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Energy and Global Change

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Title: Energy and Global Change


1
Energy and Global Change
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State of the Planet
A dynamic interactive system of bio-geo-chemical
cycles that are being significantly influenced by
an emerging intelligent life-form. This life-form
has some serious limits in cognition and
self-awareness as well as a number of other
intellectual and physical constraints. Michael
Crow
4
Impact of Humankind
  • Eliminated 20 of all bird species
  • Increased atmospheric CO2 by 30
  • Using over 50 of freshwater runoff
  • Overexploiting over 60 of marine fisheries
  • Increasing atmospheric CH4 by 140
  • Introduced over 70,000 synthetic chemicals into
    the environment

W. Clark
5
Impact of Humankind
"The balance of evidence suggests a discernible
human influence on global climate." Intergovernmen
tal Panel on Climate Change, United Nations
Most projections now suggest that the degree of
change will become dramatic by the middle of the
21st century, exceeding anything seen in nature
during the past 10,000 years.
6
Challenges of the 21st Century
  • Eliminating weapons of mass destruction.
  • Preventing the population of the planet from
    exceeding 9 billion people.
  • Sharply reducing the global rate of loss of
    biodiversity.
  • Meeting global energy needs while limiting the
    atmospheric concentration of carbon dioxide.

7
Global Warming
There is now general agreement that the Earths
temperatures are increasing, and the primary
cause is humankind. 15 of the warmest years
worldwide have occurred since 1980. It is likely
that 1998 was the warmest year in the last
thousand (from ice cores). The Arctic ice cap is
melting. So are the glaciers. The sea levels are
rising (10 inches in the past century). With
rather high confidence one can now say that
global warming is being experienced and that
greenhouse-gas increases from human activities
are its primary cause.
8
The Greenhouse Effect
CO-2 remains in the atmosphere for a century or
more. Such greenhouse gases trap some of the
solar radiation that the planet would otherwise
radiate back to space, creating a blanket that
insulates and warms the lower atmosphere. The
inevitable result of pumping the sky full of
greenhouse gases is global warming. This dries
the planet by evaporating moisture from the
oceans, soils, and plants. Additional moisture
in the atmosphere provides a swollen reservoir of
water that is trapped by all precipitating
weather systems, including tropical storms,
thunderstorms, snowstorms, and frontal
systems. Human activities aside from burning
fossil fuels also wreak havoc. The conversion of
forests to farmland eliminates trees that would
absorb carbon from the atmosphere. Fewer trees
also mean greater rainfall runoff, thereby
increasing the risk of floods.
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Global Climate Disruption
Before the industrial revolution, the
concentration of carbon dioxide was about 280
parts per million by volume (ppmv). Today we are
releasing about 7 billion tons of carbon into the
atmosphere each year, and the atmospheric
concentration has increased to 370 ppmv. At the
current rates, carbon release would increase to
15 billion tons per year with concentrations at
550 ppmv by 2050. The impact on climate would be
extraordinary and perhaps not reversible
(runaway greenhouse effect).
11
Global Energy Use
12
Current Energy Supply System
  • In 2000, worlds 6 billion people used about 450
    exajoules (billion-billion or 1018)
  • 35 from oil
  • 23 from coal
  • 20 from natural gas
  • 6 from nuclear power
  • 6 from hydropower
  • 13 from biomass fuels (e.g., wood)
  • About 30 of primary energy was used to generate
    electricity. Fossil fuels provided 63 nuclear
    provided 18.
  • The United States, with 4.5 of worlds
    population, accounts for 23 of global energy use
    and 27 of electricity production.

13
Current Energy Supply System
  • In 2000, worlds 6 billion people used about 450
    exajoules (billion-billion or 1018) (1 EJ 1
    quad 1015 BTU)
  • 35 from oil
  • 23 from coal
  • 20 from natural gas
  • 6 from nuclear power
  • 6 from hydropower
  • 13 from biomass fuels (e.g., wood)
  • About 30 of primary energy was used to generate
    electricity. Fossil fuels provided 63 nuclear
    provided 18.
  • The United States, with 4.5 of worlds
    population, accounts for 23 of global energy use
    and 27 of electricity production.

