Ocean Resources and the Environmental Issues

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Ocean Resources and the Environmental Issues

• Resources and man
• The ocean reservoir
• Food resources
• Mineral resources
• Energy resources
• Oceans and the environment
• Global climate change (e.g., Europe Cooling)
• Local weather effects (e.g., En Niño)
• Environmental degradation, waste disposal etc.

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Resources and Man

• The Malthusian trap
• The kinds of resources
• renewable versus non-renewable and potentially
  renewable
• Exhaustibility versus Sustainability

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• Craig, James R.. "Mineral Resources from the
  Ocean." WaterScience and Issues. 2003.
  Encyclopedia.com. 30 May. 2010 lthttp//www.encyclo
  pedia.comgt.
• Marine Mineral Resources
• Oceans cover 70 percent of Earths surface, host
  a vast variety of geological processes
  responsible for the formation and concentration
  of mineral resources, and are the ultimate
  repository of many materials eroded or dissolved
  from the land surface. Hence, oceans contain vast
  quantities of materials that presently serve as
  major resources for humans. Today, direct
  extraction of resources is limited to salt
  magnesium placer gold, tin, titanium, and
  diamonds and fresh water.
• Ancient ocean deposits of sediments and
  evaporites now located on land were originally
  deposited under marine conditions. These deposits
  are being exploited on a very large scale and in
  preference to modern marine resources because of
  the easier accessibility and lower cost of
  terrestrial resources. Yet the increasing
  population and the exhaustion of readily
  accessible terrestrial deposits undoubtedly will
  lead to broader exploitation of ancient deposits
  and increasing extraction directly from ocean
  water and ocean basins .
• Principal Mineral Resources

