Table of Contents
Chapter 4
- Past and Current Population Growth
- Perspectives on Population Growth
- Factors that Determine Population Growth
- Fertility and Cultural Influences
- Stable Population Sizes
- Family Planning
- Creating the Future
Chapter 4
Past and Current Population GrowthThe world population is literally increasing every second. On average, the net gain of our population increases by 2.5 people every second. With the population growing at a greater rate than ever, this gives rise to many questions about whether the earth can sustain such a large population. There are varying views on this subject. Some feel that more rigid birth control is needed to bring the population growth down. Others feel that there are enough resources to sustain a larger population and the human energy required for that is growing along with the population.
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| Doubling of World Population (Principles of Environmental Science, p.78 ) |
Perspectives on Population Growth
As we mentioned there are varying views on our exploding population growth. The economist Thomas Malthus felt that the more populations grew, the faster humans would outstrip their resources. His calculations showed that despite population increases, there was not always corresponding food production increases. Karl Marx later opined that population growth was a result of uneven distribution of resources, so population spikes resulted more from a majority of people facing from poverty and other social injustices. These views both favor ways of finding population control.
Differing viewpoints on the population increase credit our ever expanding use of technology as a way to counteract concerns about resource shortages. Many point to the fact that there is already more food being produced than the current human population needs to survive. One area these people may not give enough weight is that a reason for our surplus is that our natural resources are still relatively easy to attain. These resources are quickly becoming depleted, and unless replacements are found, our food production may plummet in future generations.
Others feel that a larger population will increase production of goods. So the more people that are on earth, the more people will be available for agriculture and mass production. This allows for a rate of production that keeps up with the population. Again, this theory depends on natural resources being readily available.
Factors that Determine Population Growth
While we estimate the world population to be 7 billion people, this is only a rough estimate, as it is impossible to get accurate numbers from every country. However, the populations of the planet are not growing equally. Poorer countries account for nearly 80% of the world population growth, while richer more stable countries contribute less, and some actually have their populations shrinking. Various reasons for this are birth control and older age of marriage in wealthier countries. Poorer countries on average very rarely use birth control, and much of the population is young. In Chad for example, nearly half of the current population is 15 or younger. While these poorer countries have the largest growth rate, they also have extremely high mortality rates. Crime and disease keep the average life expectancy much lower than in industrialized stable countries.
While some countries have explosions in their population recently, many countries have actually reversed this trend and lowered their birth rates. Worldwide, excluding Africa, fertility rates have dramatically decreased in the last half century. Some places, such as China have done this by enforcing strict birth control policies. This raises questions about basic human rights, including the right to reproduce, but the decrease in fertility rate by nearly 66% in the last 40 years has shown that it is an effective policy.
Another cause for population growth is due in much part to great advances in science and medicine. While human fertility rate has only recently began a downward trend, for the last few centuries, the human mortality rate has steadily dropped. Much of this is due to better health care being available to more people, and more access to clean water, proper nutrition, and education. So while there were not necessarily more children being born in the last few centuries, there were less people dying, which contributed to the recent population spike. The Disability Adjusted Life Years is the measure at which people can be expected to live healthy lives free from disabling disease and health concerns. You can view a global map of DALY at the World Health Organization's website, http://gamapserver.who.int/gho/interactive_charts/mbd/as_daly_rates/atlas.html.
With countries trying to control their population rates, there are new issues facing the population with dependency ratios. In countries with growing populations, people who are able to work are supporting large numbers of children. In countries with stable or decreasing populations working people are supporting larger numbers of retired people. This has some countries with decreasing populations unsure of whether they'll continue to have enough population of working age to support their economies.
Fertility and Cultural Influences
Culture can play a large part in the number of children that people produce. In countries without standardized care for the elderly, the only way to ensure you will be cared for is to have children that will provide for you when you are older. In order to ensure that you have enough children to provide for you, the pressure mounts to have as many children as possible. In other countries the number of children is seen as a status symbol, and a way of advancing upwards through society. Still other cultures take pride and joy in raising children, and their lives revolve around their young.
