Human Impact on the Biosphere

1
Human Impact on the Biosphere
2
Human Impacts

• Humans are using energy and altering the
  environment at astonishing rates
• We are altering natural processes before we even
  understand them

3
Developing vs. Developed

• In developing countries, per capita resource use
  is high but growing, as is population size
• In developed countries, population growth has
  slowed but per capita resource use is already high

4
Pollutants

• Substances with which an ecosystem has had no
  prior evolutionary experience
• No adaptive mechanisms are in place to deal with
  them

5
Air Pollutants

• Carbon oxides
• Sulfur oxides
• Nitrogen oxides
• Volatile organic compounds
• Photochemical oxidants
• Suspended particles

6
Chemistry 101

• Acid anhydrides oxides of nonmetals
• CO2, NO2 and SO3
• These react with water to form oxyacids.
• CO2 H2O ---gt H2CO3 (carbonic acid)
• HNO3 and H2SO4 are also formed in
• the atmosphere

7
Acid Rain and Architecture

• On campus we have some architectural damage
  attributable to acid rain.
• The limestone lentils and pillars on the older
  building are dissolving away!
• H2SO4(aq) CaCO3(s) ? H2O(l)
  CO2(g) CaSO4(aq)

8
Industrial Smog

• Gray-air smog
• Forms over cities that burn large amounts of coal
  and heavy fuel oils mainly in developing
  countries
• Main components are sulfur oxides and suspended
  particles

9
Photochemical smog

• Brown-air smog
• Forms when sunlight interacts with components
  from automobile exhaust
• Nitrogen oxides are the main culprits
• Hot days contribute to formation

10
Thermal Inversion

• Weather pattern in which a layer of cool, dense
  air is trapped beneath a layer of warm air

cool air
warm inversion air
cool air
11
Cities Are Often Plagued with Thermal Inversions
12
Acid Deposition

• Caused by the release of sulfur and nitrogen
  oxides
• Coal-burning power plants and motor vehicles are
  major sources

13
Effect of Ozone Thinning

• Increased amount of UV radiation reaches Earths
  surface
• UV damages DNA and negatively affects human
  health
• UV also affects plants, lowers primary
  productivity

14
Ozone Thinning

• In early spring and summer ozone layer over
  Antarctica thins
• Seasonal loss of ozone is at highest level ever
  recorded

15
Ozone in Earths Atmoshere
16
Ozone Concentration from 1962 to 1996
http//www.igf.edu.pl/igf/atmosphere.htm
17
Recipe for Ozone Loss

• The polar winter leads to the formation of the
  polar vortex which isolates the air within it.
• Cold temperatures form inside the vortex cold
  enough for the formation of Polar Stratospheric
  Clouds (PSCs). As the vortex air is isolated, the
  cold temperatures and the PSCs persist.
• Once the PSCs form, heterogeneous reactions take
  place and convert the inactive chlorine and
  bromine reservoirs to more active forms of
  chlorine and bromine.
• No ozone loss occurs until sunlight returns to
  the air inside the polar vortex and allows the
  production of active chlorine and initiates the
  catalytic ozone destruction cycles. Ozone loss is
  rapid. The ozone hole currently covers a
  geographic region a little bigger than Antarctica
  and extends nearly 10km in altitude in the lower
  stratosphere

http//www.atm.ch.cam.ac.uk/tour/part3.html
18
Protecting the Ozone Layer

• CFC production has been halted in developed
  countries, will be phased out in developing
  countries
• Methyl bromide will be phased out
• Even with bans it will take more than 50 years
  for ozone levels to recover

19
Generating Garbage

• Developed countries generate huge amounts of
  waste
• Paper products account for half the total volume
• Recycling can reduce pollutants, save energy,
  ease pressure on landfills

20
Garbage Barge Solution
21
Landfills
22
Land Use

• Almost 21 percent of Earths land is used for
  agriculture or grazing
• About half the Earths land is unsuitable for
  such uses
• Remainder could be used, but at a high ecological
  cost