Mineral Resources from the Ocean Resources
presently extracted from the sea or areas that
were formerly in the sea range from common
construction materials to high-tech metals to
water itself. Chemical analyses have demonstrated
that sea water contains about 3.5 percent
dissolved solids, with more than sixty chemical
elements identified. The limitations on
extraction of the dissolved elements as well as
the extraction of solid mineral resources are
nearly always economic, but may also be affected
by geographic location (ownership and transport
distance) and hampered by technological
constraints (depth of ocean basins). The
principal mineral resources presently being
extracted and likely to be extracted in the near
future are briefly considered here. Salt. Salt,
or sodium chloride, occurs in sea water at a
concentration of about 3 percent and hence
constitutes more than 80 percent of the dissolved
chemical elements in sea water. The quantity
available in all the oceans is so enormous that
it could supply all human needs for hundreds,
perhaps thousands, of years. Although salt is
extracted directly from the oceans in many
countries by evaporating the water and leaving
the residual salts, most of the nearly 200
million metric tons of salt produced annually is
mined from large beds of salt. These beds, now
deeply buried, were left when waters from ancient
oceans evaporated in shallow seas or marginal
basins, leaving residual thick beds of salt the
beds were subsequently covered and protected from
solution and destruction. Potassium. Like the
sodium and chlorine of salt, potassium occurs in
vast quantities in sea water, but its average
concentration of about 1,300 parts per million
(or 0.13 percent) is generally too low to permit
direct economic extraction. Potassium salts,
however, occur in many thick evaporite sequences
along with common salt and is mined from these
beds at rates of tens of millions of metric tons
per year. The potassium salts were deposited when
sea water had been evaporated down to about
one-twentieth of its original volume. Magnesium. M
agnesium, dissolved in sea water at a
concentration of about 1,000 parts per million,
is the only metal directly extracted from sea
water. Presently, approximately 60 percent of the
magnesium metal and many of the magnesium salts
produced in the United States are extracted from
sea water electrolytically. The remaining portion
of the magnesium metal and salts is extracted
from ancient ocean deposits where the salts
precipitated during evaporation or formed during
diagenesis . The principal minerals mined for
this purpose are magnesite (MgCO3) and dolomite
(CaMgCO32). Sand and Gravel. The ocean basins
constitute the ultimate depositional site of
sediments eroded from the land, and beaches
represent the largest residual deposits of sand.
Although beaches and near-shore sediments are
locally extracted for use in construction, they
are generally considered too valuable as
recreational areas to permit removal for
construction purposes. Nevertheless, older beach
sand deposits are abundant on the continents,
especially the coastal plains, where they are
extensively mined for construction materials,
glass manufacture, and preparation of silicon
metal. Gravel deposits generally are more
heterogeneous but occur in the same manner, and
are processed extensively for building
materials. Limestone and Gypsum. Limestones
(rocks composed of calcium carbonate) are forming
extensively in the tropical to semitropical
oceans of the world today as the result of
precipitation by biological organisms ranging
from mollusks to corals and plants. There is
little exploitation of the modern limestones as
they are forming in the oceans. However, the
continents and tropical islands contain vast
sequences of limestones that are extensively
mined these limestones commonly are interspersed
with dolomites that formed through diagenetic
alteration of limestone. Much of the limestone is
used directly in cut or crushed form, but much is
also calcined (cooked) to be converted into
cement used for construction purposes. Gypsum
(calcium sulfate hydrate) forms during
evaporation of sea water and thus may occur with
evaporite salts and/or with limestones. The
gypsum deposits are mined and generally converted
into plaster of paris and used for
construction. Manganese Nodules. The deep ocean
floor contains extremely large quantities of
nodules ranging from centimeters to decimeters in
diameter (that is, from less than an inch to
several inches). Although commonly called
manganese nodules, they generally contain more
iron than manganese, but do constitute the
largest known resource of manganese. Despite the
abundance and the wealth of metals contained in
manganese nodules (iron, manganese, copper,
cobalt, and nickel), no economic way has yet been
developed to harvest these resources from the
deep ocean floor. Consequently, these rich
deposits remain as potential resources for the
future. Terrestrial deposits of manganese are
still relied on to meet human needs. Phosphorites.
Complex organic and inorganic processes
constantly precipitate phosphate-rich crusts and
granules in shallow marine environments. These
are the analogs (comparative equivalents) of the
onshore deposits being mined in several parts of
the world, and represent future potential
reserves if land-based deposits become
exhausted. Metal Deposits Associated with
Volcanism and Seafloor Vents. Submarine
investigations of oceanic rift zones have
revealed that rich deposits of zinc and copper,
with associated lead, silver, and gold, are
forming at the sites of hot hydrothermal
emanations commonly called black smokers. These
metal-rich deposits, ranging from chimneyto
pancake-like, form where deeply circulating sea
water has dissolved metals from the underlying
rocks and issue out onto the cold seafloor along
major fractures. The deposits forming today are
not being mined because of their remote
locations, but many analogous ancient deposits
are being mined throughout the world. Placer
Gold, Tin, Titanium, and Diamonds. Placer
deposits are accumulations of resistant and
insoluble minerals that have been eroded from
their original locations of formation and
deposited along river courses or at the ocean
margins. The most important of these deposits
contain gold, tin, titanium, and diamonds. Today,
much of the world's tin and many of the gem
diamonds are recovered by dredging near-shore
ocean sediments for minerals that were carried
into the sea by rivers. Gold has been recovered
in the past from such deposits, most notably in
Nome, Alaska. Large quantities of placer titanium
minerals occur in beach and near-shore sediments,
but mining today is confined generally to the
beaches or onshore deposits because of the higher
costs and environmental constraints of marine
mining. Water. The world's oceans, with a total
volume of more than 500 million cubic kilometers,
hold more than 97 percent of all the water on
Earth. However, the 3.5-percent salt content of
this water makes it unusable for most human
needs. The extraction of fresh water from ocean
water has been carried out for many years, but
provides only a very small portion of the water
used, and remains quite expensive relative to
land-based water resources. Technological
advances, especially in reverse osmosis ,
continue to increase the efficiency of
fresh-water extraction. However, geographic
limitations and dependency on world energy costs
pose major barriers to large-scale extraction.
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In an essay first published in 1798, Thomas
Roberts Malthus argued that

• the power of population is indefinitely greater
  than the power in the earth to produce
  subsistence for man.

