what is environmental science?
DESCRIPTION
WHAT IS ENVIRONMENTAL SCIENCE?. IS IT?. A stream flowing through a wilderness area? A rainforest canopy alive with blooming flowers? OR Your backyard?. ANSWER: ALL OF THE ABOVE. It is more than you see—it is a complex web of relationships that connects us with the world we live in - PowerPoint PPT PresentationTRANSCRIPT
WHAT IS ENVIRONMENTAL
SCIENCE?
IS IT?
A stream flowing through a wilderness area? A rainforest canopy alive with blooming
flowers?
OR Your backyard?
ANSWER: ALL OF THE ABOVE
It is more than you see—it is a complex web of relationships that connects us with the world we live in
It is the natural world + things produced by humans
ENVIRONMENTAL SCIENCE ENVIRONMENTAL SCIENCE:
Study of how humans interact with the environment
GOAL OF ENVIRONMENTAL SCIENCE:
Understand & solve environmental problems
HOW IS THIS DONE? Env. Scientists study 2 main types of
interactions btwn humans & environment
How we use natural resources (water, plants, etc)
How our actions alter our environment
Environmental Science is an interdisciplinary science (involves many
fields of study)
Env Scientist investigates how the nesting behavior of bees is influenced by human activities such as the planting of suburban landscaping.
Ecology: study of how living things interact with each other and with
their nonliving environment Ecologist studies the relationship btwn bees & the
plants bees pollinate
WHAT IS MEANT BY:
SCIENTISTS AS CITIZENS,CITIZENS AS SCIENTISTS?
???
ENVIRONMENT THROUGH HISTORY
A. HUNTER-GATHERERS B. THE AGRICULTURAL REVOLUTION C. THE INDUSTRIAL REVOLUTION
HUNTER GATHERS People who obtained food by collecting plants & by
hunting wild animals or scavenging their remains Small groups of people that migrated from place to
place as different types of food became available Affect Environment—
Spread plants to areas where plants did not originally grow In N. Am. a combination of rapid climate change
& over hunting may have lead to disappearance of some larger mammal species ( giant sloth, giant bison, mastodon)
AGRICULTURAL REVOLUTION Eventually hunter-gather groups began to collect
seeds of plants & domesticated some of the animals This allowed human populations to grow @
unprecedentated rate An area of land can support up to 500x as many people by
farming as it can by hunting-gathering As pop. grew conc. in smaller areaspressure on local env. Changed food we eat (domesticated vs. wild species) Farmland destroyed habitat
Slash-and-burn agriculture Replacing forest with farmland on large scale soil loss,
floods, water shortage
INDUSTRIAL REVOLUTION Mid 1700’s Involved shift from energy sources (animal muscle to
fossil fuels, oil, coal) Changed society greatly: ↑ efficiency of agriculture,
industry, & transportation Introduced many + changes
Light bulb, ↑ sanitation & medical care Also came new env. problems
Artificial substances (plastics, artificial pesticides & fertilizer) in place of raw animal & plant
Most modern env. problems began during Industrial Revolution
This photograph was taken in 1968 by the crew of Apollo 8.
Photographs such as this helped people realize the uniqueness of the planet we share.
E A R T H
Earth is essentially a closed system
Closed System: the only thing that enters Earth’s atmosphere in LARGE amts is ENERGY from the SUN & the only
thing that leaves in LARGE amts. is HEAT
PROBLEMS WITH A CLOSED SYSTEM
1. Some resources are limited As pop grows
↓Resources will be used more rapidly
↓ 2. Chance that we will produce more waste more quickly than we can dispose of
Most Environmental Issues Can Be Grouped Into 3 Categories
1. RESOURCE DEPLETION
2. POLLUTION
3. LOSS OF BIODIVERSITY
1. RESOURCE DEPLETION Natural Resource: any natural material used
by humansRenewable:
Non-renewable:
Renewable & Nonrenewable Resources
RENEWABLE NONRENEWABLE
Renewable & Nonrenewable Resources
RENEWABLE
ENERGY FROM SUN
WATER
WOOD
SOIL
AIR
NONRENEWABLE
METALS Iron, Aluminum, &
CopperNonmetallic materials
Salt, Clay, SandFOSSIL FUELS
1. RESOURCE DEPLETION Natural Resource: any natural material used
by humans Renewable: can be replaced relatively quickly by
natural processes (fresh water, air, soil, trees, crops) Non-renewable: sources that form at much slower rate
than the rate consumed (minerals, fossil fuels) Once used up- will take millions of yrs to replenish Depletion: a large fraction of resources that have been used up
Deforestation: trees harvested faster than they grow
2. POLLUTION Pollution: an undesired change in air, water, or soil
that adversely affects the health, survival, or activities of humans or other organisms 2 TYPES of POLLUTANTS
1. Biodegradable Pollutants: pollutants that can be broken down by natural processes.
Ex: human sewage, newspapers Only a problem if they accumulate faster than they can be broken
down 2. Nondegradable Pollutants: pollutants that CAN’T be broken down by natural processes
Ex: Mercury, lead, some types of plastic B/c don’t break down easily can build up to dangerous levels in env.
