Unit 3 Compilation

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 Growth

    The 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.

Doubling of World Population (Principles of Environmental Science, p.78 )

    Our current population is estimated to be just over 7 billion people. It took ten years to grow from 6 billion to 7 billion. Before that, it took from the time the first humans made settlements until 1804 to reach the first billion people on earth. Throughout recorded human history the world population grew slowly. When agriculture centers and transportation became more widespread, the world population begin to increase steadily. However, the current tripling of the world population in the last hundred years has many concerned that humans as a species are growing too fast.

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

Demographic Transition (Principles of Environmental Science, p 90)

    Demographer Frank Notestein noticed a pattern in human population cycles that he referred to as Demographic Transition. This involved populations moving from high birth and death rates to lower birth and death rates. The graph shows the different stages of the demographic transition. Many of the current rapidly growing countries are not following this trend however, as death rates have fallen, but birth rates are remaining high. This is a large part of the recent population explosion. Still, many people feel that overall the world population should stabilize sometime in the 21st Century.

    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 Opportunity

    Cities 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

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.

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

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.  

http://www.mhhe.com/Enviro-Sci/CaseStudyLibrary/Topic-Based/CaseStudy_APlagueOfSmoke.pdf

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.  

 

 

 

Wildlife Corridor Lab Project

Objective

The objective of this lab is to show the benefits of wildlife corridors, both to wildlife and humans. One of the effects of human expansion has been Habitat Fragmentation. Wildlife corridors, aided by Conservation Easements, will allow wildlife to be able to roam over greater areas without being encroached upon by human development. This will create Landscape Linkages that well help reduce unnecessary human/wildlife interactions, reduce inbreeding, and allow the bypass of manmade abiotic occurrences that cause impediment to movement by many native species.

Procedure

In Northern Arizona, the construction of several highways, and their expansion from 2 lanes to 4 lanes, have fragmented the wildlife habitats. This has lead to issues with many large animals having unfortunate interactions with humans. Northern Arizona is a diverse range of ecological zones, with a topography ranging from snowy mountain peaksalong with some areas that could be considered high desert. Ecotonal features include aspen-fir pine forests, to temperate grasslands, This wide range of ecological zones of course also leads to a wide range of animal species that use one or more of these zones as their natural habitat. The expansion of man has cut right through the middle of these zones, especially with freeway and highway construction, that often has no built in means of allowing wildlife to cross unimpeded. Highways 89N, 180, and 64 form a rough triangle that begins in Flagstaff, and loops northward to the Grand Canyon, with the San Francisco Peaks at the center. This triangle of highways encompasses an area of nearly 120 square miles, and causes a serious impediment to animals stuck within this triangle. These animals are trying to roam for food or mating reasons. Some species also need to migrate to warmer southern climates during the winter months.

Norther Arizona highways preventing wildlife migration.

Two of the species that I have chosen for the wildlife corridor project are Cervus canadensis, or Elk, and Ursos americanus, or the black bear. These species are two of the largest mammals present in Northern Arizona's mammal demographic and can be among the most disruptive when it comes to human and animal interactions. Both species have high spatial requirements, and would be considered umbrella species. Elk, which had originally been extirpated in Northern Arizona, but have since been reintroduced, have a range of 20-30 square miles, and must consume 15-20 lbs of vegetation a day. They prefer higher altitudes during the summer, and migrate to lower altitudes during winter months (http://www.azgfd.gov/h_f/game_elk.shtml). Black bears forage in areas up to 50 square miles, and prefer berries or grass, but will adapt to whatever food is available (http://www.azgfd.gov/h_f/game_bear.shtml).

While Elk are not normally a danger to humans, they are often times involved in vehicle accidents on highways. Elk can weigh between 600-1200 pounds, and can cause devastating injuries and damage to vehicles, not to mention the injuries or death of the elk involved.

This female elk is nearly the same size as the full sized truck.

Black bears are less commonly involved in vehicle accidents, but with human encroachment cutting down their natural habitats, they are becoming a nuisance in neighborhoods foraging for garbage instead of their natural dietary menu.

Both the Elk and Black Bear would benefit greatly from a wildlife corridor to alleviate current dangers to both humans and wildlife. With temporal access to wildlife corridors available to the animals, there would be a drastic reduction in vehicle accidents involving elk, and allow black bears to roam further as needed to sustain their dietary needs and mitigate forming a dependence on human garbage and waste. Going forward, the pre-existence of wildlife corridors free from human development and light pollution will allow for elk and black bear to continue to migrate and forage as needed, while marking clear areas where human expansion will be prohibited or severely limited. This will help to ensure the diversity of future generations of the species, as well as maintaining proper species birth rate with the genetic interchange provided by the wildlife corridors. While helping to maintain core habitats his will also help to ensure continued future safety for motorists and residents.

Results

Wildlife corridors would greatly expand the range of elk and black bears.

