Transcript Slide 1

It is in vain to dream of a wilderness distant
from ourselves.
- H. D. Thoreau -
Environmental Science is the study of the interactions
between humans and the world around them, living
and non-living.
Ecology – the study of living organisms and the web
of relationships that binds us all together in nature –
how organisms interact with one another and with the
abiotic components of the environment.
Biosphere – the skin of life on the planet – from about
11,000 meters below sea level to about 9,000 meters
above sea level.
Most life is 200 meters below the surface to 6000
meters above the surface.
THE BIOSPHERE IS A CLOSED SYSTEM. THINK OF EARTH AS
A SMALL, ROCKY BALL FLOATING IN THE VACUUM OF
SPACE WITH A THIN FILM OF ATMOSPHERE ABOUT 100 KM
THICK.
IF YOU HAD A CAR THAT COULD GO STRAIGHT UP, YOU
COULD BE IN SPACE IN 1 HOUR.
THE ONLY OUTSIDE CONTRIBUTION TO THIS CLOSED
SYSTEM IS SUNLIGHT AND A LITTLE BIT OF SPACE DUST.
ALL MATERIALS NECESSARY FOR LIFE MUST BE RECYCLED.
WE ARE DEALING WITH LIMITED RESOURCES – SOME MORE
SO THAN OTHERS.
KEY POINT #1 – EARTH IS A CLOSED SYSTEM
ECOSYSTEM – SHORT FOR ECOLOGICAL SYSTEM – THE
COLLECTION OF ALL INTERACTING LIVING AND NON-LIVING
THINGS IN A GIVEN AREA.
THE GLOBAL ECOSYSTEM IS THE BIOSPHERE.
FOR THE PURPOSES OF STUDY, WE CAN BREAK THE
BIOSPHERE DOWN INTO SMALLER, REGIONAL
ECOSYSTEMS THAT HAVE COMMON CHARACTERISTICS –
BIOMES.
THE COMMON BIOMES ARE:
- TUNDRA
- TAIGA
- TEMPERATE FORESTS
- GRASSLANDS
- DESERTS
- RAIN FORESTS
IN ADDITION TO THESE, YOU ALSO HAVE THE AQUATIC
IN AN ECOSYSTEM, WE ARE CONCERNED WITH THE BIOTIC
AND THE ABIOTIC COMPONENTS.
THE ABIOTIC COMPONENTS ARE THE NONLIVING THINGS
SUCH AS CLIMATE, SOIL TYPES, ROCKS, SUNLIGHT,
NUTRIENTS, ETC.
THE BIOTIC COMPONENTS ARE THE LIVING ORGANISMS
THAT OCCUPY THE ECOSYSTEM. THESE CAN BE
CLASSIFIED A COUPLE OF DIFFERENT WAYS.
THE SIMPLEST DIVISION ARE THE SPECIES. SPECIES ARE
THE DIFFERENT KINDS OF ORGANISMS.
A SPECIES IS A GROUP OF ORGANISMS THAT WOULD
NORMALLY INTERBREED.
ALL BREEDS OF DOGS ARE BASICALLY THE SAME
SPECIES, AS THEY COULD ALL INTERBREED.
ALL HOMO SAPIENS ARE THE SAME SPECIES.
RACOONS WOULD BE A SEPARATE SPECIES FROM
SKUNKS.
SO, POPULATIONS CAN HAVE A CERTAIN AMOUNT OF GENETIC
VARIATION.
ALL POPULATIONS THAT LIVE IN A GIVEN AREA AT A
GIVEN TIME WOULD MAKE UP A COMMUNITY.
THE INTERACTIONS BETWEEN POPULATIONS CAN
INVOLVE MAY KINDS OF INTERACTIONS. THESE CAN
VARY FROM POSITION ON THE FOOD CHAIN TO
REGULATION OF POPULATION SIZE.
GENERALLY, THE MORE DIVERSE THE POPULATIONS IN
A COMMUNITY ARE, THE MORE STABLE THE
COMMUNITY.
THE GREATER THE INTERCONNECTIVITY OF THE FOOD
WEB, THE MORE RESISTENCE TO DISTURBANCE.