Economics also factor greatly into the decision to have children. While it may seem counterintuitive, it is actually easier for families in poorer countries to add more children. Since care and the cost of living is already low, another child will not add much burden, and is a potential source of income as they grow up. In industrialized countries, the effect is opposite. Richer countries have higher standards of care for children, as well as more expensive education. This puts a heavier financial burden on a family, and may limit the number of children a family will have. In addition, changing social views of family size also affects fertility rates in industrialized countries. While in the United States large families were once the norm, this view has changed over the last 50 years, and fertility rates have decreased mostly due to personal choice.
Stable Population Sizes
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| Demographic Transition (Principles of Environmental Science, p 90) |
While some countries are still growing, many others are following the trend of Demographic Transition. Many countries that would be considered poor by world standards are still showing they are able to control population size. This is attributed to the idea that even the poorer countries are still growing economically, and this reduces the desire for large families. In addition governments of less developed countries have many examples to follow in regards to the benefits of population control, so it is easier and takes less time to implement. The rapid growth of mass communication also makes it easier to educate and exchange information about social and cultural change.
Countries attempting to curtail population growth to avoid exceeding resources tend to go about it in different ways. Two examples are from India. The states of Kerala and Andra Pradesh both are trying to get a grip on population growth. Kerala is taking the course that population growth is due to social injustice, and not enough sharing of available resources. Andra Pradesh employs the method of offering economic rewards and punishments for families that have more than the allotted number of children. While much debate can be had over which method is correct, both countries have had noticeable results in pursuing their goals of population control.
Improved human rights for women also helps as a form of birth control. Women that are more educated and with more access to different opportunities will tend to have less children as they explore other options besides motherhood. It is important that women be given opportunity to improve their lives, as many cultures allow the men to control all aspects of family life, which can still lead to high birth rates when women are relegated to motherhood as the only career choice.
Family Planning
Taking the time to be conscious about raising children allows people to be as confident as possible when to have a child, or when to add another child. Family planning can allow families to still have several children, but have the children spaced out to ease economic and physical hardships. Family planning is not a new concept, as it is believed that many ancient civilizations practiced forms of birth control to maintain a sustainable population. The idea or acceptance of constant child birth is a relatively new idea from the last couple of centuries.
In addition to careful planning, there are also medical means of birth control. While some may have cultural or religious aversion to forms of birth control, there is always the tried and true method of abstinence. There are many methods and medicines that will soon be available that will very nearly let couples determine whether they will conceive a child or not.
Creating the Future
We have a unique opportunity based on the time we live in now. With the world population trending upward, we can make active choices whether to contribute to the world population or to voluntarily partake in birth control methods. While many feel that the population growth will level off soon, there are no guarantees of that. Societies today are much more accepting of life choices that include not having children or having fewer children than previous generations. This may help tip the balance in favor of long term human survival as we attempt to ensure that enough resources for survival are available for future generations.
Chapter 14
- Cities are Places for Opportunity
- Urban Planning
- Sustainable Development
- Trade, Development, and Jobs
Chapter 14
Cities are Places for OpportunityCities are the quickest growing population centers in the world. In these times where people do not need to rely on hunting and farming for themselves, many are moving to cities, to enjoy wider job opportunities and socialization. While these population centers can cover over natural landscaping for hundreds of square miles, cities can efficiently house and sustain people with a smaller ecological footprint than if the same number of people were scattered across the countryside. While cities can lead the way in innovation, they often must fight against areas of extreme poverty and high pollution rates.
The rate at which modern cities are growing is astounding. In 1900, only 13 cities had populations over the 1 million mark. There are now more than 300 cities with at least 1 million residents. China has had the largest growth of cities in the last 30 years. As China has ended much of its collective farming and factory work, citizens have moved into cities in search of work. Chine now has over 100 cities with populations over 1 million. This has put obvious stress on these cities that were not built with such large populations in mind. China has hired a British firm to assist in creating "eco-cities" that will focus on being self-sufficient with a lower output of pollution.