23
Green Revolutions

• Improvements in crop production
• Introduction of mechanized agriculture and
  practices requires inputs of pesticides,
  fertilizer, fossil fuel
• Improving genetic character of crop plants can
  also improve yields

24
Data From the UN
25
INDIA REACHING 1 BILLION ON AUGUST 15 NO
CELEBRATION PLANNEDLester R. Brown and Brian
Halweil

• Falling water tables are now also threatening
  India's food production.
• The International Water Management Institute
  (IWMI) estimates that withdrawals of underground
  water are double the rate of aquifer recharge.
• As a result, water tables are falling almost
  everywhere.

http//www.worldwatch.org/node/1656
26
Aquifer Depletion
http//www.uwgb.edu/dutchs/EarthSC202Notes/Grndh2o
.htm
27
Deforestation

• Removal of all trees from large tracts of land
• 38 million acres logged each year
• Wood is used for fuel, lumber
• Land is cleared for grazing or crops

28
Clear Cutting of Forests
29
Effects of Deforestation

• Increased leaching and soil erosion
• Increased flooding and sedimentation of
  downstream rivers
• Regional precipitation declines
• Possible amplification of the greenhouse effect

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Regions of Deforestation

• Rates of forest loss are greatest in Brazil,
  Indonesia, Mexico, and Columbia
• Highly mechanized logging is proceeding in
  temperate forests of the United States and Canada

32
A heavy duty tree chopper for cutting down trees
in a logging operation.
33
Rainforests
34
Forests Burning
35
Reversing Deforestation

• Coalition of groups dedicated to saving Brazils
  remaining forests
• Smokeless wood stoves have saved firewood in
  India
• Kenyan women have planted millions of trees

36
NAIROBI (AFP) Feb 23, 2005

• NAIROBI (AFP) Feb 23, 2005Kenyan Nobel peace
  laureate Wangari Maathai on Wednesday urged
  developing nations to help fight global warming
  and support the Kyoto Protocol on climate change
  by joining her tree-planting campaign.

37
Destroying Biodiversity

• Tropical rainforests have the greatest variety of
  insects, most bird species
• Some tropical forest species may prove valuable
  to humans
• Our primate ancestors evolved in forests like the
  ones we are destroying

38
Primates

• Many primate species are threaten or endangered.

39
Desertification

• Conversion of large tracts of grassland to
  desertlike conditions
• Conversions of cropland that result in more than
  10 percent decline in productivity

40
Global Desertification Vulnerability
41
The Dust Bowl

• Occurred in the 1930s in the Great Plains
• Overgrazing and prolonged drought left the ground
  bare
• 1934 winds produced dust storms that stripped
  about 9 million acres of topsoil

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Caption "Dust Over Texas." Huge boiling masses
of dust that blocked out the sun were common
sights in Texas during the Dust Bowl years. In
"To Hold This Soil", Russell Lord, 1938.
Miscellaneous Publication No. 321, U.S.
Department of Agriculture.
44
Human Tragedy
45
Ongoing Desertification

• Sahel region of Africa is undergoing rapid
  desertification
• Causes are overgrazing, overfarming, and
  prolonged drought
• One solution may be to substitute native
  herbivores for imported cattle

46
Linear dunes of the Sahara Desert encroach on
Nouakchott, the capital of Mauritania. The dunes
border a mosque at left (photograph by Georg
Gerster).
http//pubs.usgs.gov/gip/deserts/desertification/
47
Water Use and Scarcity

• Most of Earths water is too salty for human
  consumption
• Desalinization is expensive and requires large
  energy inputs
• Irrigation of crops is the main use of freshwater

48
Mean Annual Precipitation
49
Water Distribution
50
Negative Effects of Irrigation

• Salinization, mineral buildup in soil
• Elevation of the water table and waterlogging
• Depletion of aquifers

51
Salinization, mineral buildup in soil
http//waterquality.montana.edu/docs/methane/irrig
ation_suitability.shtml
52
Groundwater

• Aquifers - Porous layers of sand, gravel, or rock
  lying below the water table.
• Artesian - Pressurized aquifer intersects the
  surface. (Water flows without pumping)
• Recharge Zone - Area where water infiltrates into
  an aquifer.
• Recharge rate is often very slow.
• Presently, groundwater is being removed faster
  than it can be replenished in many areas.

