Unit 1: APES Courtesy of Ann McClung Revised by S. Purser 8-2010
Chapter 1 Environmental Problems, Their Causes, and Sustainability
Introduction Environment External conditions that affect living organisms Ecology Study of relationships between living organisms and their environment Environmental Science Interdisciplinary study that examines the role of humans on the earth Many different groups of people are concerned about environment! See spotlight p. 3
Linear Growth Quantity increases by a constant amount per unit of time Ex: 1,3,5,7,9, … When plotted on a graph, growth of money yields a fairly straight line sloping upward
Exponential Growth Quantity increases by a fixed percentage - starts off slowly, then grows to enormous numbers Result is a J-shaped curve Humans are the only species growing this way today. How does this impact our environmental resources?
Rule of 70 How long does it take a population to double? Resource use Population size Rule of 70 70 divided by the percentage growth rate = doubling time in years Currently, the human population growth rate (world wide) is 1.3%. In what year, do you predict the world population will have doubled?
Resources for Life Capital = wealth Solar Capital Energy from the sun (including wind, hydro & biomass) Provides 99% of the energy used on earth Earth Capital Planet’s air, water, soil, wildlife, minerals, natural purification, recycling, pest control,… (natural resources)
Sustainability The ability of a system to survive and function over a defined period of time This means living within one’s means - not depleting capital! If you have $1,000,000 in your bank account… 10% interest Sustainable living requires spending less than $100,000 per year The same applies to earth’s natural capital!
Two Options for Survival in the Face of a Growing Population • Live sustainably by eliminating waste and discontinuing the depletion and degradation of resources. • Overcome these problems with ingenuity, economic growth, and technology.
Economic Growth - Key Terms Economic Growth Increase in the capacity to provide goods and services for people’s use Throughput of Matter and Energy Resources used to produce goods and services through an economy – varies with location and products High throughput = more consumption per person
Economic Growth - Key Terms Gross National Product – GNP Measures economic growth in a country Market value in current dollars of all goods and services produced within and outside of a country by the country’s businesses during one year Gross Domestic Product – GDP Market value in current dollars of all goods and services produced only within a country during one year
Economic Growth - Key Terms More Developed Countries (MDC) Highly industrialized Average per capita GNP above $4000 Higher life expectancy Less Developed Countries (LDC) Low to moderate industrialization Average per capita GNP below $4000 (Africa, Latin America, and parts of Asia)
Economic Growth - Key Terms Development Change from a society that is largely rural, agricultural, illiterate, poor and rapidly growing population Globalization An more socially, economically, and environmentally interconnected world. Per Capita GNP GNP divided by the total population Shows one person’s slice of the economic pie
Wealth Gap The gap between the rich, middle-income and poor has widened More than 1 billion people survive on less than one dollar per day Poverty and Environmental degradation go hand in hand
Perpetual & Renewable Resources • Perpetual – renewed continuously (solar) • Renewable(on human scale)– can be replenished rapidly as long as it is used sustainably (forests, grasslands, wild animals, fresh water, fresh air, fertile soil)
Tragedy of the Commons Common Property Resources Resources owned by none, but available to all users free of charge May result in depletion or degradation of the resource Examples – ocean pollution, deforestation, abuse of national parks, grazelands Solutions? Limit access, regulations, reduce population, convert public to private ownership http://blog.nature.org/2009/10/sanjayan-tragedy-commons-ostrom-conservation-nature-conservanc/
Nonrenewable Resources Nonrenewable/Exhaustible Resources Exist in a fixed quantity in the earth’s crust and can be used up – ex. Fossil fuels & minerals Solutions: Reduce – ex: product with less packaging Refuse – don’t buy it at all! Recycling Collecting and reprocessing a resource into new products Reuse Using a resource over and over in the same form – example?
What is Your Ecological Footprint? It is YOUR impact on the environment • The amount of biologically productive land and water needed to supply renewable resources and absorb waste for each YOU! • Currently, each person’s ecological footprint is 20% greater than can be sustained indefinitely. • Result? polluted air and water, waste overload, poorer health, less biodiversity, etc. • We need four more planet Earths to meet the consumption levels of the U.S. Take the quiz! Ecological Footprint
Pollution Any addition to air, water, soil, or food that threatens the health, survival, or activities of humans or other living organisms May be added by human activity OR natural causes
Point Source Pollutants From a single, identifiable source Smokestack of a power plant Drainpipe of a meat-packing plant Exhaust pipe of an automobile
Non-point Source Pollutants Dispersed and often difficult to identify sources Runoff of fertilizers and pesticides Storm Drains (#1 source of oil spills in oceans)
Issues of Concern with Pollutants Chemical Nature How active and harmful it is to living organisms Concentration Amount per unit volume or weight of air, water, soil or body weight Persistence Time it stays in the air, water, soil or body
Solutions: Prevent it! Input Pollution Control Slows or eliminates the production of pollutants often by switching to less harmful chemicals or processes
Solutions: Clean it up! Output Pollution Cleanup Involves cleaning up pollutants after they have been released Most expensive and time consuming
Causes of Environmental Problems Developing Countries • increasing population • poverty • exploitation of resources for survival • Lack of education • Disease/poor health care Developed countries • High per capita resource use & resulting pollution and environmental degradation • Technology pollution • NOTE: affluence can also lead to environmental improvements!
Major Environmental Problems Biodiversity Depletion Air Pollution Water Pollution Waste Production Food Supply Problems See fig 1-9, p. 12
Model of Environmental Impact Population (P) x Consumption per person (A) X Technological impact per unit consumption (T) = Environmental impact of population P x A x T = I See Fig 1-11, p. 13
Hunter-Gatherers Had only three energy sources: Sunlight in captured plants Fire Their own muscle power Very little impact on environment
Agricultural Revolution Agricultural Revolution Cultural shift that began in several regions of the world Involved a gradual move from a lifestyle based on nomadic hunting Agro-forestry Planting a mixture of food crops and tree crops
Agricultural Revolution Slash-and-burn Cutting down trees and other vegetation and then burning the underbrush to clear small patches of land Subsistence Farming Family grew only enough food to feed itself.
Environmental Worldviews How people think the world works What they think their role in the world should be What they see as right and wrong environmental behavior (environmental ethics)
Planetary Management Worldview Increasingly common during the past 50 years. We are the planet’s most important species We are in charge of the rest of nature
Planetary Management Worldview There is always more All economic growth is good Potential for economic growth is limitless Our success depends on how well we manage earth’s system for our benefit
Earth-Wisdom Worldview Nature exists for all of the earth’s species, not just for us There is not always more Not all forms of economic growth is beneficial to the environment Our success depends on learning to cooperate with one another and with the earth
Working with the Earth Earth Wisdom Learning as much as we can about how the earth sustains itself Adapt to ever-changing environmental conditions Integrating such lessons from nature into the ways we think and act
Feedback Loops A feedback loop occurs when an output of a system is fed back as an input Two kinds of feedback loops Positive Negative Positive or Negative?
Feedback Loops Positive loops are runaway cycles where a change in a certain direction causes further change in the same direction Melting of permafrost will release methane which will accelerate global warming Negative loops help to maintain stability in a system Ex. Predator/Prey relationships help to maintain balance in populations… OR… blood sugar/insulin
Synergy vs Chaos Synergy occurs when two or more processes interact so the combined effect is greater than the sum of the separate effects Chaos occurs in a system when there is no pattern and it never repeats itself Noise versus Music