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Adam Smith (1723-1790),
the British philosopher and economist, argued, in
his celebrated treatise An Inquiry into the
Nature and Causes of the

• Wealth of Nations (1776), that every individual
  in pursuing his or her own good is led, as if by
  an invisible hand, to achieve the best good for
  all. Therefore any interference with free
  competition by the government is almost certain
  to be injurious.

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First Green Revolution in this century took place
in developed countries during 1950-70.
First Green Revolution
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Second Green Revolution has occurred in
developing countries since mid-1960s.
Second Green Revolution
First Green Revolution
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Currently,
the annual food production world-wide, including
grains, poultry, seafood and meat,

• is about 4 billion tons per year, or
• about 4½ lbs per person per day.

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An average American diet world-wide is clearly
impossible, without a proportionate increase in
the worlds food production.
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Lesson?Get used to the Indian diet!Alternative?
Grow more food!
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That requires

• Land and
• water

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Being largely stenohumid as well
as stenothermal, agricultural crops impose a
rather restricted range of climatic conditions.
Farmland therefore tends to be in short supply.
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Most of the Earth is covered by water

• ...water, water, every where
• nor any drop to drink!

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But the supply of land too is limited...
and barely a fifth of it is available
for farming related activities.
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Economic growth exacerbates the demand for water,
e.g.,

• with economic growth at 7-10 per year, poultry
  consumption is rising at the rate of 15 per year
  in China, Indonesia and India - water demands of
  this nontraditional industry are only likely to
  grow
• we need about 250,000 gallons of water to produce
  a ton of corn, 375,000 gallons to produce a ton
  of wheat, 1,000,000 gallons to produce a ton of
  rice, and 7,500,000 of water to produce a ton of
  beef.

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How much water do we have?
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The availability of water too is a limiting
factor. An average human needs about 300,000
gallons of water annually, including 250,000
gallons for growing food. Indeed, nations with
under 150,000 gallons of annual per capita water
supply face severe limits to their growth.
Mass of the present hydrosphere
Karl K. Turekian GLOBAL ENVIRONMENTAL CHANGE
(Prentice Hall, 1996)
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Hydrospheres lower limit
Conventional estimate assumes a total groundwater
storage of about 1,700 quadrillion gallons. This
gives the estimate of hydrospheres total water
content as 3.5x1020 gallons.
Underground water (0.5) Surface water
(0.02) Atmospheric moisture (0.001)
Oceans (97)
Ice (1.2)
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An alternate assumption is that pores in
sediments contain about 80,000 quadrillion
gallons of ground-water (almost 50 times the
conventional estimate). This yields an estimate
of about 4x1020 gallons of water in the entire
hydroshere.
Ice (1) Surface water (0.002) Atmosphere (0.001
)
Ground- water (19)
Groundwater (19)
Oceans (80)
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The exhaustibility of extractive earth resources
is a problem if we take (a) the Malthusian
perspective, that exhaustibility limits
socioeconomic growth or (b) the neo-Malthusian
perspective, that resource exploitation has
environmental limits.the Ricardian perspective,
that progressive depletion raises costs and
lowers quality but poses no problem if we take
the cornucopian view, that technological
innovation will always provide substitutes and
alternates.
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Long-run inflation-adjusted world prices for
nonferrous metals (aluminum, copper, tin and zinc)
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Average world crude oil prices
20
10
1925
1950
1975
2000
38
1991 commercial energy use by source
World
USA
Hydel, Geothermal, Solar etc.
Biomass 4
Bio- mass
Nuclear
6
11
Oil 33
5
5
7
Coal 27
Natural gas 18
Sources US Department of Energy and
Worldwatch Institute
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Farming Industry
Trans- portation
Food
Home
Industrial societies
Advanced agri- cultural societies
Early agri- cultural societies
Hunter-gatherer societies
Primitive societies
0
20
40
60
80
40
Hubbard curves for world petroleum output and
prospects assuming resource estimates of
60
3.0 x 1012 barrels
2.2 x 1012 barrels
1.4 x 1012 barrels
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Actual
20
Production
0
1900
2000
2100
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'THE END OF THE OIL AGE is in sight,' says U.S.
petroleum geologist M. King Hubbert.... If
present trends continue, Dr. Hubbert estimates,
production will peak in 1995 -- the deadline for
alternative forms of energy that must replace
petroleum in the sharp drop-off that follows.
Oil, the Dwindling Treasure M. King Hubbert
National Geographic, June, 1974
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Oceans as the energy reservoir

