K45: Strategies Technology
Reducing / Eliminating /
Reversing Climate Change
Part 1
RECAP OF THE
SCALE OF THE
PROBLEM, IN 14
SLIDES
Strategy… to Accomplish What?
• 1. Is our goal to return to a state of stable sea level close to
today’s? Stable temperatures, and a stable climate? This is
either impossible, or will require MASSIVE, IMMEDIATE and
wrenching change far more severe than the populace
believes
• 2. Or, is our goal to do what we can to slow our descent into
climate chaos, but not at the price of economic growth or
population freedom? This is more do-able, still requires very
large political and economic changes. It still results in a (less)
disastrous future for thousands of years, compared to
business-as-usual.
• You decide, students – it is more your world
than mine: Alas, you will inherit what my
generation and those before have left you.
To Identify Technologies, We Need to
Appreciate the Scale of the Problem
• 93% of greenhouse heating has gone into the ocean, which has 700
times more thermal capacitance than the atmosphere, and where it will
prevent the thin atmosphere above it from cooling off at all – for
thousands of years – even if we halt ALL CO2 emissions and somehow
re-freeze Arctic permafrost and halt other methane release
• The Arctic permafrost will continue to thaw since temperatures will not go
back down, and this carbon therefore will contribute greenhouse forcing
at poorly known levels, even if we end industrial civilization overnight.
• +1.5 above 2012 temps or +2.3C above pre-industrial) is enough to thaw
the entire Siberian permafrost, and likely the rest of the Earth’s
permafrost (Vaks et al. 2013, and here, and Lawrence et al. 2007. It’s
already begun). Here in 2016, we are already at ~+1.3C above preindustrial temperatures
• +2C is realistically inevitable, soon, and climate negotiators even 4 years
ago said only a complete cessation of all industrial civilization will prevent
+2C. Scientists are even less optimistic than that. Especially today.
From former NASA/Goddard Space
Science Institute’s Prof. James Hansen…
• “The paleoclimate record makes it clear that a target to keep
human made global warming less than +2°C, as proposed in
some international discussions, is not sufficient - it is a
prescription for disaster. Assessment of the dangerous
level of CO2, and the dangerous level of warming, is made
difficult by the inertia of the climate system. The inertia,
especially of the ocean and ice sheets, allows us to introduce
powerful climate forcing such as atmospheric CO2 with only
moderate initial response. But that inertia is not our friend - it
means that we are building in changes for future generations
that will be difficult, if not impossible to avoid."
See 2011 http://www.giss.nasa.gov/research/briefs/hansen_15/
A 2016 peer-reviewed version of his comprehensive evaluation of
our climate past and future is described and linked here
Therefore, Even With Little or No Further
Human-Caused CO2 emissions… +2C will
Happen Well Before the End of This Century
• At 400ppm CO2, sea levels rise inexorably for many centuries, rising
eventually ~80 feet or more (we’re at 405 ppm in 2016)
• It requires a reduction in GHG emissions of ~67% merely to halt
rising atmospheric CO2 and hold at current levels (Matthews and
Weaver 2010)
• From Ice Age paleo data which had much milder forcing, there were
pulses of sea level rise of ~+2 ft per decade and lasting centuries,
making it impossible to have ports or conduct international trade in any
form resembling today.
• However, these pulses were from a time when the Earth had much
more ice to melt than today, and the evidence suggests these pulses
were from the Canadian Laurentian ice sheet (no longer exists), so
possible future pulses would have to happen from Greenland or
Antarctica
To Halt Climate Change…
• Requires immediate end to all carbon emissions, including
those from livestock and tropical methane sources
• Requires preventing tipping point thawing of the Arctic
carbon sources (if that’s still possible)
• Requires re-freezing the West Antarctic so it may reanchor to the grounding line
• Requires pulling heat from the oceans to the atmosphere
where, with low enough CO2, it may radiate to space
• This requires not only a cessation of all carbon emissions,
it requires a massive commitment to developing and
deploying a technology for CO2 removal from the
atmosphere, significantly in addition to that naturally due
to oceans and plants, and finding somewhere to put it
which is stable long term, regardless of cost.
At This Late Date, it Requires
a COOLING World
• …to halt polar thaw.
• But it is change per se, which is so damaging to ecosystems
and human civilization, in either warming or cooling
direction.
• Think of the danger in engineering this - Climate change
now in the cooling direction
• Think of the massive political and social resistance that such
a climate shift would cause, and ask whether you think we
will do it, for the sake of future generations unborn and uncared about so far.
• When Paris, London, Florida, Venice,…. are underwater, it
will be too late to recover those priceless heritage cities by
re-freezing the poles.
