Environmental Problems, Their Causes, and Sustainability Chapter 1 Environmental Problems, Their Causes, and Sustainability

Environmental Science Is a Study of Connections in Nature … the study of how the earth works, how we interact with the earth and how to deal with environmental problems. The goals of environmental science are to learn: how nature works how the environment effects us how we effect the environment how to deal with environmental problems how to live more sustainably

Sustainability Is the Central Theme of This Book Sustainability, is the ability of earth’s various systems to survive and adapt to changing environmental conditions indefinitely. Key idea: Protect your capital and live off of the income it provides

Natural Capital = Natural Resources + Natural Services Natural resources – materials or energy in nature that are useful (sometimes essential) to humans. Natural services – functions of, or processes in nature which support life and human economies Solar capital – energy from the sun

Resources Resource – anything obtained from the environment that fulfills a need or want Directly available for use (sun, air, water, wind) Not directly available for use (iron, coal, crops) Perpetual – on a human time scale are continuous solar energy Renewable – can be replenished rapidly (e.g. hours to several decades) forests, grasslands, fresh air, fertile soil Nonrenewable – in a fixed supply or not replenished on a human time scale fossil fuels, iron, copper, salt

Some Sources Are Renewable…Some Resources Are Not Renewable Sustainable yield – the highest rate at which a renewable resource can be used without reducing its available supply Environmental degradation – when resource supply shrinks as a result of overuse Recycling and reusing extends supply of nonrenewable resources. Recycling processes waste material into new material. Reuse is using a resource over again in the same form.

Overexploiting Shared Renewable Resources: Tragedy of the Commons Three types of property or resource rights: Private property – owned by a person Common property – owned by a group Open access renewable resources – own by no one, available to all, no charge Tragedy of the commons – common property/ open access resources will be exploited Solutions – laws or policy reducing resource access or use OR convert the resource to private ownership

Natural Capital Use and Degradation Humanity’s ecological footprint has exceeded earth’s ecological capacity.

Pollution Found at high enough levels in the environment to cause harm to organisms. Point source – known source Nonpoint source – unknown or multiple sources Pollutants can have three types of unwanted effects: Can disrupt / degrade life-support systems Can damage health and property Can create nuisances such as noise and unpleasant smells, tastes, and sights

Experts Have Identified Five Basic Causes of Environmental Problems Population growth Wasteful and unsustainable resource use Poverty Failure to include the harmful environmental costs of goods and services in their market prices Insufficient knowledge of how nature works

Resource Consumption and Environmental Problems BOTH poverty and wealth can lead to environmental degradation: Underconsumption People who live in poverty are concerned with survival, not the environmental implications of their actions. Overconsumption Affluenza: unsustainable addiction to overconsumption and materialism.

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

Aldo Leopold’s Environmental Ethics Through writings and teaching, became a pioneer in the area of conservation Land ethic; the way we treat the Earth is a moral issue: Individuals matter … land is to be loved and respected is an extension of ethics. We abuse land because we regard it as a commodity…

Science, Systems, Matter, and Energy Chapter 2 Science, Systems, Matter, and Energy

THE NATURE OF SCIENCE What do scientists do? Collect data. Form hypotheses. 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. Scientific Law 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. 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. Models are simplifications of “real-life”. 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 Ex. – soil erosion Negative (corrective) feedback loop causes a system to change in the opposite direction Ex. – a furnace turning itself off

Feedback Loops: Feedback can take so long that a system reaches a threshold or a tipping point and changes. Time delays between the input and the output can make it difficult to predict the outcome. Synergistic interaction – processes and feedbacks in a system can amplify the results. 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. 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.

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 (CH4) is the only exception. All other compounds are inorganic.

Organic Compounds: Carbon Rules Hydrocarbons: compounds of carbon and hydrogen atoms Ex. methane (CH4) Chlorinated hydrocarbons: compounds of carbon, hydrogen, and chlorine atoms Ex. DDT (C14H9Cl5) Simple carbohydrates: certain types of compounds of carbon, hydrogen, and oxygen Ex. glucose (C6H12O6)

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. Law of conservation of matter. Physical change maintains original chemical composition. Chemical change involves a chemical reaction which changes the arrangement of the elements or compounds involved. 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. 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. Energy efficiency is a measure of how much useful work is accomplished before it changes to its next form.

Mechanical energy (moving, thinking, living) 2nd Law of Thermodynamics Mechanical energy (moving, thinking, living) Chemical energy (photosynthesis) Chemical energy (food) Solar energy Waste Heat Waste Heat Waste Heat Waste Heat Figure 2.14 The second law of thermodynamics in action in living systems. Each time energy changes from one form to another, some of the initial input of high-quality energy is degraded, usually to low-quality heat that is dispersed into the environment. Figure 2-14