14
The Current Situation
Importance of energy Energy costs typically
absorb 7 to 10 of the cost of living (and are
key factors in inflation and recession). Energy
is a major contributor to dangerous and complex
environmental problems at every scale. Energy
issues can trigger issues in international
security, from conflict over oil and gas reserves
to nuclear weapons proliferation. In 2000, more
than 75 of world's energy was produced from
fossil fuels.
15
The Current Situation
The reliability of energy supplies is decreasing
because of political instability and increasing
demand, at a time when many countries are
becoming more dependent on those supplies. The
United States is heavily dependent on foreign
oil, and natural gas prices have doubled in
recent months. Overall consumption of electrical
power is increasing, and is likely to rise from
40 to 70 by 2050 (think computer!) During the
next decade, the role of renewables, particularly
wind and biomass, will increase, but not nearly
enough to fill present requirements. The U.S.
and other developed countries will find it
necessary to devote far more attention, including
increased RD, to multiple risk and energy
trade-offs involving coal, nuclear power,
petroleum, natural gas, and electric power.
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Coal
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Coal
U.S. coal reserves are enormousan order of
magnitude larger than oil and gas reserves
(140,000 EJ). Unfortunately, coal is a dirty,
inconvenient fuel for most uses which causes
significant environmental impact and danger to
public health due to pollutants released during
the direct combustion (flyash particulates, SO-2,
CO-2, NO), materials handling problems, and the
environmental and health problems associated with
coal mining.
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Oil
28
Oil and Gas
During the first half of the 20th Century our
society made a transition from wood and coal as
its primary energy sources to petroleum and
natural gas. These resources are limited. Some
believe that the prospective scarcity of oil
combined with the instability of the regimes of
oil-rich nations will cause a steep rise in
hydrocarbon prices over the next two
decades. Some believe that depletion is now close
to the psychologically important half-way mark.
But optimists believe that htis turning point is
still decades away, and that with new
technologies, reserves are far larger
(particularly with tar sands).
29
Oil and gas
Exxon believes "that for the next 25 to 50 years,
the oil available to the markets is for all
intents and purposes infinite." But scarcity is
not the only reason why the world might move away
from oil. The unnerving votality of oil prices,
together with growing concern about the
environmental imapct of hydrocarbons, is already
spurring the search for alternatives. "The stone
age did not end because the world ran out of
stone, and the oil age will end long before the
world runs out of oil!"
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M. King Hubberts Peak
  • U.S. oil production peaked in the 1970s
  • The imbalance between domestic production and
    consumption has led to our extreme dependence on
    Middle East oil
  • When will global oil production peak?
  • Certainly some time during this century.
  • Within next few decades?
  • Within next decade?
  • Note the disruption that will occur when global
    consumption exceeds production!

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Natural Gas
  • Natural gas has become the preferred fuel for new
    generating capacity.
  • Thus far, at least, the discovery of new reserves
    is increasing faster than our consumption.
  • Gas-turbine plants are relatively inexpensive to
    build and much cleaner than coal.
  • But, natural gas supplies are limited, and the
    cost of natural gas fluctuates widely (currently
    about twice as expensive as coal).

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United States Energy Vulnerability
The fraction of U.S. oil imports from the OPEC
cartel and, within it, from the politically
volatile Persian Gulf, is likely to increase over
time. Currently the U.S. gets half of its oil
imports from OPEC and half of that amount from
the Persian Gulf. The Persian Gulf has almost
30 of world oil production, 43 of exports, and
65 of proven reserves.
40
Biomass
41
Biomass
  • Wood, crop residues, dung, and other combustible
    wastes are the main source of energy for a
    majority of the worlds population (65 EJ or
    15).
  • 60 of biomass supplied by wood, most of which is
    cut and burned faster than it is replaced.
  • Furthermore, biomass contributes to CO-2 buildup,
    both through deforestation and combustion.