So while “Let’s all ride bikes to solve global warming”
sounds wonderful, it’s nowhere near the level of wrenching
change necessary
These Goals Are in Sharp Conflict with
the Aims of the Third World Nations, the
Existing Energy Corporations, Our
Political Structure, and Civilization’s
Infrastructure
• Global CO2 diffusion time is weeks. My CO2 emissions
become EVERYone’s CO2 very quickly
• In a competitive world, this is a big problem
• Counting on global voluntary action to solve this, is noble…
and futile. Only GLOBAL government enforced policy
action of an extreme nature could hope to halt climate
change. Since there is no GLOBAL government nor
prospect of one which could enforce this, I am not
optimistic
China and India together emit almost twice the CO2 as the
U.S., and mostly from coal, and new coal plants continue to
be built, albeit at a slowing rate late in 2015. Other growing
Asian countries add to this.
.
While there are Some Good
Trends in Some Developed
Countries…
• Scotland just shut down their last coal-fired power plant
in 2016
• CO2 emissions per $ of GDP is starting to decline in the
U.S. and Europe
• China is scaling back their plans to bring online new
coal-fired power plants
• Conservation is a relatively easy and painless option not
sufficiently pushed. For example, in the U.S. it is
estimated that about ¼ of people’s electricity bill is due
to devices which are “off” but yet in “vampire mode”
…Global Carbon Emissions. Not just totals, but the actual RATE of
emissions, continue to increase (but 2015’s global [not U.S.] economic
recession gave a pause), mostly from Asia. Since 2100, carbon
emissions are rising at DOUBLE the rate (3%/year) that they were in
the final quarter of the 20th century. Graphs here as of 2012
So it’s a VERY tough reversal that is
needed. What technology ideas are there
for helping us minimize the necessary
pain to Civilization?
Part 2
Alternative Energy
Wind, Hydro, Solar,
Geothermal Energy Sources
• Astrophysicist Frank Shu argues (Shu
2008) that the most promising energy
sources which can compete in the sheer
volume of energy which our society
currently requires, are…
• --- solar photovoltaics
• --- nuclear power
• --- Others argue wind and geothermal also
make some sense.
Potentially, Solar Energy Dwarfs
Other Renewables, Wind Next
A. Solar Photovoltaics
Solar Photovoltaics: Good…
• Solar PV’s Advantages:
• --- rapidly getting cheaper
• --- carbon nanotube-based solar may provide improved
power/cost ratios
• --- rooftop panels allow distributed systems “off the grid”
and therefore
• *** provide no easy targets for terrorists (cyber-terrorism
threatens all, but individual rooftop PV least)
• *** allow energy independence and are the ultimate in
“local”, motivating their care by owners
• --- few if any moving parts to break, only occasional
further investment (batteries mainly) once purchased
• --- in warm climates, rooftop systems also lower heat
load to structures, lowering air conditioning costs. As the
Earth warms, more and more of us will be in “warm
climates”
Solar rooftop system in Germany. Large
subsidies helped get solar going in this
cloudy northern country
Rooftop Solar is Appealing
• In the US, if every building had rooftop solar,
it could supply as much as 39% of our 2013
electricity (Gagnon et al. 2016 in a white
paper from the National Renewable Energy
Lab)
• However, even uber-optimist Mark
Jacobson sees rooftop solar only giving 7%
of the US power by 2050, and that is with
“enormous, heroic assumptions about social
and political change” (quote)
From Gagnon et al. 2016
With subsidies and govt support, global solar installations
growing. But Europe (blue) scaled back subsidies, severely
hurting deployment as this graph shows
Solar PV Accessible Power Potential, Including Cloud Cover
Solar PV price/watt 1977-2011
Solar PV module costs 1985-2011
In the US Solar PV Prices
Continued to Drop for Both
Residential and Utility-Scale
Solar and Wind are Rising as
Percentage of US total Power
But Govt. Subsidies Have Had a
Strong Boost on the Spread of Solar
Energy
• Nothing inherently wrong with this, especially
given the huge subsidies ongoing for fossil carbon
• The Solar Investment Tax Credit , was scheduled
originally to end in 2016 but now extended as part
of the appropriations bill voted on at the end of
2015. The solar subsidy end in Europe clearly had
a major impact on spread as we saw a few slides
back. Subsidy loss in the U.S. was predicted to
cause 80,000 jobs lost.
• .
Levelized Cost of Electricity:
LCOE
• “Levelized cost”=LCOE = The average
total cost to build and operate a powergenerating asset over its lifetime, divided
by the total energy output of the asset over
that lifetime.
