1. THE HUMAN IMPACT ON EARTH’S ENVIRONMENT
Grotzinger • Jordan
Understanding Earth
Sixth Edition
Chapter 23:
THE HUMAN IMPACT ON EARTH’S ENVIRONMENT
© 2011 by W. H. Freeman and Company

2. The Human Impact on Earth’s Environment
Chapter 23
The Human Impact on Earth’s Environment

3. About Human Impact
Human population is immense and resources are being consumed at an astounding rate.
Balancing resource usage versus environmental protection is challenging.
It remains to be seen if we can use our resources for sustainable development.

4. Lecture Outline Civilization as a global geosystem
2. Fossil-fuel resources
3. Alternative energy resources
4. Global change

5. Lecture Outline
5. Earth system engineering and management

6. 1. Civilization as a Global Geosystem
Civilization exists at the thin interface between the climate, plate tectonic, and geodynamic systems.
Human civilization has profoundly altered the planet, especially in the last 200 years.

7. Civilization as a Global Geosystem: Human Population Growth

8. Human population increase now doubles every 47 years.
1. Civilization as a Global Geosystem
Human population increase now doubles every 47 years.
Humans now alter the global environment on a scale that is staggering compared to natural processes.

9. ● Example of human’s changes ● one third of forests cleared
1. Civilization as a Global Geosystem
● Example of human’s changes
● one third of forests cleared
● humans move more soil and rock
than all natural processes
● dams and reservoirs now trap 30% of all river sediments
● coolants have damaged the critical ozone layer
● carbon dioxide levels up by 40%

10. ● Natural energy resources ● Renewable energy resources
1. Civilization as a Global Geosystem
● Natural energy resources
● Renewable energy resources
● biomass (wood burning)
● Non-renewable energy resources
● fossil fuels (oil, gas, coal)

11. ● After 1850: the rise of the U.S. fossil fuel economy.
1. Civilization as a Global Geosystem
● Before 1850, most U.S. energy
was from wood burning.
● After 1850: the rise of the U.S.
fossil fuel economy.
● by 1900, coal was ~ 70%
● by 1950, fossil fuel was ~ 90%

12. ● Global energy consumption ● quad = 1015 Btus
1. Civilization as a Global Geosystem
● Global energy consumption
● quad = 1015 Btus
● U.S. in 2004 = 100 quad
● global (2004) = 440 quad
● global (2020) = 600 quad

13. Civilization as a Global Geosystem:
U.S. Energy Consumption

14. Civilization as a Global Geosystem:
U.S. Energy System

15. Civilization as a Global Geosystem: Projected Energy Consumption

16. ● Global carbon flux from energy production
1. Civilization as a Global Geosystem
● Global carbon flux from energy
production
● Huge increase from natural rates of carbon transfer
● Carbon economy
● Carbon dioxide is a
greenhouse gas

17. ● Fossil fuel resources and reserves ● Resources – have been
discovered
● Reserves remain in the Earth

18. 2. Fossil-Fuel Resources: Remaining Nonrenewable World Energy

19. ● May move to reservoirs ● Raw petroleum: crude oil
2. Fossil-Fuel Resources
● How oil and gas forms
● Formed in source beds
● May move to reservoirs
● Raw petroleum: crude oil
● Natural gas: methane

20. ● Crude oil forms under limited conditions called the “oil window”
2. Fossil-Fuel Resources
● How oil and gas forms
● Crude oil forms under limited
conditions called the “oil window”
● Crude oil resides in porous rock
called an oil reservoir (oil trap)
● Similar conditions apply to gas

21. 2. Fossil-Fuel Resources:
Traps for Oil and Gas

26. ● Distribution of oil resources ● Middle East 2/3 of oil
2. Fossil-Fuel Resources
● Distribution of oil resources
● Middle East 2/3 of oil
● U.S. Gulf Coast and
Caribbean
● Other areas

27. 2. Fossil-Fuel Resources: Estimated World Oil Reserves

28. ● Oil production and consumption ● 2004-2008, 30 billion barrels/yr
2. Fossil-Fuel Resources
● Oil production and consumption
● , 30 billion barrels/yr
● U.S. consumes three times what it produces
● U.S. trade deficit is largely due to oil importation

