1. Human Impacts on the Environment
Environmental Science

2. Pollution–any environmental contaminant that causes damage or harm
air
land
water

3. Types of pollutants
Chemical– car exhaust, oil, smoke stacks, pesticides
Solid– litter, trash, soot, plastic
Biological– sewage, decaying material
Thermal– excess heat in an aquatic habitat harms the ecosystem
Radiation– radioactive waste

4. Overpopulation One major cause is lack of education.
Effects
Overuse/misuse of resources
Encroachment on natural habitats
Increased pollution
Failed infrastructure
One major cause is lack of education.
Earth’s human population in 2013– 7 billion
Estimated carrying capacity 4-16 billion

5. Habitat Destruction Overuse Group D Pollution First bullet point here
Encroachment
Overuse
Group D
First bullet point here
Second bullet point here
Third bullet point here

6. Deforestation Approximately 18 million acres are lost each year
Reasons
timber harvest
commercial or residential development
create farmland
Effects
loss of biodiversity
loss of rare or currently unknown species
increased erosion
Increased carbon dioxide in atmosphere
Deforestation

7. Desertification
Drought is a natural cause Humans contribute by allowing overgrazing and irresponsible farming Erosion by wind and water are the most significant effects

8. Biodiversity– the number and variety of species in an ecosystem Biodiverse ecosystems are healthier
Anything that threatens biodiversity, causing species to become threatened, endangered, or extinct, weakens the ecosystem.

9. Threatened Species
The species’ numbers are in decline, and the species is likely to become endangered.

10. Endangered species
The numbers are so low that the species is likely to become extinct without immediate protective measures

11. Extinction– if a species has not been present in 50 years
Dodo
Extinction– if a species has not been present in 50 years
Chinese river dolphin
Root-spine palm
Stephen’s Island wren

12. Biodiversity
Humans benefit from biodiversity through
Medicines
Agriculture
Industry
Ecosystems are interconnected in many ways (it’s not always obvious)
Biodiversity increases sustainability
How many species have become extinct before they were even discovered?
How much biodiversity has been lost, while still unknown?

13. Modern impact of humans on environment began during the industrial revolution
Drastic increase in use of fossil fuels (coal, oil, natural gas)
Land damage from mining those fossil fuels
Rapid urbanization (led to pollution, waste, lack of infrastructure, diseases)
200+ years of pollution (air, land, and water)
Extreme increase in greenhouse gas emissions

14. Individuals can evaluate their own carbon footprint– a measure (in pounds) of each person, group, or company’s emissions of greenhouse gases
Anything that uses electricity– heating/cooling, household lighting, electronics
Using your car
Waste products

15. Conservation & Sustainability
Prevent pollution
Recycling
Reduce carbon footprint
Limit consumption
Limit waste
Reduce use of fossil fuels
Individual or group efforts to preserve or protect the environment– biodiversity & natural resources

16. Partial History of Environmentalism in the US
Early 1900s– Theodore Roosevelt enacted the American Antiquities Act (established National Parks & other preserved wildlife areas)
1936– National Wildlife Federation founded
1962—Rachel Carson publishes Silent Spring
1963– Clean Air Act
1965– Water Quality Act
1970– First Earth Day
1972- Clean Water Act
1980– Superfund
1990-National Environmental Education Act
2001– U.S. rejects Kyoto Protocol (emissions control)

17. Climate change– the big debate
Are atmospheric carbon dioxide levels rising?
Is Earth’s average temperature increasing enough to cause a difference?
Is this a naturally-occurring phenomenon?
Is this a catastrophe that humans have caused?

18. Effects of climate change
Shrinking glaciers
Loss of sea ice
Rising sea level
Longer, more severe heat waves & droughts
Increased risk of fires & floods
Stronger storms
Change in weather patterns