pests. These chemicals are called pesticides. Scientists have found that pesticides often end up in our food and they can cause health problems – especially for kids. The seas are in danger. They are filled with poison: industrial, chemical, nuclear waste. Every ten minutes one kind of animal, plant or insect dies out for ever. And if nothing is done our earth will die in about 30 years from now. So what can we do to protect our environment?
I think that we should recycle our used things, we should plant more trees, we should not waste resources but try save them, we also must make smoke from factories and car’s fumes more clean, we must not dump industrial waste to seas and rivers …Now people are beginning to realize that environmental problems are not somebody else’s. They make different organization, whose aim is conservation. For example “ GREEN PEACE ”, “ FRIEND OF THE EARTH ” and others. Everyday millions people from all over the world do everything to protect our environment, and they need for our help. I think we ought to help them, just to make our future better.
Technology and environment http://wikibin.org/articles/technology-and-environment-2.html |
Introduction Modern technologies have a profound impact on the environment. As indicated by the I=PAT equation, the total environmental impact (I) is the product of human population size (P) times material affluence (A) times the resource use or pollution generated by particular technologies (T) used. Technology affects all three factors, i.e., the size of the human population (P) by strongly influencing the fertility rate and death rate, the standard of living (A, or per capita GDP, Gross Domestic Product) by continually stimulating economic growth, and also the degree of resource use and pollution generated per unit GDP created (T). Technology and Population From a historical perspective, technological revolutions have coincided with population explosions. There have been three major technological revolutions, i.e., the tool-making revolution, the agricultural revolution, and the industrial revolution, all of which allowed humans more access to food, resulting in subsequent population explosions. For example, the use of tools, such as bow and arrow, allowed primitive hunters greater access to high energy foods (i.e., animal meat). Similarly, the transition to farming about 10,000 years ago greatly increased the overall food supply, which was used to support more people. Food production further increased with the industrial revolution as fossil-fuel driven machinery and fossil-fuel derived fertilizers, herbicides, and pesticides were used to increase land under cultivation as well as crop yields. In short, similar to bacteria that multiply in response to increased food supply, humans have increased their population as soon as food became more abundant as a result of technological innovations. Significant increases in human population also occur whenever the fertility rate exceeds the death rate for extended periods of time. For the last two centuries, sanitation and medical treatment technologies have greatly reduced death rates, causing overpopulation with concomitant environmental degradation and pollution. However, contraceptive technologies, by reducing the fertility rate, have the opposite effect of reducing population pressures and environmental impacts. In summary, depending on whether a particular technology causes a decrease or increase in human population size, it will have positive or negative environmental impacts, respectively. Technology and Affluence Advances in science and technology during the last 200 years have been the main driving force behind the more than 100-fold rise in global industrial output and the 450-fold increase in gross domestic product in the United States. Since economic output grew much faster than the size of the human population, material affluence (A) or per-capita GDP has increased about 14-fold between 1820 to 1989 in the industrialized nations. There are at least three fundamental reasons why new technologies increase material affluence. First, by replacing human labor with machines run primarily on fossil energy, labor productivities have risen dramatically resulting in increased production and concomitant consumption. Second, by creating new products and services never seen before, large demands are generated and fueled by mass-media advertising, resulting in increased material consumption. Third, by relentlessly increasing technological efficiencies, more industrial output can be produced with less input of labor, capital, energy, and minerals, resulting in decreased costs of products and services and thus increased consumption. The phenomenon that efficiency improvements stimulate material consumption of the very resources that were supposed to be conserved by increasing efficiency is called or Jevons paradox. In summary, advances in technology have been the main driver behind increasing per capita affluence (A) and material consumption. Technology and Environmental Impact The application of technology often results in unavoidable environmental impacts, which according to the I=PAT equation (see above), is measured as resource use or pollution generated per unit GDP. Environmental impacts caused by the application of technology are inherently unavoidable for several reasons. First, given that the purpose of many technologies is to exploit, control, or