Water and Energy Versus The Ideal US Population - Assignment Example

US CONSUMPTION OF ENERGY AND LUXURIOUS ITEMS AFFECT BIODIVERSITY AND CONSERVATION EFFORTS AROUND THE WORLD Introduction Species extinction is occurring at an alarming rate, up to 1000 times faster than their natural rate of extinction. Scientists estimate that as many as 137 species disappear from the Earth each day. This adds up to an astounding 50,000 species disappearing every year.1 Over exploitation is the major factor causing serious treats to the biodiversity, this includes over hunting, over fishing, felling forests, habitat destruction and pollution. Tropical forests are disappearing at a rate of 76,000 km2 per year. This results in the estimated loss of 4000 to 6000 species per year. Human beings are encroaching on the habitats of many species. Land is constantly being converted from its natural state into farms, cattle grazing areas, mines, housing developments, golf courses, office buildings, shopping malls, and other urban and suburban areas. For all species, smaller habitats mean fewer food and shelter resources. Scientists have discovered that decreasing the size of natural habitats—even if these habitats are protected in nature parks or preserves—increase the chances of species going extinct. Smaller, isolated habitats are like islands, completely separated from one another. As a result, species living in these habitats compete with each other and with humans for limited resources. Since their populations are so small, they have fewer mates with whom to reproduce, diminishing the genetic diversity of their populations. If other habitats are not close by, species may not be able to migrate or to disperse seeds to other habitats. Many of the worlds natural resources are being used by humans faster than they can replace themselves. Commercial sea life, such as lobsters, swordfish, and salmon, are over-harvested, while species like dolphins and sea turtles sometimes die in fishing nets. A $10-billion-a-year market in wildlife and wildlife products threatens African elephants and rhinos, Asiatic bears, pandas, and tigers, seahorses, corals, and tropical plants and birds with extinction. People buy wildlife and wildlife products to use as pets, medicines, gourmet foods or decorative objects. Each year, consumers in the United States alone buy as many as 12,000 primates, 2.5 million orchids, 200,000 live birds, 2 million reptiles, 250 million tropical fish, and millions of wildlife products. Nearly one-quarter of this trade—around $2.5 billion—is illegal because the species being poached are endangered. What’s more, the illegal poaching of wildlife is worsened by deforestation. Once habitats are accessible by roads, it is easier to take animals from their natural environments.2 Scientific evidence is increasing as to rapid population growth in the United States that is causing the deterioration of life-supporting environmental resources (Bartlett and Lytwak, 415-428; Grant, 2000, 2003; Pimentel and Pimentel, 145-167; Sachs, 649). Genuine concerns are expressed about consumption of energy and luxurious items by the United States and its impact on biodiversity and conservation efforts around the world. Yearly Americans are using twice as much fossil energy as the total solar energy captured by all plants through photosynthesis in the United States. Petroleum geologists warn of the approaching end of the petroleum and natural gas era, and even coal reserves are not inexhaustible. Furthermore, uncontrolled U.S. population growth, intensifying soil erosion and degradation on agricultural lands, the overuse of water resources, and pollution combine to reduce the carrying capacity of the ecosystem, not only for humans but for all animals, plants, and microbes. The United States is home to about 750,000 species of plants, animals, and microbes. Human population expansion accompanied by the loss of natural habitats due to urbanization, highways, and agriculture is the major cause of biodiversity loss (Pimentel and Pimentel, 2003). Environmental biologists have outlined two general reasons. First the utilitarian reasons: We rely on a large number of animal, plant, and fungal species for various purposes including food and medicine. In fact, as Simon Levin notes, about forty percent of “all prescription drugs in the United States contain active ingredients originally derived from nature”. In addition to the benefits from individual species, humans also benefit from maintaining healthy ecosystems; disturbing these ecosystems can adversely affect human health. For instance, Lyme disease emerged in the northeast United States because of changes in the forest ecosystem of that region. The creation of new species by the natural process of speciation usually occurs in time spans of many thousands of generations, far exceeding human lifetimes (Biodiversity, 1-11). A major contributor to depletion and extinction, second only to habitat loss, is the unnatural introduction of species into new environments. Species have sometimes invaded new habitats naturally (e.g. when land bridges have become established) but human exploration and colonization has dramatically increased the spread of species. Whenever man has settled far away from home, he has intentionally introduced his familiar animals and plants.  Many other species (e.g. rats) have been accidentally transported around the world.  These forms that have been transplanted as a result of human actions are called exotic, alien, introduced or non-indigenous species.   Many exotics have disastrous effects on native flora and fauna. They often leave behind the factors that have evolved with them and that control their population and spread. In their new habitat there may be fewer predators or diseases, so their populations grow out of control.  