Chapter 1 Environmental Problems, Their Causes, and Sustainability

What is Environmental Science?  The goals of environmental science are to learn: how nature works how nature works how the environment effects us how the environment effects us how we effect the environment how we effect the environment how we can live more sustainably without degrading our life-support system how we can live more sustainably without degrading our life-support system … the study of how the earth works, how we interact with the earth and how to deal with environmental problems.

 Sustainability, is the ability of earth’s various systems to survive and adapt to environmental conditions indefinitely.  The steps to sustainability must be supported by sound science. Figure 1-3 Sustainability: The Integrative Theme

Environmentally Sustainable Societies  … meets basic needs of its people in a just and equitable manner without degrading the natural capital that supplies these resources. Figure 1-4

RESOURCES  Perpetual On a human time scale are continuous On a human time scale are continuous  Renewable On a human time scale can be replenished rapidly (e.g. hours to several decades) On a human time scale can be replenished rapidly (e.g. hours to several decades)  Nonrenewable On a human time scale are in fixed supply On a human time scale are in fixed supply

Nonrenewable Resources  Exist as fixed quantity Becomes economically depleted. Becomes economically depleted.  Recycling and reusing extends supply Recycling processes waste material into new material. Recycling processes waste material into new material. Reuse is using a resource over again in the same form. Reuse is using a resource over again in the same form. Figure 1-8

Our Ecological Footprint  Humanity’s ecological footprint has exceeded earth’s ecological capacity. Figure 1-7

POLLUTION  Found at high enough levels in the environment to cause harm to organisms. Point source – known source Point source – known source Nonpoint source – unknown or multiple sources Nonpoint source – unknown or multiple sources Figure 1-9

Pollution  Pollutants can have three types of unwanted effects: Can disrupt / degrade life-support systems Can disrupt / degrade life-support systems Can damage health and property Can damage health and property Can create nuisances such as noise and unpleasant smells, tastes, and sights Can create nuisances such as noise and unpleasant smells, tastes, and sights

ENVIRONMENTAL PROBLEMS: CAUSES AND CONNECTIONS  The major causes of environmental problems are: Population growth Population growth Wasteful resource use Wasteful resource use Poverty Poverty Poor environmental accounting Poor environmental accounting Ecological ignorance Ecological ignorance

Natural capital degradation  The exponential increasing flow of material resources through the world’s economic systems depletes, degrades and pollutes the environment. Figure 1-11

Poverty and Environmental Problems Figure 1-12

Resource Consumption and Environmental Problems  Underconsumption 1 of 3 children under 5, suffer from severe malnutrition. 1 of 3 children under 5, suffer from severe malnutrition.  Overconsumption Affluenza: unsustainable addiction to overconsumption and materialism. Affluenza: unsustainable addiction to overconsumption and materialism. Figure 1-13

Connections between Environmental Problems and Their Causes  I = PAT  I = P x A x T I = Environmental Impact I = Environmental Impact P = Population P = Population A = Affluence (per capita consumption) A = Affluence (per capita consumption) T = Technology T = Technology

Connections between Environmental Problems and Their Causes Figure 1-14

SUSTAINABILITY AND ENVIRONMENTAL WORLDVIEWS  Technological optimists: suggest that human ingenuity will keep the environment sustainable. suggest that human ingenuity will keep the environment sustainable.  Environmental pessimists: overstate the problems where our environmental situation seems hopeless. overstate the problems where our environmental situation seems hopeless.

Four Scientific Principles of Sustainability: Copy Nature  Reliance on Solar Energy  Biodiversity  Population Control  Nutrient Recycling Figure 1-16

Aldo Leopold’s Environmental Ethics  Individuals matter.  … land is to be loved and respected is an extension of ethics.  We abuse land because we regard it as a commodity… Figure 1-A

Chapter 2 Science, Systems, Matter, and Energy

Core Case Study : Environmental Lesson from Easter Island  Thriving society 15,000 people by ,000 people by  Used resources faster than could be renewed By 1600 only a few trees remained. By 1600 only a few trees remained.  Civilization collapsed By 1722 only several hundred people left. By 1722 only several hundred people left. Figure 2-1

THE NATURE OF SCIENCE  What do scientists do? Collect data. Collect data. Form hypotheses. Form hypotheses. Develop theories, models and laws about how nature works. Develop theories, models and laws about how nature works. Figure 2-2

Scientific Theories and Laws: The Most Important Results of Science  Scientific Theory Widely tested and accepted hypothesis. Widely tested and accepted hypothesis.  Scientific Law What we find happening over and over again in nature. What we find happening over and over again in nature. Figure 2-3

Limitations of Environmental Science  Inadequate data and scientific understanding can limit and make some results controversial. Scientific testing is based on disproving rather than proving a hypothesis. Scientific testing is based on disproving rather than proving a hypothesis. Based on statistical probabilities.Based on statistical probabilities.