• The LCOE can also be regarded as the
minimum cost at which electricity must be
sold in order to break-even over the
lifetime of the project
2015 Renewables LCOE’s for broad range of countries,
from EnergySolutions. Roughly comparable to Fossils.
Utility solar still beats rooftop costs, (onshore) wind
even cheaper. Range of forward discount rates don’t
change relative positionings
Solar and Wind LCOE in 2013; Roughly 50% higher
than coal. But 2016 coal got much cheaper
Projected levelized costs ($/MWh) for
power plants entering service in 2020
•
•
•
•
•
•
•
•
•
•
•
•
$48 – Geothermal ($44 with subsidies), but in rare loc’s
$74 -- Land-based Wind
$75 – Conventional Nat Gas
$84 -- Hydroelectric
$95 -- Advanced nuclear (online date 2022, not 2020)
$100 – Nat Gas with Carbon-capture
$100 -- Biomass
$125 -- Solar PV ($114 with subsidies)
$144 – Coal with Carbon-capture
$197 -- Off-shore wind
$240 -- Solar Thermal
Source: IEA Data on next slide (note however that the IEA has
tended to underestimate the cost drops in solar in the past)
Cost For Solar vs. Fossil Fuels: Improving
Every Year to 2014. ($ per GigaJoule).
(In 2015+, strong price decline in fossil fuels, however)
But can solar PV costs
continue to fall? Not as fast…
• Technology advances have wrung most of the
theoretical Carnot efficiency out of solar
already. The theoretical maximum for a singlejunction cell is 34%
• Modern PV cell efficiencies range from the high
teens to 44% for the most advance (noncommercial) multi-junction cells, very close to
the theoretical 48% maximum.
• However, these cells cost ~100x the cheaper
cells, while delivering only ~4x the efficiency
Unlike Moore’s Law, and computer power
Solar’s future efficiency gains will be quite
slow
More important for cost…
• The technological gains in efficiency are mostly
already accomplished, as are the gains due to
economies of manufacturing scale.
• Solar is already a significant industry, with scaling
mostly accomplished, especially by the Chinese
• Gains will likely continue, but be significantly slower
• BEWARE of promoters who simply extrapolate past
curves into the future, ignoring the true source of
the future costs
Polysilicon Prices – Past Decade. Price
spike due to shortage, then a glut, and
then stable cost past 2 years
Solar PV Module price declines have
halted in the recent years.
This is also seen in the past decade’s deviation from
Swanson’s Power Law, note the steepening lately – falling
module costs are not leading to increased shipments at same
rate as earlier, as more of the costs are not in the modules,
but other costs which are not falling at nearly that rate…
Another way to see the slowing gains in solar PV cost and efficiency is from
the profitability of solar PV companies, as reflected in their stock charts.
Today’s largest solar PV manufacturers: Sunpower, First Solar, JK Solar,
Canadian Solar… all peaked in 2008, while the S&P 500 stock average
(brown curve) peaked in 2015. Below; Sunpower (SPWR in black) is typical,
and down 40% since mid 2014…. signs of a mature industry.
As of 2014: (source)
• Hardware: $1.76 per watt (44% of total cost)
• Install Labor and Electrician: $0.68 per watt (17% of total
cost)
• Permits: $0.08 per watt (2% of total cost)
• Marketing/Outreach: $0.82/watt (20% of total cost)
• Overhead/Profit: $0.66 per watt (17% of total cost)
• Total system cost: $4 per watt ($16,000 for typical home)
• Hardware is already less than half the total cost
• Unless all these costs can come down at high rates (not
likely), simple extrapolation of past trends is far too rosy a
projection. Beware agendas from the “growth is not to be
questioned” policy people (see K43 PowerPoints)
So: We see that the remaining
solar PV costs…
• … are in labor and materials, electronic
components like inverters, and other segments
which have already matured and are not
plummeting in cost
• For the panels alone, solar PV is down to
$0.61/watt - but total installed cost for a
homeowner is 7 times higher; $4/watt
• These facts argue that the large drops in solar
costs have already occurred, and future drops
will be more incremental
Hardware is already less than half
the total cost of Solar installations
• Permits, labor, marketing, profit, are 56% as of 2014
• And even the “Hardware” includes items which are already
mature technology; supporting structures, wiring, metal fab…
• And photo-voltaic chips, which increasingly are a minor part of
the costs.
• Add in, that most theoretical efficiencies are already
accomplished, and the conclusion is clear: Solar costs are not
going to follow “Moore’s Law” like silicon computer speed has.
But what about adoption rates?
• The one positive is that a legitimate case can be made for a
“tipping point” here, where the costs for new installation, with
all disadvantages included, is cheaper than alternatives. Then
adoption rates can spike upward.
A big problem…
• For a given country - when it’s after dark,
it’s after dark for the whole country (except
for Russia maybe).