ECOSYSTEMS ARE DYNAMIC SYSTEMS COMPOSED OF
THE COMMUNITY OF LIVING ORGANISMS AND THE
ABIOTIC COMPONENTS OF THE ENVIRONMENT.
KEY POINT #2 - EVERYTHING IN NATURE IS
LINKED.
AN UPSET TO ONE POPULATION OR ONE
ABIOTIC COMPONENT CAN UPSET THE
ENTIRE ECOSYSTEM.
LIMITING FACTOR – A FACTOR (ABIOTIC
COMPONENT) THAT WOULD LIMIT GROWTH IF
IN SHORT SUPPLY.
HABITAT – PLACE WHERE AN ORGANISM LIVES
NICHE – RELATIONSHIP TO ITS ENVIRONMENT OR THE
ROLE IT PLAYS – HOW IT USES THE RESOURCES IN ITS
ENVIRONMENT
SIMILAR SPECIES CAN OCCUPY THE SAME HABITAT AS
LONG AS THEIR NICHES ARE DIFFERENT.
IF NICHES OVERLAP, COMPETITION RESULTS.
HUMANS ARE SO ADAPTABLE THAT THEY CAN SURVIVE
(EVEN THRIVE) IN ANY BIOME. WE ARE OUTCOMPETING
ALL OTHER SPECIES.
OTHER SPECIES DON’T HAVE BIG GAME RIFLES, CHAIN
SAWS, BULLDOZERS, OR HIGH EXPLOSIVES.
40 TO 100 SPECIES PER DAY GO EXTINCT.
ORGANISMS CAN BE CLASSIFIED BY THE FUNCTION THEY
PLAY IN THE ENVIRONMENT. FOR EXAMPLE:
-PRODUCERS – ORGANISMS THAT CAN PRODUCE THEIR
OWN FOOD, E.G., GREEN PLANTS THAT CAN USE
PHOTOSYNTHESIS TO TAKE CARBON DIOXIDE, WATER, AND
SUNLIGHT TO PRODUCE CARBOHYDRATES
-CONSUMERS – ORGANISMS THAT CONSUME (EAT) OTHER
ORGANISMS, INCLUDING PRODUCERS. THESE CAN BE
DIVIDED INTO:
-HERBIVORES – EAT ONLY PRODUCERS
-OMNIVORES – EAT ALL KINDS OF ORGANISMS
-CARNIVORES – DON’T EAT PRODUCERS, JUST
CONSUMERS
-SCAVENGERS – EAT LEFT OVER PARTS OF CONSUMERS
-DECOMPOSERS – DECOMPOSE REMAINS OF OTHER
ORGANISMS
EVERYTHING WE MAKE, MODIFY, OR GROW
USES A SYSTEM OR A PROCESS. SINCE WE
ARE LIVING IN A CLOSED SYSTEM, WE WOULD
HOPE THAT ALL OF OUR
SYSTEMS/PROCESSES ARE SUSTAINABLE.
A SUSTAINABLE PROCESS – ONE THAT CAN
BE CONTINUED AT THE SAME LEVEL FOR
FUTURE GENERATIONS.
SUSTAINABLE – CAPABLE OF BEING
CONTINUED
SUSTAINABILE PROCESS
RENEWABLE AND
NON-RENEWABLE
RESOURCES
RAW
MATERIAL
S
GOODS AND
SERVICES
PROCESS
W
A
S
T
E
PRODUCT
S
MATERIALS
RETURNED TO THE
ENVIRONMENT
RENEWABLE RESOURCES – RESOURCES THAT CAN BE
REGROWN OR REGENERATED
NONRENEWABLE RESOURCES – RESOURCES THAT ARE
LIMITED – ONLY A FINITE AMOUNT EXISTS
CAN YOU GIVE EXAMPLES??
IS OUR CURRENT WAY OF LIFE SUSTAINABLE?
OR, YOU COULD ASK THE QUESTION “IS LIFE
SUSTAINABLE?”
DOES ANYONE CARE?
SO, WHERE ARE WE NOW?
