UNIT 3 COMPILATION

Unit 3 Compilation

 1. Human Populations

        A. Population Growth

           1. Then & Now

        B. Population Growth Perspectives

           1. Effect of environment/culture on human population growth

           2. Benefits of population growth

        C. Factors that determine Population Growth

           1. Demography

           2. Overall Population

           3. Fertility

           4. Rise of Life Expectancy

             a. Implications of living longer

        D. Demographic Transition

           1. 2 ways to complete demographic transition

        E. Creating the Future

2. Economics and Urbanization

        A. Cities are Places of Crisis and Opportunity

           1. Urban Agglomerations & Megacities

           2. Rapid Growth of Large Cities

           3. Congestion, Pollution & Water Shortages

           4. Lack of Sufficient Housing

        B. Urban Planning

           1. Transportation

           2. Smart Growth & Urbanism

         C. Economics & Sustainable Development

           1. Sustainable Development

           2. Classical & Neoclassical Economics

           3. Ecological Economics

            4. Renewable & Non-Renewable Resources

         D. Trade, Development & Jobs

           1. International Trade

3. Sold & Hazardous Waste

        A. Waste Products

           1. Municipal Sold Waste

        B. Waste Disposal Methods

         1. Open Dumps/Ocean Dumping

         2. Landfills/Sanitary Landfills

         3. E-waste

         4. Incinerators

       C. Shrinking the Waste Stream

         1. Recycling

         2. Composting

         3. Reducing Waste

      D. Hazardous & Toxic Waste

        1. Hazardous Waste

        2. Federal Legislation regulates waste

        3. Toxic Release Inventory

        4. Processing & Storing Hazardous Waste

           a. Producing less waste, converting to less hazardous

       substances, storing permanent waste (permanent

       retrievable storage & secure landfills).

4. Climate & Air Pollution

        A. The Atmosphere

           1. 4 Distinct Zones

           2. Energy within the atmosphere

           3. Ocean Currents

         B. Climate Change Over Time

           1. Climate History

           2. Natural Climate Swings (3 Milakovitch Cycles)

           3. El Nino/Southern Oscillation

        C. Climate Change Happening Faster Than Normal

          1. Intergovernmental Panel on Climate Change

          2. Changes in heat waves, sea level & storms

          3. Greenhouse Gases (CO2, CH4, N20)

          4. Evidence of Climate Change

          5. Disputes over climate evidence

HUMAN POPULATIONS

        The human population is increasing rapidly now more than ever before. As of 2010, the human population count was estimated to be around 7 billion and growing at 1.13% per year. Some people are concerned that because of this boom, overpopulation will cause environmental harm and depletion of resources while others believe that the amount of living humans allow us to overcome certain problems we may encounter, whether it’s environmentally, socially or economically.

        Since the beginning of the Industrial Revolution, many have argued about the causes and effects of population growth. Both Thomas Malthus and Karl Marx developed their own theories about human population growth and they affect the environment and cultures. Malthus concluded that population tends to increase at an exponential rate while food production remained either stable or gradually increased. He argued that human populations would outdo their food supply and fall into starvation, crime and unhappiness. Karl Marx presented  a different view than Malthus, stating that population growth was a result of poverty, resource depletion, pollution and other social problems. To slow population growth, Marx said that people needed to be treated equally and not feel oppressed or exploited from social situations.  

        There are some benefits to population growth, such as larger markets around the world, more workers, and the efficiency of goods. It also increases human ingenuity and intelligence which in turn can create new resources.

        To determine population growth, there are several factors that economists consider. They consider demographics, or demography, which includes important statistics about people, like births, deaths, where the live and the total population size. There are basically two distinct demographic worlds that we live in: one if poor and growing rapidly and the other is rich and the population growth is decreasing. The poor parts of the world are mainly occupied by people who live less-developed countries, such as Africa, Asia, and Latin America. Astonishingly, these countries make up about 80% of the entire world population and are responsible for more than 90% of the world’s projected future population growth. In the rich parts of the world, such as North America, Western Europe, and Australia, the people living here choose to have a very low number of children or none at all, which accounts for the decreasing population number in this part of the world.

        Fertility is an important factor to consider when talking about population growth and the most accurate statistic of fertility is usually the crude birth rate, which is the number of births in a single year per thousand persons. Economists also study the total fertility rate, which is the number of children that are born to the average woman in a given population during the span of her reproductive life. Zero population growth (ZPG) occurs when births and immigration in a population equal the deaths plus emigration. This does not occur very often, and it typically takes several generations for ZPG to take place in a population.

