Environmental Issues, Their Causes & Sustainability

Chapter One

Environment, Ecology, & Environmental Science

• Environment - all external conditions and factors that affect living organisms

• Ecology - study of relationships between living organisms and their environment

• Environmental Science - examines the effect of humans on the earth’s environment– How the earth works– How to deal with the problems we face– It is an interdisciplinary science - natural and social

sciences.

How rapidly is the human population growing?

• It took 60,000 years to reach 1 billion

• It took 130 years to reach 2 billion

• It took 30 years to reach 3 billion

• It took 17 years to reach 4 billion

• It took 12 years to reach 5 billion

• It took 10 years to reach 6 billion

• 48% of earth’s land area has been modified by man.

Population Growth rate

• % change over time

• Positive and negative rates– More births than deaths each year– For every 5 babies born each second, two

people die– Negative rates- high mortality rates, emigration

Exponential Growth

• development at an increasingly rapid rate in proportion to the growing total number or size; a constant rate of growth applied to a continuously growing base over a period of time

• Also called Geometric Growth– Follows a geometric pattern of increase– 2,4,8,16,32, etc.

Makes a J- curve

• Called this because of its shape

• To find Doubling Time

• Use Rule of 70

• Divide Percent increase into 70

• Human population is growing in this manner

Arithmetic Growth

• Increases at a constant amount per unit of time

• 1,3,5,7, etc.

• Also called Linear Growth

• Graph will be a sloping straight line

• Food production is increasing in this manner

Environmentally Sustainable Society

• Satisfies the basic needs of the people without depleting or degrading its natural resources and therefore preventing current and future generations from meeting their basic needs.

• Live off the natural income replenished by soils, plants, air and water and not depleting the natural capital that supplies this income.

Population and Sustainability

• Overpopulation is root cause of many environmental problems– Depletion of water– More land needed to grow food and house our

families– More pollution is generated by our growing

industrialization– Mass extinction from habitat loss

Carrying Capacity

• The number of people earth can support without using resources faster than the planet can replenish them

• A population that exceeds the carrying capacity CANNOT be sustained– Not enough food, water, other vital resources

What is our carrying capacity?It depends on several factors: type and quantity of available resources, how those resources are distributed, the amount of resources each person uses

Ecological Footprint

• The amount of land needed to produce the resources needed by the average person in a country.– Ecological footprint of people in developed

countries is large compared to people in developing countries.

– If all people in the world consumed what we do in the U.S. it would take three planets to support them.

United States

The Netherlands

India

CountryPer Capita Ecological Footprint(Hectares of land per person)

10.9

5.9

1.0

Capital

• Wealth – to an economist• Solar capital – energy from the sun

– Direct sunlight and indirect forms such as windpower, hydroelectric, and biomass

• Natural capital – (natural resources) air, water, soil, biodiversity, etc. Also called natural resources.

• Our existence depends completely on the sun and the earth.

What is economic growth?

• An increase in a country’s capacity to provide goods and services for its population’s use.

• Its measured by Gross National Income (GNI) Used to be called Gross National Product

• Market value of all goods and services produced within a country for final use during a year.

• Usually calculate per capita GNI - GNI divided by total population

• Gross Domestic Product – GDP – the market value in current dollars of all good and services produced within a country during a year.

• Gross World Product – GWP – market valut in current dollars of all goods and services produced in the world during a year

• Per capita GNI in purchasing power – GNI PPP/total population at mid-year. A way to compare people’s economic welfare among countries.

What is economic development?

Improvement of living standards by economic growth

Developed Countries

• Highly industrialized

• High per capita GNI

• Have 20% of world’s population

• Have 85% of world’s wealth and income

• Use 88% of its natural resources

• Generate 75% of its pollution & waste

Developing Countries

• Low to moderate industrialization

• Low per capita GNI

• Most are in Africa, Asia, and Latin America

• Have 80% of the world’s population

• Have 15% of its wealth and income

• Use only 12% of its natural resources

Development

• The change from a largely rural society, mainly agricultural, illiterate, and poor with a rapidly growing population to one that is mostly urban, industrial, educated, and wealthy with a slow-growing population..

Globalization

• The process of global social, economic, and environmental change that leads to an increasingly integrated world.– Economic indicators - global economy has grown and

there are many transnational corporations– Information & communication - many people have

Internet access– Environmental effects - diseases and pollutants

transported across international borders & global climate change

RESOURCES

• RESOURCE - anything obtained from the earth to meet human needs and wants– Food, water, shelter, manufactured goods,

transportation

Types of resources

• PERPETUAL - renewed continuously– SOLAR ENERGY– WIND, TIDES,

FLOWING WATER

• RENEWABLE - can be replenished fairly rapidly– AIR, WATER, SOIL,

BIODIVERSITY

• NONRENEWABLE - exist in a fixed quantity– FOSSIL FUELS

– METALLIC MINERALS

– NONMETALLIC MINERALS

Sustainable yield

• The highest rate at which a potentially renewable resource can be used indefinitely without reducing its available supply.

• Environmental degradation - results when a resource’s natural replacement level is exceeded.

The Tragedy of the Commons

• 1968 - Garrett Hardin

• “If I don’t use it, someone else will”

• Overusing that which belongs to all or us– Air, water, ocean– Called COMMON PROPERTY OR

FREE-ACCESS RESOURCES

Nonrenewable resource

• Exist in fixed amounts in the earth’s crust and can be completely used up– Include energy resources such as coal, oil natural gas

& uranium– Metallic mineral resources - iron, copper– Nonmetallic mineral resources - salt, sand, clay

• Mineral - hard, crystalline material formed naturally

• Also called exhaustible resources

Economic depletion

• When 80% of a mineral is used up and it becomes more expensive to retrieve it than the mineral is worth.

• Five choices at this point:– Reduce or use less, reuse or recycle existing

supply - does not apply to nonrenewable energy sources- use less or try to find a substitute or do without.

Recycling - collect and reprocess resource into new products.

Reuse - Use resource over & over again.Cannot recycle nonrenewable

energy sourcesReserve - known deposit from which a useable mineral can be extracted at a profit at current prices.

Pollution

• Any addition to air, water, soil or food that threatens the health, survival, or activities of humans or others

• Can be natural such as a volcano or anthropogenic - due to human activities

• POINT SOURCES - come from a single identifiable source - a wastewater treatment plant

• NONPOINT SOURCES - come from sources that are difficult to identify.

Solutions to Pollution

• CLEANUP - usually only temporary

• PREVENTION - the best way - slow or eliminate pollutant reaching environment.

Key Environmental ProblemsFIVE ROOT CAUSES

• Overpopulation• Waste of resources• Poverty• Not including

environmental costs of economic goods and services in their market prices

• Trying to manage and simplify nature with too little knowledge of how nature works.

Connections

• Model developed by Paul Ehrlich and John Holdren- 1970’s

• Population x Affluence x Technology = Environmental Impact

• P = number of people• A = number of units of

resources used /person• T = Env. Degredation

& pollution/unit of resource used

• I = environmental impact of population

P x A x T = I

Results

• Developing countries have more people but use less resources / person

• Developed countries have less people but use more resources/person

• Ends up that both have effects on environment

• Environmental worldview - how people think the world works, their role, and right and wrong behavior (environmental ethics)

• Planetary management worldview- humans are the most important and should manage the planet

• Environmental wisdom worldview - we are a part of nature and resources are limited. We must manage.