• Therefore we need much better ways of
storing generated energy. Having
distribution lines cross-continent and intercontinental to connect sunny places to
dark places is very unlikely to be politically
possible
The Inconsistent Sun
• Power generation is at the mercy of weather, and completely
unavailable at night
• Power needs are greater in cold climates, but those are also where the
sun is weakest
• Typical duty cycle means a “1 GW solar plant” is actually only able to
deliver ~20% of that 1 GW averaged over a year of night time, weather,
cleaning, etc.
• Requires better storage technology to be feasible for high powered
society (says Elon Musk). Progress is happening here.
• And requires a very different grid based on the highly variable and
unpredictable outputs of solar (and wind). Expensive to re-build
such infrastructure
• Still, even given the existing power grid, rooftop solar can be a nobrainer for feeding energy into the grid and lowering carbon footprint and
lowering personal utility bills. And empowers individuals, and we all feel
better when we feel “in control”, in all areas of life.
One Way Solar Can Beat this
is…
• Solar Thermal: Using solar power to heat
a molten salt solution to far above the
boiling point of water, store it in a wellinsulated lining, and use it to boil water to
drive power turbines for long after the sun
has set
• It’s not quite as cheap, but getting there.
There are research projects on this in the
Mojave Desert
A Solar Thermal Power Plant
Solar
Panels
Covering
Canals.
More
Surface
Area Put to
Good Use,
Cutting
Evaporation
as Well
Going 100% Solar PV: Area Required Today is “Small”. A PV
panel area the Size of Spain or 497,000 sq km (2015) in a
sunny low latitude location, could supply the World today,
but need 40% more by 2030 (Dept of Energy)
Utility-Scale Solar Farms
Is Utility-Scale the Way to Go?
• Utilities are trying to take advantage of subsidies
and cheap desert land leases, and also keep
control of the electric power supply by building
vast solar farms.
• But these impact sensitive habitat, are ugly, and
require expensive transmission line losses
compared to local solar.
• Local (rooftop) solar seems far more attractive,
but it is less efficient as it needs it’s own power
conditioners, and… not enough rooftop area to
power the world
Utility-Scale Solar Farms:
Shadowing Local Flora
• This is a problem with current massive
solar farms… they are tough on the local
ecology
• Research at UCSC on solar cells which
are transparent at wavelengths needed by
plants, and placed much higher,
minimizing local ecological damage
• See local news
Topaz Solar Farm: borders Carrizo Plain National Monument, home to many
endangered species and the last large tract of unspoiled California Great
Valley ecosystem. Additional Space given to lessen effect on local animals.
Combining Utility Solar +
Wind
• Home-based wind systems not as efficient as
utility-scale wind because wind velocities are much
lower near ground level. Although is still worth
doing in some places (like Salinas Valley?)
Solar: Utility Scale, or Rooftop?
• Hernandez et al. (2015) find that roof-top solar can
supply 3-5x more energy than needed to power
California (behind paywall Nature: Climate Change ,
and discussed here)
• Other studies say there’s not enough rooftops to do
the job globally.
• I’m skeptical, but hopeful. Have no opinion at this
moment. Does this assume huge technology gains
that are frankly speculative?
Solar Roadways and Bikeways?
• Heavily criticized as too expensive and fragile
when first announced, the company SolaRoads
is having some success in their testing of a solar
bikeway, producing good solar power, expected
to produce 70 kwh/year per square meter when
finished. An effort and testing in France also is
worth following here
• The road/bike way has solar panels protected by
thick shatter-proof glass.
• Will it work? Is it cost-effective? Tempting; It’s a
lot of ground area otherwise wasted, but it’s a
tough environment and robust performance still
unproven, and how expensive will it be to route
resulting power from such expansive distributed
sources? Totally unlike power plant distribution.
Solar Manufacture: Carbon Cost
• 2008 study found 280 kwh input energy is
needed to produce 1 square meter of solar
panel
• Some more recent advertising claims are of 1.4
years to pay back carbon footprint.
• 2-3 years payback is more the average seen in
current (2015) literature.
• ~25 year life of a panel, so roughly 10x carbon
value in solar vs. fossil fuel
• 280 kwh/m2 means about 2.2x1014 kwh needed
to make enough solar panels to power the world
1 Kwh of power, generated by a mix of fossil
fuels, generates about 2.2 lb of CO2
• So that’s 2.2 x 2.2 x 1014 lb of CO2 to make enough
solar panels to power the Earth
• That’s 2.4 x 1011 tons of CO2
• That’s 240 gigatons of CO2 , or about 6-7 years of
total current global emissions of CO2 from all
sources. That’s a lot, but not discouraging.
