Environmental ScienceIntroduction

What is Environmental Science?Environmental science is the systematic study of our environment and our place in it.As shown in Fig. 1.2, environmental science draws on many fields of knowledge to fully understand a problem and solve it.

1-*

We Inhabit a Remarkable Planet1-*We live in an incredibly prolific and colorful world that is unique in the universe. Temperatures here are mild and relatively constant. Plentiful supplies of clean air, fresh water, and fertile soil are regenerated by biogeochemical cycles and biological communities.

Our Planet Has an Amazingly Rich Diversity of Life1-*Millions of beautiful and intriguing species populate the earth and help sustain a habitable environment. This vast multitude of life creates complex, interrelated communities.

1.2 Crises and OpportunitiesWith over 7 billion people on Earth, we are adding about 80 million more each year.Present trends project a world population between 8 and 10 billion by 2050. The impact of that many people on our natural resources and ecological systems strongly influences many of the other problems we face.

1-*

Environmental and Political Challenges: Climate ChangeHuman activities have greatly increased concentrations of carbon dioxide and other greenhouse gases over the last 200 years.Climate models indicate that by 2100, if current trends continue, global mean temperatures will probably warm between about 2 and 6 C.

1-*

Environmental and Political Problems: HungerOver the past century, global food production has increased faster than human population growth, but hunger remains a chronic problem. At least 60 million people face acute food shortages due to weather, politics, or war.1-12

Environmental and Political Problems: Clean Water1.1 billion people lack access to safe drinking water.Every year polluted water contributes to the death of more than 15 million people.40 percent of the population live in countries where water demands now exceed supplies.1-*

Environmental and Political Problems: Marine ResourcesMore than a billion people depend on seafood for their main source of animal protein.According to the World Resources Institute, more than three-quarters of the 441 fish stocks for which information is available are severely depleted or in urgent need of better management.1-*

How Do We Describe Resource Use and Conservation?When we consider resource consumption, an important idea is throughput, the amount of resources we use and dispose of.Ecosystem services refers to the services or resources provided by environmental systems. Usually we rely on these resources without thinking about them.The tragedy of the commons refers to how population growth inevitably leads to the overuse and destruction of common resources.09/22/101-*

Ecosystem Services09/22/101-*

Environmental ScienceWhat is it?

EnvironmentWord is derived from the French environner which means to encircle or surround

We live in two worlds1) The natural world that has evolved over billions of years.2) The world of social institutions and artifacts that MAN(kind) has created using Science technology and Political institutions*

Environment DefinitionsAs we live in two worlds there are two definitions

A) The circumstances and conditions that surround an organism or group of organisms.

B) The social and cultural conditions that affect an individual or a community. *

Environment ScienceThe systematic study of our environment and our place in it.It integrates information from biology, chemistry, geography and agriculture plus many more disciplines . It is inclusive and holisticIt applies information to improve the ways we treat our EarthIt is mission-orientatedIt implies a responsibility: to get involved and correct the problems and damage we have created.*

ScienceComes from the Latin word for knowing it is a process for producing knowledgeScience rests on the assumptions that the world can be known and that we can learn from and through careful Empirical study and logical analysis.It depends on making precise observations of natural phenomena and formulating reasonable theories to make sense of those observations

*

Scientific ThinkingIts value is that it reduces our tendency to rely on emotional reactions and unexplained assumptions.Example, something strange was seen in the air, it must have been an UFOOr Lettuce is a plant, lettuce is green, so all plants are green. (Deductive)Lettuce is a plant, lettuce is edible, so all plants are edible. (Deductive)*

Scientific ThinkingScientists are skeptical.They do not accept proposed explanations until there is substantial evidence to support them. They search for testable evidence.Every explanation is only provisional as new evidence can arise. Ex. The world is flat Scientists strive to be methodical, rigorous and unbiased.*

Scientific DesignReproducibility. Can a scientist repeat the observation to show that the initial finding was not a fluke.To avoid variance in natural studies scientists use Controlled studies where comparisons between experimental and controlled populations are identical, as far as possible, in every factor except for the one being studied.*

Scientific DesignBlind experiments are set up to avoid investigator bias where experimenters unconsciously treat the experimental and control group differently.Placebo effectDouble- blind design where neither the subject nor the experimenter knows who are receiving the experimental or controlled treatments*

Scientific DesignDeductive reasoning: Start with the general principle and then work down by testing. For example, "All men are mortal. Harold is a man. Therefore, Harold is mortal." For deductive reasoning to be sound, the hypothesis must be correct. It is assumed that the premises, "All men are mortal" and "Harold is a man" are true. Therefore, the conclusion is logical and true.