53
Depleting Groundwater

• Groundwater is the source of nearly 40 of fresh
  water in the US.
• On a local level, withdrawing water faster than
  it can be replenished leads to a cone of
  depression in the water table,
• On a broader scale, heavy pumping can deplete an
  aquifer.
• Ogallala Aquifer
• Mining non-renewable resource.

54
Depleting Groundwater
55
Ogallala Aquifer

• Extends from southern South Dakota to central
  Texas
• Major source of water for drinking and irrigation
  
• Overdrafts have depleted half the water from this
  nonrenewable source

56
Ogallala Aquifer

• The Ogallala Aquifer within the boundaries of
  the North Plains Groundwater Conservation
  District is declining at an average of 1.74 feet
  per year (1,082,631 acre ft).
• The aquifer is cut off from
• natural recharge sources.

http//www.npwd.org/Ogallala.htm
57
Aquifer Problems
58
Sink Holes and Karst Topography
CaCO3 H2SO4 ? CaSO4 H2O CO2
http//www.soils.umn.edu/academics/classes/soil212
5/doc/1-snkle.htm
59
Water Pollutants

• Sewage
• Animal wastes
• Fertilizers
• Pesticides
• Industrial chemicals
• Radioactive material
• Excess heat (thermal pollution)

60
Groundwater Pollution
61
Wastewater Treatment

• Primary treatment
• Use of screens and settling tanks
• Addition of chlorine to kill pathogens
• Secondary treatment
• Microbes break down organic matter
• Tertiary treatment removes additional toxic
  substances rarely used

62
Sewage Treatment

• More than 500 pathogenic bacteria, viruses, and
  parasites can travel from human or animal
  excrement through water.
• Natural Processes
• In many areas, outdoor urination and defecation
  is the norm.
• When population densities are low, natural
  processes can quickly eliminate waste.

63
Municipal Sewage Treatment

• Primary Treatment - Physical separation of large
  solids from the waste stream.
• Secondary Treatment - Biological degradation of
  dissolved organic compounds.
• Effluent from primary treatment transferred into
  trickling bed, or aeration tank
• Effluent from secondary treatment is usually
  disinfected (chlorinated) before release into
  nearby waterway.

64
Municipal Sewage Treatment

• Tertiary Treatment - Removal of plant nutrients
  (nitrates and phosphates) from secondary
  effluent.
• Chemicals, or natural wetlands.
• In many US cities, sanitary sewers are connected
  to storm sewers.
• Heavy storms can overload the system, causing
  by-pass dumping of raw sewage and toxic runoff
  directly into watercourses.

65
Municipal Sewage Treatment
66
CSO Tunnels and Treatment Facilities (Atlanta, GA
2005)

• The tunnel is part of a storage and treatment
  system that involves capturing and storing
  combined sewer overflows. The overflows are
  stored in a large underground tunnel in bedrock
  similar to the rock that comprises Stone
  Mountain. When a storm is over, the captured CSO
  volume is conveyed to a separate treatment system
  for removal of pollutants and reduction of
  harmful bacteria with sodium hypochlorite
  disinfection followed by dechlorination with
  sodium bisulfite before discharge to receiving
  waters. The City is building two facilities, the
  West Area CSO storage tunnel and the East Area
  CSO underground linear storage facility to handle
  the overflows.

