Population and the Environment:

As the century begins, natural resources are under increasing pressure, threatening public health and development. Water shortages, soil exhaustion, loss of forests, air and water pollution, and degradation of coastlines afflict many areas. As the world’s population grows, improving living standards without destroying the environment is a global challenge.

Most developed economies currently consume resources much faster than they can regenerate. Most developing countries with rapid population growth face the urgent need to improve living standards.

Environment getting worse:

In the past decade in every environmental sector, conditions have either failed to improve, or they are worsening:

• Public health:
  Unclean water, along with poor sanitation, kills over 12 million people each year, most in developing countries. Air pollution kills nearly 3 million more. Heavy metals and other contaminants also cause widespread health problems.

• Food supply:
  Will there be enough food to go around? In 64 of 105 developing countries studied by the UN Food and Agriculture Organization, the population has been growing faster than food supplies. Population pressures have degraded some 2 billion hectares of arable land — an area the size of Canada and the U.S.

• Freshwater:
  The supply of freshwater is finite, but demand is soaring as population grows and use per capita rises. By 2025, when world population is projected to be 8 billion, 48 countries containing 3 billion people will face shortages.
• Coastlines and oceans:
  Half of all coastal ecosystems are pressured by high population densities and urban development. A tide of pollution is rising in the world’s seas. Ocean fisheries are being over exploited, and fish catches are down.

• Forests:
  Nearly half of the world’s original forest cover has been lost, and each year another 16 million hectares are cut, bulldozed, or burned. Forests provide over US$400 billion to the world economy annually and are vital to maintaining healthy ecosystems. Yet, current demand for forest products may exceed the limit of sustainable consumption by 25%.

• Biodiversity:
  The earth’s biological diversity is crucial to the continued vitality of agriculture and medicine — and perhaps even to life on earth itself. Yet human activities are pushing many thousands of plant and animal species into extinction. Two of every three species is estimated to be in decline.
• Global climate change:
  The earth’s surface is warming due to greenhouse gas emissions, largely from burning fossil fuels. If the global temperature rises as projected, sea levels would rise by several meters, causing widespread flooding. Global warming also could cause droughts and disrupt agriculture.

• Population and sustainable development

  Environmentalists and economists increasingly agree that efforts to protect the environment and to achieve better living standards can be closely linked and are mutually reinforcing. Slowing the increase in population, especially in the face of rising per capita demand for natural resources, can take pressure off the environment and buy time to improve living standards on a sustainable basis.^3,8,11,12

  • As population growth slows, countries can invest more in education, health care, job creation, and other improvements that help boost living standards.¹¹ In turn, as individual income, savings, and investment rise, more resources become available that can boost productivity. This dynamic process has been identified as one of the key reasons that the economies of many Asian countries grew rapidly between 1960 and 1990.⁵
  • In recent years fertility has been falling in many developing countries and, as a result, annual world population growth has fallen to about 1.4% in 2000 compared with about 2% in 1960. The UN estimated recently that population is growing by about 78 million per year, down from about 90 million estimated early in the 1990s.¹⁰ Still, at the current pace world population increases by about 1 billion every 13 years. World population surpassed 6 billion in 1999 and is projected to rise to over 8 billion by 2025.
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  • Globally, fertility has fallen by half since the 1960s, to about three children per woman.¹⁰ In 65 countries, including 9 in the developing world, fertility rates have fallen below replacement level of about two children per woman.⁹ Nonetheless, fertility is above replacement level in 123 countries, and in some countries it is substantially above replacement level. In these countries the population continues to increase rapidly. About 1.7 billion people live in 47 countries where the fertility rate averages between three and five children per woman. Another 730 million people live in 44 countries where the average woman has five children or more.⁷
  • Almost all population growth is in the developing world. As a result of differences in population growth, Europe’s population will decline from 13% to 7% of world population over the next quarter century, while that of sub-Saharan Africa will rise from 10% to 17%. The shares of other regions are projected to remain about the same as today.⁶
  • As population and demand for natural resources continue to grow, environmental limits will become increasingly apparent.⁶ Water shortages are expected to affect nearly 3 billion people in 2025, with sub-Saharan Africa worst affected.² Many countries could avoid environmental crises if they took steps now to conserve and manage supplies and demand better, while slowing population growth by providing families and individuals with information and services needed to make informed choices about reproductive health.
  • Family planning programs play a key role. When family planning information and services are widely available and accessible, couples are better able to achieve their fertility desires.⁴ “Even in adverse circumstance — low incomes, limited education, and few opportunities for women — family planning programs have meant slower population growth and improved family welfare,” the World Bank has noted.¹