IN BIOLOGICAL SYSTEMS, THERE IS A PHENOMENON
KNOWN AS CARRYING CAPACITY.
CARRYING CAPACITY REPRESENTS THE MAXIMUM
POPULATION THAT AN ENVIRONMENT CAN
MAINTAIN FOR A GIVEN SPECIES. WHEN AN
ORGANISM’S POPULATION EXCEEDS THE CARRYING
CAPACITY, THE ORGANISM’S POPULATION CAN NO
LONGER BE MAINTAINED, AND POPULATION DIE-OFF
OCCURS.
FACTORS IN NATURE THAT LIMIT CARRYING
CAPACITY ARE USUALLY:
- FOOD SUPPLY
- PREDATORS
- DISEASE
- CLIMATE
HUMANS HAVE HAD THE UNIQUE ABILITY TO DEAL
WITH THESE LIMITATIONS, SO OUR POPULATION
HAS GROWN.
ONE FACTOR WHICH MAY LIMIT GROWTH IN THE
FUTURE IS THE RATE AT WHICH WE USE NATURAL
RESOURCES.
IN A SENSE, IT IS A CRISIS OF
UNSUSTAINABILITY.
THERE ARE TWO PLAYERS IN THE CURRENT
CRISIS:
- POPULATION
- CONSUMPTION
MANY ENVIRONMENTALISTS THINK THAT
WE REACHED UNSUSTAINABLE USE OF
NATURAL RESOURCES IN THE MID 1980’S –
THAT WE ARE CURRENTLY USING NATURAL
RESOURCES AS IF WE HAD 1.4 EARTHS.
HOWEVER, IF EVERYONE LIVED LIKE WE LIVE
IN THE U.S., IT WOULD TAKE AT LEAST 2.5
EARTHS TO SUSTAIN OUR LIFE STYLES.
THE WORLD IS OBSESSED WITH ECONOMIC
GROWTH.
PEOPLE WANT TO CONSUME.
- NOVELTY
- USEFULNESS
- CONVENIENCE
- COMPETITION – WHO CAN HAVE THE MOST
KEY POINT #3: ECONOMIC GROWTH = INCREASED
RESOURCE USE
“As population grows, we need more jobs, and that
requires growth that becomes more difficult as
techlonogical efficiency and productivity improvements
drive down the number of people needed to create the
goods we produce.” From “The Great Disruption”
AFTER BASIC NEEDS ARE MET, GROWTH HAS NO
POSITIVE IMPACT ON QUALITY OF LIFE.
NEW ETHICS:
1)EARTH HAS A LIMITED SUPPLY OF RESOURCES.
2)HUMANS ARE A PART OF NATURE, SUBJECT TO ITS
LAWS.
3)SUCCESS STEMS FROM EFFORTS TO COOPERATE WITH
THE FORCES OF NATURE.
TRAGEDY OF THE COMMONS – EVEN ARISTOTLE
RECOGNIZED THAT PROPERTY SHARED FREELY BY MANY
PEOPLE OFTEN RECEIVED THE LEAST CARE.
ENVIRONMENTALISTS USE A TERM CALLED “HUMAN
FOOTPRINT” TO TALK ABOUT HOW AN INDIVIDUAL’S
LIFESTYLE IMPACTS THE ENVIRONMENT.
THIS CAN BE EXPRESSED TWO WAYS. FIRST, IF
EVERYONE ON EARTH LIVED AS YOU LIVE, HOW
MANY EARTHS WOULD IT TAKE TO SUPPORT THE
POPULATION IN A SUSTAINABLE MANNER.
SECOND, HOW MUCH LAND WOULD IT TAKE TO
SUPPLY THE RESOURCES TO SUPPORT YOUR LIFESTYLE
IN A SUSTAINABLE MANNER.
THERE ARE SEVERAL SITES THAT HAVE HUMAN
FOOTPRINT CALCULATORS. ONE OF THE BETTER
ONES IS :
http://www.footprintnetwork.org/en/index.php/GFN/
GO TO THIS SITE AND CLICK ON “FOOTPRINT FOR
YOU” TO CALCULATE YOUR FOOTPRINT.