67
Milestone Completion Date for West Tunnel October
2007
These will collect storm water for treatment.
http//www.cleanwateratlanta.org/CSOTunnels/
68
Oxygen-Demanding Wastes

• Water with an oxygen content gt 6 ppm will support
  desirable aquatic life.
• Water with lt 2 ppm oxygen will support mainly
  detritivores and decomposers.
• Oxygen is added to water by diffusion from wind
  and waves, and by photosynthesis from green
  plants, algae, and cyanobacteria.
• Oxygen is removed from water by respiration and
  oxygen-consuming processes.

69
Oxygen-Demanding Wastes

• Biochemical Oxygen Demand - Amount of dissolved
  oxygen consumed by aquatic microorganisms.
• Dissolved Oxygen Content - Measure of dissolved
  oxygen in the water.
• Effects of oxygen-demanding wastes on rivers
  depend on volume, flow, and temperature of river
  water.
• Oxygen Sag - Oxygen levels decline downstream
  from a pollution source as decomposers metabolize
  waste materials.

70
Oxygen Sag
71
Water Wars?

• Per capita amount of freshwater available is
  decreasing
• International conflicts over water use and
  quality have already occurred
• Building dams or dumping pollutants effect
  countries downstream

72
Weiss Lake Organization Declares War!
Weiss Lake Improvement Association is the
environmental and ecological watchdog for Weiss
Lake and against Metro Atlanta from taking our
WATER. (Coosa River Drainage)
73
Energy Use

• Only 10 percent of energy used in developed
  countries is from renewable sources
• Less developed countries rely more heavily on
  renewable sources (primary biomass)

74
Fossil Fuels

• Coal, oil, natural gas
• Main energy source of developed countries
• Burning of fossil fuels contributes to global
  warming

75
http//faculty.virginia.edu/setear/courses/globwar
m/images.htm
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78
Oil

• Reserves are declining
• Many reserves are in ecologically fragile
  wilderness areas
• Environmental costs of extracting and
  transporting reserves from such areas are high

79
Total Energy Consumption
80
Domestic Product
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Oil and Gas Injection Wells

• Typically, when oil and gas are extracted, large
  amounts of salt water (brine) are also brought to
  the surface. This salt water can be very damaging
  if it is discharged into surface water.

83
Coal

• Extensive reserves exist
• Mining is very destructive
• Burning coal releases sulfur dioxides that cause
  acid deposition

84
Coal Strip Mining
http//en.wikipedia.org/wiki/Surface_mining
85
EPA targets utilities mercury pollution

• Coal-burning power plants in the United States
  now emit an estimated 48 tons a year of mercury,
  and the EPA rule aims to reduce that to 31.3 tons
  in 2010, 27.9 tons in 2015, and 24.3 tons in
  2020.
• Updated 303 p.m. ET March 15, 2005 (AP)

http//www.msnbc.msn.com/id/6448213/did/7185001
86
How Mercury Gets into the Food Chain
http//www.msnbc.msn.com/id/6448213/did/7185001
87
EPAs Cap and Trade Policy

• EPA sets yearly limits on mercury emissions
• Industry is assigned a quantity of tradable
  mercury emissions certificates
• These are bought and sold by power companies
  (bid/ask system).
• Some companies over pollute and some under
  pollute
• Each year the EPA reduces allowable emission
  quantities leading to an economic solution to
  pollution

88
Nuclear Energy

• Used extensively in some energy-poor developed
  countries
• Little support in the United States
• Emits fewer air pollutants than burning coal, but
  creates radioactive wastes
• Potential for meltdown

89
Chernobyl Accident - 1986

• Core meltdown at a nuclear power plant in the
  Ukraine
• 31 immediate deaths, radiation sickness and death
  for others
• Cloud of radiation spread by winds across Europe
• Long-term health impacts downwind

