Human Impact on the Biosphere Those Pesky Humans

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

Human Activity and the Carbon Cycle • We are releasing CO 2 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.

FACTS WE KNOW Global temperatures have increased 0. 5 -1. 0°F since the late 19 th century. http: //content. answers. com/main/content/wp/en/thumb/8/87/280 px-Instrumental_Temperature_Record. png

FACTS WE KNOW The snow cover in the Northern Hemisphere and floating ice in the Arctic Ocean have decreased. 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? http: //healthandenergy. com/images/global 2. gif Cartoon from Brookings Register Coastal flooding

What’s so bad about warming up a little? http: //en. wikipedia. org/wiki/Hurricane_Katrina More severe storms http: //i. a. cnn. net/cnn/2005/WEATHER/08/25/tropical. storm/story. katrina. 915 p. jpg

http: //www. claybennett. com/pages/ocean_temps. html What’s so bad about warming up a little? Changes in Gulf Stream http: //zfacts. com/meta. Page/lib/Atlantic_conveyor. jpg

What’s so bad about warming up a little? Weather extremes Heat waves and drought Brookings Register

What’s so bad about warming up a little? http: //www. metro. co. uk/news/article. html? in_article_id=35720&in_page_id=34 Changing habitats means loss of species

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

THE OZONE LAYER

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 been depletion monitoring the ______ of ozone in our atmosphere and have discovered a hole in the ozone layer Antarctica over ______. http: //ozonewatch. gsfc. nasa. gov/facts/hole. html

What’s the cause of Ozone Depletion? Chlorofluorocarbon (CFC’s) molecules _______ released from air conditioners, aerosol spray cans, fire extinguishers, and industry destroy ozone ________ http: //www. atm. ch. cam. ac. uk/tour/part 3. html

THAT’S WHY. . . http: //www. roundrocktexas. gov/images/spray_cans_large. jpg AEROSOL _______spray cans no longer contain CFC propellants. AIR CONDITIONERS Gases in __________ refrigerators are collected and _______ and recycled.

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

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

3. Which of the following is a side effect of acid rain. A. Large animals B. Cancer C. Damage to trees D. Rusty cars • The ozone layer protects Earth by absorbing – • A. cosmic dust • B. solar heat • C. ultraviolet radiation • D. white-light frequencies

BIOACCUMULATION

Biological Magnification/ Bioaccumulation • Biological magnification/ Bioaccumulation occurs when pesticides build up in animal tissue as you move up a food chain.

Example: _____ DDT 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 MOSQUITOES ________ http: //www. michigan. gov/images/mosquito_65147_7. jpg

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: //imagecache 2. allposters. com/images/pic/ARG/21033~Parachute-Cats-Posters. jpg

DDT in the United States DDT causes birds to lay fragile eggs with ______ shells so eggs would break when sat on. American Bald Eagle was declared endangered in 1967. It has since been “threatened” reclassified as ___________

THREATENING BIODIVERSITY

The sum of the genetically based variety of all the organisms in the BIODIVERSITY biosphere = __________ stability to the Biodiversity gives _____ ecosystems that we are so dependent productivity and on, enhances their ______, provides an important source of new medicine and other _____ food products _____, .

Threatening Biodiversity There are 3 basic ways that human actions threaten biodiversity: • Introducing non-native species • Hunting organisms to extinction • Habitat destruction

BIODIVERSITY THREAT One of most important threats to biodiversity come from apparently harmless plants or animals that humans transport into new habitats = INVASIVE SPECIES ___________ PREDATORS New habitats don’t have ______ and parasites that control the population in their native habitats, so invasive species INCREASE rapidly. populations _______

EXAMPLES OF INVASIVE SPECIES http: //psephos. adam-carr. net/countries/a/australia/images/australiamap. gif 24 rabbits turned loose for hunting in 1859 in Australia, reproduced at such a rapid rate they have taken over the continent. It is still a major problem and rabbit diseases have been purposely introduced to try to control the population http: //en. wikipedia. org/wiki/Image: Wild_rabbit. jpg

Hunting Organisms to Extinction

Habitat Destruction Development of natural areas for cities or agriculture http: //www. simtropolis. com/idealbb/files/SG_Shopping. Center. JPG

BIODIVERSITY THREAT http: //www. lubee. org/images/about-threats-1. jpg Tropical rainforests are disappearing at a rate of about 80 acres per minute.

http: //www. abc. net. au/newsitems/200506/s 1384632. htm BIODIVERSITY THREAT Changes in Brazilian rainforest over 30 years The tropical rainforests once covered more than 14% of the earth's total land surface, but now cover less than 6%.

Can lead to species Extinction

Endangered Species

Worlds Rarest Animal

ONCE THOUGHT EXTINCT

WHAT CAN WE DO? ? ?

WHAT DOES IT MEAN? REMEMBER! Everything is connected. BIODIVERSITY is a measure of the

CONSERVING BIODIVERSITY Examples of efforts to keep a species from becoming extinct: Captive breeding __________ (raised and protected in zoos until population is stable, then returned to wild http: //www. blackfootedferret. org/

Practice Questions • A species that enters an environment where it has not lived before is called an • A. endangered • B. invasive • C. Threatened • D. Predator • A species whose population is declining so rapidly that it could become extinct is • A. non-native • B. fragmented • C. endangered • D. Invasive

Ecology Study Guide • Chapter 3 study guide questions • Notes on Energy Flow – Food webs – Food Chains – Energy Pyramids – Biomass Pyramids

§ Cycles – Water – Carbon – Nitrogen § Biological communities § Biomes

• 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