Effects and causes of overpopulation

                                                                                                                                                                                                                                                                                 

Reasons of increase in population

                  

Affects of overpopulation on society and environment

The effects of population growth are varied and vast. While population growth, of any species, may be beneficial to a certain extent, there may come a time when the number in the populationexceeds the natural resources available to sustain it. This is referred to as overpopulation. The consequences of such an event are severe and major.

The population growth of any animal, if left uncontrolled can become burdensome. Farmers have noted, for many centuries, what the effects of an uncontrolled predator population can do to livestock. Once their natural prey run out, or are harder to find, the predators may turn to domesticated animals, despite the risks. This can cause a severe hardship on any family depending on those animals for survival.

However, when most think of a growing population, they do not think of other animals. The prime fear in most people’s minds is the population growth of their own species. As humans leave a much larger footprint on the environment than any other creature, uncontrolled overgrowth can be especially devastating.

First, as the population grows the opportunities for quality, available housing may become an issue. More people crowded into less space is not a good combination in any locality. As space is taken up, it becomes more valuable. Eventually, it begins to affect to poorest in the area. In the long run the effect of population growth may be substandard housing or homelessness.

In other cases, access to food and clean water may be the main issue. This is an even more immediate problem than housing. As more people are faced with unsanitary sources of food, disease and famine begin to take root. If left unaffected, it will sweep through an entirepopulation. In some cases, entire countries may be affected by the situation. Finding a solution often requires a multi-national effort.

Another negative effect of population growth is waste control. When there are relatively few people, controlling waste is a much simpler task. However, as populations grow, the waste increases dramatically. Finding a spot for this waste, or treating it in a way that does not poison the environment, is critically important. Regions of the world that do not have the ability to do this will find it leads to a number other serious issues and becomes a massive public health problem.

In general, the problem is not population growth in itself, it is a mismanagement of natural resources and waste that cause the majority of the problems. Many places have found effective strategies for dealing with such issues. Other locations, usually because of a lack of relative wealth, and perhaps engineering knowledge, have fallen behind.

Causes of overpopulation

The root causes for overpopulation are multifaceted and complex.

From a historical perspective, technological revolutions have coincided with population explosions. There have been three major technological revolutions – 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 (e.g. 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 theindustrial revolution as machinery, 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 occur whenever the birth rate exceeds the death rate for extended periods of time. Traditionally, the fertility rate is strongly influenced by cultural and social norms that are rather stable and therefore slow to adapt to changes in the social, technological, or environmental conditions. For example, when death rates fell during the 19th and 20th century – as a result of improved sanitation, child immunizations, and other advances in medicine – allowing more newborns to survive, the fertility rate did not adjust downward fast enough, resulting in significant population growth. Prior to these changes, seven out of ten children died before reaching reproductive age, while today about 95% of newborns in industrialized nations reach adulthood.^[73]

Agriculture has been the main factor behind human overpopulation. This dates back to prehistoric times, when agricultural methods were first developed, and continues to the present day, with fertilizers, agrochemicals, large-scale mechanization, genetic manipulation, and other technologies.

Morgan Freeman, in a discussion about human overpopulation, described what he blamed as “the tyranny of agriculture”.