While it may not be possible to create wildlife corridors that are 1000 ft wide, as recommended by Monica Bond, it should be possible to mark off regions that are more than a 1000 ft wide, with multiple access areas. The most economically feasible way to do this with the existing highways would be the creation of culverts that pass underneath existing highways or wildlife overpasses that go over the highways. These would need to be created large enough and wide enough to allow these large animals through. Having several of the culverts or overpasses available in the selected corridor areas would be beneficial, as it would allow multiple herds of elk through, as well as allowing the elk the opportunity to avoid using the same paths as their natural predators. The culverts would need to be built in higher ground areas, to avoid the likelihood of flooding, and to avoid build-up of debris due to flooding that would block access to the culverts. Care would need to be taken to monitor possible blockages during winter months as well, as this would be when elk would be more likely to be migrating due to the weather conditions. Blocked culverts would force elk to cross roads on the surface, again endangering human vehicle traffic and the elk themselves. This highlights the need for adaptive management, to ensure that changing conditions do not curtail previous wildlife corridor efforts.

Wildlife culvert

Wildlife overpass

Conclusion

This project demonstrated the benefits of creating wildlife corridors for both humans and species that have had their natural habitats reduced. With the use of wildlife corridors, animals are able to roam closer to their natural ranges in pursuit of food and breeding needs. Additionally wildlife corridors that use culverts or overpasses help wildlife avoid human highways, which of course can have damaging consequences.

Unfortunately I also learned that in Arizona wildlife corridors have become victims of budget cutbacks (http://azstarnet.com/news/science/environment/article_7012945a-07d2-5ff6-909a-8f37d1738468.html). In addition to stopping ongoing studies for new wildlife corridors, longtime consultants on the placement of wildlife corridors have also been let go. This will make future wildlife corridors an uphill battle to be created and maintained.

While I had heard about wildlife corridors being needed for endangered species, I didn't realize how vital these corridors are even for our local wildlife. I can certainly appreciate the need for wildlife to not be limited in their territory by artificial barriers, as well as helping ensure motorist safety. I hope that Arizona will be able to find the funding it needs to keep wildlife corridors alive, as the long-term benefits should outweigh short-term cash flow issues.

Wildlife Corridor Poster

 

Unit 2 Compilation

Table of Contents

Chapter 6

• Forests of the World
  
• Grasslands
  
• Parks and Preserves
  

Chapter 6

Forests of the World

    One of our greatest natural resources that we have on our planet are the forests. These forests provide several ecological functions, including regulating the climate, regulating water runoff, purifying our air, and supporting rainfall among other benefits. These forests also provide the raw materials for many industrial sources. Trees provide wood for endless building all over the world. In harvesting wood for profit, or to clear more agricultural space, care is often not being taken about the permanent damage being done to forests that are thousands of years old, and the many life forms that call the forests home.

    Current estimates indicate that we have currently only about 50% of the forests remain. This could lead to unforeseen consequences since forests play such a vital role in worldwide environment. Forests are large sources of carbon, and the burning and destruction of these forests are releasing large amounts of carbon into the atmosphere, which can lead to increased global warming. The moisture that is cycled through forests also effects other regions of the earth. Rain in the Midwest United States often times originates over the Amazon forest. With heavy deforestation in the Amazon, this could lead to increased drought conditions thousands of miles away.

    Controlling deforestation can be difficult because it is a large business venture. Wood transactions account for nearly $100 billion dollars of trade per year. The majority of the use is for creating paper for developed countries, and most of the rest is used as a fuel source. So deforestation can be labeled as harmful, but large scale changes are unlikely to occur until alternatives to creating paper or providing fuel are found. One way this could be done is through better management of harvesting lumber, but so far this is only done in about 25% of currently harvested forests.

    Brazil and Indonesia are currently the world leaders in deforestation. It is estimated that Brazil loses 1 acre of forest every second. This of course has a huge effect on the earth's biodiversity, since about 50% of all animal, plant, and microbial species are believed to reside in rain forests such as the Amazon rain forest in Brazil. One of the literally brightest examples that we can see are the Monarch Butterflies that live in forests near Mexico City for 5 months of the year (http://www.mhhe.com/Enviro-Sci/CaseStudyLibrary/Topic-Based/CaseStudy_DisappearingButterfly.pdf).  The type of specialized conditions the Monarch's need only make up about 2% of Mexico's current forest system. While Mexico has attempted to protect this rare forest areas, native people's depend on the harvesting of this wood to survive. This shows the dilemma facing any attempts to regulate deforestation.

Migrating Monarch's.

    Fortunately most countries now realize what a vital resource that forests are, and they need to be sustained for global benefit. While most deforestation occurs to either harvest valuable wood or clear valuable agricultural space, a large percentage is also carried out by native residents who need the land or wood to provide for their families. A new global program REDD (Reducing Emissions from Deforestation and Degradation) has recognized this issue, and is attempting to now pay local residents a yearly stipend in exchange for not deforesting. While it is too early to see if the results are positive, it is a positive step a global stance on the importance of preserving our forests.