They are then called invasive exotics. Prey organisms may not have evolved defense mechanisms and native species may not compete successfully for space or food, so are often pushed to extinction. Since exotic species are self-perpetuating, they can be more permanent problems than other threats to biodiversity including overexploitation and habitat loss. Exotics are a factor contributing to the endangered or threatened status of 42% of animals and plants on the U.S. endangered species list (Bryant, 2002). The greatest threat to most wild species is destruction, fragmentation, and degradation of their habitats. In the United States, tall-grass prairies have been reduced by 98 %, virgin forests by 95 %, wetlands by 50 %. About 50 % of tropical rain forests have been deforested by 1995. Legal and illegal commercial hunting has led to the extinction or near extinction of many animal species, such as the American bison and the passenger pigeon. There are several different reasons why humans hunt animals, including subsistence, sport and commerce. Subsistence hunters kill animals for food. This type of hunting caused the extinction of animals in the past but is not a very big concern today as most people no longer rely on hunting for their food supply. Sport hunting is when hunters kill animals for recreation. Like subsistence hunting, this caused extinction of animals in the past. Today it is of little concern as countries control sport hunting with licenses and regulations. Commercial hunting is when hunters kill for profit. This type of hunting is what causes extinction of animals today. Tigers, cheetahs, snow leopards, all of which are valued for their furs, are some of the animals that are endangered because of commercial hunting. Although these species and many others are now protected from commercial hunters, some still hunt them illegally as they can be sold on the black market for a high price. Commercial fishing is also a very big business that threatens the diversity of fish stocks as over-fishing is quite common. The northern cod fishery off the coast of eastern Canada is a prime example of this type of destruction. The fishing industry off the Grand Banks of Newfoundland was shut down in the mid-1990s to allow cod stocks to recover from over-fishing. This moratorium is still in place today, as fish numbers have still not recovered (Pidwirny, 2001). In the last 50 years intensive farming has developed and now only the most productive species of crops and animals are being grown and reared. This means that many different varieties of domestic animals, fruit and vegetables are in danger of becoming extinct. If farmers are growing only one type of crop it is more difficult for that crop to resist attack by disease than if the farmer was growing lots of different types – since different crops may be susceptible to different diseases. Therefore the more species we have of plant and animal, the greater the chance that they can resist different disease, pests or other environmental changes. The deforestation for agricultural activities is yet another problem causing major loss to biodiversity in the United States. One of the major threats to biodiversity is the application of more than 500,000 kg (1 billion pounds) of pesticides each year, applied primarily to U.S. agriculture. Surprisingly little pesticide reaches the target pests (less than 0.01%) — this means that more than 99.9% pollutes the environment where it kills many beneficial organisms (Pimentel, 1995). About 72 million birds are killed by pesticides each year. Pesticides also non-fatally poison 300,000 humans per year in the U.S. (Pimentel and Pimentel, 2003). Trade of animal products Many people dont realize when they buy a product made of an animals hide or body, or buy a shell or piece of coral that their purchase could be contributing to the loss of endangered species. Although habitat destruction and fragmentation are the biggest threats to biodiversity on a global scale, trade in wildlife and wildlife products also seriously harms many individual species. Estimates of the size of legal and illegal trade in wildlife and wildlife products vary widely, but by any measure, its clear that trade is booming. Legal trade in wildlife and wildlife products (excluding timber and fisheries) has grown from perhaps a $3 or 4 billion businesses in the late 1980s to at least $10 billion today, and involves more than 350 million plants and animals. Another $5-8 billion in illegal trade is estimated to occur every year. The sources of traded species and their uses vary. Live animals are captured in native habitats and sold as pets or for research, or are killed and their parts sold for medicines, food, clothing, and accessories. A majority of some animals, like primates and live lizards, are raised in captivity specifically for the international market. Wild plants are commonly traded for use in botanical and pharmaceutical medicines. The value of medicinal plant exports in 1995 from approximately 100 countries was $880 million. Monitoring trade is essential to species survival. With adequate warning that a populations reproductive capacities are dipping in the wild, countries can opt to regulate trade volumes, or launch or increase complementary captive breeding or cultivation programs. For example, monitoring of American Ginseng (Panax quinquifolius)—commonly harvested from the wild in Canada and the United States and exported to East Asia where it is used widely in traditional medicine—eventually showed the need for trade protection. A 1996 study of harvest