• And likely a significant underestimate - you’d have to
first build the infrastructure to make all those
factories before powering them. And the supporting
industry (inverters, etc)
Jobs in Solar are Rising
B. Wind Power
Wind Turbines: Good Energy
Return on Investment
• EROI = “Energy Return on Investment”;
How long does it take to recover the
energy you invested in manufacture and
operation?
• EROI for commercial wind turbines is only
~7 months.
• Wind produces a tiny ~12g of carbon per
MWh (million watt-hours) of power over
the life of the turbine.
Some Good Features of Wind
Power
• Blades need to be high above ground to
access better wind speeds, but this also
allows ground below to be used for e.g.
farming – not true of solar.
• Farmers, in fact, are quite happy to earn
royalty income by allowing turbines built
on their land
• Wind is essentially solar power in another
form, from pressure differences caused by
differential heating of land
The “Wind Turbines Kill Birds”
Myth
• Fossil fuel interests complain commercial wind
turbines kill large numbers of birds.
• Even granting for the moment that the fossil fuel
corporations and their paid promoters which
make these claims actually care about birds, the
claim is vastly untrue...
• Wind turbines kill 0.27 birds/Gwh, while fossil
fueled power plants kill 9.4 birds/Gwh, or 50x
greater Sovocool (2012).
• Even nuclear kills more birds (0.6 per Gwh) than
wind.
And For Birds, Wind Farms are the
Least of their Worries
A Few Claim Nearby Wind
Turbines Make them Sick
• But no evidence of physical causation.
• Instead, seems most consistent with the “nocebo effect”
• “They list another possible reason for the sickness as
Somatoform Disorders which is ‘the unconscious
expression of stress and anxiety as one or more physical
symptoms.” Either one is basically claiming the problems
are all in the person’s head. The American Psychological
Association also conducted a study and came to the
conclusion if people think physical problems are caused
by the turbines, they will have them.’ (source)
• No doubt this will remain a favorite theme for the antirenewable energy lobbies to use
The big technology and cost advances were in the early days.
When it became cost-competitive, it got onto a linear deployment
rate still seen today (green curve, and next slide). In part too - the
best, most concentrated wind sites were built out first
Still, wind is gaining at a modest linear
rate, now 5% of U.S. generating power
Wind, Unpredictable. Tough on a current grid built
for predictability?.
Maybe Not. Wind for a given
Turbine will be variable, Yes
• But only the average over a large collected area really
matters to grid operators.
• The wind power turbine-to-turbine is uncorrelated
enough that it tends to average out well enough to not be
a problem
• This white paper (admittedly not necessarily unbiased,
but it does have quantitatives) argues wind power is less
affected by downtime than fossil fuel plants, since the
power per turbine is much less than for a single fossil
fuel plant which may be go down for maintenance,
accidents, etc
• Finds in Texas that wind variability will impose negligible
additional cost for required additional capacity
C. Energy Storage Technology
• How to power our transportation – cars, trucks, rail?
• A recent (Duduta et al. 2011) advance in battery
technology made at MIT is a hopeful sign. If it
works as hoped, it may double the energy density of
current batteries, and also make possible the ability
to "fuel up" at the pump with an oil-like rechargable
electrolyte much like we do with gasoline cars at the
moment. Read about it here.
• A new all-liquid-metal battery technology suggests
the possibility of very high storage densities at
relatively low cost. “Flow batteries”.
• Other battery technologies here
• But, so far the electrolyte liquid doesn’t stay
charged for very long
An Ideal “Battery” would have high Energy Density
(compact) and also high Energy RATE (the zoom factor, and
quick re-charge) capacity (upper right corner). So far, we
have to compromise…
Load Balancing When
Renewables Are Included
• Our grid requires precise 60 hz current be
always available. Different power sources
can accommodate to the varying load and
inherent inability of solar and wind to
output consistently.
• Nuclear: always on, full tilt
• Coal, hydro, can easily ramp up/down as
needed
• Solar, wind can ramp down. Not up
Graphene Capacitor Cars?
• Ultra Capacitors as energy storage are far safer
than high-capacity batteries in an accident, but
energy density hasn’t yet been competitive.
• 2016 prototype car from Edison Electric proposes
graphene (a form of carbon) energy storage to
enable ~300 mile range, and charge in only 5
minutes, making it very competitive with gasoline
cars
• On the other hand, similar claims and promise for
ultra-capacitor powered cars came from EEStor over
a decade ago in 2006… promising delivery by 2007.
Still unfulfilled.
The Promise of Graphene is
Large
• Graphene is a two-dimensional structure of
carbon – “thin, transparent, about 200 times
stronger than steel and conducts electricity
better than copper. When it comes to storing
energy, ‘It is about seven times better
performing than lithium-ion’ Monaghan said.