otherwise “improve” upon nature for the perceived benefit of mankind while at the same time the myriad of processes in nature have been optimized and are continually adjusted by evolution, it is clear that any disturbance of these natural processes by technology will automatically result in negative environmental consequences. Second, the conservation of mass principle and the first law of thermodynamics (i.e., conservation of energy) dictate that whenever material resources or energy are moved around or manipulated by technology, environmental consequences are inescapable. Third, according to the second law of thermodynamics, order can be increased within a system (such as the human economy) only by increasing disorder or entropy outside the system (i.e., the environment). Thus, technologies can create “order” in the human economy (i.e., order as manifested in buildings, factories, transportation networks, communication systems, etc.) only at the expense of increasing “disorder” in the environment. According to a number of studies, increased entropy is likely to be correlated to negative environmental impacts. The following is a list of various environmental impacts brought about by the application of specific technologies. Climate change Climate change is the result of increasing atmospheric carbon dioxide concentrations which is caused primarily by the combustion of fossil energy sources such as petroleum, coal, and natural gas. Such massive alteration of the global carbon cycle has only been possible because of the availability and deployment of advanced technologies, ranging in application from fossil fuel exploration, extraction, distribution, refining, and combustion in power plants and automobile engines. Potential negative environmental impacts caused by increasing atmospheric carbon dioxide concentrations are rising global air temperatures, altered hydrogeological cycles resulting in more frequent and severe droughts, storms, and floods, as well as sea level rise and ecosystem disruption. Air pollution Air pollution is caused by the introduction of chemicals, particulates and biological materials into the atmosphere, resulting in reduced visibility and various negative impacts on human health. Primary air pollutants include sulfur oxides, nitrogen oxides, carbon monoxide, volatile organic compounds, toxic metals such as mercury and lead, chlorofluorocarbons, ammonia, and particulate matter. The main sources of these pollutants are industrial processes and a global transportation system fueled by fossil energy, i.e., the application of various advanced technologies is directly responsible for air pollution. Chemical pollution The chemical industry produces over 100 million tons of synthetic organic chemicals each year, with over 65,000 different compounds in commercial use. These synthetic chemicals cause serious negative environmental impacts for several reasons. First, they are widely dispersed in the global environment. Second, many of these chemicals do not degrade naturally and bioaccumulate in the tissues of living organisms, including humans. Third, since many of these compounds have been artificially created, they do no integrate well into existing naturally occurring processes, generally do not biodegrade, and often cause unexpected harm to biological receptors. For example, many synthetic organic chemicals are carcinogenic and some of them, such as pesticides, DDT, PCBs, dioxins, and plasticizers, are mimicking the effects of hormones even at very low concentrations, thereby affecting sexual development of animals. The proximate cause of chemical pollution are the chemical manufacturing technologies employed by the petrochemical industry, indicating that advances in these technologies have been responsible for the massive chemical pollution of the planet. Water depletion Agricultural irrigation technologies such as high powered water pumps, dams, and pipelines are responsible for the large-scale depletion of fresh water resources such as aquifers, lakes, and rivers. Humans appropriate more than 50% of the planet’s fresh water, mostly for use in irrigation. As a result of this massive diversion of freshwater, lakes, rivers, and creeks are running dry, severely altering or stressing surrounding ecosystems, and contributing to the extinction of many aquatic species. Topsoil Loss The industrialization of agriculture during the last 150 years, specifically the wide-spread use of fossil fuel powered farm machinery for plowing, has resulted in massive top soil loss. Soils are currently lost at the rate of inches per decade while it takes hundreds of years for one inch of new topsoil to form. In the United States, 90% of the cropland is losing topsoil at a rate faster than is being formed. Worldwide, about one third of arable land has been lost due to erosion. Species extinction The extinction of species is caused primarily by habitat loss due to increasing human population and economic development, and chemical pollution. Advances in technology have significantly contributed to the various causative factors of species extinction. Presently, rates of extinction are about 1 million times greater than the rate at which new species are formed, resulting in an alarming decline in biodiversity. About one quarter of all bird species have already gone extinct during the last 2000 years. |
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