Human psychology and the cycle of entrenched poverty, as well as the rest of the world’s reaction to it, are also causative factors. Areas with greater burden of disease and warfare, contrary to popular belief, do not experience less population growth over the long term, but far more over a sustained period as poverty becomes further entrenched. This is because parents and siblings who have experienced calamitous conditions suffer from a kind of post traumatic stress syndrome about losing their family members and overcompensate by having “extra” babies. These extra babies and calamities fuel a vicious cycle, and only in the small minority of cases does it cease. As this cycle is compounded over generations, calamities such as disaster or war take on a multiplier effect. For example, the AIDS crisis in Africa is said to have killed 30 million to date, yet during the last two decades money and initiatives to lower population growth by contraception have been sidelined in favor of combating HIV, feeding the population explosion that we see in Africa today. In 1990, this continent’s population was roughly 600 million; today it is over 1,050 million, 150 million more than if the HIV/AIDS crisis had never occurred

FRESHWATER AVAILABILITY VS. POPULATION GROWTH

We started off with the initial value of fresh water availability for the United States to be 4,477,000,000 m³, and for India to be 500,000,000,000 m³. After these initial numbers, the per capita fresh water use was multiplied by the population and the resulting amount was then subtracted from the overall fresh water available. India’s per capita fresh water use was 1211 m³, and the US ’s per capita fresh water use was 6932 m³ (Census 2004). In order to analyze the increase in water use, we assumed that the per capita water use was the same for all habitants of each country. Per capita water use takes into consideration all the discrepancies and achieves an overall rate. In addition, this graph does not include any excess in-flow of freshwater, which could ultimately affect the rate at which water is used. However, this does not impact the hypothesis being proven due to the growing population, which will ultimately still decrease the amount of available water.

FOREST AREA VS. POPULATION

Deforestation issues arise partly because of the growing masses of poor people who depend on biomass for energy . Furthermore, the migration from rural areas to urban areas has sparked a growing demand for timber, lumber, and paper. Evidently, this rapidly depletes the forests . This loss of forest leads to greater problems since forests have much control over the ecological balance, biodiversity, and quality of the environment. Forests can check for soil erosion, water retention, and conserve and regulate the water cycle. It also retains carbon in order to balance the CO₂ and O₂ in the atmosphere, thus reducing greenhouse gas emissions . growth forests, and 99% of its tall grass prairie. Every day, an estimated nine square miles of U.S. rural land is lost to development . If we destroy our forests it means that global warming will be even a greater of a problem because of the increase in greenhouse gases. Also, we will lose many animals because they lose their habitat. The food chain will thus be disrupted. So, many countries experience forest loss, but at different rates. The US nears crashes sooner than India because people in the US consume much more wooded products and construction of paved areas is more frequent.

Affects of growing population

Over six billion people exist on earth today and an increase of about 97 million people occurs annually (Greep 1998). A growing population leads to several environmental issues as well as social problems. An increasing population can be attributed to several variables. Within countries, we can credit the growth to increased immigration or lack of migration. Lack of education and contraceptive use and the need or desire for more children also adds to the population. In more developed countries we can attribute the population rises to better medical care, thus a longer lifespan and/or fewer deaths. As a result of this overpopulation we experience social issues such as increased rates of poverty, crime, disease, and environmental problems such as increased global warming, natural disasters, loss of habitat, pollution, and more. These threats are very necessary to be addressed, as they will affect people worldwide. It is important that we look at these problems since every human has the ability to prevent future damages and adjust their lifestyles to decelerate this increase in population.

In order to further understand such population growth and how it affects our environment, we looked at the developed country of the United States and compared it to the developing country of India. We ask, “How do the environmental impacts due to overpopulation of these two countries compare?” Although these two countries differ in their political systems, natural environments, and economic standings, they both have been experiencing rapid population growth. The reasons for the growth differ in the severity of each factor, but similar environmental impacts occur.

We predict that with an increasing population, both countries will experience much loss of forest area, loss of freshwater and high amounts of pollution. These in turn affect almost all, if not all, the other dimensions of an ecosystem.