42
Hydroelectric
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Hydroelectric Power
  • One of only two sources of carbon-free energy
    (the other being nuclear fission) currently
    producing a significant fraction of the worlds
    energy supply (currently 7 or 27 EJ per year).
  • Further expansion is limited by geography and
    environmental impact. (In fact, pressure is
    building to dismantle dams and return rivers to
    natural flows.)

46
Geothermal
47
Geothermal
The thermal energy contained in the upper 10 km
of the earths crust can be tapped in a variety
of ways dry steam fields (e.g., the Geysers
plant in California) wet steam fields, pumping
fluids through hot igneous rocks associated with
recent volcanism, and tapping geopressurized
basins containing large volumes of trapped
geofluids under abnormally high temperature and
pressure.
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Problems
  • Fields are of limited magnitude and rapidly
    depleted over a few decades.
  • Geothermal fluids withdrawn from the earth
    contain a variety of noxious substances,
    including CO-2, H2S, arsenic, mercury, and even
    radioactive materials. (In fact, the Geysers
    plant has the highest radioactivity level of any
    power plant in the United States!)
  • The environmental and safety impact of geothermal
    plants are very high.

51
Renewable Energy Sources
52
Renewable Energy Sources
  • Numerous possibilities
  • Wind Power
  • Solar Power (both thermal and electric)
  • Ocean Thermal Gradients
  • BUT, currently renewables supply only about 4 EJ
    (1) of worlds energy source.
  • Lots of problems, caused primarily by highly
    dilute nature of energy concentration.

53
Wind Power
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Wind Power
  • Wind power has been harnessed for thousands of
    years, but only in last decade to generate
    electricity (currently 0.14 EJ).
  • Only 5 of earths land area is windy enough to
    cost-effectively produce electricity.
  • Intermittent and unpredictable nature.

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Solar Power
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Solar Power
  • Currently produces only about 0.5 EJ, primarily
    through solar thermal collectors.
  • Solar resource is huge. About 500,000 EJ falls
    on earth each year. But it is highly dilute, and
    the challenge is to capture and deliver solar
    energy economically.
  • Two approaches
  • Passive solar thermal collectors
  • Solar generated electricity (e.g., photocells)

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The Principal Constraint Cost
The diffuse, intermittent nature of solar power
(and other renewables) requires extremely capital
intensive systems in order to capture and convert
this energy to useful forms. It typically takes
20 to 30 years to pay back the capital costs of
solar installations (compared to 3 to 4 years for
coal and nuclear plants). (In fact, some claim
that one can never recover either the costs or
the total energy invested in building the plants.)
67
Nuclear Fission
68
Nuclear Fission
  • The only current carbon-free energy source that
    could be deployed on a significant scale.
  • Currently 434 nuclear reactors providing 17 of
    worlds electricity (350 GW) and 6 of its
    energy.
  • In nuclear-intensive scenarios, the number of
    nuclear plants would increase to 1,000 to 2,000
    by 2050, supplying 70 to 110 EJ or 30 to 40 of
    worlds electricity.
  • Conventional uranium resources could easily
    support a high growth scenario for at least 50
    years. Furthermore, recent studies have
    suggested that uranium could be extracted from
    seawater for less than 100 per kilogram.
  • The best U.S. nuclear plants produce electricity
    at lower cost than the best coal-fired plants.
    In Japan, nuclear generated electricity is
    somewhat less expensive than fossil-fuel
    generated electricity.

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A new environmentalist view of nuclear power
Many people in the environmentalist community are
concluding that nuclear power needs another look,
since it is the only non-carbon emitting form of
energy capable of massive expansion. They realize
there are problems safety concerns, radioactive
waste disposal, proliferation of nuclear weapons
technology, and cost (the most serious). But the
growing belief is that all of these problems are
solvable, and that we should be investing far
more than we are today in making nuclear power a
viable, expandable energy option once again.
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The Breeder Reactor
  • By converting fertile materials such as U-238
    into fissile materials such as Pu-239, the
    breeder reactor will be characterized by an
    essentially limitless fuel supply.
  • However, it will require the use of fuel
    reprocessing to extract plutonium and fabricate
    it into fuel elements for further use.
  • Since the breeder reactor is based on plutonium,
    it raises concerns about the possibility of
    proliferation of nuclear weapons capability.