• Graphene is lighter, more conductive, does not
need cooling, charges faster and has a long life
cycle, he added, adding that it is also cheaper
than lithium-ion, costing about $300/kW
compared with about $1,000/kW for li-ion”.
I’ve seen “Wonder Breakthroughs”
Announced for Batteries for Many
Years
• But, still not much has happened commercially.
Instead, incremental improvement in older
technologies like lithium-ion. Elon Musk agrees – his
massive battery factory being built in Nevada now is
for Lithium-Ion.
• Wall Street-savvy observers have noted: Strong
danger of “conflict of interests” – overly rosy
announcements are often made to attract venture
capital. This is how Wall Street works unfortunately.
As more than a casual Wall St observer, my
personal observations can completely confirm this.
D. Hydroelectric Power
Hydroelectric is very cost
effective
• But, most of the usable and economical
sites are already dammed; it’s not
scalable, is costly to local ecologies, and
expensive and damaging to remove dams
once they silt up.
• Also, climate-caused drought will hurt midlatitude river flows going forward.
• But power can be constant on (unlike
wind, solar)…. (at least until reservoir runs
dry, or silts up… then constant off!)
• Hydroelectric accounted for 50% of U.S.
renewable energy, and 6.8% of electricity
generation in the U.S. in 2013
• Globally, hydro supplies 16% of total
electricity generation (not the same as
total energy generation)
• And expected to grow at about 3% per
year for coming years (source)
The Downside of Hydro-Electric
• Most hydro plants are in tropical or mid-latitude
areas, and flooding upstream land kills trees and
plants which, when now deprived of oxygen,
generate methane on decay
• The greenhouse gas emission rates, in many
cases, are equal to that of a large oil-fired power
plant. So, you get “clean” electricity at the dam, at
the expense of comparable GHG emissions in the
backed-up water behind the dam.
• Global methane emissions are still dominated by
tropical flood lands as of today
• Globally ~60,000,000 people displaced by dams
E. Geothermal Energy
• In rare places it is high grade and very
cost-effective (like Iceland), but most
places you can only access average
annual temperature, via digging many
meters down with pipes and access lowgrade thermal energy which is slow to
replenish, given low conductivity of soils.
• This is still quite useful to do for heating
and cooling homes and should be more
adopted than it is.
• No good for high-grade needs like fuel,
transportation, etc.
F. Nuclear Power
Nuclear Reactors are Just
Steam Engines
• Nuclear reactors are just steam engines that use
something other than wood or coal to stoke the
boiler. They use the heat generated by nuclear
fission reactions of certain heavy elements.
• Nuclear has some advantages:
• --- it’s “always on”, unlike solar
• --- its carbon emissions are minimal (even
including mining the uranium or thorium currently)
• --- it’s very energy-dense and can supply a lot of
power in a small area, so is intriguing for use in
technologies for pulling CO2 out of the
atmosphere.
Back to Fission: Conventional Light-water
Nuclear Reactor
Cerenkov Radiation as high energy particles slowed by water
Cooling and condensing steam
back to liquid, using cooling towers
Nuclear Fusion?
• Fusing hydrogen into helium, as the sun does, releases 100x
more energy per pound than even nuclear fission, and the
ocean has plenty of deuterium.
• Easier to fuse deuterium (D) and tritium (T), two heavy
hydrogen isotopes.
• Incredibly attractive: inexhaustible D fuel, essentially no
radioactive waste, and hybrid fission/fusion ideas can destroy
otherwise long-lived nuclear waste, using some for energy.
• Incredibly difficult to confine D,T to high density and millions
of Kelvin at the same time, so it’s still… “in the future”.
• Tritium, at the moment, can only be obtained by fission
reactors. That’s a problem.
• However, Lockheed-Martin claims to be working on a
compact fusion reactor which they say will work. We shall
see…
Doc Brown to the Rescue? Not
Quite
Nuclear – the Advantages
over Solar/Wind
• It’s “always on”, just like current carbon-fueled power
plants. This means minimal change to an existing
grid built with this assumption
• They can be sited almost anywhere, weather not
relevant (cooling water needed for current designs
though)
• They take up far less land than equivalent solar and
wind installations. Costs discussed later.
• Carbon footprint is very low, although on-going
fueling and enrichment/security costs are significant
vs. no fuel costs for solar, wind, geothermal, hydro
Nuclear – the Disadvantages
vs. Solar/Wind: Safety
• All reactors are necessarily big and very expensive. No carsized “Mr. Fusion” is on anyone’s horizon
• Safety - When they go wrong, they can go VERY wrong.
