1. Human Impact on the Environment, Part 1

2. Acid Rain Burning coal sends smoke high into the atmosphere
The smoke contains lots of sulfur
Sulfur + water vapor = sulfuric acid
Rain and snow carry sulfuric acid back to Earth as acid rain

3. Harmful effects of acid rain
Loss of aquatic species diversity
Decline in amphibians - young cannot develop properly in acidic water
Destruction of trees due to lower pH levels in ground water
7 is heaven, below is woe!

4. Ozone Layer Ozone is Earth’s shield against ultraviolet radiation
Chlorofluorocarbons (CFCs) are chemicals that destroy ozone
High over the Poles, where it is very cold, CFCs stick to frozen water vapors and catalyze the conversion of ozone (O3) into oxygen (O2)

5. Agreements to end CFC production
The US and 92 other countries signed agreements in the early 1990s
Vast majority of CFCs that have been manufactured have not yet reached the upper atmosphere
Due to great stability, CFCs already in the atmosphere will remain there and continue to destroy ozone for more than a century

6. Places CFCs were often used:
Propellant in aerosol dispensers
Coolant in refrigerators and air conditioners
Foaming agent in the production of plastic foam cups and containers

7. How does depletion of the ozone layer affect human health?
Ozone depletion will increase the number of people who develop:
Cataracts
Skin cancer
Retinal Cancer

8. Global Warming CO2 in the atmosphere influences global temperatures
The chemical bonds in CO2 absorb solar energy, trapping heat in the atmosphere

9. How can we reduce CO2 production?
Reducing the burning of fossil fuels such as coal, oil, and natural gas
Fossil fuels are the remains of ancient organisms that have been transformed by pressure and heat into carbon-rich substances
When fossil fuels are burned, carbon atoms combine with oxygen atoms yielding carbon dioxide

10. Effects of deforestation

11. Reducing deforestation
Over the last 50 years, half the world’s rain forests have been destroyed for pasture and farmland or for timber
Loss of species
Loss of genetic diversity
Loss of potential cures for disease
Loss of nutrients in soil
Loss of livelihood for native peoples

12. Non-replaceable Resources
Loss of top soil
repeatedly turning over soil to eliminate weeds
allowing animals to overgraze
practicing poor land management; wind and rain remove more and more
Unnecessary depletion of ground water
watering lawns
washing cars
running fountains

13. Pollution
Since the Industrial Revolution, society has assumed that the environment can “absorb” pollution
The most disastrous incidents of pollution involve industrial chemicals that are toxic or carcinogenic

14. Examples of Disastrous Events
In the early 1970s, Lake Erie was so polluted from large amounts of industrial chemicals that few fish could survive there.
The Exxon Valdez ran aground on the Alaska coast in 1989, spilling 11 million gallons of oil and killing thousands of marine animals.

15. Population Growth
The development of agriculture provided new and more dependable sources of food
The spread of better sanitation and improved medical techniques has lowered the death rate

16. Growth Rates
The annual worldwide population increase is about 1.7 percent
At that rate, the world’s population will double in 40 years
The annual rate of growth is not divided equally among countries
America is 0.8 percent
Kenya is 3.7 percent

17. How can we solve the world’s problem of population growth?
Thailand: families encouraged to have only 2 children; reduced the growth rate from 3.2% to 2.4% in 30 years
Mexico: the number of children per family has dropped from 5 to less than 3 in last 30 years
Other countries:
Family planning
Financial benefits for fewer children

18. Some food for thought:
Unlike most organisms, humans often use more resources than are needed for survival.
The higher the standard of living, the lower the carrying capacity becomes.
The amount of resources available to support the human population is finite
The more resources each individual uses, the fewer the number of people who can survive on these resources becomes.
Proceed to Part 2

19. Human Impact, Part 2

20. Solving Environmental Problems

21. Reducing use of landfills
Over 130 million tons of trash is discarded in landfills each day.
Of America’s 20,000 landfills, over 16,000 have reached capacity and are closed.
70% of this trash is recyclable.

22. Americans alone produce over a half a ton of garbage per person every year – about 3.5 pounds per day.
In your lifetime, you will throw away 600X your adult weight in garbage – a legacy of almost 90,000 lbs that you will leave your children.

23. Recycle
Making aluminum from recycled cans uses 90-95% less energy than making it from raw materials and reduces related air pollution by 95%.
Our nation throws away enough aluminum every 3 months to rebuild our entire commercial air fleet.
Between 50-60% of the aluminum cans used in America are recycled.

24. What you can do to help: Your lifestyle affects the environment
Recycle cans, bottles, plastic, & newspapers
Use alternative forms of transportation:
ride a bike or walk
take public transportation
car pool
Having a sound knowledge of ecology is the essential tool that you will need to help

25. Public Education Inform the public
Explain the problem in understandable terms
Present alternative actions
Explain probable costs and results

26. Political Action
The public, through its elected officials, selects and implements a course of action
Exercise your right to vote
Write to elected officials
Support special interest groups

27. Reduce, Reuse, Recycle
Don’t TRASH our world