human impact on the biosphere. those pesky humans! humans have a large impact on the environment and...
TRANSCRIPT
Human Impact on the Biosphere
Those Pesky Humans!
• Humans have a large impact on the environment and the organisms we share it with.
• This is due to our– Ever increasing population size.– Ever increasing use of both renewable and
non-renewable resources.
Humans Affect the Biosphere in 4 Essential Ways:
A. Global Climate Change and Acid Rain
B. The Ozone Layer
C. Biological Magnification/Bioaccumulation
D. Threatening Biodiversity
GLOBAL CLIMATE CHANGE AND ACID RAIN
A.
Human Activity and the Carbon Cycle
• We are releasing CO2 and other related forms of carbon into the atmosphere at a much faster rate than they are absorbed.
• This is due to the ever increasing rate at which we:– Clear-cut and burn forests for housing and farming– Burn fossil fuels
• These activities have resulted in the phenomenon of global warming.
Global temperatures have increased 0.5-1.0°F since the late 19th century.
FACTS WE KNOW
http://content.answers.com/main/content/wp/en/thumb/8/87/280px-Instrumental_Temperature_Record.png
The snow cover in the Northern Hemisphere and floating ice in the Arctic Ocean have decreased.
FACTS WE KNOW
Graph & glacier pix: http://nsidc.org/sotc/glacier_balance.html polar bears: http://www.metro.co.uk/news/article.html?in_article_id=35720&in_page_id=34
What’s so bad about warming up a little?
Coastal flooding
Cartoon from Brookings Register
http://healthandenergy.com/images/global2.gif
What’s so bad about warming up a little?
More severe stormshttp://i.a.cnn.net/cnn/2005/WEATHER/08/25/tropical.storm/story.katrina.915p.jpg
http://en.wikipedia.org/wiki/Hurricane_Katrina
What’s so bad about warming up a little?
http://zfacts.com/metaPage/lib/Atlantic_conveyor.jpg
Changes in Gulf Stream
http://www.claybennett.com/pages/ocean_temps.html
What’s so bad about warming up a little?
Weather extremes
Brookings RegisterHeat waves and drought
What’s so bad about warming up a little?
Changing habitats meansloss of species
http://www.metro.co.uk/news/article.html?in_article_id=35720&in_page_id=34
Acid Rain
• The burning of fossil fuels also releases nitrogen and sulfur compounds.
• These compounds combine with water vapor in the air to produce acids.
• The acids then migrate for miles and fall as acid rain.
Effects of Acid Rain
Effects of Acid Rain
THE OZONE LAYER B.
OZONE LAYER
• The ozone layer protects us from UV light.
• UV light causes cancer, eye damage, and can damage plant tissue
http://pubweb.bnl.gov/users/xujun/www/bnl/ozone_layer_1.gif
WHAT WE KNOW
Scientists have beenmonitoring the ____________of ozone in our atmosphereand have discovereda hole in the ozone layer over ____________.
depletion
Antarctica
http://ozonewatch.gsfc.nasa.gov/facts/hole.html
What’s the cause of Ozone Depletion?
Chlorofluorocarbon molecules _______released from air conditioners, aerosol spray cans, fire extinguishers, and industry________________destroy ozone
http://www.atm.ch.cam.ac.uk/tour/part3.html
(CFC’s)
_____________spray cans no longer contain CFC propellants.
Gases in ___________________and _____________ are collected and recycled.
THAT’S WHY . . .AEROSOL
AIR CONDITIONERS
http://www.roundrocktexas.gov/images/spray_cans_large.jpg
refrigerators
Pop Quiz
• Have out a sheet of Paper and number it 1-4.
• Read each question and write down only the letter of your choice.
• Good Luck
Pop Quiz
1. Which of the following is an example of ecological succession?
• A. spring followed by summer
• B. tadpole becoming a frog
• C. meadow replacing a field
• D. predators eating prey
2.What is the main suspected
environmental problem associated with the burning of fossil fuels?
• A. depletion of fresh water
• B. depletion of ozone
• C. global cooling
• D. global warming
Pop Quiz
3. Which of the following is a side effect of acid rain.
A. Large animalsB. CancerC. Damage to treesD.Rusty cars
• The ozone layer protects Earth by absorbing –
• A. cosmic dust• B. solar heat • C. ultraviolet radiation • D. white-light
frequencies
BIOACCUMULATION C.
