Chapter-II-Students-copy.pdf

Chapter II: The natural environment and the human economy: an ecological perspective Learning Objectives: After completing the module, the students are expected to: 1. Surveys various possibility of the future; 2. Outlines the challenges in the environment, society, government and to the...

Chapter II: The natural environment and the human economy: an ecological perspective Learning Objectives: After completing the module, the students are expected to: 1. Surveys various possibility of the future; 2. Outlines the challenges in the environment, society, government and to the people; 3. Understand the basic principles governing the nature, structure, and function of ecosystems; 4. Summarize the recycling process in the ecosystem; and 5. Infer how Ecology affects the human economy. I. Introduction The premise that societies can germinate the seeds of their own destruction has long fascinated scholars. In 1798, Thomas Malthus published his classic An Essay on the Principle of Population, in which he foresaw a time when the urge to reproduce would cause population growth to exceed the land’s potential to supply sufficient food, resulting in starvation and death. In his view, the most likely response to this crisis would involve rising death rates caused by environmental constraints, rather than a recognition of impending scarcity followed either by innovation or self-restraint. As the scale of economic activity has proceeded steadily upward, the scope of environmental problems triggered by that activity has transcended both geographic and generational boundaries. When the environmental problems were smaller in scale, the nation-state used to be a sufficient form of political organization for resolving them, but is that still the case? Whereas each generation used to have the luxury of being able to satisfy its own needs without worrying about the needs of generations to come, intergenerational effects are now more prominent. Historically, our society has been remarkably robust, having survived wars and shortages, while dramatically increasing living standards and life expectancy. Yet, actual historical examples suggest that Malthus’s self-extinction vision may sometimes have merit. Example below examines two specific cases: the Mayan civilization and Easter Island. 1 Case no. 2. 1 2  II. Discussion A. Future Environmental challenges Future societies will also face challenges arising from resource scarcity and accumulating pollutants. Many specific examples of these broad categories of problems are discussed in detail in the following chapters. This section provides a flavor of what is to come by illustrating the challenges posed by one pollution problem (climate change) and one resource scarcity problem (water accessibility). 1. Climate Change Energy from the sun drives the earth’s weather and climate. Incoming rays heat the earth’s surface, radiating heat energy back into space. Atmospheric “greenhouse” gases (water vapor, carbon dioxide, and other gases) trap some of the outgoing energy. Without this natural “greenhouse effect,” temperatures on the earth would be much lower than they are now and life as we know it would be impossible. It is possible, however, to have too much of a good thing. Problems arise when the concentration of greenhouse gases increases beyond normal levels, thus retaining excessive heat somewhat like a car with its windows closed in the summer. Since the Industrial Revolution, greenhouse gas emissions have increased, considerably enhancing the heat-trapping capability of the earth’s atmosphere. According to the U.S. Global Change Research Program (USGCRP) (2014): Evidence from the top of the atmosphere to the depths of the oceans, collected by scientists and engineers from around the world, tells an unambiguous story: the planet is warming, and over the last half century, this warming has been driven primarily by human activity—predominantly the burning of fossil fuels. As the earth warms, the consequences are expected to affect both humans and ecosystems. Humans are susceptible to increased heat, as shown by the thousands of deaths in Europe in the summer of 2003 due to the abnormal heat waves. Human health can also be affected by diseases such as Lyme disease, which spread more widely as the earth warms. Rising sea levels (as warmer water expands and previously frozen glaciers melt), coupled with an increase in storm intensity, are expected to flood coastal communities with greater frequency. Ecosystems will be subjected to unaccustomed temperatures; some species will adapt by migrating to new areas, but many others are not expected to be able to react in time. While these processes have already begun, they will intensify throughout the century. Climate change also has an important moral dimension. Due to their more limited adaptation capabilities, many developing countries, which have produced relatively small amounts of greenhouse gases, are expected to be the hardest hit as the climate changes. 