        An interesting factor to point out in regard to population growth is that of life expectancy, which simply means the average age that a newborn is expected to stay alive in any given population or society. The life expectancy has increased over the past several decades due to the increase of certain medicines, better nutrition, cleaner water and a good education. Living longer does have certain social implications however, like dependency ratios. This term describes the number of nonworking people compared to those who are working in a given population.

        When we talk about demographic transition, we are using it to describe the pattern of transition from high birth and death rates to low birth and death rates. There have been two very different and opposing views/approaches on demographic transition and how the Indian states of Kerala and Andra Pradesh view the regulation of population growth. In the state of Kerala, citizens and those in chage provide an equal share of social benefits to everyone, especially those involved in family planning. This view assumes that there are enough resources available for everyone, but it is the lack of justice that causes hunger, poverty, violence and environmental damage, not lack of resources. In the state of Andra Pradesh, its leaders have developed a strategy of stressing birth control rather than encouraging social justice. While both states approach demographic transition much differently, they have haltered population growth, which is beneficial in their countries because the population does not exceed the amount of resources needed to sustain life for those living.

        So what kind of population growth should we expect within the next several decades? The majority of professionals who study demographics are convinced that the world population will stabilize during the twenty-first century. Once this happens, professionals say that we can expect the human population to reach nearly 8 to 10 billion people, dependent on the success of family planning programs and other contributing factors.

Economics and Urbanization

        Over half of the human population reside in cities all over the world, and this number is expected to rise over the next century. The overwhelming majority of urban growth will take place in the less-developed countries, where population is rising much faster than the need for necessities like water supplies, schools, transportation and roads, and infrastructures. Urban agglomerations are beginning to form all over the world, and this simply means the conjoining of several municipalities. Some have even become mega-cities, meaning their population is over 10 million people. Although cities are the site of massive overpopulation, they can bring several benefits like their ability to make greater economic gains due to the population. Innovation also occurs the most in large cities, and resources/goods are more readily available to humans.

        We can expect large cities to continue to grow, and China represents the largest demographic change in human population history. Since the era of farming and factory work came to an end in 1986, an estimated 250 million people have relocated from rural areas to cities. China continues to expand their urban centers and build 400 new ones with populations around 500,000 over the span of the next 20 years. China already accounts for nearly half of the concrete and one-third of the steel used in construction around the world.

        The drawback of big cities is that they are more susceptible to congestion, pollution and water shortages. We think that big cities in the United States like New York City, Los Angeles and Houston are bad when it comes to traffic, but countries like Indonesia are much worse. Jakarta, Indonesia is considered one of the most densely populated cities in the world and traffic is a nightmare on a daily basis. Pollution from non-regulated factories and traffic has decreased the air quality in many urban populations. China and its cities are among the worst when it comes to air pollution due to the increased use of private automobiles. They are now the leader in producing the most greenhouse gases and a third of China’s urban residents are exposed to harmful air pollution levels daily. Urban cities have found it difficult to afford the building of waste treatment systems for their quickly growing populations. Unfortunately, only one-third of humans living in urban areas have safe and clean sanitation services. When you think about how many billions of people inhabit the earth, that’s not very much at all!

Another problem in many urban areas is the ability to find clean drinking water. In China, nearly 70% of their surface water is so bad that it’s not suitable for human use. Many cities and urban areas also lack sufficient housing, which can lead to several problems on its own. Families often live in slums, where they live in unsafe, crowded small rooms with inadequate ventilation and sanitation. Shantytowns, which are living quarters made of corrugated metal, brush, plastic sheets and other materials, grow on the edge of many cities. They can house a large amount of people, but they usually lack clean water, sanitation, or electrical power.

When we talk about urban planning, we want to consider the factors that make cities run smoothly and successfully. One of those factors is the importance of transportation to city development because it’s been such a hard feat in the past. In today’s world, nearly every working American owns a private automobile to get them to and from places around them. While freeways have helped aid transportation, it has become a problem in the larger cities being that it causes traffic congestion. We see more freeways in the United States than anywhere else in the world; countries like Europe have mass transit systems in their urban areas, which has helped them preserve historic sites and landmarks as well as avoid the sprawl.  

Many large cities have become urban, meaning that planners and architect have strived to make them more appealing, efficient and livable for humans. A lot of the large cities that surround us have undergone urbanism and for that reason, have grown larger and expanded because of it. Planners, builders, and other professional have proposed several reasons as to why urbanism can be beneficial for a city and its people. Some of the reasons include being able to determine in advance where development will take place, maintaining recreational space and promoting efficient land use, limiting the size of cities or organizing them into groups of 30-50,000 people, encouraging walking or the use of small, energy efficient vehicles, and promoting more flexible and diverse housing for people.