29. ● Oil production and consumption ● Hubbert’s peak shows the
2. Fossil-Fuel Resources
● Oil production and consumption
● Hubbert’s peak shows the
time of maximum production
● U.S. peak in 1970
● Global peak very soon

30. 2. Fossil-Fuel Resources: U.S. Oil Production and Hubbert’s Peak

31. 2. Fossil-Fuel Resources: Projection of World Oil Production

32. ● Oil and the environment ● oil spills during production
2. Fossil-Fuel Resources
● Oil and the environment
● oil spills during production
● oil spills during transportation
● contribution of carbon dioxide
to the atmosphere

33. ● Natural gas and the environment ● methane is a greenhouse gas
2. Fossil-fuel Resources
● Natural gas and the environment
● methane is a greenhouse gas
● easy transportation (pipelines
and LNG ships)
● contribution of carbon dioxide
to the atmosphere

34. ● Coal and the environment ● mining pollution problems
2. Fossil-Fuel Resources
● Coal and the environment
● mining pollution problems
● burning and acid rain problem
● contribution of carbon dioxide
to the atmosphere

35. ● Types of coal (by % carbon) ● lignite (70% carbon) ● subbituminous
2. Fossil-Fuel Resources
● Types of coal (by % carbon)
● lignite (70% carbon)
● subbituminous
● bituminous
● anthracite (90% carbon)

36. 2. Fossil-Fuel Resources:
Coal Fields of the U.S.

37. 2. Fossil-Fuel Resources: Typical Coal Strip Mine
West Virginia

38. ● Unconventional fossil fuels ● tar sands ● oil shales
2. Fossil-Fuel Resources
● Unconventional fossil fuels
● tar sands
● oil shales

39. Thought questions for this chapter
In what ways does Earth’s internal heat contribute to the formation of fossil-fuel resources?

40. ● steam drives turbines that make electricity
3. Alternative Energy Resources
● Nuclear energy
● fission of uranium-235
● releases heat
● heat makes steam
● steam drives turbines that
make electricity

41. ● Nuclear energy reserves ● mineable uraninite
3. Alternative Energy Resources
● Nuclear energy reserves
● mineable uraninite
● 240,000 quads available

42. ● Nuclear energy and its hazards ● environmental contamination
3. Alternative Energy Resources
● Nuclear energy and its hazards
● environmental contamination
lasts a long time
● waste disposal problems; no
good plan in place for wastes
● security concerns

43. 3. Alternative Energy Resources: Planned U.S. Nuclear Waste Repository
Yucca Mountain Nuclear Waste Repository, Nevada

44. ● electricity generation in several ways
3. Alternative Energy Resources
● Solar energy
● electricity generation in several
ways
● risk-free and non-depletable
● technology is expensive and
inefficient

45. 3. Alternative Energy Resources: Solar Energy Collectors in Germany

46. ● Hydroelectric energy ● water and gravity ● clean and inexpensive
3. Alternative Energy Resources
● Hydroelectric energy
● water and gravity
● clean and inexpensive
● 3 quad/year from this source

47. 3. Alternative Energy Resources:
Three Gorges Dam, Yangtze River, China

48. ● ethanol (replaces gasoline)
3. Alternative Energy Resources
● Biofuels
● carbon neutral
● ethanol (replaces gasoline)

49. 3. Alternative Energy Resources:
Switchgrass, a Biofuel Grown in the U.S.

50. ● uses 30-m high windmills ● requires large open space
3. Alternative Energy Resources
● Wind power
● uses 30-m high windmills
● requires large open space

51. 3. Alternative Energy Resources: Altamont, California Windmill Area

52. ● Geothermal ● 40 quads accessible ● disposal problems
3. Alternative Energy Resources
● Geothermal
● 40 quads accessible
● disposal problems

53. Thought questions for this chapter
Are you an oil optimist or an oil pessimist? Explain why.
What issues related to the use of nuclear power can be addressed by a geologist?
Contrast the risks and benefits of nuclear fission and coal combustion as energy sources?