3  Dealing with climate change will require a coordinated international response. That is a significant challenge to a world system where the nation-state reigns supreme and international organizations are relatively weak. 2. Water Accessibility Another class of threats is posed by the interaction of a rising demand for resources in the face of a finite supply. Water provides a particularly interesting example because it is so vital to life. According to the United Nations, about 40 percent of the world’s population lives in areas with moderate-to-high water stress. (“Moderate stress” is defined in the U.N. Assessment of Freshwater Resources as “human consumption of more than 20 percent of all accessible renewable freshwater resources,” whereas “severe stress” denotes consumption greater than 40 percent.) By 2025, it is estimated that about two-thirds of the world’s population—about 5.5 billion people—will live in areas facing either moderate or severe water stress. This stress is not uniformly distributed around the globe. For example, in parts of the United States, Mexico, China, and India, groundwater is already being consumed faster than it is being replenished, and aquifer levels are steadily falling. Some rivers, such as the Colorado in the western United States and the Yellow in China, often run dry before they reach the sea. Formerly enormous bodies of water, such as the Aral Sea and Lake Chad, are now a fraction of their once-historic sizes. Glaciers that feed many Asian rivers are shrinking. According to U.N. data, the continents most burdened by a lack of access to sufficient clean water are Africa and Asia. Up to 50 percent of Africa’s urban residents and 75 percent of Asians are estimated to lack adequate access to a safe water supply. The availability of potable water is further limited by human activities that contaminate the remaining supplies. According to the United Nations, 90 percent of sewage and 70 percent of industrial waste in developing countries are discharged without treatment. And climate change is expected to intensify both the frequency and duration of droughts, simultaneously increasing the demand for water and reducing its supply. Some arid areas have compensated for their lack of water by importing it via aqueducts from more richly endowed regions or by building large reservoirs. This solution can, however, promote conflict when the water transfer or the relocation of people living in the area to be flooded by the reservoir produces a backlash. Additionally, aqueducts and dams may be geologically vulnerable. For example, in California, many of the aqueducts cross or lie on known earthquake-prone fault lines (Reisner, 2003). The reservoir behind the Three Gorges Dam in China is so vast that the pressure and weight from the stored water have caused tremors and landslides. 4  Case no. 2. 2 B. Meeting the challenges Solving problems such as poverty, climate change, ozone depletion, and the loss of biodiversity requires international cooperation. Because future generations cannot speak for themselves, the current generation must speak for them. Current policies must incorporate our obligation to future generations, however difficult or imperfect that incorporation might prove to be. International cooperation is by no means a foregone conclusion. Global environmental problems can result in very different effects on countries that will sit around the negotiating table. While low-lying countries could be completely submerged by the sea level rise predicted by some climate change models, arid nations could see their marginal agricultural lands succumb to desertification. Other nations may see agricultural productivity rise as warmer climates in traditionally intemperate regions support longer growing seasons. 5  Countries that unilaterally set out to improve the global environmental situation run the risk of making their businesses vulnerable to competition from less conscientious nations. Industrialized countries that undertake stringent environmental policies may not suffer much at the national level due to offsetting increases in income and employment in industries that supply renewable, cleaner energy and pollution control equipment. Some specific industries facing stringent environmental regulations, however, may well face higher costs than their competitors, and can be expected to lose market share accordingly. Declining market share and employment resulting from especially stringent regulations and the threat of out-sourced production are powerful influences. The search for solutions must accommodate these concerns. The market system is remarkably resilient in how it responds to challenges. As we shall see, prices provide incentives not only for the wise use of current resources, but also for promoting innovations that can broaden the menu of future options. Yet, as we shall also see, market incentives are not always consistent with promoting sustainable outcomes. Currently, many individuals and institutions have a large stake in maintaining the status quo, even when it poses an existential threat. Fishermen harvesting their catch from an overexploited fishery are loath to reduce harvests, even when the reduction may be necessary to conserve the stock and to return the population to a healthy level. Farmers who depend on fertilizer and pesticide subsidies will give them up reluctantly. Coal companies resist any attempt to reduce carbon emissions from coal-fired power plants. How will societies respond? The fundamental question is how our society will respond to these challenges. One way to think systematically about this question involves feedback loops. Positive feedback loops are those in which secondary effects tend to reinforce the basic trend. The process of capital accumulation illustrates one positive feedback loop. New investment generates greater output, which when sold, generates profits. These profits can be used to fund additional new investments. Notice that with positive feedback loops, the process is self-reinforcing. Positive feedback loops are also involved in climate change. Scientists believe, for example, that the relationship between emissions of methane and climate change may be described as a positive feedback loop. Because methane is a greenhouse gas, increases in methane emissions contribute to climate change. The rise of the planetary temperature, however, is triggering the release of extremely large quantities of additional methane that was previously trapped in the permafrost layer of the earth; the resulting larger