*

Scientific designInductive reasoning: Starts with a series of events and then from those you derive a theory. makes broad generalizations from specific observations. Even if all of the premises are true in a statement, inductive reasoning allows for the conclusion to be false. Heres an example: "Harold is a grandfather. Harold is bald. Therefore, all grandfathers are bald." The conclusion does not follow logically from the statements.*

*

Deductive reasoningOne of the most common and useful forms of deductive reasoning is the syllogism. The syllogism is a specific form of argument that has three easy steps.1. Every X has the characteristic Y. 2. This thing is X. 3. Therefore, this thing has the characteristic Y.

*

Inductive reasoningInductive reasoning is making a conclusion based on a set of empirical data. If I observe that something is true many times, concluding that it will be true in all instances, is a use of inductive reasoning.*

Inductive reasoningFor example, after seeing many people outside walking their dogs, one may observe that every dog that is a poodle is being walked by an elderly person. The person observing this pattern could inductively reason that poodles are owned exclusively by elderly people. This is by no means a method of proof for such a suspicion; in fact, in the real world it is a means by which people and things are stereotyped*

Scientific DesignAnalytical thinkingCreative thinkingLogical thinkingCritical thinkingReflective thinking*

Scientific DesignThinkingAnalytical thinking

Creative thinking

Logical thinking

Critical thinking

Reflective thinking

QuestionsHow can I break this problem down into its partsHow can I approach it in a new and inventive way How can orderly deductive reasoning helpWhat am I trying to accomplish, how will I know I have succeededWhat does it all mean*

Hypothesishypothesis 1596, from M.Fr. hypothese, from L.L. hypothesis, from Gk. hypothesis "base, basis of an argument, supposition," lit. "a placing under," from hypo- "under" + thesis "a placing, proposition." A term in logic; narrower scientific sense is 1646; hypothetical is 1588.hypothesis. (n.d.). Online Etymology Dictionary. Retrieved January 11, 2010, from Dictionary.com website: http://dictionary.reference.com/browse/hypothesisa proposition, or set of propositions, set forth as an explanation for the occurrence of some specified group of phenomena, either asserted merely as a provisional conjecture to guide investigation (working hypothesis) or accepted as highly probable in the light of established facts. 2. a proposition assumed as a premise in an argument. 3. the antecedent of a conditional proposition. 4. a mere assumption or guess.hypothesis. (n.d.). Dictionary.com Unabridged. Retrieved January 11, 2010, from Dictionary.com website: http://dictionary.reference.com/browse/hypothesis*

The Scientific Method is an Orderly Way to Examine Problems1. Make an observation and identify a question: Your flashlight doesnt light and you think to yourself: what might be wrong?2. Propose a hypothesis: The flashlight doesnt work because the batteries are dead.3. Test your hypothesis: If I replace the batteries then the flashlight should work.4. Gather data from your test: After you replaced the batteries, did the light turn on?5. Interpret your results: If the light works now, then your hypothesis was right; if not, then you should formulate a new hypothesis, perhaps that the bulb is faulty, and develop a new test for that hypothesis.1-*

**Sciences such as biology, chemistry, earth science, and geography provide important information. Social sciences and humanities, from political science and economics to art and literature, help us understand how society responds to environmental crises and opportunities. Environmental science is also mission oriented, we all have a responsibility to try to do something about the problems we have created.

**Imagine that you are an astronaut returning to the earth after a long trip to the moon or Mars. What a relief it would be, after experiencing the hostile environment of outer space, to come back to this beautiful, bountiful planet (fig. 1.2). Although there are dangers and difficulties here, we live in a remarkably prolific and hospitable world that is, as far as we know, unique in the universe.

Compared with the conditions on other planets in our solar system, temperatures on the earth are mild and relatively constant. Plentiful supplies of clean air, fresh water, and fertile soil are constantly regenerated by biological communities.