77
Nuclear Fusion
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Approaches
  • Magnetically-confined thermonuclear fusion
  • Intertially-confined thermonuclear fusion
  • Laser Fusion
  • Particle Beam Fusion
  • Other? (Cold Fusion)

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The Challenges
  • We have yet to demonstrate proof of principle
    for controlled thermonuclear fusion, in which we
    are able to generate more energy from fusion
    reactions than we expend in heating, confining,
    or compressing the fusion fuel. (This would be
    analogous to Fermis achievement of the first
    fission chain reaction in 1942.)
  • The technological challenge of engineering a
    controlled thermonuclear reactor into a safe,
    economically competitive power plant looks
    formidable indeed.
  • Although a fusion reactor would have essentially
    an infinite fuel supply (it could burn the
    oceans), it will depend on exotic materials that
    are more limited in supply.
  • And, like fission reactors, fusion reactors will
    emit intense radiation and produce radioactive
    materials that must be handled and disposed of

94
Hydrogen
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Hydrogen
Hydrogen is technically NOT a fuel. It is an
energy "carrier", since more energy has to be
invested in producing it that it will
generate. But hydrogen is the idea energy
carrier It is abundant, it has a simple
chemistry, and it produces energy perfectly
cleanly. Through the use of gas transport or fuel
cells, it could become the ideal transportation
"fuel". The big question Where do we get the
energy to produce it, e.g., by stripping the
carbon out of today's hydrocarbon fuels.
97
Another way to look at things
The toward "decarbonization" is the heart of
understanding the evolution of the energy
system Wood burns about 10 carbon atoms for
each H. Coal approaches parity with 1 or 2 C per
H Oil has 1 C per 2 H's Natural gas (methane)
has 1 C per 4 H's And the ultimate is burning
hydrogen itself.
98
Distribution of energy
The distribution of coal and oil is clumsy. The
preferred configuration for energy distribution
is a grid that can be fed and bled continously at
variable rates i) gas pipelines ii) electrical
transmission networks Here, again, we see that
hydrogen and electricity are the ideal energy
carriers, since they can function on a grid.
99
Ad Hoc Committee on Hydrogen Initiatives
  • Preliminary Report

100
Charge
To conduct a quick scan of various approaches to
building a significant energy research program
addressing alternative energy supplies with a
particular focus on hydrogen options. Key
approach A SWOT (strengths-weaknesses-opportunit
ies-threats) analysis of possible initiatives.
101
Motivation
  • There are few contemporary challenges facing our
    nation more threatening than the unsustainable
    nature of our current energy infrastructure.
  • Every aspect of contemporary society is dependent
    upon the availability of clean, affordable,
    flexible, and sustainable energy sources.

102
The Challenge
  • Our current energy infrastructure, heavily
    dependent upon hydrocarbons, is unsustainable.
  • Our environment is seriously impacted by current
    energy sources.
  • The security of our nation is threatened by our
    reliance on foreign energy imports.
  • Both the nation and major research universities
    such as UM must give a far higher priority to
    energy research.

103
Committee Membership
  • James J. Duderstadt, Science and Engineering, UM
    (Chair)
  • Arvind Atreya, Mechanical Engineering, UM
  • Francois Castaing, Chairman of the Board, New
    Detroit Science Center
  • James Cook, Chief Technology Officer, Retired,
    CMS Energy
  • James Croce, Chief Executive Officer, NextEnergy
  • Robert Culver, USCAR Director, Retired, Ford
  • Gregory Keoleian, School of Natural Resources
    Environment, UM
  • James MacBain, College of Engineering, UM
  • Johannes Schwank, Chemical Engineering, UM
  • Levi Thompson, Jr., Chemical Engineering, UM
  • John R. Wilson, TMG/ENERGY
  • Lynn Cook, Support Staff, UM OVPR
  • Lee Katterman, Support Staff, UM OVPR

104
Criteria
  1. Achieving national energy independence
  2. Minimizing impact on global climate
  3. Addressing the particular needs of the
    transportation industry.