Remember, in the real world, bad engineers get jobs too.
• They were economically viable only when the government
stepped in to insure them. Are they economically viable
when they must be privately insured? Any Libertarian
wanting to support nuclear should consider that.
• Is no private company willing to insure a nuclear power
plant? If there are premiums to be collected over/above the
claims to be payed out, why are private insurance
companies not looking to exploit this opportunity? …or have
they in fact run their own risk/reward numbers and decided
it’s not worth it? (this is not sarcasm, I’m genuinely
wondering).
• There may be solutions to some of these… read on.
Nuclear – the Disadvantages: Waste
• Nuclear Waste – conventional waste is radioactive for tens
to hundreds of thousands of years. Stolen waste can
provide the material for a “dirty bomb” with no technological
savvy required. A “dirty bomb” can spread radioactivity
packaged around dynamite (for example) far and wide
which can be much more damaging than the dynamite
alone can do.
• Merely the threat of using such a bomb can apply great
political leverage. Even low grade nuclear waste therefore
provides a very tempting target for terrorists. In 2016
Belgium, this is proving to be more than a theoretical threat
• There may be solutions to these problems. Read on…
• Nuclear power safety standards and enforcement are poor
and need major upgrades. This will significantly increase
the cost of building reactors
• These problems do not exist for wind, solar, biofuels,
geothermal, and other renewables
Don’t worry about “The China
Syndrome”, worry about the
“Homer Simpson” Syndrome
• Nuclear Regulatory Commission
employees caught surfing the web for porn
while on the job (Washington Times
article)
• Regulators sleeping with the industry
people (literally) that they’re supposed to
be regulating.
How Many Reactors Are
Operating Today?
• As of March 1, 2011, there were 443 operating
nuclear power reactors spread across the planet
in 47 different countries [source: WNA]. 66 new
reactors are in planning or construction (source)
• In 2009 alone, atomic energy accounted for 14
percent of the world's electrical production.
Break that down to the individual country and the
percentage skyrockets as high as 76% for
Lithuania and 75% for France [source: NEI].
• In the United States, 104 nuclear power plants
supply 20 percent of the electricity overall.
Breeder Reactors – The Solution?
• Breeder reactors convert long-lived radioactive by-products into
power and into (relatively) short-lived radioactive by-products –
requiring storage for ~several centuries, rather than thousands of
years as with conventional reactors. They produce nuclear fuel as
they run, and so are also fuel-efficient.
• Capital costs are ~25% higher than for conventional reactors. With
the abundance of Uranium, breeders were not thought economical,
however with the worries about radioactive waste storage, they are
now more interesting.
• Supplies will exhaust with current designs in a matter of decades,
but with breeders and intelligent design using Thorium, could last for
well over 1000 years at current power needs (Shu 2011)
• Require a large starter of U235 to provide fast neutrons for fissioning
other nuclei. U235 is rare (0.7% of natural uranium is U235), but
available, so expensive enriching facilities still needed.
• For the waste to be safe after just a few centuries, requires very high
grade separation of actinide series chemical elements.
• From the Yale 360 forum, this article argues in favor of Breeder
technology, and this is a rebuttal
Should we give Nuclear another
chance?
• It’s possible that nuclear has been given an unfair knock from a few
bad accidents. Need better oversight in engineering, and PRIVATE
insurance, would insure lower odds of costly and dangerous
accidents. It was, at one time, hailed as a clean and low-cost new
power source…. before Chernobyl
• Chernobyl killed only 31 people directly, but estimates of excess
cancer deaths from the radiation cloud range from 9,000 (U.N. and
Atomic Energy Commission) to 25,000 (Union of Concerned
Scientists) to ten times higher (Greenpeace) - it’s easy to see the
correlation with “green”ness, but I myself am not in a position to say
who’s most correct.
• Japan’s Fukishima disaster in 2011 is still being assessed, but was
the only other “Level 7” nuclear disaster. Direct excess cancer
deaths here are expected in the hundreds, although many argue this
is too conservative.
• Mining of Uranium involves radon left in the tailings seeping into
ground water, and according to the International Atomic Energy
Agency, and here, this adds about 40,000 excess cancer deaths per
year, worldwide.
However ALL these death rates
Pale…
• … in comparison to deaths caused by fossil fuels, even
without global warming’s eventual casualties
• Black lung, emphysema, cancer, heart disease, air
pollution’s many other health effects.
• 13,000 deaths per year in the U.S. alone from coal dust
• Even hydroelectric has a worse record than nuclear… A
string of dam failures in China once killed 230,000
people.