One of the main reasons cities are growing is that farming and agriculture have been largely mechanized. This means that many of the people who used to work on farms or other labor that has been taken over by machines are now moving to cities to seek new opportunities. This leads to pollution and health problems due to overcrowding. Many large cities have inadequate sewer systems to handle the population. This contributes to issues with clean water being available for everyone, and can spread disease quickly in crowded settings. Many cities do not have the resources to create or expand existing sewer systems to meet the needs of the population.
In addition to being unable to provide clean water, oftentimes sufficient housing is also lacking in large cities. This can lead to undesirable parts of cities being converted to slums. Slums are legal housing areas but are often poorly constructed and house more people than can safely live there. Slums can seem like ideal places to live for people who are forced to live in shantytowns. Shantytowns are illegal settlements where people gather together and construct temporary homes out of whatever materials are available. Since they are illegal living areas, there are no municipal services to aid with garbage, sewer, or crime. Many cities are realizing that shantytowns and slums house a significant portion of their workforce, and are doing what they can to improve living conditions in these areas.
Urban Planning
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| Urban Sprawl (Principles of Environmental Science, p. 347) |
Urban planning is most noticeably visible when it comes to mass transportation. As countries became wealthier people living in cities wanted more personal space for themselves. This lead to people living further outside cities, but still requiring quick access to work and shopping areas. This is known as urban sprawl. Especially in the United States highway construction was seen as way to link these new rural communities with urban centers. While these worked early on, now these cities are faced with having too much traffic on the highways, which results in higher pollution and traffic accidents. While many cities are now scrambling to once again invest in public transportation in an effort to cut down on traffic and pollution, it often comes at high expense as areas need to be retrofitted for light rails or bus lines.
City planners can play a vital role in helping to curb or eliminate urban sprawl. By focusing on in-filling locations already available in cities, as opposed to building on empty land, population can grow without increased land use. Careful planning allows for population and cultural growth while reducing pollution and unneeded building. Portland and Atlanta are examples of both methods. Portland has increased its population by 50%, but only increased its land use size by 2% in a 20 year period. This helped reduce pollution by 86%. In contrast Atlanta allowed urban sprawl, and along with increased traffic and taxes, pollution went up 5% in the same time span.
By following guidelines established by neo-traditionalist urban planners, more cities can reap the benefits of careful urban planning. Some of these guidelines include maintaining greenbelts in urban areas, as this provides recreational space and encouraged efficient land use. Locate everyday shopping and services in areas where people can easily reach them, preferably within walking distance or easily accessed by public transportation. Promoting diverse housing allows developers to take advantage of in-filling in urban areas, and can help save energy and land costs. Some areas will allow for making cities more self-sustainable by having areas where food can be grown locally. This will contribute to natural pollution control and maintain urban greenbelts. These are just a few of the many ideas that proper urban planning can employ.
Sustainable Development
Urban planning and city centers allow many people to gather in one place. This can lead to great collaboration and exploration of new ideas. This is needed today as we seek to promote sustainable development. Sustainable development entails not only being able to better our lives today, but to make sure that the means and resources are in place to allow future generations to enjoy the same developments. As the goal of most countries is to increase their overall wealth, sustainable development is a key factor of economic decisions.
Classic economic theory views natural resources as finite. This means that eventually resources we may take for granted will eventually run out. This drives prices on these resources, and people are free to buy and sell these goods at whatever price they choose. New economic theory expands on these ideas, and includes labor, knowledge, and capital into the economic cycle. While natural resources may run out, knowledge can replace these resources with new substitutes. This allows economic cycles to keep moving as a steady availability of resources will replace any that are lost.
Ecological economics also play into the idea of sustainable development. This view of economics places value on natural resources that we often take for granted. Things such as air and water purification by natural means has great impact on our lives. By taking these factors into account, great value is placed on natural forests and clean water sources. Instead of land being valued just for what can be built there, land can be valued for the natural services it provides as well. This theory argues that quality of life can still grow without having to consume more and more natural resources. By using renewable and more efficient energy, we can preserve ecological capital, while still increasing measurable quality of life factors.
These are all theories of course, and no one can be sure exactly how the future will play itself out. We can take heed of computer models that play out these scenarios and try to learn from them. If natural resource consumption continues at its current rate, there could be catastrophic shortages within this century. However, if continued innovation is encouraged, and natural resources can be used more efficiently or replaced, then these computer models project a sustained standard of living for the world population.