    It is not only rain forests in developing countries that are in danger. Even in developed countries like the United States and Canada face issues of deforestation, especially in "Old Growth" areas. While the trees in these areas are large since they can be thousands of years old, and provide much raw materials, these forests are also home to unique species that do not exist elsewhere in the world. This is cause for much controversy in the United States, and even Presidential decrees to protect forests from further road construction has been overturned, and then reinstated. This again shows that there are no easy solutions that will make everyone happy.

    Another man-made danger to North American forests comes from forest fires. The Forest Service had a policy of controlling and putting out any forest fires that occurred on public land. While this was done with the intent of preserving the forests, it is now recognized that forest fires are a natural part of the biological cycle that forests undergo. The fires clean out old and sick vegetation, and provide fuel for new generations of growth. With the control of wildfires however, many forests are now overpopulated with weak trees instead of fewer strong healthy trees. Efforts to correct these short sighted mistakes will now cost billions of dollars in forest clean-up, and there are again many opposing views on how it should be done.

Grasslands

    Another prominent biome that is in danger are the natural grassland areas of the planet. Currently grasslands which include prairies, savannas, and open woodlands occupy about 25% of the earth's surface. While these areas are attractive for being easily adapted to urban, agricultural, or residential areas, they are still home to many species of plant and animal life. It is estimated that these natural grasslands are actually disappearing 3 times faster than the rain forests.

    About 33% of the degradation of grassland areas can be attributed to overgrazing. When these lands are overgrazed, there is not enough vegetation to trap rainwater. The water then escapes the areas, and there is not enough moisture left to nourish new generations of vegetation. This also leads to natural wells and springs being depleted. This degradation can also affect the climate, as the now barren land reflects more heat, which in turn drives away rain clouds, starting the cycle of turning a once natural grassland into a desert environment.

    In the United States alone, only about 30% of grazing grassland is considered to be in fair condition, and 55% is considered to be in poor or very poor condition. These overgrazed grasslands have opened up regions to be taken over by inedible plants such as sage and mesquite, which further diminishes the amount of grassland left to be used. The call for public land to no longer be allowed to be used for grazing is of course opposed by ranchers who use the land for grazing. As they provide a large percentage of the beef supply in the country they feel that access to these lands is vital to continue to meet demand for food.

    Some alternatives that are currently being practiced are rotational-grazing, and alternate meat providers. With rotational-grazing, animal herds are confined to smaller areas. This ensures a uniform grazing and fertilization of the land, as opposed to the animals roaming freely and eating only the choicest plants. This allows the grasslands to recover more evenly. Alternate meat sources are also gaining in popularity. As animals such as bison, elk, and wildebeest's graze on a wider variety of plants than domestic animals, they are able to sustain themselves on smaller parcels of land. They are also more naturally resistant to extreme weather and predatory animals. There also appears to be a larger financial gain to be had from the leaner meats than from traditional beef.

Cattle herds

Parks and Preserves

    While the idea of setting aside land to be undisturbed by development is not new, as evidenced by Ancient Greece having sacred forests, and Britain setting aside Royal parks, most societies are making greater efforts to create park areas. It is estimated that currently 14% of the world's land area has been designated as a Park or a Preserve. While this should be encouraging news, upon closer examination we find that there is a wide range of what is considered a Park or Preserve.

    There are currently 5 designations for park areas, ranging from Ecological reserves with little to no human presence to public recreation areas that can have millions of visitors per year. Naturally the public recreation areas with large amounts of human traffic can have issues with actually preserving the environment. While nature preserves attempt to limit human intervention, this can greatly depend on the management and money available to ensure that the borders of the park are enforced. Many of these preserves are also in remote areas that receive little human traffic but also have little biodiversity due to their remote nature.

    Another issue with popular parks or preserves is that they are being overrun either in the form of visitors or by ever expanding industrial needs. Some parks have opened up to deforestation or dam-building for energy. Other parks are overrun with visitors which has a large impact on the natural ecology of the region. In Yellowstone park for instance, the wildlife has long since lost their fear of man, and now depend on human garbage for a large part of their diets. The congestion in these parks also has negative effects, such as pollution from the large number of cars driving through the area. Again there are many proposals for how to protect these natural preserves, but very little actual action that is taking place due to political considerations.

    There is also the consideration of marine preserves. While 14% of land areas have a park designation, only about 5% of marine areas have the same designation. This has lead to overfishing and destruction of coral regions that house many types of aquatic life. It is predicted that at current rates, within 50 years there will be no visible coral reefs left anywhere on the planet. While the marine areas that have been fortunate enough to be designated as protected have about 30% more biodiversity than unprotected areas, it is still felt that these areas are not large enough for long term protection of marine biomasses.

    There is also an issue of how much land can be dedicated to parks and preserves. There are different opinions on whether large preserves or smaller scattered preserves are more viable. While smaller preserves spread biomes out, thus protecting against disease or natural disasters wiping out populations, some animals need large territory. In this case there is a growing case for creating wildlife corridors. While taking up less land than large preserves, these corridors can link smaller preserves, and give larger animals the territory needed to roam, while still spreading out the various preserves to protect against natural disasters wiping out limited species. There will still be a need for larger preserves though, as some species require the density and solitude that can only be provided by being deep within preserves, as opposed to being on the 'edge' where there is more exposure to various weather effects and outside species.