54. ● The risk of fossil-fuel burning ● global warming due to
4. Global Change
● The risk of fossil-fuel burning
● global warming due to
greenhouse gasses
● ocean acidification
● species loss due to
biosphere changes

55. Global Warming / Greenhouse Gasses
4. Global Change:
Global Warming / Greenhouse Gasses
● Since the industrial revolution
● methane up 150%
● carbon dioxide up 36%
● nitrous oxide up 18%

56. Global Warming / Greenhouse Gasses
4. Global Change:
Global Warming / Greenhouse Gasses
● Anthropogenic (human) change
● global average 0.6oC increase
● rise due to greenhouse gasses
● global warming will continue into
the 21st century

57. Global Warming / Greenhouse Gasses
4. Global Change:
Global Warming / Greenhouse Gasses

58. Global Warming / Greenhouse Gasses
4. Global Change:
Global Warming / Greenhouse Gasses

59. Global Warming / Greenhouse Gasses
4. Global Cchange:
Global Warming / Greenhouse Gasses
● Consequences of global warming
● changes in regional weather
● changes in the cryosphere
● sea-level rise
● species and ecosystem
migration

60. Predicted Surface Temperatures 2070-2100 as an Increase over 1960-1990
4. Global Change:
Predicted Surface Temperatures as an Increase over

61. Melting of the Arctic Ice Cap by 2030
4. Global Change:
Melting of the Arctic Ice Cap by 2030

62. An Animal Facing Imminent Extinction
4. Global Change:
An Animal Facing Imminent Extinction

63. Global Warming / Greenhouse Gasses
4. Global Change:
Global Warming / Greenhouse Gasses
● Potential catastrophic changes
● destabilization of glaciers
● shut-off of thermohaline
circulation in the oceans
● methane release from the
seafloor and permafrost

64. ● Ocean absorption of CO2 ● sea water acidity is rising
4. Global Change:
Ocean Acidification
● Ocean absorption of CO2
● sea water acidity is rising
● affects ability of shellfish and coral to form their hard parts
● affects health and survival of marine life

65. ● Effects of the Anthropocene or the ‘age of man’ (1780 to date)
4. Global Change:
Loss of Biodiversity
● Effects of the Anthropocene or the ‘age of man’ (1780 to date)
● deforestation of vast areas
● mass extinction of species
● biosphere-wide impacts

66. The Deforestation of Haiti
4. Global Change:
The Deforestation of Haiti

67. Thought questions for this chapter
Do you think a geologist several thousand years from now will consider the industrial revolution the beginning of a new geologic epoch?

68. 5. Earth System Engineering and Management
● We face daunting problems.
● continued use of fossil fuels
means doubling CO2 in the atmosphere in 50 years
● an extraordinary collaboration
of scientists, leaders, and the public is needed

69. 5. Earth System Engineering and Management
● What is needed
● energy policy
● use of alternative fuels
● engineering the carbon cycle
● stabilizing carbon emissions
● sustainable development

70. 5. Earth System Engineering and Management

71. Thought questions for this chapter
What do you think will be the major sources of the world’s energy in the year 2030? 2100?
Do you think we should act now to reduce carbon emissions or delay until the science of climate change is better understood?
Is the United States justified in insisting that developing countries that now use much less fossil fuel than developed countries agree to limit their carbon emissions?

72. Thought questions for this chapter
Do you think that future scientists and engineers will be able to intervene and prevent catastrophic changes in the Earth system?

73. Key terms and concepts Biofuel Carbon economy Carbon sequestration
Anthropogenic
Biofuel
Carbon economy
Carbon sequestration
Fossil fuel
Global change
Hubbert’s peak
Hydroelectric energy
Natural resource
Nonrenewable energy
Nuclear energy
Oil shale
Oil trap
Oil window
Quad

74. Key terms and concepts Reserve Resource Solar energy
Renewable resource
Reserve
Resource
Solar energy
Stabilization wedge
Sustainable development
Tar sands