and trade levels of American Ginseng found that demand had increased rapidly, but the amount of wild American Ginseng harvested and exported had remained relatively constant. This indicated that the United States and Canada were protecting wild populations reasonably well. However, further study in 1999 alerted the U.S. Fish and Wildlife Service that it was time to institute a new policy in 18 states that would limit Ginseng exports to wild-harvested roots no less than five years old. Cultivated roots, on the other hand, can be harvested at any age. Demand for exotic pets in the United States fuels the reptile trade. For example, the United States dominates the import of lizards that numbered to 640,793 in the year 1997. Similarly, Europe and the United States share responsibility for most of the world trade in live apes, monkeys, and other primates. What that data does not reveal, however, is what percent of the trade consists of species raised in captivity rather than captured in the wild. More than 90 percent of the U.S. imports of live lizards, for example, consist of green iguanas bred for the pet trade on farms in Central and South America. Of course, even breeding programs arent a fail-safe solution to species survival in the exporting countries; without adequate wild stocks of reptiles, captive breeding stocks may decline. The United States is the worlds largest market for wildlife and wildlife products and imports an estimated $300 million worth of illegal wildlife every year. Trade bans may seem an obvious way to protect species, but there is the danger that a ban may make the species more valuable and appealing to poachers. The more endangered an animal or plant becomes, the higher its black market price, and the more poaching and illegal trade occurs. For some species, bans have proven effective. In 1992, the United States—one of the biggest importers of parrots for pets—enacted national legislation (the Wild Bird Conservation Act) which banned imports of all wild-caught threatened parrots listed in Convention on International Trade in Endangered Species (CITES). As a result, parrot imports into the United States fell dramatically. Recent research suggests that the Wild Bird Conservation Act may also have contributed to reduced poaching rates for 10 banned parrot species; in 8 years poaching rates fell from 50 to 20 percent (Wagener, 2001). Americans eat large amounts of animal products, totaling nearly 800 pounds per person per year, including dairy products. Approximately one-third of their calories are from animal sources and two-thirds from plant sources. These animal products contribute excellent protein quality to the diet, but increase the fat intake of the average American to about 40% of the calories consumed (Pimentel, 1994). The world’s appetite for meat is razing forests at an accelerating rate. In Central America, 40 percent of all the rainforests have been cleared or burned down in the last 40 years, mostly for cattle pasture. In the process, natural ecosystems where a variety of plant and animal species thrive are destroyed and replaced with monoculture grass. It takes far more fossil-fuel energy to produce and transport meat than to deliver equivalent amounts of protein from plant sources. This heavy use of carbon-rich fuels also contributes significantly to the emissions of global-warming gases. The US Department of Commerce reports that in the U.S., 56 million acres of land produce hay for livestock. While only 4 million acres produce vegetables for human consumption. Such inefficient use of land means that food production will not keep up with population growth. As Earth becomes more crowded, poor populations are increasingly venturing into wildlife reserves for meat. Poaching and black marketing of bush meat is decimating remaining populations of gorillas, chimpanzees, and other primates (Worldwatch Institute, 2004). There are several species in United States that has become extinct. Grizzlies once roamed most of the western and southwestern United States, but by the turn of the century, populations south of Canada were dramatically shrinking. Grizzlies already were extinct in a number of states as a result of eradication programs that included hunting, trapping and poisoning. Though grizzlies probably numbered fewer than 1,000 animals south of the U.S./Canada border -- qualifying them as an endangered species -- political pressure and lack of data instead led in 1975 to the grizzlys listing as threatened in the lower 48 states. The western boreal toad, also known as the western toad, boreal toad and northwestern toad, is an amphibian two to five inches long that lives in small ponds, marshes and streams. It is nocturnal, coming out at night to hunt for insects and find mates. In winter, it hibernates in moving currents below the waters surface. This cold-adapted toad, once common over much of the western United States and up into Alaska, is greatly depleted in much of its range. The southern Rockies boreal toad, a genetically distinct population once prevalent in Colorado, Wyoming and New Mexico, has disappeared from more than 80 percent of its known habitat in Colorado, has become rare in Wyoming and is considered extinct in New Mexico. Declines in western boreal toad numbers have been occurring for at least a decade and have accelerated in the last three to five years. Scientists and environmentalists are particularly concerned because the reasons for recent rapid declines of this and other amphibians remain unknown. Habitat loss and fragmentation play critical roles in the decline of the western boreal toad. As western lands are developed, many wetlands that once served as home to the animal