1. Human Impact on the Environment

2. Industrial Revolution
A. Rapid Human Population Growth has had a major negative impact on the environment
Industrial Revolution
Medical Advancements
Farming Advancements

3. 1. Estimated population size as per the U.S. Census Bureau:
a. World: 7.2 billion
Global Population Growth
Population size
Year
Doubling Time
1 billion
4 billion
2 billion
8 billion
1975
1850
1930
2017
all history
80 years
42 years
45 years
b. United States: 319 million
2. Overpopulation is at the root of nearly all environmental problems such as pollution and resource depletion.

4. B. Biodiversity
1. Number of different organisms in an ecosystem
2. Increased biodiversity 
a. Increased Stability
b. Genetic variation for survival during environmental changes
c. Potential medicines & food crops

5. C. Water Problems
1. Thermal Pollution: nuclear power plants dump hot waste water into rivers/lakes  decreases dissolved oxygen  fish suffocate/die

6. Nuclear

9. Chernobyl, Ukraine
1986

10. Fukushima, Japan
2011

13. 2. Fertilizers: supply nutrients to help plants grow; runoff into streams/rivers Rapid plant/algae growth (Algal Bloom/Eutrophication)
 Lots of algae die  Lots of decomposers deplete oxygen  Fish suffocate/die

16. 3. Pesticides – used to kill insect pests (Ex. DDT)
a. May also harm/kill harmless insects/animals
b. Can be taken in by producers and then passed through a food chain
 Biomagnification (chemicals increase in concentration as they pass from one trophic level to the next)

18. D. Land Problems
1. Littering of Nonbiodegradable Wastes – cannot be broken down (plastic, aluminum, glass, diapers)

19. 2. Deforestation: Removal of Forests
 Increased CO2 levels ( Global Warming)
 Erosion (removal of soil by wind/water)
 Habitat Destruction  Decreased Biodiversity

20. 3. Exotic/Invasive Species
Organisms imported into an area from another region
No natural predators  Reproduce Rapidly  Overpopulation  Out-competes native species  Disrupts food chain/Decreases biodiversity
Examples: Purple loosestrife plant, Japanese beetle, gypsy moth, zebra mussels

21. 4. Overhunting/Overfishing/Direct Harvesting (removal of specific organisms)
Endangered Species (may soon completely disappear)
Could lead to the extinction of that species
Passenger
Pigeon
Dodo Bird

22. E. Air Problems
CFCs (Chlorofluorocarbons) – used in aerosols, refrigerators, air conditioners
 Ozone Depletion
*Allows more UV radiation to reach Earth’s surface (causes skin cancer)

26. a. Air Pollution  lung cancer, heart disease, asthma
2. Burning of fossil fuels (coal, oil, natural gas) by cars and factories
a. Air Pollution  lung cancer, heart disease, asthma
b. Increased greenhouse gases (i.e. CO2) causes Global Warming (Global Climate Change)

27. b. Increased greenhouse gases (i. e. CO2)
b. Increased greenhouse gases (i.e. CO2) causes Global Warming (Global Climate Change)
 changes in climate/weather patterns (warmer environments that organisms can’t live in, more frequent intense storms, drought, wild fires,)
 polar ice caps & glaciers melt  rise in sea level (flooding) & habitat loss
 sea ice melts  polar bears can’t reach their prey & die from starvation

30. 1909
2004
McCarty Glacier, Alaska

31. 1909
2000
Toboggan Glacier, Alaska

34. c. Release of Sulfur Dioxide & Nitrogen Dioxide causes Acid Rain (rain with low pH)
Harms aquatic ecosystems
Harms plants
Damages limestone & marble buildings

35. F. Ways to Fix the Problems
1. Educate the public
2. Tradeoffs: Costs vs. Benefits
3. Environmental Laws:
Protected Habitats
Regulate Overhunting/Overfishing
Control/Limit Pollution
Prevent importation of foreign species
4. Reforestation – replant trees

36. 5. Conservation of Nonrenewable (fossil fuels) and some Renewable (trees) Resources
Reduce, Reuse, Recycle
Alternate (renewable) energy sources – solar, wind, water, etc.

38. Geothermal

39. Alternative Energy Sources for Electricty Production
Pros
Cons
Potential meltdown can
irradiate an area making
it inhospitable (ex. Chernobyl)
Dangerous nuclear waste
Efficient
High-yielding
Nuclear Power
Renewable
Free energy source
No pollution
Currently….
Solar
(photovoltaic)
Not very efficient
Expensive technology
Renewable
Free energy source
No pollution
Large footprint
Aesthetically displeasing
Migratory birds may die
Wind
Efficient and renewable
Free energy source
No pollution
Hydroelectric
(Dams)
Disrupts river ecosystems
No longer economical
Renewable
Free energy source
No pollution
Can only use near
thermal “hot spots”
(for high energy yield)
Geothermal

40. controlling insect populations without using pesticides
6. Biological Pest Controls -
controlling insect populations without using pesticides
a. Release natural predators
b. Pest-resistant plants
c. Insect Traps (Pheromones)
d. Release sterilized male insects