Another dilemma that faces global economies is the use of shared resources. While it may benefit a poorer family to have more children to generate more income, in the end these children will consume more resources, lowering the standard of living for everyone. This has been studied in natural resource availability as well, as there are many examples of overharvesting of resources, whether it was mineral, land, or animal. Sharing of property for the benefit of the community was often a required means of survival for many earlier civilizations. In areas or civilizations where communal property was instead owned by just a few, the depleting of these resources often quickly followed. The same pattern holds true in modern times, where land that was traditionally shared by families or villages was split into private sectors, the land was often exploited for its resources and then abandoned. So while communal sharing can be seen as a good thing in theory, it is often more difficult in practice to sustain.
Trade, Development, and Jobs
Global trade has been viewed as a way to attempt to distribute wealth more evenly throughout the world economy. Buying products that can be produced cheaper in other countries has been viewed as a win-win scenario, as it allows consumers to buy more of a product, while infusing other countries with money to raise their standards of living. In reality though the global economy still tends to flow through just a few large rich corporations. Goods that are produced cheaper and faster in other countries are often done at the expense of pollution control and other shortcuts that can have damaging long term effects on the environment.
While the World Bank Organization deals in large multi-million dollar loans, many of the projects it funds are open to criticism as they tend to be projects that are meant to help the global economy, but without weighing the cost of localized damage. In contrast, many countries are finding it more worthwhile to invest in smaller loans, sometimes as little as a few dollars, to people who have little or no collateral. While these transactions may pale in number to large loans for countries, by targeting individuals who are willing to work, the banks see much greater rates or return on their investments, along with boosting local economy.
One of the cities at the forefront of Urban Planning is Vauban, Germany. While Vauban doesn't ban automobiles, it is designed around foot and bicycle traffic. There is convenient public transportation, and the town has been built with this in mind, so shops, banks, and places of business are easily accessible. Living arrangements are also built with urban planning in mind, as residences are not stand alone features, but still maintain privacy and quality of life standards due to creative and careful planning. This model shows that we can create cities that are much more self-sufficient, however it will require a change of social mindset to get most people to try and adopt to this type of lifestyle.
Chapter 13
- Waste Production
- Waste Disposal
- Reducing Waste
- Toxic Waste
Chapter 13
Waste Production
The United States is one of the leading producers of waste products in the world. Every year, on average, each person produces 3.6 tons of waste. While much of this can be recycled, much of the waste is considered municipal solid waste, which is difficult to recycle. On average each person produced 4.6 lbs of municipal solid waste, which is 2-5 time as much as other countries.
The waste we produce is identified as the waste stream. Every item that we dispose of and are unable to reuse contributes to this waste stream. Much of what goes into the waste stream would be reusable if we were to separate the waste efficiently. In addition hazardous waste gets mixed into the waste stream, and can cause environmental damage.
Waste Disposal
There are many methods of disposing of waste. Many of them have undesirable side effects. In many parts of the word the most common form of waste disposal is simply dumping garbage in any available area. In developing countries this can lead to large area of waste that grow with no safety measures in place. Even in developed countries like the United States, this kind of dumping still occurs, although it is illegal. Enough illegal dumping occurs in the United States to equal the oil spill of the Exxon Valdez disaster.
The world's oceans are the next prominent waste disposal area. For years countries and ships at sail have dumped their garbage into the ocean, assuming it would all just sing to the bottom and disappear. Unfortunately most of this waste does not disappear, instead killing thousands of marine animals every year due to trapping them or poisoning. There are now large gyres, or islands of garbage that are floating in many of the world's oceans. This garbage is not degrading, and instead just keeps accumulating. We are still working on way to try and break down these large garbage islands.
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| Island of Garbage in the Great Pacific Garbage Patch |
Landfills, which account for 54% of municipal waste, are slowing being transformed not only into recycling areas, but also into new sources of energy. As garbage is buried beneath the ground, methane gas forms. In the past, this gas was simply allowed to escape into the atmosphere, which contributed to global warming. Now this gas is being captured and used for energy. In fact some landfills even mix the garbage with water to speed up the transformation process.