methane emissions intensify the temperature increases, resulting in the release of more methane—a positive feedback. Human behavior can also deepen environmental problems through positive feedback loops. When shortages of a commodity are imminent, for example, consumers typically begin to hoard the 6 commodity. Hoarding intensifies the shortage. Similarly, people faced with shortages of food may be forced to eat the seed that is the key to more plentiful food in the future. Situations giving rise to this kind of downward spiral are particularly troublesome. In contrast, a negative feedback loop is self-limiting rather than self-reinforcing. Perhaps the best-known planetary-scale example of a negative feedback loop is provided in a theory advanced by the English scientist James Lovelock. Called the Gaia hypothesis, after the Greek concept for Mother Earth, this view of the world suggests that the earth is a living organism with a complex feedback system that seeks an optimal physical and chemical environment. Deviations from this optimal environment trigger natural, nonhuman response mechanisms that restore the balance. In essence, according to the Gaia hypothesis, the planetary environment is characterized by negative feedback loops and, therefore, is, within limits, a self-limiting process. C. Ecosystem structure and function “An ecosystem is defined as a community of lifeforms in concurrence with non-living components, interacting with each other.” Generally, an ecosystem is composed of four components: the atmosphere (air), the hydro- sphere (water), the lithosphere (earth), and the biota (life). The first three comprise the abiotic or non- living components of the ecosystem, whereas the biosphere is its biotic (living) component. It is important to recognize that the living and non-living components of an ecosystem interact with each other. The dynamic interaction of these components is critical to the survival and functioning of the ecosystem, just as breathing and eating are essential to the survival of animals. Furthermore, these components are capable of coexisting so that the ecosystem itself is “alive” (Schneider 1990; Miller and Spoolman 2010). For example, soil is a living system that develops as a result of interactions between plant, animal, and microbial communities (living components) and parent rock material (abiotic components). Abiotic factors such as temperature and moisture influence the process of soil development. What makes this image an ecosystem of a forest is not one single entity. It is rather the interactions of the trees (the seemingly dominant feature of the ecosystem) with the air, water, rocks, and the various living organisms that use the forest shade as their habitats and source of sustenance. The Forests help in maintaining the temperature of the earth and are the major carbon sink. Several functions are being served by the abiotic components in the ecosystem. First, the abiotic components are used as a habitat (space) and an immediate source of water and air for organisms. 7 Second, they act as a reservoir of the six most important elements for life: carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), and phosphorus (P). These elements constitute 95 percent of all living organisms. Furthermore, the earth contains only a fixed amount of these elements (or any other element). Thus, continual functioning of the ecosystem requires that these elements be recycled since they are critical to the overall welfare of the ecosystem. The biotic component of the ecosystem consists of three distinct groups of organisms: the producers, consumers, and decomposers. The producers are those organisms capable of photosynthesis: production of organic material solely from solar energy, carbon dioxide, and water. This organic material serves as a source of both energy and nutrients, which are required by all living organisms. Examples include terrestrial plants (such as trees and crops) and aquatic plants (such as phytoplankton). The consumers are organisms whose survival depends on the organic materials synthesized by the producers. The consumers represent organisms of all sizes ranging from large predator animals (such as elephants and whales) to small parasites (such as mosquitoes and even bacteria). The consumers’ dependence on the producers may take different forms. Some consumers (herbivores, such as rabbits) are directly dependent on primary producers for energy. Others (carnivores, such as lions) are indirectly dependent on primary producers. The last group of living organisms are the decomposers. These include micro-organisms, such as fungi, yeast, bacteria, etc., as well as a diversity of worms, insects, and many other small animals that rely on dead organisms for their survival. They survive and obtain energy by decomposing materials released by plants and consumers to simpler compounds, such as CO2, H2O, phosphate ions (PO3-4), and so on. This, as will be shown shortly, is what keeps material cycling within the ecosystem. The discussion has so far dealt with what is known as the structural organization (i.e., how the components and the relationships of biotic and abiotic elements of an ecosystem are organized and defined) of the ecosystem. The next step is to examine not only how the basic components of an ecosystem are organized but also how they become integrated through transformation of matter and energy. However, for any movements or transformations of energy and matter to occur—in other words, for the ecosystem to perform its intended function—an external source of energy is needed. For our planet the primary source of this energy is solar radiation: the energy from the sun. Solar energy, then, fuels the flow of energy and matter in an ecosystem. The fundamental question is: where does life start and end in this system that, from a purely physical viewpoint, is manifested by a continuous transformation of matter and energy? Regulating the essential ecological processes, supporting life systems and rendering stability, are the nutshell of the functions of the ecosystem. Adding to the functions of the Ecosystems are the following: 1. It is also responsible for the cycling of nutrients between biotic and abiotic components. 