    While preserving marine and land biomes is a worthy goal, as we have seen it is often easier said than done. Many factors come into play, political, cultural, and biological. While each group has its own advocates, there needs to be balance met between all groups in order to have the best sustained chance of making sure these parks and preserves last and serve their intended function.

Chapter 10

• Water Resources
  
• Water Compartments
  
• Water Pollution
  

Chapter 10

Water Resources

    One of the most important resources, perhaps the most important, to sustained life on earth is water. Water is used in one form or another by almost all life on earth. In humans water makes up nearly 60% of our bodies. Without water our bodies would be unable to break down and distribute vital nutrients to keep us alive. Without water we would be fortunate to survive for more than a few days. Despite the obvious need for water it is yet another natural resource that is in danger mostly due to human interference.

Chart of Water Distribution  (Principles of Environmental Science, p. 242)

    All water as we know it is part of the hydrologic cycle. Water can start out in the ocean, evaporate, come down on land thousands of miles away as rain, pass thru living organisms and eventually makes its way back to the ocean through rivers and streams. Along the way it can be detoured by plants who absorb it and allow it to evaporate back into the atmosphere before it makes its return to the oceans. The hydrologic cycle has many influences on where the water ends up, as solar energy, rainforests, and mountain ranges help to dictate where the water ends up in rain format. Because of these influences water is not distributed evenly across the planet, which makes preserving water resources even more crucial.

Water Compartments

    Distribution of water across the planet is broken down into Compartments. Water has a residence time that it will stay in any one compartment. For example a single water molecule may be in the ocean for thousands of years before it finally evaporates and makes its journey to another compartment. The ocean is the biggest water compartment on the planet, holding about 90% of all the water on earth.

    Of all the water on earth, only about 2.4% of it is fresh water, which is what is needed by most land based forms of life to survive. Of this 2.4%, 90% of that fresh water is currently frozen in glaciers, ice caps, and snowfields. Runoff from these glaciers and snowfields is still able to provide large amounts of fresh water needs to billions of people. However these glaciers and snowfields are being reduced yearly, a large portion of which is attributed to global warming. If these glaciers were to disappear that could leave billions of people without freshwater supplies.

    The largest compartment of fresh water is called groundwater. Groundwater is rain that has percolated through earth and soil to form saturated underground zones. Many times this water is funneled into aquifers, which can range from a few hundred feet to vast underground rivers. For instance there is evidence of an underground sister river to the Amazon, Rio Hamza. This river is thought to be about 4km underground, and follow roughly the same path as the Amazon (http://www.guardian.co.uk/environment/2011/aug/26/underground-river-amazon). The flow of these underground aquifers can vary greatly. The Rio Hamza is thought to only move about 1mm/hour. Often times these aquifers can be tapped and used to supply wells or may produce natural springs. Again we run into problems of humans overusing these precious freshwater supplies. Aquifers can take years to recharge, and pollution can seep into them, damaging the aquifer as a source of fresh water.

    Rivers and lakes are another major water compartment. Rivers provide a relatively small amount of fresh water as they flow quickly, and depend on other sources to keep them full and flowing. Lakes contain large amounts of surface water, but not all of it is unpolluted, and most of the lake water is found in just a few of the giant lakes in the world. Unfortunately not all of this lake water is fresh. Lakes are still importance sources of fresh water. There are also wetlands, while they may not contain as much surface water, it is these zones that slow down water runoff, and allow the recharging of aquifers.

Water Pollution

    The biggest threat to our freshwater supplies is pollution. Pollution refers to any adverse physical, biological, or chemical change in the quality of fresh water. Some of this pollution occurs naturally, but the vast majority of it is from man-made sources.

Drainpipe near ocean (knowledge.allianz.com accessed 3/7/12)

    There are two basic ways for fresh water to become polluted. These are referred to as point and non-point sources of pollution. Point pollution is where a known source of pollution interacts with a water supply, such as drain pipes or sewage runoffs. These points are easier to monitor because they are easily identified and don't move. Non-point pollution refers to any point where pollution interacts with water sources, but are not easy to identify because these non-point sources can occur anywhere. This includes water runoff from fields, golf courses, and industrial areas, often after rainstorms. While these points are harder to track, they generally occur at predictable times coinciding with storms or floods. Non-point pollution also occurs when airborne chemicals are transported, sometimes thousands of miles, before falling into water sources with rain.

    There are various types of water pollution, and they are commonly broken down into categories. These categories include pathogens, biological oxygen demand, and plant nutrients and cultural eutrophication.

    Pathogens are disease causing organisms that end up in water supplies. These diseases include typhoid, cholera, dysentery, polio, and hepatitis. The main cause of these pathogens is human and animal waste. When the waste leeches into fresh water supplies, it exposes all who drink it to these diseases. Currently up to 25 million deaths per year can be traced back to these waterborne pathogens. While these diseases are rare in developed countries with sanitation systems, in underdeveloped countries these diseases account for nearly 80% of all sickness. The amount of dangerous pathogens in water can be measures by tracking coliform bacteria, which is the same kind of bacteria that would be present in human and animal intestines.