While we attempt to find better ways to dispose of waste, many countries again take advantage of developing countries and use them as waste dumps for toxic substances that are illegal to dump in their own countries. China was a major waste dump for toxic materials, but this has since been outlawed. Now India and many poor African countries are the dumping ground for hazardous material. Electronic waste, such as televisions and computers, are major sources of these new toxic forms of waste. In poorer countries, local people will comb through this e-waste in search of valuable components to sell, exposing themselves to dangerous toxins.
Incineration is another common form of waste disposal. One benefit of incineration is that energy can be captures from the waste and converted to energy. While this sounds like good use of waste, often times incinerators can cause environmental damage due to burning of toxic materials. Currently the EPA feels that the health risks from incinerators is light enough to allow their continued use. Incinerators that sort garbage better are more expensive to run, and can be cost prohibitive.
Reducing Waste
Recycling is a major way we can contribute to shrinking the waste stream. In many cases recycling materials is cheaper than outright disposal. In addition recycling helps conserve natural resources. It takes large amounts of oil to create new plastic, while recycling plastics only take 50-60% of the energy needed to create new plastics. Trees are another valuable resource that could be better preserved if paper were recycling more often. In the short term recycling helps ease the strain on waste disposal areas, and long term it well help to make sure more natural resources are available for the future.
Composting is a way or recycling yard waste. Normally lawn clippings and other landscaping waste would be buried in landfills. With composting, this waste can instead be converted into mulch, to help enrich landscaped areas, just as would occur naturally in the wild. Composting can also be another large source of methane, and some European countries are creating methane plants to take advantage of this process.
We can also make an effort to reuse many materials. Anything from clothing to recaptured parts from automobiles can be put to use again, and save the natural resources needed to create new products. In less developed countries this is actually a common way of acquiring goods, and something that more developed countries can learn from.
The best way to reduce waste however, is with careful planning of how materials are originally created. Finding ways to create products with less natural resources will cut down on the waste produced. In addition simple things like reducing the amount of packaging for materials can add up to billions of tons of waste materials that won't need to be disposed of.
Toxic Waste
Toxic or hazardous waste is a growing concern as we consume more products and produce more waste that contains dangerous materials. Toxic or hazardous material is classified as substances that are known to be fatal to humans, be toxic or carcinogenic to humans or other life, is ignitable at 60 degrees C, is corrosive, or is explosive. Many of these materials are either recycled or converted to non-hazardous waste, however this is not always the case with many forms of hazardous substances.
In the United States, the government has created Federal regulations to help control how hazardous waste is disposed of. These regulations attempt to discourage toxic or hazardous waste dumping, or even just abandoning of sites that contain hazardous materials, by levying heavy fines for anyone associated with the land or dumping sites. While these rules have been eased slightly to allow more time to see if these sites can be cleaned of toxic materials, it is a good form of discouraging blatant abuse of hazardous material disposal.
In addition the United States government has created a Superfund, designed to help clean up many sites that were contaminated and then abandoned. While the original plan called for many of the production industries to cover the bill, the burden has since been shifted to taxpayers. In addition red tape and legal battles have slowed down the progress of site cleanup that the Superfund was designed to assist with. Hopefully in the future the Superfund will be put to better use to assist with environmental cleanup.
Brownfields are areas known as contaminated property, often times abandoned industrial sites. These areas are unused land that no one wants to use due to toxic hazards. Regulations stipulate that these areas must meet certain levels of purity, such as children being able to eat from the dirt of an area, before they can be put to any kind of use. These levels of cleanliness are often too expensive to make them attractive land purchases, and the area continue to sit abandoned and contaminated.
A recurring issue we face is how to dispose of hazardous waste. While there are methods for converting it to non-hazardous waste, many feel that it is safer to store these chemicals permanently. The best way to do this is in enclosed areas that can be monitored carefully for any kind of leaks. This provides the benefit that these materials are easily retrievable, and if no methods of disposal are discovered, it will be easier to treat these materials. This has a higher cost to it then most dumping processes, but may be the safest way to handle the materials for the foreseeable future.
