aim: how have humans impacted the earth?

JUNE 2008One birth every.................................. 7 seconds One death every.................................. 13 seconds One international migrant (net) every............ 29 seconds Net gain of one person every..................... 10 seconds

World 6,785,186,332

12:15 GMT (EST+5) Jun 08, 2009

U.S. 306,617,138

Human population growth is the root of many environmental issues.

•Overuse of non-renewable resources

•Destruction of habitats

•Deforestation

•Pollution

•Atmospheric changes

Increased industrialization demands more resources and energy use.

This has positive and negative effects on humans and ecosystems

Industrialization

Eutrophication is caused by enrichment of the aquatic biomes from fertilizers and wastes. (too much of a good thing)

Eutrophic Lake

•reduces the content of water in the soil and groundwater as well as atmospheric moisture•reduces soil cohesion, so that erosion, flooding and landslides often ensue. •reduces biodiversity •reduces possible medicinal advances•Adds to global warming

Soil, Thermal, Noise, LightSoil, Thermal, Noise, Light

Acid Precipitation is caused mainly by combustion of fossil fuels.

Acid rain cause the rapid erosion of statues and destruction of lakes

Average pH profiles in U.S. in 1999

Why is the eastern U.S. so high in acid rain? Air Pollution

PART II

DO NOW:Which animal has modified

ecosystems more than any other animal and has had the greatest

negative impact on world ecosystems?

1. gypsy moth 2. zebra mussel 3. human 4. shark

A major reason that humans have negatively affected the environment in

the past is that humans have

1. frequently lacked an understanding of how their activities affect the environment

2. passed laws to protect certain wetlands 3. attempted to control their population

growth 4. discontinued the use of certain chemicals

used to control insects

Green House Effect: Climatic change caused by increasing Greenhouse Gases

(carbon dioxide)

Which factor is a major cause of global warming?

1. increased burning of fuels 2. increased number of green plants 3. decreased mineral availability 4. decreased carbon dioxide in the atmosphere

Introduced Species: species from another ecosystem is a problem because there usually

aren’t natural checks May reduce Biodiversity!

Nile perch (Lake Victoria) Brown tree snake (Guam)

Argentine ants Caulerpa (seaweed)

Zebra Mussels in the Great LakesHas reduced Biodiversity!

Imported animal species often disrupt an ecosystem because in their new environment, they will most likely

1. eliminate the genetic variation of the autotrophs

2. increase the number of mutations in the herbivores

3. have no natural enemies 4. be unable to produce offspring

The importation of organisms such as the Japanese beetle and gypsy moth to areas where they have no natural

enemies best illustrates1. the use of abiotic factors to reduce pest

species 2. the selection of species to mate with each

other to produce a new variety 3. attempts by humans to protect extinct

species 4. a human activity that disrupts existing

ecosystems

African elephant tusks consist of high-quality ivory. In recent years, the

elephant population in certain African wildlife preserves has decreased. This

decrease is most likely due to

1. air pollution 2. human exploitation 3. biocide use 4. importation of Japanese beetles

Trade-offs:

solving environmental issues involves trade-offs. There are

always costs associated with social decisions.

Solar Energy reduces dependence on fossil fuel but it is expensive.

Nuclear Power provides electricity without fossil fuel but generates nuclear wastes.

Societies must decide on proposals and assess risks, costs, benefits and trade-offs.

SUMMARY

Which situation has had the most negative effect on the ecosystems of Earth?

1. use of air pollution controls 2. use of natural predators to control insect

pests 3. recycling glass, plastic, and metals 4. increasing human population