3. LOSS OF BIODIVERSITY Biodiversity: number & variety of species that
live in an area. Extinction is a natural process Only limited info about how modern
extinction rates compare with those of other periods in Earth’s history
All species have economic, scientific, aesthetic, recreational value…so it is important to preserve them
THE ENVIRONMENT & SOCIETY
How does a society use/share a common resource?
A neighborhood park? Open ocean?--- not owned by any nation
YET People from many countries use the ocean for
fishing & transportation
“TRAGEDY OF THE COMMONS”
1968- ecologist Garrett Hardin published essay “Tragedy of the Commons”
Described the attitude with which people use resources & became the theoretical backbone
of the environmental movement
A common theme is the idea of bioethics
“TRAGEDY OF THE COMMONS”
Hardin argued: Main difficulty in solving environmental
problems is the conflict between
short-term interests of individuals AND
long term welfare of a society
“TRAGEDY OF THE COMMONS” To illustrate his point he
used example of the commons
Commons: area of land that belonged to the whole village
It was in best short-term interest of an individual to put as many animals as possible
“If I don’t use this resource, someone else will”HOWEVER
If too many animals grazed on the commons animals destroy grass now everyone suffered
EVENTUALLY Commons were replaced by closed fields owned by
individual who were careful to prevent overgrazing
“TRAGEDY OF THE COMMONS”
POINT OF HARDIN’S ESSAY? Someone or some group has to take
responsibility for maintaining a resource
If no one takes that responsibility the resource can be overused & become depleted
WHAT HARDIN DID NOT CONSIDER
Social nature of humans- we live in groups & depend on one another
We can solve environmental problems by planning, organizing, considering scientific evidence, proposing a solution
The solution may override interests of indivual in short term BUT improves environment for everyone in long term
Earth’s Natural Resources are our modern “COMMONS”
ECONOMICS & THE ENVIRONMENT
In addition to social pressures—economic forces influence how we use resources
A. Supply & DemandB. Cost & BenefitsC. Risk Assessment
SUPPLY & DEMAND When the demand for a product increases
while the supply remains fixed, the cost of the product will increase. Ex.: if the supply of oil decreases:
1. Pay higher price2. Use less oil3. find new sources of energy
COST & BENEFITS Cost of environmental solutions can be high Cost-benefit analysis: balances the cost of
action against the benefits one expects from it. To INDUSTRY: the cost of pollution control
may outweigh the benefitsBUT
To a nearby COMMUNITY: benefits may be worth the higher price
RISK ASSESSMENT Tool that helps us to create cost-effective ways
to protect our health & environment One of the costs of any action is the risk of an
undesirable outcome
DEVELOPED vs. DEVLOPING COUNTRIES
DEVELOPED COUNTRIES
Higher avg. incomes
Slower pop. Growth
Diverse industrial economies
Stronger social support system
USA, Canada, Japan, countries of W. Europe
DEVELOPING COUNTRIES
Lower average incomes
Faster population growth
Simple & agricultural based economics
Lack of social support systems
African nations, Some Asian areas
DEVELOPED vs. DEVLOPING COUNTRIES
Environmental problems in developed countries tend to be related to consumption
In developing nations, the major environmental problems are related to population growth
WHAT DO YOU THINK THE ENVIRONMENTAL PROBLEMS
OF EACH COMSUMPTION PATTERN ARE?
Consumption Trends Ecological Footprint: shows the productive area of
Earth needed to support one person in a particular country
For a person in a developed country –the ecological footprint is an avg. 4x as large as a person in a developing country
Developed nations use ~ 75% of the world’s population, even though they make up only ~ 20% of the world’s population.
Critical Thinking Environmental Problems are complex Balance between rights of individuals/property
owners and society as a whole
Be careful when reading about issues for “BIAS”
Bias in Environmental Issues Passion for cause may lead to distortion of
facts Political clout may oversimplify
environmental impact Media sensationalizes issues
Learn to think critically, consider the source, listen to many viewpoints
SUSTAINABILITY