Sustainable development is derived from two separate meanings; sustainability, which means living on the earth’s renewable resources without damage to ecological process; development means to improve one’s life. Combined, these two words can mean the effort to meet the needs of the present without compromising the ability of the future peoples to meet their own needs. In order to better understand sustainability, it’s important to know about all the different resources that humans use, and also, how we view those resources in regard to the environment. Classical Economics believes that natural resources like iron, gold, water and land exist in fixed amounts. Therefore, as population grows, these resources become more limited and reduce overall quality of life, increases competition, and causes the population to decline over time. Neoclassical Economics believe that resources fall under labor, knowledge, and capital. In other words, labor and knowledge are resources since they are necessary to create goods and services. Unlike the resources in Classical Economics, these resources are not finite because every new person can add more labor and energy to the existing economy. Ecological Economics uses ecological ideas of system functions and recycling to the definition of resources. More simply stated, this way of thinking is aware of nature efficiency and acknowledges the importance of the functions of ecosystems for the sustainability of human economies and cultures. There are 2 types of resources that exist on land: Renewable and non-renewable resources. Renewable resources are naturally recycled and replenished at a steady state. Examples of renewable resources are fresh water, living organisms, air, and food resources. Non-renewable resources exist in small amounts, like mineral, fossil fuels, and groundwater.

In order to keep a society full sustained, there needs to be some type of resource distribution and several wealthy nations have come together to disperse wealth to the poorer countries of the world. International trade plays an important role in this area because it gives us the opportunity to take advantage of the best or cheapest products from all over the world. One disadvantage with international trade is that it externalizes costs on a grand scale, and environmental costs can be exported to places where pollution is not controlled by legal authorities.

Solid & Hazardous Waste

        We humans all produce waste in almost all the things we do on a regular, daily basis. The United States alone produces a staggering 11 billion tons of waste per year, equaling about 3.6 tons of waste per person. Municipal Solid Waste is the most common type of waste that is produced every year, and it comes from our homes, work offices, and cities. It is one of the more difficult wastes to manage and recycle because it contains many different kinds of materials.

        Waste can be disposed through several different methods: open dumps/ocean dumping, landfills/sanitary landfills, e-waste, and incinerators. Open dumps still remain the most common form of disposing waste products, while ocean dumping sees nearly 55 million pounds of waste, including packaging, bottles and cans, dumped at sea every year. The dumping of plastic debris into oceans has become a continuing problem for these large bodies of water, and scientists continue to find ways to solve this ongoing problem, which is damaging our ecosystem tremendously.

        Landfills receive the biggest amount of our waste, about 54 percent every year. Sanitary landfills are designed to contain waste, and operators of these landfills have to compact and cover it every day with dirt, to diminish smells and litter, and to keep insects and rats from entering the landfill. Sanitary landfills are also required to manage methane and are the single most source of methane in the United States, and they also help aid in controlling pollution.

        E-waste, or thrown out electronics, account for one of the greatest sources of toxic material; even worse, this toxic material is going into many countries that are not equipped with the right methods to control all of the waste. Most of this material goes to dumps or landfills, and only a small amount of it is actually recycled for future use. Several cities have begun to use waste incinerators to dispose of waste and other toxic materials since the rate of garbage is at times too much to keep up with. With incinerators, waste is burned instead of recycled, and nearly 45,000 metric tons of garbage is burned daily in the United States alone! Some incinerators produce steam and give off heat, which can become a useful resource if used in this manner. On the downside, incinerators can cause certain health risks because of the ash and emissions that are released into the atmosphere. The residue from the ash can contain toxic components which can be harmful to humans, but the EPA is taking proper measures to ensure the peoples’ safety when it comes to incinerators.

        There are several ways in which waste can be reduced, and one of the most common ways is by recycling. Recycling is the re-processing of discarded materials to make new products from them. Aluminum is among the most valuable material to recycle because it can be used for hundreds of purposes and is also very lightweight. Recycling can save money, energy and space and greatly reduces the pressure on landfills and incinerators. It also lowers the need for raw resources, reduces energy consumption and air pollution, and reduces litter. Another process that some cities use to reduce waste is through composting. Composting is the breakdown of organic matter under oxygen-rich conditions. This process creates nutrient-rich soil that aids in water retention, slows the erosion of soil, and greatly improves crops. One of the advantages of composting is that after months of composting takes place, natural microorganisms will decompose organic material into rich and usable compost for yards or gardens. Reducing waste is considered to be the most effective and also the cheapest way of regulating and waste. Reducing waste has many benefits, like saving money and increasing overall efficiency. There are several things that we can do reduce waste ourselves, like buying foods that contain a minimal amount of packaging, buying reusable products that are also easy to recycle, composting your yard or garden, and helping your community create systems for disposing electronics properly.