**Perhaps the most amazing feature of our planet is its rich diversity of life. This vast multitude of life creates complex, interrelated communities where towering trees and huge animals live together with, and depend upon, such tiny life-forms as viruses, bacteria, and fungi. Together, all these organisms make up delightfully diverse, self-sustaining ecosystems, including dense, moist forests; vast, sunny savannas; and richly colorful coral reefs.**There are over 7 billion people on earth, about twice as many as there were 40 years ago. We are adding about 80 million more each year. Although demographers report a transition to slower growth rates in most countries, with improved education and health care, present trends project a population between 8 and 10 billion by 2050 (fig. 1.5). The impact of that many people on our natural resources and ecological systems strongly influences many of the other problems we face.**The atmosphere normally captures heat near the earths surface, which is why it is warmer here than in space, but human activities such as burning fossil fuels, clearing forests and farmlands, and raising ruminant animals have greatly increased concentrations of carbon dioxide and other greenhouse gases. In the past 200 years, atmospheric CO2 concentrations have increased about 30 percent. Climate models indicate that by 2100, if current trends continue, global mean temperatures will probably increase by 2 to 6C compared to 1990 temperatures (3.6 and 12.8F: fig. 1.6a), far warmer than the earth has been since the beginning of human civilization.**Over the past century, global food production has increased faster than human population growth, but hunger remains a chronic problem because food resources are unevenly distributed. At the same time, soil scientists report that about two-thirds of all agricultural lands show signs of degradation. The biotechnology and intensive farming techniques responsible for much of our recent production gains are too expensive for many poor farmers. Can we find ways to produce the food we need without further environmental degradation and can we distribute food more equitably? In a world of food surpluses, currently more than 850 million people are chronically undernourished and at least 60 million people face acute food shortages due to weather, politics, or war (fig. 1.6b).*Water may be the most critical resource in the twenty-first century. Already at least 1.1 billion people lack access to safe drinking water and twice that many dont have adequate sanitation. Polluted water contributes to the death of more than 15 million people every year, most of them children under age 5. About 40 percent of the world population lives in countries where water demands now exceed supplies, and the UN projects that by 2025 as many as three-fourths of us could live under similar conditions (fig. 1.6c).**As noted in the opening case study, the ocean is an irreplaceable food resource. More than a billion people in developing countries depend on seafood for their main source of animal protein, but most commercial fisheries around the world are in steep decline. (fig. 1.6d). According to the World Resources Institute, more than three-quarters of the 441 fish stocks for which information is available are severely depleted or in urgent need of better management. Canadian researchers estimate that 90 percent of all the large predators, including bluefin tuna, marlin, swordfish, sharks, cod, and halibut, have been removed from the ocean.*The natural world supplies the water, food, metals, energy, and other resources we use. Some of these resources are finite; some are constantly renewed. When we consider resource consumption, an important idea is throughput, the amount of resources we use and dispose of.

Ecosystem services, another key idea, refers to services or resources provided by environmental systems (fig. 1.8). Provisioning of resources, such as the fuels we burn, may be the most obvious service we require. Supporting services are less obvious until you start listing them: these include water purification, production of food and atmospheric oxygen by plants, or decomposition of waste by fungi and bacteria. Regulating services include maintenance of temperatures suitable for life by the earths atmosphere, or carbon capture by green plants, which maintains a stable atmospheric composition. Cultural services include a diverse range of recreation, aesthetic, and other nonmaterial benefits.

Are there enough resources for all of us? One of the answers to this basic question was given in an essay entitled Tragedy of the Commons, published in 1968 in the journal Science by ecologist Garret Hardin. In this classic framing of the problem, Hardin argues that population growth leads inevitably to overuse and thendestruction of common resourcessuch as shared pastures, unregulated fisheries, fresh water, land, and clean air. This classic essay has challenged many to explore alternative ideas about resource management.*******************You may already be using the scientific method without being aware of it. Suppose you have a flashlight that doesnt work. The flashlight has several components (switch, bulb, batteries) that could be faulty. If you change all the components at once, your flashlight might work, but a more methodical series of tests will tell you more about what was wrong with the systemknowledge that may be useful next time you have a faulty flashlight. So you decide to follow the standard scientific steps.

In systems more complex than a flashlight, it is almost always easier to prove a hypothesis wrong than to prove it unquestionably true. This is because we usually test our hypotheses with observations, but there is no way to make every possible observation. The philosopher Ludwig Wittgenstein illustrated this problem as follows: Suppose you saw hundreds of swans, and all were white. These observations might lead you to hypothesize that all swans were white. You could test your hypothesis by viewing thousands of swans, and each observation might support your hypothesis, but you could never be entirely sure that it was correct. On the other hand, if you saw just one black swan, you would know with certainty that your hypothesis was wrong. As youll read in later chapters, the elusiveness of absolute proof is a persistent problem in environmental policy and law. You can never absolutely prove that the toxic waste dump up the street is making you sick. The elusiveness of proof often decides environmental liability lawsuits.

*