1. Ecosystem Recycling
“each substance travels from the abiotic portion of the environment into living things and back again”

2. The Water Cycle Continuous process of recycling earth’s water
- evaporation
- precipitation
- runoff
- infiltration
- transpiration
- condensation

3. Human Impact on Water Cycle
Acid Deposition – pH of ~5.5
Formation
a. NOx and SOx released into atmosphere
SOx – coal burning power plants
NOx – automobile emissions
b. combine with molecules in atmosphere and turn into nitric
acid and sulfuric acid lowering the pH of precipitation
c. reduced in US due to Clean Air Act

4. Effects
a. lowers pH of water
b. decrease in species diversity
d. erode statues, monuments, and buildings
e. harm tree species (NC mtns – Mount Mitchell)
- decrease photosynthetic activity in leaves
- leaches out important nutrients from soil

5. The Carbon Cycle
Cellular respiration, combustion (burning), and decomposition of organic matter are major sources of CO2
By burning fossil fuels, we increase the amount of CO2 in the atmosphere
Carbon source (release of C) v Carbon sink (storage of C)

7. Human Impact on CO2 Global Climate Change
a. “changes in global climate”
b. natural causes
ex) El Nino
- 3-7 years, alters patterns in temperatures and precipitation
c. anthropogenic (human causing)
ex) fossil fuel combustion, deforestation
→ Global Warming
* rising of sea levels, flooding, beach erosion

8. Greenhouse Gas Effect

9. 2 most common gases in atmosphere
a. N2 (78%) and O2
b. not greenhouse gases
Greenhouse Gases
a. H2O – water vapor
b. CO2 – carbon dioxide
c. N2O – nitrous oxide
d. CFCs - chlorofluorocarbons
e. CH4 - methane

10. Sources of Greenhouse Gases * natural sources
Volcanic eruptions
CO2, ash (absorbing sunlight)
Decomposition and digestion
CH4 (wetlands, termites)
Denitrification
N2O in low oxygen situations
Evaporation
H2O (land)
Evapotranspiration
H2O (plants)

11. Anthropogenic Source Gas Fossil Fuels CO2 Agricultural practices
CH4 and N2O
Deforestation
Landfills
CH4
Industrial production of chemicals
CFCs
-phased out by Montreal Protocol
- HCFCS introduced but still have high Greenhouse Warming Potential

12. Changes in CO2 and Global Temperatures
Increasing CO2 Concentrations
a. Charles David Keeling
1. Mauna Loa Observatory
2. CO2 levels vary seasonally and
increase from year to year
- seasonal (photosynthesis)
- annual increase (fossil fuels
and deforestation)

13. Ozone Depletion
1. CFC’s get into the atmosphere and “eat” the ozone
2. found in propellants of aerosol cans and coolants of air
conditioners and refrigerators
3. banned by the Montreal Protocol
4. VERY PERSISTANT
5. leads to increased exposure to harmful UV-rays leading
to increased skin cancer and cataracts

14. The Nitrogen Cycle
All organisms need nitrogen to make proteins and nucleic acids
Nitrogen fixing bacteria transform nitrogen through nitrogen gas (N2) → ammonia (nitrogen fixation) → nitrite (nitrification) → nitrate (NO3-which plants use).
Ammonification
Lighting and volcanoes – direct source of NO2 and NO3

16. Human Impact Eutrophication
a. runoff of nitrogen and phosphorus (fertilizers)
into nearby water
b. algal blooms → excessive growth of algae
c. algae dies consuming available oxygen in water
(dead zones)
Waste Lagoons – Hog Farms
a. excessive nitrogen
b. contaminate drinking water

17. Natural Resources and Pollution

18. Natural Resources “useful things found in the environment” Two Types
1. Renewable – can be replenished
ex) sunlight, air, plants, animals
2. Nonrenewable – cannot be
replenished
ex) metal, fossil fuels, minerals, water
Conservation – process of preserving natural resources and using them wisely

20. Pollution “unwanted things in the environment”
ex) toxic waste, smoke/exhaust
2 Classifications
1. Biodegradable – can be decomposed
2. nonbiodegradable – cannot be decomposed

21. Sources of Pollution Agriculture
A. pesticides → DDT → enters water → protists absorb it → eagles and falcons eat the fish → DDT causes thin shells when birds lay their eggs
* bioaccumulation

22. Industry
A. dumping things and smoke stacks
B. two laws
- Clean Air Act → regulates criteria air pollutants
- Clean Water Act → regulates pollution in local water
- Safe Drinking Water Act → protects our drinking water