    Biochemical oxygen demand is a standard measure of water contamination. The more waste products present in water, such as sewage, the more oxygen will be depleted due to decomposers using large amounts of the oxygen to metabolize the waste. This oxygen depletion makes it difficult to impossible for most aquatic forms of live to survive. The more waste in the water, the greater the oxygen depletion will be. This can cause large pockets of BOD zones where little to no life will be found.

BOD chart.

    Another source of contamination in water supplies comes from plant nutrients and cultural eutrophication. While eutrophic waters are normally a sign of a healthy system, there can be too much of a good thing. Again this usually results as a result of human intervention. When nutrients are introduced into water, this can lead to population explosions of algae and other aquatic plants. This leads to higher bacterial levels, and leads to lack of water clarity. The algae not only consumes large amounts of oxygen, but can also be outright toxic to marine life. This causes dead zones where other forms of marine life cannot survive.

    An example of this is seen in the case study A Flood of Pigs (http://www.mhhe.com/Enviro-Sci/CaseStudyLibrary/Topic-Based/CaseStudy_AFloodOfPigs.pdf). As hog farms were flooded in North Carolina waste, dead pigs, and nitrogen was then washed into rivers and bays. This influx of waste created depleted oxygen zones that killed existing marine life. The dead zone was estimated to be an area of nearly 350 square miles.

    Another pollutant of water supplies are naturally occurring minerals, metals, and salts. While these are naturally occurring chemicals have always mixed with water, the rates at which they do so now are greatly accelerated by manmade processes such as mining. At the increased rates of absorption into the water supplies, these chemicals can quickly reach toxic levels.

    Metals are a highly toxic substance, and do not break down easily. Therefore they can accumulate in water and organisms that live there. As example of this is mercury. As mercury is introduced into marine food webs, it builds up through each level of the food chain. The mercury can than reach dangerous levels in top marine predators. Due to this cumulative effect it is advisable not to eat certain types of predator fish very often, to avoid mercury buildup in our own bodies. These metals can also be present outright in the water, especially near mining areas, making the water itself dangerous to consume.

    Salts are also another source of pollution. Salt in low concentrations is non-toxic. However salt used for things such as melting ice off roadways can then leach back into water systems. The salt buildup can get so high that it reaches toxic levels, destroying fresh water ecosystems. Acids from industrial zones also contribute to water pollution. The amount of acidity can change the pH levels of water zones, damaging native aquatic life.

    Of course there is also man-made chemicals that contribute to water pollution. Chemicals used in the creations of plastic and fertilizers are highly toxic and have often been improperly disposed of. These chemicals, which often will not degrade on their own, are often washed into water compartments where they then build up to dangerous levels.

    With all the dangers to our water supplies, there is a growing belief that it is safer to consume bottled water. Unfortunately this is not always the case. Many experts feel that local tap water is often safer than bottled water due to stricter and more consistent monitoring of the water. Many brands of bottled water can come from relatively untested aquifers or is simply recycled tap water.

    The largest source of water pollution in the United States is sediment. This is another naturally occurring source of pollution that reaches dangerous levels due to manmade projects that greatly speed up the cycle that dumps sediment into rivers. This sediment quickly fills lakes and rivers, which can bury plant and animal life present in the rivers. This sediment can travel through rivers and then buildup in oceans as well, causing pollution problems there. Another side effect of industrial areas is that it can have a broad impact on water temperatures. The sudden raising or lowering of water temperature can wreak havoc with marine life that is acclimated to expect constant or slowly changing temperatures.

Chapter 7

• Global Nutrition
  
• Food Quantity
  
• Food Diversity
  
• Soil Quality
  

Chapter 7

Global Nutrition

    A major issue facing the world is the number of starving or undernourished people in the world. What makes this large scale problem harder to comprehend is that there is more food than ever being produced in the world. In Chapter 7 we learn about global food production, and the issues still facing getting this food properly distributed, as well as the environmental effects of this production explosion.

    Our food production today no longer depends on local farmers bringing their goods to the market. Agriculture is a big business, and it is always trying to use the latest advancements in technology to grow even more food for less costs. A prime example of where this is being done is Brazil. The Cerrado region, long thought to be low quality grasslands, has been transformed into a huge agricultural area thanks to advancements in farm equipment and knowledge of battling poor soil. While this has increased the amount of food available to the world, it has had its share of costs. The grasslands are being wiped out, losing a large ecosystem, and many family farms have been taken over and the people displaced.

    As we amaze ourselves at how much food production has risen, we can then be sobered by the fact that 1 in every 8 people on the planet is chronically hungry. 90% of these people live in underdeveloped countries, and have neither the means or the money to access these surplus food supplies being produced. These people still literally live and die with the results of their local crops and animal herds. The ability to have adequate meals everyday is referred to as food security. It is becoming accepted that food security is important in multiple ways. It is estimated that these underdeveloped countries could increase their economic growth by $120 million per year if they could keep their workforce healthy with food security.

