Post on 18-Dec-2015
World’s Population Population Size Growth Characteristics (exponential, logistic)
• Growth Rate• Doubling Time – Rule of 70
Population Distribution• Developed Countries• Developing Nations
Resource Distribution• Developed Countries• Developing Nations
Overpopulation• People • Resource
Natural Resources
Perpetual Renewable Nonrenewable
• Fossil fuels• Mineral
Metallic Non metallic
• Strategic minerals
Some Sources Are Renewable and Some Are Not
Natural Resource• Anything we obtain from the
environment to meet our needs• Some directly available for use: sunlight• Some not directly available for use:
petroleum
Perpetual resource• Solar energy
Some Sources Are Renewable and Some Are Not (2)
Renewable resource• Several days to several hundred years
to renew• E.g., forests, grasslands, fresh air, fertile
soil
Sustainable yield• Highest rate at which we can use a
renewable resource without reducing available supply
Some Sources Are Renewable and Some Are Not (3)
Nonrenewable resources • Energy resources• Metallic mineral resources• Nonmetallic mineral resources
Reuse
Recycle
Ecological Footprints: A Model of Unsustainable Use of Resources
Ecological footprint: the amount of biologically productive land and water needed to provide the people in a region with indefinite supply of renewable resources, and to absorb and recycle wastes and pollution
Per capita ecological footprint
Unsustainable: footprint is larger than biological capacity for replenishment
Total Ecological Footprint (million hectares) and Share of Global Biological Capacity (%)
Per Capita Ecological Footprint (hectares per person)
United States 2,810 (25%) United States 9.7
European Union 2,160 (19%) European Union 4.7
China 2,050 (18%) China 1.6
India 780 (7%) India 0.8
Japan 540 (5%) Japan 4.8
2.5Unsustainable living2.0
1.5Projected footprint1.0
Nu
mb
er
of
Eart
hs
0.5
Ecological footprint Sustainable
living
1961 1970 1980 1990 2000 2010 2020 2030 2040 2050
Year
0
Points of View
Neo malthusian Cornucopian Anthropocentric Biocentric Ecocentric Stewardship Environmental Justice
Different Views about Environmental Problems and Their Solutions
Environmental ethics: what is right and wrong with how we treat the environment
Planetary management worldview• We are separate from and in charge of nature
Stewardship worldview• Manage earth for our benefit with ethical
responsibility to be stewards Environmental wisdom worldview
• We are part of nature and must engage in sustainable use
Principles
Sustainability• Carrying Capacity• Ecological Footprint
Spaceship Earth Tragedy of the Commons (Hardin) Basic Law of Ecology Gaia Hypothesis Precautionary Principle - When there is a great threat of
serious environmental damage, we should not wait for scientific proof before taking precautionary steps to prevent potential harm
Feedback / Feedback Loops Feedback- when one part of the system changes
Those changes affect another part of the system Which affects the first change
Negative feedback- an increase in output leads to a later decrease Self-regulating, or stabilizing
Positive feedback- an increase in output leads to a further increase in the output Destabilizing
Scientific Method
Observation Hypothesis / Prediction (If ….., then…..) Experimental design
• Step by step• Relates to the hypothesis• Clearly identify variables
Control Independent (manipulated) Dependent (responding)
Data Collection - Quantitative Repeatability Data Analysis Error Analysis Conclusions
Energy
Energy = ability to do work Types of Energy KE, PE, Solar, Nuclear, Chemical, Electrical,
Mechanical, Thermal, etc. Heat = total energy Temperature = proportional to the average kinetic energy Power = rate of doing work; rate of energy consumption Energy Quality
• High• Low
Energy Efficiency• Simple : [(Eout)/(Ein)] * 100 (% efficiency)
• Net Energy : (Eout) – ALL energy inputs (mining resource, processing, transportation, losses in use)
Productivity• GPP – gross primary productivity• NPP = GPP – R (R = respiration) Net primary productivity
Laws / Concepts Relating to Energy Flow
First Law of Thermodynamics – Law of Conservation of Energy• Conservation of Energy implies conservation of matter (b.c.)• E = mc2 (Einstein)
Second Law of Thermodynamics – Law of Degradation of Energy – Entropy No conversion of energy is 100% efficient
Maximum Power Principle the system that gets the most energy and uses it most efficiently will survive in competiton with others (Nature tends to shorten the food chain)
Thermal gradient heat flows, spontaneously, from warmer to cooler.
Basic Chemistry Concepts
Atom – fundamental particles Nucleus – dense, positively charged center
• Protons positively charged• Neutrons neutral
Electrons outside the nucleus (orbit the nucleus); negative charge- Atomic number = number of protons Mass Number = number of protons + neutrons Isotope = same atomic number, different mass number Allotrope = more than one form is stable (O2, O3) Ions = charged particles; lost or gained electrons
Radioactive Isotopes• Uses• Half-life• Emissions
a – alpha least penetrating, equivalent to a helium nuclei b – beta equivalent to an electron g – gamma most penetrating
Nuclear Reactions• Nuclear Fission – larger particles to smaller particles• Nuclear Fusion – smaller particles to larger particles• Nuclear Waste
High level Low level
Chemistry Con’t
Bonding• Ionic – metals + non metals; transfer electrons• Covalent – non metal + non metal; share electrons, form bonds• Hydrogen bonding – intermolecular force; N, O, and F only
Compounds• Inorganic• Organic• Diatomic – H, O, N, F, Cl, Br, I• Biologically Important Organic Compounds
Carbohydrates Lipids Nucleic Acids Proteins
• Acids / Bases pH scale generally 0 – 14 pH = -log [H+]