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