    Famine also plays a large part in global nutrition. Usually the source of these famines can be traced back to political disruption rather than inadequate ability to produce food. People are forced to leave their crops out of fear, or have their food confiscated by military forces. These refugees then often converge in other areas where there is not enough food to support the sudden influx of people, leading to famine.

Food Quantity

    Every human needs a balanced diet to be relatively healthy, and have the needed energy to be productive. However it is estimated that nearly half of the world's population is undernourished. This could mean vitamin or mineral deficiency as opposed to outright starvation.

    Lack of essential vitamins and minerals can lead to a myriad of health problems, most of them that severely affect children. Vitamin A, something that is common in green leafy vegetables, is lacking in many people's diets. This can lead to blindness or neurological problems. Diseases related to lack of nutrition or protein affect many children in underdeveloped countries. The main food that sustains undernourished people are usually starchy foods that have little nutritional value. While science has food ways to try and combat the chronic malnutrition faced by many people, the opposition to these scientific methods is equally strong. Golden rice, a rice that is rich in Vitamin A, was introduced as a way to provide this missing nutrient to underdeveloped countries. The world reaction was mixed at best, as there are many who opposed Genetically Modified food, and others who didn't want to make the underdeveloped countries dependant on handouts from other countries (http://www.mhhe.com/Enviro-Sci/CaseStudyLibrary/Topic-Based/CaseStudy_GoldenRice.pdf).

    On the flip side of global hunger is the growing epidemic of obesity. It is estimated that there are now more obese people than underfed people, 1 billion to 850 million. While food security helps keep people well nourished, imbalanced diets, can lead to obesity. Obesity increases risk of many other nutritional diseases, such as diabetes. In the United States, one of the most food secure nations in the world, 400,000 people a year die from obesity related causes. This is nearly the same amount of people who die from smoking related diseases. Food security alone isn't enough to ensure a proper balanced diet.

    The largest current problem with global malnutrition appears to have more to do with food distribution rather than food production. Many countries produce an over abundance of food, and then ship this food to poorer countries. However the food there is often possessed by only a few, and does not reach many who need it. This food can also undercut local food economy, leaving local farmers with an inability to make a living. Even in wealthier countries food distribution is uneven, as nearly 40% of prepared food is disposed of rather than actually being consumed.

Food Diversity

    Despite the rich diversity of food across the planet, humans rely on just a few major crops for the majority of our diet. Wheat and rice form staple foods for nearly 5 billion people. In the United States corn is the most consumed crop, whether directly, or indirectly. In addition to being a common food item, corn is also used in many processed foods, and is fed to livestock which is then consumed by humans.

    In addition to grains being a part of the world's diet, meat consumption is also raising. As with agriculture, technological advances have allowed for more livestock to be raised on less food and less time than ever before. A large part of the world's grain sources actually go to feeding livestock. The massive amount of food used to feed livestock for meat consumption is an overall indicator of global wealth, since it costs much more to feed animals for consumption than to consume the feed directly.

    Seafood is another source of food for much of the world. Fish is an excellent source of protein, and accounts for about 15% of protein consumed worldwide. In addition it is also the main source of protein for underdeveloped countries, as fish are more readily accessible than livestock. However, as with much of our other natural resources, fish are becoming harder to attain. Overfishing of many of the worlds natural fisheries have led to dwindling fish populations. In efforts to maximize the number of fish caught, habitats and other sea creatures are destroyed as they are caught up on nets and hooks intended for other fish. Aquaculture, or growing fish in controlled environments is becoming an increasing larger part of the fish supply. These have their own drawbacks however, as it's harder to sustain carnivorous fish in these environments, and they controlled areas make disease and waste products a danger to other species.

    While it is good that enough food is being produced to provide food security for more people, there is also a cost for the increased production. Many environments are destroyed in order to make room for more agricultural space, and the pollution from these areas can be damaging to surrounding areas. In addition many of the drugs used to fight diseases in livestock are leading to new strains of pathogens that are more resistant that ever to antibiotic drugs. While we may enjoy the lower prices and ease of access to previously rare foods, we need to take into consideration the cost to the environment for what could be considered luxuries.

Soil Resources

    While farmers are finding ways to maximize their crop yields, one of the natural resources they are using up to do so is soil. Soil contains minerals, decomposed organic materials, and living organisms. These contribute to providing a fertile environment for plants to grow in. Under ideal circumstances it takes a year to generate 1mm of fertile soil. We are going through soil at a much higher rate.

    Soil consist of six components. There is sand and gravel, silts and clays, dead organic material, soil fauna and flora, water, and air. Various mixtures of these components lead to a variety of soils, some more ideal for growing crops than others. Generally deep black soils are rich in nutrients as they contain much decayed organic material, and are best for growing plant life.