        Hazardous waste has become a large concern in regard to getting rid of waste, and keeping the environment clean of it. Hazardous waste is any discarded liquid or solid material that is considered to be fatal to humans/laboratory animals, toxic, ignitable, corrosive, or highly explosive/reactive. The Federal legislation regulates hazardous waste and there are two specific laws that relate to hazardous waste management and disposal in the United States. The Resource Conservation and Recovery Act (RCRA) is a program that requires extensive testing and management of toxic and hazardous chemicals/substances. Those who handle these chemicals must log and keep account of everything that they handle and what happens to it from year to year. The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) is a program that focuses on containing, maintaining, and cleaning up abandaoned toxic waste sites. This program also allows the EPA to take action if there is a potential threat that any toxic chemical could find its way into the environment and harm people. The Toxic Release Inventory also plays an important role in keeping the public informed and safe from toxic chemicals and materials. Their job is to provide a list a list of locations where regulated toxic materials are being handled. It also requires that workers and manufacturing facilities report yearly on the releases of more than 300 chemicals to be available to the public so that they can get information about what, if any, chemicals are present in their area. There are several things that we can do to process and store hazardous waste in a safe and efficient way. One way we can do that is by simply producing less waste as a whole, meaning that we should work to recycle and reuse materials as often as possible because it will not only help eliminate hazardous waste, but also reduce pollution. Second, we can use and convert to less hazardous substances and several processes are present to make hazardous materials less toxic. Among those processes are physical treatments, which isolate certain substances by using charcoal or resin filters to absorb the toxins. Incineration is a second method that can be used, where waste is heated and burned for a prolonged period of time until the waste is completely gone. Chemical processing is a third method in which materials are transformed to make them non-toxic. 

     There are certain materials that we have in our environment that cannot be reduced or destroyed, and in this case, permanent retrievable storage is used. Permanent retrievable storage is the act of placing waste storage containers in a tight and secure place where they can be inspected on occasion and accessible if needed. The drawback here is that it is an expensive investment because it requires frequent monitoring, but the advantage is that there is control of keeping highly toxic substances from leaking into groundwater. Secure landfills also store hazardous waste materials, and contain several different layers of soil and clay that all have a specific function in helping to pump out and treat materials that may not belong.

Climate & Air Pollution

        When we discuss climate, we must first look at the atmosphere, as it plays a big role in how climate and temperature changes and differs in different parts of the world. The earth’s atmosphere consists of gas molecules and has four distinct zones of different temperatures, all depending on how solar energy is absorbed in each zone. The four zones are Troposphere, Stratosphere, Mesosphere, and Thermosphere. The Troposphere is the layer directly adjacent to the earth’s surface, and within this zone, air circulates in vertical and horizontal convection currents, which constantly circulate heat and moisture around the globe. The troposphere is much denser than all of the other layers because gravity keeps most air molecules very close to the earth’s surface.

Above the troposphere is the stratosphere, which has a similar makeup like the troposphere, but has almost no water vapor and nearly a thousand times more ozone. The stratosphere is much warmer than the troposphere because the ozone within it absorbs a lot of UV light and solar energy. Above the stratosphere is the Mesosphere, where temperature decreases once again before increasing. The last layer, above the mesosphere, is the Thermosphere, which is the heated layer whose temperature changes with height. In the lower portion of the thermosphere, intense pulses of high-energy radiation make ions glow, which we can assimilate with northern or southern lights.

The atmosphere often captures solar energy near the equator and some of it will reach the outer atmosphere, which is then reflected by clouds and atmospheric gases in the air, as well as carbon dioxide, water vapor, ozone, and methane. The change of energy intensity is important to consider when talking about the atmosphere because the gases that create our atmosphere let light energy pass through, giving us daylight. The most effective and abundant gases found in the atmosphere are water vapor, carbon dioxide, methane, and nitrous oxide. We have all heard the term greenhouse effect, and it used to describe the catching of energy by gases throughout the atmosphere. Ocean currents also influence climate, air and temperature conditions. Warm and cold ocean currents occur from wind pushing on the ocean’s surface and the water moves, giving deep water wells room to replace it, thus creating deeper ocean currents. Water density also plays a big role in ocean currents, being that large currents cycle and carry water north and south and redistribute heat from low to high latitudes.