105
A Note
Although the initial charge was aimed at
assessing roadmaps to a possible hydrogen
economy, with an emphasis on hydrogen as an
energy fuel, the committee believed it important
to broaden this discussion to include an array of
alternative energy options characterized by zero-
or low-hydrocarbon emissions. This discussion
involved long-term energy options for both
stationary and mobile applications.
106
Themes of Tomorrow
"The whole history of mankind's use of energy is
the history of decarbonization of fuels. As
societies have grown weathier, they have shifted
from dirty solid fuels with a high carbon content
(wood, coal) to liquid hydrocarbon fuels with a
lower content, and ultimately to clean-burning
gases." Energy Survey 2001, The Economist
107
Decarbonization
"The most powerful force for decarbonization
through the ages has been the market, and it is
no accident that the historic decarbonization
trend has stalled in recent decades, when
governments have taken to meddling in energy
markets. It was only in the 1950s when
governments began to tinker with price controls
and later, reacting to cries of shortages by the
energy industry, allocated fuels among sectors of
consumers, that we began to recarbonize the
energy system."
108
A Hydrogen Economy
By 2050 consumption of natural gas and hydrogen
will surpass that of coal and oil, and by the end
of the century these gases will have more than
75 of the global energy market. Hydrogen is the
ideal energy carrier 1) It is abundant. 2) It
has a simple chemistry. 3) It produces energy
perfectly cleanly. But how do we make it? We need
a central energy source such as nuclear power!
109
Distributed Energy
110
Distributed Energy
The bright new hope is micropower, e.g., fuel
cells or microturbines, where power is
distributed close to the end-user rather than
distant stations. Advances in software and
electronics hold the key to micropower, as they
offer new and more flexible ways to link parts of
electricity systems together. In the end,
thought, it may not be the technology that
determines the success of distributed generation
but a change in the way that people think about
electricity. Distributed energy will mean the
transition from an equipment business to a
service business.
111
Energy Resources
112
M. King Hubberts Peak
  • U.S. oil production peaked in the 1970s
  • The imbalance between domestic production and
    consumption has led to our extreme dependence on
    Middle East oil
  • When will global oil production peak?
  • Certainly some time during this century.
  • Within next few decades?
  • Within next decade?
  • Note the disruption that will occur when global
    consumption exceeds production!

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Estimated Reserves
Coal 140,000 EJ
Oil 10,000
Gas 10,000
Uranium (LWRs) 5,000
Uranium (Breeders) 120,000
Bituminous 20,000
Tar Sands 10,000
Other Gases 10,000
Uranium (seawater) 2,400,000 (480 M EJ in breeders)
115
Estimated Reserves
Coal 140,000 EJ
Oil 10,000
Gas 10,000
Uranium (LWRs) 5,000
Uranium (Breeders) 120,000
Bituminous 20,000
Tar Sands 10,000
Other Gases 10,000
Uranium (seawater) 2,400,000 (480 M EJ in breeders)
In 2000, the world produced 450 EJ of primary
energy.
116
Conservation
117
Conservation
Since energy has always been cheap and plentiful,
our society has tended to substitute
energy-intensive technologies for labor-intensive
processes. Today the average American consumes
energy at a rate some 6 times the world average
and over 80 times the average in underdeveloped
nations. Clearly is room for greater energy
efficiency.
118
Approaches
  • Technological advances in energy production and
    utilization.
  • Shifting our society away from energy-intensive
    goods and services (e.g., the automobile).
  • Placing artificial constraints on economic
    growth, since there is a strong, direct
    correlation between economic growth and energy
    consumption. (As a rule of thumb, the drop in
    energy consumption by one barrel of oil a day
    eliminates one job in the labor market!)