    Soil is complex and highly susceptible to outside influences. Dead plant matter is recycled by bacteria and microscopic life forms. These organisms are found in the first few centimeters of soil, where they create pockets of air as they burrow through the earth. Climate, topography, and the parent material of soil are also large influences on the quality of soil. In conditions that are too hot or cold, decomposition happens to slowly or too quickly to benefit plant life. In areas that are too steep, water runoff occurs too quickly, preventing the soil from drawing nutrients from the water, or even being washed away. Parent material is the bottommost layer of the soil, and dictates the primary makeup of the topsoil layer.

Soil Horizons (Principles of Environmental Science, p. 164)

    Soil is divided into layers, A, E, B, C, and the parent material. The majority of food produced depends on quality A soil. In fertile areas, the A soil can be up to 6 feet deep. However erosion and over farming has made these areas rare. Most soil has less than 1-2 feet of A layer, and desert areas have little to none. Fertile topsoil is an important natural resource, and steps must be taken to ensure that topsoil is renewed for continued plant production.

Chapter 11

• Earth Processes
  
• Minerals and
  
• Geology and Mineralogy
  
• Effects of Resource Extraction
  
• Conserving Resources
  
• Geologic Hazards
  

Chapter 11

Earth Processes

    Earth processes are descriptive of how dynamic our planet is. The earth's crust is constantly moving, and occasionally tectonic plates will collide or rub against each other, causing earthquakes. The earth consists of a solid inner core, a fluid outer core, and a mantle. These features are then covered by the earth's crust.

Earth's Layers (Principles of Environmental Science, p. 272)

    The earth's crust is broken into sections called tectonic plates. These plates are constantly moving and shifting, forming new landmasses over millions of years. Magma from the earth's core comes up through cracks in the earth's crust, and forms underwater mountain ranges. These underwater mountain ranges have higher peaks and lower valleys than any mountain ranges on the surface of the earth. As an example of how much these tectonic plates move, Australia and Antarctica were thought to have once been a part of Africa before breaking apart and moving thousands of miles away over millions of years.

Minerals and Rocks

    Minerals are inorganic solids that make up crystal structures. The kind of mineral formed depends on the chemical composition. Metals are created from minerals, but are no longer crystalline after being smelted, so are no longer minerals. Rocks are combinations of minerals held together in a solid mass, forming a larger overall structure.

    There are three basic kinds of rocks, igneous, metamorphic, and sedimentary. The names refer to how the rocks were formed. Igneous rocks are formed by lava that cools. Metamorphic rocks form over time as they are molded by the tectonic plates folding and heating them. Sedimentary rocks form when loose minerals are consolidated over time, but without the extreme pressure or head of igneous or metamorphic rocks. The way these rocks are formed is referred to as the rock cycle.

    Over time rocks are broken down by weathering. This can occur mechanically or chemically. Mechanical weathering refers to rocks being broken down naturally over time by water. Chemical weathering occurs when water mixes with acids and changes the makeup of the rock. These makes the rocks more susceptible to mechanical weathering. The particles from these rocks are then transported by wind and water to form deposits of sedimentation.

Geology and Mineralogy

    One of the features of earth that makes it unique, other than the presence of life, is the rich mineral diversity found on the planet. There are currently over 4,400 different types of minerals, far more than have been found on neighboring planets. The reason for this is thought to be the combination of the movement of tectonic plates, and the presence of oxygen. The movement of the plates has allowed concentrations of minerals to crystallize and form new minerals. Oxygen released by plant life over millions of years has also oxidized minerals, creating new varieties. Harvesting of these minerals is a profitable business, as these minerals are used in much of the products we produce.

    Metals are valuable due to their malleable nature, light weight, and strength. Iron is the most consumed metal, followed by aluminum, manganese, copper, and nickel. These metals have great economic value, and are widely traded on the global market. Like all resources however, there is a finite limit to their availability.

    Minerals are also important economically. Minerals provide everything from the ability to create glass, treat acidic soil, creating roads, and building materials. Minerals also form gemstones, which are often quite valuable, and actively used for trade and transportation of wealth. Diamonds are an example of valuable gemstones, and also an example of the extreme measures humans will go through to acquire them. Violence, wars, and other humanitarian crimes are carried out in order to acquire these gemstones.

    Natural gases are also a highly valued natural resource. Deposits of oil, coal, and natural gas provide much of the energy that modern countries use every day. These resources are also finite, and research is underway to try and find alternative energy sources that are renewable, environmentally friendly, and more cost efficient.

Effects of Resource Extraction

    We use all of these minerals and natural gasses in our daily lives, as they are used to create everyday items such as glass, plastic, and electronics. Reliance on these items means we need to constantly be harvesting these resources, and that can have adverse effects on the environment. Water and air pollution are serious by-products of mining, as the methods used to obtain minerals and metals often leave toxic chemicals behind. These chemicals then become airborne or make their way into water sources.

    There are several methods of mineral extraction currently being practiced, and all have cause varying degrees of damage to the environment. Some common forms of mining are underground mining, placer mining, well drilling, strip mining, and mountain top removal. All these methods cause varying degrees of damage to the environment, and some leave toxic lakes and slag piles that can contaminate areas for years. It is currently estimated that in the in United States alone over 12,000 miles of rivers and streams are currently contaminated by mining runoff. The estimated cost of cleaning up these areas is currently $70 billion dollars. Mining companies are currently working on developing new methods of extraction that are less damaging or easier to reclaim the environment.

