Intro to environmental science

The Environment (Earth)

Life has existed on earth for 3.8 billion yrs.

Earth well suited for life

Water over ¾ of planet

Habitable temperature, moderate sunlight

Atmosphere provides oxygen and carbon dioxide Soil with essential minerals for plants

Human Impacts on Environment-

Population

Modern humans appeared ~300,000 years ago in

Africa and quickly expanded

Now, human population is ~8 billion (2022) Growing exponentially

Estimates of ~ 10 billion by 2050

We are the most

significant agent of

environmental change

Population

About 40% of people live in extreme poverty

Cannot meet basic needs for food, clothing, shelter, health 2.50 US dollars/day

Difficult to meet population needs without exploiting earth’s resources

Highly Developed Countries (HDC)

Complex industrialized bases, low population growth, high per capita incomes

Ex: US, Canada, Japan

Less Developed Countries (LDC)

Low level of industrialization, very high fertility rate, high infant mortality rate, low per capita income

Ex: Bangladesh, Mali, Ethiopia

Low Income Economies

$1,085 or less

Lower-Middle Income Economies

between $1,086 and $4,255

Upper-Middle Income Economies

between $4,256 and $13,205

High Income Economies

$13,205 or more

Gap Between Rich and Poor

Large gap between wealthy and poor citizens

Differential access to electricity, cars, modern medicine

Ex: China, India, Brazil, Mexico

Essential resources

Rapidly increasing population can quickly overwhelm or deplete, especially locally

Resource consumption can far outweigh needs of survival

Affluent nations use larger portions and can exhaust resources globally

Natural resources

Substances or materials that people obtain from nature and use to survive and thrive.

Renewable resources

Non renewable resources

Renewable resources

Resources that can be replaced within 100 years.

Direct solar energy

Energy of winds tides, flowing water

Clean air

Fresh water

Biological diversity (forest, food crops, fishes)

Nonrenewable resources

Resources that cannot be replaced within 100 years.

Metallic minerals (gold, tin)

Non-metallic minerals (salt, phosphates, stone)

Fossil fuels (coal, oil, natural gas)

Fertile soil

Consumption

Human use of materials and energy

Unsustainable Consumption

Occurs when the level of demand on a country’s resources damages or depletes the resource enough to reduce the quality of life for future generations

Caused by overpopulation and/or overconsumption

Ecological Footprint

The average amount of land, water and ocean required to provide that person with all the resources they consume

Earth’s Productive Land and Water

11.4 billion hectares

Amount Each Person is Allotted (divide Productive Land & Water by Human Pop.)

1.8 hectares

(1.62 in 2011) (1.52 in 2017)

Number goes down because human population go up

Current Global Ecological Footprint of each person

2.7 hectares

Humans Ecological overshoot (Everything is exhausted)

IPAT Model

Measures 3 factors that affect environmental impact (I)

I (environmental impact) = P (number of people) x A ( Affluence: good consumption per person) x T (environmental effective technology (pollution / good consumption )

Environmental Sustainability

The ability to meet the current human need for natural resources without compromising the needs of future generations

Environmental sustainability requires

Understanding the effects of our actions on the Earth, and that the Earth resources are not infinite = limited

Garrett Hardin

Solving environmental problems is the

result of the struggle between:

Short term welfare

Long term environmental stability and societal welfare

Common Pool Resources (CPR)

Garrett used common pastureland in medieval Europe to illustrate the struggle

Elinor Ostrom

Collective self-governance

Common-pool resources can be effectively managed collectively, without government or private control.

Sustainable Development-Systems Concept

Economic development that meets the needs of the present generation without compromising future generations

Environmental Science

An interdisciplinary study of human relationship with other organisms and the earth

Biology

Study of life

Ecology

The study of relationships and interactions between living organisms and their physical chemical and biological environment

Geography

the scientific study of Earth's lands, features, inhabitants, and natural and human phenomena

Chemistry

studies matter, its composition, structure, properties, and the changes it undergoes during chemical and biochemical reactions

Geology

the scientific study of the Earth, its physical structure, composition, history, and the natural processes that shape it over time

Physics

the fundamental natural science that studies matter, energy, space, time, and the forces that connect them

Economics

a social science that studies how individuals, businesses, governments, and societies allocate scarce resources to satisfy unlimited wants and needs

Sociology

the scientific study of human society, social behavior, patterns of social relationships, and social institutions

Demography

the statistical and scientific study of human populations, including their size, structure, density, distribution, and how they change over time

Politics

is the process by which individuals and groups make collective decisions, set rules and laws, and distribute power and resources within a society.

System

A set of components that interact and function as a whole

Global Earth Systems

Climate, atmosphere, land, coastal zones, ocean

Ecosystem

A natural system consisting of a community of organisms and its physical environment

Earth Systems

Most of earth’s systems are in dynamic equilibrium or steady state

dynamic equilibrium

Rate of change in one direction equals that in other

Negative feedback

Change triggers a response that counteracts (reverses) the changed condition

Positive feedback

Change triggers a response that intensifies the changing condition

Ex: polar and glacial ice melt, color change leading to more rapid melting

Variable

A factor that influences a process

The variable may be altered in an experiment to determine its effect on the outcome

Usually one variable

Control

The variable is not altered

Allows for comparison between the tests of when we alter the variable and when we do not alter the variable

Theory

Integrated explanation supported by large body of observations and experiments, and evaluated by peer review

Simplifies, clarifies, and predicts new relationships within the natural world

Truth in science

Absolute truth is not possible in science

Simplifies, clarifies, and predicts new relationships within the natural world

Knowledge evolves as new evidence is found

Five Steps to Addressing An Environmental Problem

Scientific assessment, risk analysis, public education and involvement, political action, long-term evaluation