119
Global Warming
120
Global Warming
If the oil-import picture for the U.S. and the
world in the decades ahead is unsettling, the
climate-change implications of the steep
continued rise of global carbon emissions under
business as usual are positively alarming. The
atmospheric concentration of CO-2 today is nearly
33 above its pre-industrial level (370 ppmv).
There is no doubt that this increase has been
mainly due to human activities (initially
deforestation, but in last 100 years,
overwhelmingly from fossil fuel burning). The
changes in the Earths climate now being
experienced are on track to predictions (increase
of 1 degree F, sea level up by 4 to 10 inches,
more unstable weather patterns).
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Carbon dioxide concentrations
Historically, the atmospheric concentration of
carbon dioxide rose from a pre-industrial level
of 280 ppmv in 1750 to 370 ppmv in 200, driven in
the first part of this 250 period mainly by
deforestation and in the latter part of the
period mainly by fossil-fuel combustion. If we
continue at the current pace of fossil fuel
combustion, concentrations will reach 550 ppmv by
2050, over 700 ppmv by 2100, and likely continue
to 1100 ppmv soon thereafter. Besides CO-2
increase, atmospheric concentrations of other
greenhouse gases is increasing (methane, nitrous
oxide, tropospheric ozone, and halocarbons).
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What evidence do we have?
  • The 7 hottest years since 1860 occurred in the
    1990s.
  • Observed increases in CO-2 track almost perfectly
    with known increases in human CO-2 production.
  • Ice core data show that natural fluctuations in
    atmospheric CO-2 hav been only plus or minus 10
    ppmv over past 10,000 years.
  • Carbon-14 analysis of tree rings dating back to
    1800 confirms this.
  • Recent Arctic Climate Impact Assessment (with
    average temperate increases twice that of rest of
    planet6 C?

126
How serious is this?
The global climate change caused by human
activity and above all by fossil fuel combustion
is both the most dangerous and the most
intractable environmental problem that
civilization faces. It is the most dangerous
because climate creates the envelope of
environmental conditions within which all other
processes that operative in support of human
well-being have to be able to function. It is
the most intractable of environmental problems
because its fundamental changes are so deeply
embedded in our way of life. John Holdren
127
Implications of business-as-usual
  • Global average surface temperature up 2 to 6 C by
    2100 (UN IPCC-2001)
  • Sea level would be 20 to 100 centimeters higher
  • Might see a multimeter sea-level rise from
    disintegration of the polar ice sheets and a
    runaway greenhouse effect from the decomposition
    of methane-bearing compounds.
  • (NOTE Arctic Climate Impact Assessment
    suggestions this could begin this century!)