Chapter 9
- The Atmosphere
- Climate Change
- Accelerated Climate Change
Chapter 9
The Atmosphere
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| Atmospheric layers (Principles of Environmental Science, p. 208) |
Our atmosphere contains many layers. There is the Troposphere, Stratosphere, Mesosphere, and Thermosphere. Each of these levels of earth's atmosphere play a vital role in sustaining life on earth. The atmosphere layers absorb about 50% of the solar energy provided by the sun. This solar energy that makes it through is then absorbed by different materials. This contributes to the cycle of life here on earth, as it powers such vital roles as photosynthesis. In addition the atmosphere helps capture heat from the sun, otherwise our temperatures would be on average about 36 degrees Fahrenheit lower than they are now. This "greenhouse effect" is cause for concern. As industrial pollution contributes to the thickness of the atmosphere, more heat is being retained. This could cause damaging long term effects at the average temperatures of the earth increase, damaging plant and animal life.
Heat is redistributed around the earth by various methods. One is evaporated water, which then moves to other areas of the planet and becomes rain. The oceans also redistribute this heat, by moving warmer waters from southern regions to northern ones, and cooler waters in the opposite direction. This method of heat redistribution is known as thermohaline. This relates to global warming because as our temperatures increase, glaciers and icecaps begin to melt. This infusion of cold icy water into the major ocean currents can dramatically alter temperatures around the globe.
Climate Change
As concerns with global warming arise, the question that is asked is just how fast climate change can occur. We have usually assumed climate change to be something that happens over centuries, not the span of a human lifetime. New techniques of drilling into ice sheets allows scientists to study ice cores. These cores show how oxygen rates have varied in the air going back hundreds of thousands of years. While these ice cores show that the climate has varied dramatically, the main correlation has shown that carbon dioxide levels have a direct correlation to global temperature. This is alarming as our current amount of carbon dioxide is almost 33% higher than it has been at any time in the last 1 million years of history, and is continuing to rise.
The movement of earth through space also plays a role in climate conditions. These cycles however take course over thousands of years, and do not cause extreme variation in temperatures. One of the most well known climate effects is the phenomenon known as El Nino. This 3-5 year cycle causes major weather shifts on a global scale. Part of the country that are normally hot and dry receive large amounts of rainfall, and normally wet areas have drought like conditions. There is growing concern that as global warming increases, the El Nino effect is becoming more frequent.
El Nino has a direct effect on people's lives, as the extreme dryness that comes to normally moist areas can have dangerous results. In Indonesia, the normally moist climate becomes extremely dry while the Southwest United States receives most of the moisture. This has lead to large fires that contaminate the air. In 1997, 20 million people were treated for airborne illnesses that could be contributed to the thick smoke caused by these fires.
Accelerated Climate Change
This global warming trend has become one of the most important environmental issues facing humankind. Its effects are global, and affect not only humans living today, but could have profound effects on future generations. As more and more scientists study this trend, it has become clear that human activity is responsible for at least 90% of the warming activity. This report was compiled by the IPCC (Intergovernmental Panel on Climate Change). The report can be found at http://www.ipcc.ch.
Projections by the IPCC show that global warming will continue to have profound effects on the globe. Temperatures that increase by as much as 10 degrees Fahrenheit, and ocean levels rising by as much as 20 feet would cause huge disruptions to major population centers. These changing conditions can also lead to droughts and food shortages, which in turn would cause political turmoil. While governments struggle with how to avert these possible crisis's, many researches feel that finding alternative energy sources will be the biggest benefit to combating global warming. Currently coal provides much of the world's power sources. Coal however also reduces high amounts of carbon dioxide into the atmosphere, which we learned was directly tied to increasing the "greenhouse effect".
This global warming trend is something that should not be ignored. If we do continue to ignore the issue and use energy such as coal that contributes to global warming, then we will likely face serious disruptions to our ecological and economic systems as a result. While governments try to find ways to deal with the issue without losing means of producing energy, we can make individual contributions by attempting to have a smaller carbon footprint. This may buy us enough time to allow for global changes in how we use energy and hopefully trigger a reversal in global warming.