• Already, about one-third of oil comes from the
  oceans, advances in drilling technology will
  increase that.
• Other ocean-based energy sources include

• Methyl hydrate gel
• Ocean Thermal Energy Conversion (OTEC) or
  thermocline
• Kelp farming for methane
• Tides, Waves etc.

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http//www.nrel.gov/otec/resource.html
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That Climate Thing

• Global warming and its consequences
• The anthropogenic contributions

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The 1950-91 hydrographic data off California
coast show that the sea surface waters (0-100m)
became 0.8oC warmer in the 35-year period
between 1950-56 and 1985-91 which
DT (oC)
0
0.3
0.6
0.9
1.2
0
100
200
300
Distance off California coast (km)
400
500
400
300
200
100
0
100
500
raised the sea level sur-face by 3.10.7 cm.
95
1985-91
Note Warming by 1oC the top 100 m of ocean with
15oC temperature and 3.4 salinity should raise
the sea level by 2.2 cm.
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1950-56
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Source D. Roemmich, SCIENCE v. 257, p. 373-375
(July 17, 1992).
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Global warming will hurt the poor nations most!
Change in average national crop yield by the
year 2,060 compared to yield corresponding to no
change in climate (based on the ocean-atmosphere
coupling model) - SCIENCE NEWS, Aug 1992
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Evaporation 60,000 km3
Precipitation 95,000 km3
Precipitation 285,000 km3
Run-off 35,000 km3
Ocean Storage
1,370,000,000 km3
The Hydrological Cycle
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The 1900-94 trends reveal a general tendency
towards greater precipitation (a) at higher
latitudes and (b) on land
Change in precipitation (1900-94)
20
0
Thomas Karl, Neville Nicholls Jonathan
Gregory THE COMING CLIMATE, Scientific American,
May 1997
-20
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Evaporation 60,000 km3
Precipitation 95,000 km3
Precipitation
Run-off 35,000 km3
285,000 km3
Ocean Storage
1,370,000,000 km3
The Hydrological Cycle
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In summary,

• Human ingenuity has defied the Malthusian Trap,
  that the power of population exceeds that of the
  earth.
• This has resulted in modifying the most basic of
  natures processes - the hydrological cycle.
• Perhaps technology defies the Gandhian dictum,
  that nature has enough for our need, but not for
  our greed.

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What will happen if worlds population and
economic growth continue at the 1990 levels,
assuming no major policy changes or technological
innovations
Population
Resources
Pollution
2100
2000
1900
1950
2050
Donella Meadows et al., Beyond the Limits
Confronting Global Collapse, Envisioning a
Sustainable Future (Chelsea Green, 1992)
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Exhaustibility of extractive earth resources

• is a problem if we take
• the Malthusian perspective, that exhaustibility
  limits socioeconomic growth
• the neo-Malthusian perspective, that resource
  exploitation has environmental limits or
• the Ricardian perspective, that progressive
  depletion raises costs and lowers quality but
• poses no problem if we take the cornucopian view,
  that technological innovation will always provide
  substitutes and alternates.