128
Global warming vs. climatic disruption
Simply to talk about global warming (or the
greenhouse effect) does not do justice to what is
going on because the average warming conceals
large changes in patterns and extremes of hot and
cold, wet and dry, the tracks of storms and so
on. We really need to understand this as
disruption. Even the term global climate change
which better describes the variety of things
going on, does not adequately express that we are
messing up this system on which our well-being
depends.
129
The impact and the intractability
The potential for disruption by the greenhouse
effect is staggering reductions in the
productivity of farms and forests and fisheries,
increases in the frequency and intensity of
destructive storms, changes in the geographic
distribution of disease organisms, rises in sea
level imperiling coastal property, losses in
biodiversity, etc. But the investment in world
energy systems, mostly a fossil fueled energy
system, is about 10 trillion at replacement
cost. The average lifetime of these energy
facilities is 30 to 40 years. Hence you cannot
change the system rapidly.
130
The know nothing, do nothing faction
While it is generally true that the people in
this fction dont know anything, they are wrong
in asserting that nobody else knows anything and
that we shouldnt do anything. We dont know
everything about this subject, but we know a lot.
And what we know suggests that the downside
risks of failing to deal with it are very large.
There is a significant probability of serious
damage to our economy, to the public health, to
the function of ecosystems. The real question
In the face of very large downside risks from
failing to address this problem, and the very
modest costs of addressing it, is it prudent to
do nothing? You dont need a rocket scientist or
a Nobel laureate economist to answer that
question! John Holdren
131
The Current Situation
The reliability of energy supplies is decreasing
because of political instability and increasing
demand, at a time when many countries are
becoming more dependent on those supplies. The
United States is heavily dependent on foreign
oil, and natural gas prices have doubled in
recent months. Overall consumption of electrical
power is increasing, and is likely to rise from
40 to 70 by 2050 (think computer!) During the
next decade, the role of renewables, particularly
wind and biomass, will increase, but not nearly
enough to fill present requirements. The U.S.
and other developed countries will find it
necessary to devote far more attention, including
increased RD, to multiple risk and energy
trade-offs involving coal, nuclear power,
petroleum, natural gas, and electric power.
132
Impact of Near Term Business as Usual
  • The U.S. will be increasingly dependent on oil
    from the Middle East.
  • Regional air-pollution impact of fossil-fuel
    combustion, will grow alarmingly in much of
    world.
  • Disruption of global climate by CO2 will become
    the dominant environmental problem of 21st
    Century, imperiling productivity of farms,
    forests,and fisheries, rendering many of the
    worlds cities unlivable in the summer, putting
    coastal property at risk from rising sea level ,
    and imposing a panoply of other adverse impacts
    on human health, property, and ecosystems.
  • Economic growth will be curtailed by constraints
    on growth of energy supply from environmental
    costs.

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Reducing Carbon Emissions
Current recommendations are to set a target to
reduce 2010 carbon emissions by 10 below 1990
levels. But over the longer term we are talking
about deeper reductions. To stabilize the
atmospheric concentration of CO-2 at twice its
pre-industrial levels, we would have to cut
todays emissions worldwide by at least 50. To
stabilize the concentration at anywhere near
where it is today, you would have to cut fossil
fuel carbon dioxide emissions a factor of more
like 5 or 6 fold. Under a business-as usual
scenario, contributions from non-carbon emitting
sources would have to increase 15-fold in the
21st century to stabilize greenhouse gases.
134
Approaches
  • Constraints (e.g., Kyoto Protocol)
  • Technology
  • Conservation
  • Non carbon emitting (nuclear power, renewables)
  • Economic Incentives
  • Taxes on carbon emissions
  • Allowing constraints to be bought and sold

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Policy Efforts
  • Earth Summit in Rio Nations agreed to pursue
    stabilization of greenhouse gas concentrations in
    the atmosphere at a level that would prevent
    dangerous anthropogenic interference with the
    climate system.
  • Intergovernmental Panel on Climate Change (1995)
    Concluded that global warming was occurring.
  • The 1997 Kyoto Protocol An effort to get
    developed nations to take actions to reduce
    emissions, setting targets and timetables. (The
    United States has thus far failed to ratify this
    agreement.)

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The Kyoto Protocol
  • Calls for reducing carbon emissions 5 below 1990
    levels by 2012.
  • But U.S., as worlds biggest emitter, has to
    reduce 7 below 1990s. With the robust economic
    expansion of the past decade, this would amount
    to 30 below business as usual. Possible costs
    as much as 4 of GDP.
  • U.S. has not (and probably will not ratify) the
    Kyoto agreements. Instead prefers buying out
    of constraints with other less polluting nations.

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What else can be done?
  • Reduce the energy-intensive nature of our society
    (although this will be very difficult in view of
    the energy needs of developing nations).
  • Reverse deforestation by planting trees and other
    CO-2 absorbing vegetation.
  • Capture and store CO-2 (much as radioactive
    waste)
  • Make a massive shift to non-carbon-emitting
    energy sources such as nuclear power, perhaps
    coupled with new technologies based on a hydrogen
    and a liquid fuel.
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