    After the minerals are extracted from the ground, the rock ore is then smelted to extract the precious metals. These methods are just as damaging to the environment if not more so than the extraction from the earth. Heating of the ore can produce massive air pollution, and spreading of toxic chemicals that can destroy life and vegetation. Other methods of extraction include soaking piles or ore in chemical baths. These chemical containers are supposed to keep the chemicals from being absorbed into the ground, but leaks are common.

Conserving Resources

    As we have come to the realization that there are a finite amount of resources available, and the extreme damage done to the environment to acquire those resources, there have been efforts to promote conserving our existing resources. One way this is done is by recycling metals and products that have already been extracted or produced. This allows us to save money and energy on extraction of new materials, and often times recycling the materials has a significantly smaller environmental footprint than the original extraction. Two prime examples of this are aluminum and steel. Aluminum can be reclaimed from recycled materials at a fraction of the cost that it takes to harvest new aluminum. There are new minimills which can reform scrap iron and steel and again run at a fraction of the cost of a traditional steel mill that is creating the steel from scratch. New United Stages regulation require that all new steel must contain at least 28% recycled material.

    In addition to recycling old materials, advances in manufacturing fields have allowed for the creation of new materials that require less raw metals or minerals. This phasing out of heavy reliance on metals such as iron or steel will hopefully curb the need to mine these raw materials, and not have to damage the environment further.

Geologic Hazards

    As we learned earlier the earth is constantly in motion. Tectonic plates collide and cause seismic events. These events have shaped the earth as we know it today. These are incredible forces at work, and they still happen, sometimes with devastating results to the human population.

Tsunami Devistation

    Earthquakes are unpredictable and can hit with devastating suddenness. On March 11, 2011 a 9.0 magnitude earthquake struck off the coast of Japan, and caused a tsunami that had waves that reached 30-feet in height (http://www.huffingtonpost.com/2012/02/27/japan-earthquake-anniversary-photos_n_1303476.html?ref=japan-tsunami). The earthquake and tsunami claimed over 19,000 lives, and caused up to $300 billion dollars of damage. In 2004 a tsunami near Indonesia killed over 230,000 people. These earthquakes occur when edges of tectonic plates push past one another. If the plates have trouble passing one another, the pressure builds up until there is a giant release, which results in an earthquake. It is recently being discover that geologic activity by humans can also possibly lead to seismic activity, resulting in man-made earthquakes.

    Volcanoes are another natural feature on earth that has helped to form earth as we know it today. Without volcanoes we might not have as much fertile soil for agriculture, as volcanic ash has formed the basis for many of these fertile areas. These volcanic eruptions can cause large amounts of damage and disruption to the environment. Ash and gas from volcanoes can remain in the atmosphere for years, causing damage to the atmosphere and even affecting global temperatures. Populations that have not heeded warning signs of impending volcanic eruptions have often paid a heavy price as well, as an eruption can happen so quickly and spew toxic gases in the air that anyone in the surrounding area has little chance of survival.

    Floods are another naturally occurring geologic event that can do much damage to human populations. While people have settled next to rivers due to the convenience provided, they are usually making their homes in known flood plains. These flood plains may not flood constantly, but have flooded before and are likely to flood again. Floods can be sudden and severe, but also do lasting damage as the waste and silt carried by the water can contaminate wide areas, making it difficult for people to survive with no fresh water sources. The damage done by the floods also has high monetary costs, as these areas are usually also associated with agricultural, and the loss of crops can be damaging to the global economy. There are signs that global warming can also trigger these floods, as it affects rainfall patterns, and can cause severe rain in unexpected areas. Human measures taken to diminish flood damage has had some success, but can oftentimes make floods worse than they would have originally been. Flood controls structures are designed to keep water moving, however when water continues to accumulate and swell, eventually one of these structures will fail, and the damage will be disastrous in the area where the water finally breaks through.

    Landslides also can cause property damage and loss of life. Especially in areas where land is expensive, people will build in unsafe areas. These areas can also become more prone to landslides due to terrain deformation that can occur from activities such as logging or mining. These landslides can occur quickly and can destroy anything in its path.

    Naturally occurring erosion can also cause massive damage to man-made structures. As people like to build in areas right near water, the ground they build on is often unstable and susceptible to flooding. In the United States the government contributes to this by providing disaster insurance that will rebuild houses lost to flooding, but only if it is constructed in the same area. This can lead to a constant cycle of houses being destroyed and rebuilt at increasing cost to the general public. Building in these areas can also contribute to environmental damage, as the buildings can interfere with natural vegetation that would normally protect these areas from erosion or flood damage.

    While the global economy currently depends on harvesting the earth's resources, the damage being done to retrieve these resources may never be undone. Going forward we need to make aware decisions on how we can personally contribute to preserving our environment, and also which policies we choose to support on a global scale.