Biological Magnification/Bioaccumulation
• Biological magnification/ Bioaccumulation occurs when pesticides build up in animal tissue as you move up a food chain.
Example:_____ was first modern insecticide
It was cheap, stayed active for long time, and kills many different insects
Used to control agriculture pests and disease carrying _______________
DDT
http://www.michigan.gov/images/mosquito_65147_7.jpg
MOSQUITOES
DDT in Borneo
• DDT was used in Borneo to kill mosquitoes. Lizards ate the mosquitoes. Cats ate the lizards. Cats began dying.
• With no cats, the rat population grew.• Rats began spreading disease.• They came up with an interesting solution…..
Parachuting Cats
http://imagecache2.allposters.com/images/pic/ARG/21033~Parachute-Cats-Posters.jpg
DDT in the United States
DDT causes birds to layeggs with ___________shells so eggs would break when sat on.
American Bald Eagle was declaredendangered in 1967. It has since beenreclassified as _____________________
fragile
“threatened”
THREATENING BIODIVERSITYD.
The sum of the genetically basedvariety of all the organisms in thebiosphere = ___________________
Biodiversity gives __________ to theecosystems that we are so dependenton, enhances their ____________, andprovides an important source of new_____, ________, and other _________.
BIODIVERSITY
stability
productivity
food medicine products
Threatening Biodiversity
There are 3 basic ways that human actions threaten biodiversity:
• Introducing non-native species• Hunting organisms to extinction• Habitat destruction
BIODIVERSITY THREATOne of most important threats tobiodiversity come from apparentlyharmless plants or animals thathumans transport into new habitats =_____________________
New habitats don’t have ____________and parasites that control the populationin their native habitats, so invasive speciespopulations _____________ rapidly.
INVASIVE SPECIES
PREDATORS
INCREASE
EXAMPLES OF INVASIVE SPECIES
http://en.wikipedia.org/wiki/Image:Wild_rabbit.jpg
24 rabbits turned loose for hunting in 1859 in Australia, reproduced at such a rapid rate they have taken overthe continent.
http://psephos.adam-carr.net/countries/a/australia/images/australiamap.gif
It is still a major problem and rabbit diseases have been purposely introduced to try to control the population
Hunting Organisms to Extinction
Habitat DestructionDevelopment of natural areas for cities oragriculture
http://www.simtropolis.com/idealbb/files/SG_ShoppingCenter.JPG
BIODIVERSITY THREAThttp://www.lubee.org/images/about-threats-1.jpg
Tropical rainforests are disappearing at a rate of about 80 acres per minute.
BIODIVERSITY THREAT
The tropical rainforests once covered more than 14% of the earth's total land surface, but now cover less than 6%.
http://www.abc.net.au/news/newsitems/200506/s1384632.htm
Changes in Brazilian rainforest over 30 years
Can lead to species Extinction
Endangered Species
Worlds Rarest Animal
ONCE THOUGHT EXTINCT
WHAT CAN WE DO???So…
WHAT DOES IT MEAN?REMEMBER!Everything is connected.
BIODIVERSITY is a measureof the health of an ecosystem.
Image from: Pearson Education Inc, publishing as Pearson Prentice Hall ©2006
Examples of efforts to keep a species from becoming extinct:
___________________ (raised and protected in zoos until population is
stable, then returned to wild
CONSERVING BIODIVERSITY
Captive breeding
http://www.blackfootedferret.org/
End
This lesson connects to:
• Ecological Succession– Primary vs secondary
• Population Ecology Notes– Graphs, growth rate, factors that effect
population size
• Human and the Environment– DDT, Acid Rain, Ozone layer, biodiversity, global
warming
Key Vocabulary:- ozone layer - global warming- biodiversity - ecosystem diversity- species diversity - genetic diversity- extinction - endangered species- invasive species - conservation- renewable resource - soil erosion- nonrenewable resource - sustainable use- desertification - deforestation- aquaculture - smog- pollutant - acid rain- poachers