90
Map of Chernobyl Region
91
Nuclear Power in France

• When the Civaux nuclear power plant comes on
  line sometime in the next 12 months, France will
  have 56 working nuclear plants, generating 76 of
  her electricity. (Frontline)

http//www.icjt.org/npp/drzava.php?drzava8
92

• Some Alternatives

93
Solar-Hydrogen Energy

• Photovoltaic cells use sunlight energy to split
  water
• Hydrogen gas produced in this way can be used as
  fuel or to generate electricity
• Clean, renewable technology

94
Fuel Cells
95
Farmed Hydrogen

• Photobiological Hydrogen Production
• Aquatic algae bio-engineered to produce hydrogen
  gas rather than sugars via photosynthesis
• Place algae in a clear tube, reduce sulfur, place
  in sunlight, and collect the hydrogen!

96
Hydrogen from Algae
Chlamydomonas reinhardtii
97
Shec labs System

• Mirror array focuses sunlight on a hydrogen
  generator (850 C)
• Waste gases (methane, CO2, etc) are heated and
  converted to hydrogen gas. Hydrogen gas (plus O2)
  is used to power fuel cells.

www.shec-labs.com/press/images.php
98
Wind Energy

• An indirect use of solar energy
• Wind farms are arrays of turbines
• Can supplement needs of some regions but is not
  dependable enough on it own

99
Giant wind turbines at Aapua, Sweden
http//www.xahlee.org/Whirlwheel_dir/windturbine.h
tml
100
San Gorgonio Field Near Palm Springs, CA
101
Overview of Wind Energy in California

• the year 2004, wind energy in California
  produced 4,258 million kilowatt-hours of
  electricity, about 1.5 percent of the state's
  total electricity.
• According to the Electric Power Research
  Institute, the cost of producing wind energy has
  decreased nearly four fold since 1980. The
  levelized cost of energy from wind turbines in
  1993 was about 7.5 cents per kilowatt/hour. With
  current wind research and development efforts,
  the Energy Commission estimates that newer
  technologies can reduce the cost of wind energy
  to 3.5 cents per kilowatt-hour.

http//www.energy.ca.gov/wind/overview.html
102
Electricity Costs (2003)
103
Fusion

• Energy is released when atomic nuclei fuse
• This process produces solar energy
• Attempts to mimic this process on Earth require
  use of lasers, magnetic fields
• Not yet a commercially viable energy source

104
Fusion Reaction

• Note Fusion tutorial available at website below.

http//hif.lbl.gov/tutorial/tutorial.html
105
Changes in the World of Life

• Adaptations of species have changed the
  environment
• Photosynthetic organisms that arose during the
  Proterozoic altered the atmosphere by adding
  oxygen
• Change is natural

106
Humans and Change

• Unlike previous species, human have the capacity
  to observe and make decisions about the changes
  they bring about.
• A couple of examples of using misplaced
  resources.

107
Gas for the Greenhouse

• "By transporting CO2 by pipeline from the Shell
  refineries in Pernis to the cultivators in the
  Westland, the emission of greenhouse gas can be
  greatly reduced. At the same time, the farmers
  can save a lot of money there is no more need
  for them to produce their CO2 themselves".

http//www.radionetherlands.nl/features/science/05
1107rf
108
OCAP Waste CO2 Used in Greenhouses
6 CO2 6 H2O sunlight ?
C6H12O6 6O2
109
Anything Into OilChanging World Technologies,
Inc.
Carthage, Missouri, turkey plant accumulates
1.3 million gallons a day of turkey grease,
guts, fat, and feathers that is stored in
lagoons and sent to waste treatment
facilities Estimated production of fuel oil,
500 barrels a day.
http//www.perc.org/perc.php?id290
Twenty tons of slaughterhouse turkey parts,
freshly dumped by a truck, await processing into
oil, gas, and minerals at the thermal conversion
process plant in Carthage, Missouri. When the
plant reaches full capacity in the fall, it will
process 10 dump trucks of leftovers, one tanker
truck of blood, and one tanker truck of
discarded restaurant grease every 24 hours.