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Depletion time based on the Limits to Growth
scenario
S 5xS
S 5xS
Aluminium 2003 2027 Chromium 2067 2126 Coal 2083
2122 Cobalt 2032 2120 Copper 1993 2020 Gold 1981
2001 Iron 2065 2145 Lead 1993 2036 Manganese 201
8 2066
Molybdenium Natural Gas Nickel Petroleum Platinum
Silver Tin Tungsten Zinc
2006 2017 1994 2021 2025 2068 1992 2022 2019 2057
1985 2014 1987 2033 2000 2044 1990 2022
Depletion time or the exponential index, TE,
is computed here by solving this equation
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The depletion time of selected resources based on
the Limits to Growth scenario
Five times the current stock
Current stock
1980
2000
2040
2020
2060
1960
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Reserve inadequacy of advanced material elements
beyond the year 2000 (S. Fraser, A. Barsotti
D. Rogich Resources Policy, March 1988)
Arsenic 1.7 Barium 1.3 Bismuth 1.2 Cadmium 1.6
Gold 1.9 Indium 1.4 Mercury 1.1 Silver 1.5
Tantalum 1.4 Thallium 1.9 Tin 0.8
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Long-run inflation-adjusted world prices for
nonferrous metals (aluminum, copper, tin and zinc)
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Average world crude oil prices
20
10
OPEC
1925
1950
1975
2000
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1991 commercial energy use by source
World
USA
Hydel, Geothermal, Solar etc.
Biomass 4
Bio- mass
Nuclear
6
11
Oil 33
5
5
7
Coal 27
Natural gas 18
Sources US Department of Energy and
Worldwatch Institute
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Average daily per capita energy use at various
stages of human cultural development
Farming Industry
Trans- portation
Food
Home
Industrial societies
Advanced agri- cultural societies
Early agri- cultural societies
Hunter-gatherer societies
Primitive societies
0
20
40
60
80
Daily per capita consumption in kcal
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The U.S. oil production costs and proven reserves
have been falling
30
100
28
90
26
80
70
24
60
22
1985
1990
1995
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Oil output per well is rising world-wide, though
falling in the U.S.
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The Hotelling price path
Pt Poest
PB
Po
T
Time
Quantity
Resource stock
T
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In the long run, economic growth peters out, in
the Ricardian perspective, because rising demand
forces society to exploit increasingly poorer
quality of resources.
Stationary State
Constant Real Wage
Total Product
Population or Demand
David Ricardo (1772-1823)
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As predicted by theory, the extraction costs
indeed rise exponentially
80
60
1994 World Demand
40
20
The Exponential Fit
0
0
4
8
12
16
20
Cost (US per barrel)
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U.S. oil production (1857-1995)
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The depletion curve for a typical nonrenewable
resource
Depletion Time (TE) The time when 80 of the
resource is used up
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Time
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f1
eABt

Write

• Then
• y ln f1 A Bt
• where f1 are the observed data as function of
  time (t),
• so that the constants A and B can be found by
  linear
• regression analysis.

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Estimates of the world petroleum reserves
8
6
4
2
0
1,500
2,000
2,500
billion barrels
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Hubbard curves for world petroleum output and
prospects assuming resource estimates of
60
3.0 x 1012 barrels
2.2 x 1012 barrels
1.4 x 1012 barrels
40
Actual
20
Production
0
1900
2000
2100
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Economic prosperity and energy con-sumption are
closely correlated
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USA
China
Russia
Germany
India
Japan
10
Brazil Italy
France U.K.
Mexico
Saudi Arabia Netherlands
Spain
Australia
Sweden
1
Norway Swtizerland
Singapore
0.1
0.01
0.1
1
10
GDP (PPP) in trillion US
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...and so are economic prosperity and carbon
emmissions
GDP (PPP) in trillion US
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Mahatma Gandhi (1869-1948)

• Of utmost relevance to the environmental debate
  is the Gandhian principle of enoughness, that the
  nature has enough for our need, but not for our
  greed.
• According to him, when we take more than we
  need, we are simply taking from each other,
  borrowing from the future, or destroying the
  environment and other species.

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Thank You!