MODELS AND BEHAVIOR OF SYSTEMS  Usefulness of models Complex systems are predicted by developing a model of its inputs, throughputs (flows), and outputs of matter, energy and information. Complex systems are predicted by developing a model of its inputs, throughputs (flows), and outputs of matter, energy and information. Models are simplifications of “real-life”. Models are simplifications of “real-life”. Models can be used to predict if-then scenarios. Models can be used to predict if-then scenarios.

Feedback Loops: How Systems Respond to Change  Outputs of matter, energy, or information fed back into a system can cause the system to do more or less of what it was doing. Positive feedback loop causes a system to change further in the same direction (e.g. erosion) Positive feedback loop causes a system to change further in the same direction (e.g. erosion) Negative (corrective) feedback loop causes a system to change in the opposite direction (e.g. seeking shade from sun to reduce stress). Negative (corrective) feedback loop causes a system to change in the opposite direction (e.g. seeking shade from sun to reduce stress).

Feedback Loops:  Negative feedback can take so long that a system reaches a threshold and changes. Prolonged delays may prevent a negative feedback loop from occurring. Prolonged delays may prevent a negative feedback loop from occurring.  Synergistic interaction – processes and feedbacks in a system can amplify the results. E.g. smoking exacerbates the effect of asbestos exposure on lung cancer. E.g. smoking exacerbates the effect of asbestos exposure on lung cancer.

TYPES AND STRUCTURE OF MATTER  Elements and Compounds Matter exists in chemical forms as elements and compounds. Matter exists in chemical forms as elements and compounds. Elements (represented on the periodic table) are the distinctive building blocks of matter.Elements (represented on the periodic table) are the distinctive building blocks of matter. Compounds: two or more different elements held together in fixed proportions by chemical bonds.Compounds: two or more different elements held together in fixed proportions by chemical bonds.

Organic Compounds: Carbon Rules  Organic compounds contain carbon atoms combined with one another and with various other atoms such as H +, N +, or Cl -.  Contain at least two carbon atoms combined with each other and with atoms. Methane (CH 4 ) is the only exception. Methane (CH 4 ) is the only exception. All other compounds are inorganic. All other compounds are inorganic.

Organic Compounds: Carbon Rules  Hydrocarbons: compounds of carbon and hydrogen atoms (e.g. methane (CH 4 )).  Chlorinated hydrocarbons: compounds of carbon, hydrogen, and chlorine atoms (e.g. DDT (C 14 H 9 C l5 )).  Simple carbohydrates: certain types of compounds of carbon, hydrogen, and oxygen (e.g. glucose (C 6 H 12 O 6 )).

CHANGES IN MATTER  Matter can change from one physical form to another or change its chemical composition. When a physical or chemical change occurs, no atoms are created or destroyed. When a physical or chemical change occurs, no atoms are created or destroyed. Law of conservation of matter.Law of conservation of matter. Physical change maintains original chemical composition. Physical change maintains original chemical composition. Chemical change involves a chemical reaction which changes the arrangement of the elements or compounds involved. Chemical change involves a chemical reaction which changes the arrangement of the elements or compounds involved. Chemical equations are used to represent the reaction.Chemical equations are used to represent the reaction.

ENERGY LAWS: TWO RULES WE CANNOT BREAK  The first law of thermodynamics: we cannot create or destroy energy. We can change energy from one form to another. We can change energy from one form to another.  The second law of thermodynamics: energy quality always decreases. When energy changes from one form to another, it is always degraded to a more dispersed form. When energy changes from one form to another, it is always degraded to a more dispersed form. Energy efficiency is a measure of how much useful work is accomplished before it changes to its next form. Energy efficiency is a measure of how much useful work is accomplished before it changes to its next form.

Figure 2-14 Chemical energy (food) Solar energy Waste Heat Waste Heat Waste Heat Waste Heat Mechanical energy (moving, thinking, living) Chemical energy (photosynthesis) 2 nd Law of Thermodynamics