2. It maintains a balance among the various trophic levels in the ecosystem. 3. It cycles the minerals through the biosphere. 8  4. The abiotic components help in the synthesis of organic components that involve the exchange of energy. Source: https://byjus.com/biology/ecosystem Based on the discussion so far, at a fundamental level and from a purely physical viewpoint, a functioning (living) natural ecosystem is characterized by a constant transformation of matter and throughput of energy. Furthermore, an ecosystem will continue to function to the extent that it is not buried by the weight of its own internally generated waste. This can be avoided only through continuous material cycling, which is the next topic of discussion. In fact, as indicated above, the waste from one component of the community becomes a resource for other components—waste is food. D. Materials recycling The natural recycling process starts with the formation of plant tissues through the processes of photosynthesis and bio-synthesis. At this stage oxygen is released into the environment. Virtually all of the molecular oxygen, O2, in the atmosphere and in the oceans has originated from photosynthesis. In many ecosystems the second major stage of recycling occurs when animals, as they metabolize the stored energy from plant tissues, release carbon dioxide (CO2) and organic wastes. Micro-organisms, however, perform the major recycling (decomposition). That is, the micro-organisms ultimately break down dead organic matter into its simpler (inorganic) components. This recycling is particularly important because the number of mineral elements found in the ecosystem is finite and can limit the growth and reproduction of organisms. However, decomposition may not always be complete. The oxidation process involved in decomposition largely depends on the availability of oxygen, moisture content, and the temperature of the ecosystem under consideration. For example, oxidation takes place at a much faster rate in a tropical forest than at the bottom of a lake or in a desert. Thus, in nature, material recycling is not 100 percent efficient and some amounts of organic matter may remain, only partially decomposed. This incompletely decomposed organic matter accumulated and aged over a period of time forms peat, coal, and 9 petroleum—that is, fossil fuels. This is the basis of energy so crucial to the modern human economy. It is also a large reservoir of carbon that gets released rapidly when fossil fuels are burned and contributes to global warming by releasing CO2 into the atmosphere at an unprecedented rate. The cycling and recycling process of the ecosystem is all-encompassing and demands the interaction of every facet of the ecosystem. In fact, the decomposition and recirculation of materials in the ecosystem are referred to as biogeochemical cycles; for example, the nitrogen cycle, phosphorous cycle, carbon cycle, and so on (Miller and Spoolman 2010; Pearce 1978). Given this, it is not difficult to imagine how human activities that disrupt these cycles can have significant negative impacts on ecosystem processes. E. Ecology and its implications for the human economy Human economics and ecology are inextricably linked, and here is why: as living organisms, we live in the earth’s biosphere and depend on our ecosystems in order to survive. Our ecosystem, the earth, ultimately controls our economic systems because it provides us with what we need for our economies (and everything else) to actually exist. For example, we must have water, food, and goods that we then buy, sell, or trade with others in order to profit economically. If our sources were depleted, our economy would suffer. In short, we depend on our ecosystem, sometimes without even realizing it. Understanding our vast ecosystem and how it works is vital in managing and safely interacting with it. However, because human ecology encompasses not just our natural environment, but our social and human-built environments as well, we can also look at how it affects specific economies, like our national economy or global economy. Some of the worst global environmental problems are caused by ignoring this fundamental relationship. For example, pollution is caused by overloading the atmosphere and ocean with carbon. Another example is species extinction due to habitat destruction. Today, we recognize that environmental issues are closely tied to the economy, and addressing these issues further promotes our economy’s success. In other words, the strength of an economy is dependent on the health of the ecological environment. Dr. Rowan Williams wrote an article, Ecology and the Economy Go Hand in Hand, in which he states, “To seek to have an economy without ecology is to try to manage an environment with no knowledge or concern about how it works in itself — to try to formulate human laws in abstraction from or ignorance of the laws of nature.” As you can see, you can’t have a healthy economy without a healthy ecology. Ecosystem protection is an economic investment on a larger, global scale, as well as on an individual scale. To try and separate these two subjects does not make sense. References: Hussen, A.M. (2000). Principles of Environmental Economics Second edition. Tietenberg. T. and Lewis, L. (2018). Environmental and Natural Resource Economics. 10