Over time, we have witnessed some dramatic climate changes, and now we find ourselves wondering how fast climate change will continue to occur and what can we expect from these kinds of changes? Ice cores can tell us a lot about climate history because they have given us a more clear understanding of climate history and can now study isotopes of oxygen. More importantly, cimatologists can examine how concentrations of carbon dioxide have changed in the atmosphere over time.

Ice cores have also helped climatologists determine the cause of natural climate swings over time with the assistance of the Milankovitch cycles; these cycles have helped determine the exact changes associated with periodic shifts in the earth’ orbit and tilt. There are three cycles in the Milankovitch cycle; (1) The earth’s elliptical orbit stretches and shortens over a period of 100,000 years; (2) The earth’s axis changes the angle of its tilt over a period of 40,000 years; (3) The earth’s axis wobbles over a period of 26,000 years.  

The ocean and atmosphere together have created certain oscillations in all of the world’s oceans in which the climate changes according to those oscillations. Among the most widely known of these is the El Nino/Southern Oscillation, which most greatly affects climate in the Pacific region, and at times even further, creating a great deal of monsoons and/or severe droughts in other regions. El Nino/Southern Oscillation occurs when a large pool of warm surface water in the Pacific Ocean slowly goes back and forth between Indonesia and South America. It then provides heat that creates a strong upward stream of low pressure into the atmosphere. On the other side of the Pacific, cold water replaces westward flowing surface waters, and dry air in Mexico and California is replaced by the air moving westward in route with the trade winds.

Throughout this portion, we’ve been looking at how quickly climate has changed over time, and continues to change at a fast rate. There is some supporting evidence to describe the state of climate change and knowledge and one of those is through the Intergovernmental Panel on Climate Change (IPCC). The goal of this program is to analyze scientific evidence that explains the causes and likely effects of human-caused climate change. We can also consider the potential changes in heat waves, sea level, and storms to determine climate change. According the IPCC, it is expected that sea levels will rise 7-23 inches by the end of this century, and some have even raised that number to 1-2 meters by the year 2100.

Greenhouse gases exist in the atmosphere, but the main ones are carbon dioxide, methane, and nitrous oxide. Carbon dioxide is the most important of all three because it sticks around for decades at a time in the atmosphere. Methane is not as abundant as carbon dioxide, but it absorbs a lot of energy per molecule and is staying in the atmosphere about twice as fast as carbon dioxide. Nitrous oxide is the least abundant of all three greenhouse gases, but still plays an important role in the atmosphere.

Over time, climatologists and scientists alike have gathered evidence that supports climate change and through the evidence they found, they have concluded that if current climate and warming trends continue, the end of the century will be the hottest time in the last two million years! Some of the supporting evidence includes: Polar regions have warmed up much faster than the rest of the world; The Arctic Sea is only half as thick now as it was 30 years ago; Ice shelves located on the Antarctic Peninsula are breaking apart and disappearing faster than normal; Sea level has risen worldwide about 6-8 inches in the past century; Droughts are becoming more common and widespread all over the world; Storms are becoming much stronger and damage from the storms is increasing. Those are just a few pieces of evidence that supports we are seeing a drastic and quick change in climate, and it’s possible that more evidence will come about as we continue on through the century.

While there is a handful of evidence and research that supports a major climate change in the atmosphere, there are some who dispute the evidence. The public and media may have their own different viewpoints on this topic, and they could be ignoring the evidence for several reasons; one being that change can appear threatening to some, so it’s easier to ignore it than confront it and worry about it. Second, the public may not see the evidence of scientists and climatologists very interesting or applicable, so they will just as easily ignore it.

There are some statements made by the media that climatologists and scientists have fought to defend. Among some of those statements are: (1) Reducing climate change requires us to abandon out current lifestyle; (2) A comfortable lifestyle requires high carbon dioxide release; (3) The climate has changed before, so this is nothing new; (4) Temperature changes are leveling off; (5) Climate scientists don’t know everything, and they make mistakes and false statements. Because the media is so influential on our society, scientists and climatologists know they have to work hard to convince the public that precautions need to be taken seriously in order to take action for climate change.  

This unit covered the impact that humans have on our environment, its ecosystems, and the atmosphere. I think it’s safe to say that we humans are the biggest change that needs to happen, meaning that if we want to live in a healthy, safe, and clean environment, we need to take responsibility for our actions and take the necessary steps to maintain our land. Even if they are small steps, by taking those steps, we are on the road to a more beautiful and clean environment we can call home and be proud of.