have been destroyed. Recreational activities such as hiking, camping, fishing and boating disturb the toads breeding grounds. Overgrazing, mining, logging and certain water management projects are also critical factors in habitat destruction and in loss of indispensable breeding sites. In addition, as habitat becomes increasingly fragmented, the toads have great difficulty dispersing to other areas. The jaguar, known for its distinctive spots, is the largest cat native to North America. Free-trade incentives also are expected to escalate the illegal smuggling of protected animal parts (e.g., skins), one of the primary causes of the jaguars decline during the mid-1900s (Snape and Ferris, 2005). Nearly 300 species of mussels inhabit fresh-water rivers, streams, and lakes in the United States. This is the richest diversity of mussels found in the world and an extraordinary natural heritage that needs protection. Because of the lustrous, pearl-like interior of the shells, some of these pearly mussels have important commercial value in the cultured pearl and jewelry industry. The abundance and variety of mussels have declined sharply over the past century. At the turn of the twentieth century, the shallow, swift-flowing shoal areas of many of the streams and rivers within the Ohio River basin were filled with millions of living mussels. Today, many of these areas harbor only remnant populations of mussels. Dam construction, siltation, water pollution, mining and industrial wastes, and the introduction of exotic shellfish seriously threaten their continued existence. At present, 35 mussel species are presumed extinct, 70 species are considered endangered or threatened, and nearly 60 species are species of concern nationwide. No other widespread animal group in North America has been jeopardized to this extent (Helfrich, L.A. and Neves, 2003). Conclusion In conclusion, though species extinction is a natural part of evolution, it should be noted that biodiversity is a central component of Earths life support systems and is directly relevant to human societies. The natural ecosystems of the United States have been significantly altered. We found endangered ecosystems at several levels of classification and at many spatial scales. Although losses of major regional vegetation types may have greater implications for biodiversity than losses of local plant associations, declines at any level represent depletion of biodiversity worthy of concern from conservation agencies. The loss of biodiversity is the only truly irreversible global environmental change the Earth faces today. integrated conservation plans for all ecosystems be developed in each eco-region of the United States, starting with types and regions that sustained the greatest losses and are at greatest risk of further loss. Conservation plans could be based on detailed studies of ecosystem status and trends and include quantitative analyses of ecosystem decline, ecological consequences of loss and degradation, and current and potential threats to each ecosystem. Ecosystem conservation need not be restricted to pristine sites, which are now almost nonexistent. Rather, management and, where possible, restoration plans for native biodiversity in partially disturbed sites should be considered. A sustainable management of the natural recourses, energy consumption and conservation of biodiversity is essential in United States. References Bartlett, A.A. and E.P. Lytwak. Zero Population of the United States. Population and Environment. 16: 415-428. 1995. Grant, L. Too Many People: the Case for Reversing Growth. Seven Locks Press, Santa Ana, CA. 2000. Grant, L. It’s the Numbers, Stupid! NPG Forum. (September 2003) Negative Population Growth, Alexandria, VA. 2003. Pimentel, D. and M. Pimentel. World Population, Food, Natural Resources, and Survival. World Futures 59: 145-167. 2003. Sachs, J. D. Sustainable Development. (editorial). Science 304:649. 2004. Pimentel, D. and M. Pimentel. Land, Water and Energy Versus The Ideal U.S. Population. (2004). 29 Nov 2005. Available http://www.npg.org/forum_series/forum0205.html Biodiversity. Rediscovering Biology 1-11. 27 Nov 2005. Available http://www.learner.org/channel/courses/biology/support/12_biodiv.pdf Levin, S. A. Fragile dominion: Complexity and the commons. Cambridge, MA: Perseus Books, 6. 1999. Bryant, P.J. Chapter 9: Exotic Introductions. Biodiversity and Conservation: A Hypertext Book. 27 Nov 2005. Available http://darwin.bio.uci.edu/~sustain/bio65/lec09/b65lec09.htm Pidwirny, M. Introduction to Environmental Issues. (09/12/2001) 27 Nov 2005. Available http://www.geog.ouc.bc.ca/conted/onlinecourses/geog_210/210_5_3.html Pimentel, D. Amounts of Pesticides Reaching Target Pests. Journal of Agricultural and Environmental Ethics 8: 17-29. 1995 Wagener, A. Endangered Species: Traded to Death. (August 2001) 27 Nov 2005. Available http://earthtrends.wri.org/features/view_feature.cfm?theme=7&fid=25 Pimentel, D. Food, Land, Population and the U.S. Economy. Executive Summary (Released November 21, 1994). 27 Nov 2005. Available http://dieoff.org/page40.htm Worldwatch Institute (News). Global Meat Consumption Has Far-Ranging Environmental Impacts. World Watch Magazine: July/August 2004 (June 21, 2004). 27 Nov 2005. Available http://www.worldwatch.org/press/news/2004/06/21/ Snape II W.J. and Ferris, R.M. Saving Americas Wildlife. 27 Nov 2005. Available http://www.defenders.org/pubs/savegrizz.html Helfrich, L.A. and Neves, R.J. Sustaining Americas Aquatic Biodiversity Freshwater Mussel Biodiversity and Conservation. Publication Number 420-523, (Posted October 2003). 27 Nov 2005. Available http://www.ext.vt.edu/pubs/fisheries/420-523/420-523.html Read More