• Fossil Fuels kill 320 times more people per unit
power produced than solar + nuclear combined…
• Adding in the deaths global warming will cause
show that arguments about nuclear safety, by
comparison, are a non-issue
• Fossil Fuels = 164 human deaths/TWh
• Solar = 0.44 deaths/TWh
• Nuclear = 0.04 deaths/TWh
But – a Big Problem with Nuclear is Rapidly
Escalating Cost:
Even more serious - the Time to Get
Permits For a 1 GW power plant: 13 yrs
for Nuclear vs. 1 yr for solar...
• Time we do not have. It would take political will to
change this, and technological change as well
• Meanwhile, solar costs are projected to continue to
fall
Sobering as Nuclear’s Rising
Costs Are…
• …They don’t include the cost of insuring the
power plants against disaster
• Uninsurable?
• Yes, says a study commissioned in Germany in
2011 (here) …
• …finds that insurance would cost at least as
much as the electricity produced ($0.20/KwH), at
a bare minimum, on up to 15 times the price of
the electricity produced ($3.40/KwH)
A Lecture by Frank Shu in 2011
• Discusses the advantages and disadvantages of
alternatives to “business as usual” and climate disaster
• Bottom line, solar is expensive (but he doesn’t mention
that costs are dropping rapidly, nor include externalized
costs!), carbon capture and sequestration he therefore
concludes is the short term solution, and nuclear using
breeders is the longer term solution, both to extend the
limited nuclear fuel resources, and to “burn” existing
nuclear waste.
• He does not mention nuclear cost escalations, does not
mention the tax-and-dividend strategy which changes
the cost arguments.
• Still, it’s a very worthwhile lecture on the details of how to
do nuclear properly
• Lecture Nov 2011 to U. Michigan students, (43 min)
My Thoughts
•
•
•
•
I’m no nuclear expert, and ideological emotions cloud both sides of this pro/antinuke debate, in my personal and reading experience. As I emphasize in Chapter 0,
Nature doesn’t care about my opinion, or yours, only about the Truth. That said, here
goes…
The danger of climate change disaster rises with every new day of research that
comes in. Beyond replacing fossil fuel energy currently, we MUST think seriously
about removing existing CO2 from the atmosphere on a large scale. Carbon-neutral
will not save us from serious and permanent climate change. I suspect the only
feasible way of powering the large energy needed to pull CO2 out of the atmosphere
may be nuclear power. Breeder technology is probably best, as it makes the most
use of existing isotopes and insures the long term safest nuclear waste.
What should power the grid into which your rooftop solar pumps its power? Perhaps
nuclear, but again – only if it can be privately insured and safety from theft is
absolutely insured. If insurance companies refuse to insure, that’s a bad indication.
Others make arguments that a proper balance of renewables, especially wind, could
still provide a stable grid. Given the existence of night, it would seem that stable
power would have to be transmitted over vast international distances. Security?
A de-centralized power grid, minimizing high tension lines from juicy terrorist-target
big power plants, is a necessary goal, with power generated by rooftop solar as
much as possible, and perhaps cellulosic or algae-based fuel in hybrid vehicles as a
carbon-neutral strategy for transportation, where high power density is essential.
There is a place for nuclear… whether that place is big or niche, remains uncertain.
• Fossil fuels need to be abandoned. The world’s naïve sentiment seems to
be – “OK, maybe so, we’ll inch towards other power sources, but only so
long as we don’t have to make any real sacrifices.” This attitude is a
prescription for disaster!
But There’s an Even Bigger
Problem with Going Nuclear…
• The rapidly rising CO2 emissions are coming from the 3rd
world, not Europe and the U.S.
• We won’t solve climate change unless we eliminate nearly all
carbon emissions GLOBALLY. So here’s the $64,000
question:
• Will the U.S. and Europe and their nuclear engineers provide
the technology and knowledge and materials to countries like
Egypt, Iran, African dictatorships, etc, to help them transform
their energy system to nuclear, as they envy American
wealthly lifestyles and energy footprints?
• Seems vastly unlikely, especially in a world entering an era
of climate chaos and desperation from “have not” countries.
G. Shifting from Conventional
Utilities to Distributed Energy
Ownership and Generation
• Good article (2014) here. Summary:
• “Vattenfall, a Swedish utility with the second-biggest
generation portfolio in Germany, saw $2.3 billion in
losses in 2013 due to ‘fundamental structural change’ in
the electricity market. The problem is well documented:
high penetrations of renewables with legal priority over
fossil fuels are driving down wholesale market prices -sometimes causing them to go negative -- and quickly
eroding the value of coal and natural gas plants. At the
same time, Germany's energy consumption continues to
fall while renewable energy development rises.”
• All it took is strong legal framework. Government
commitment to a renewable future.
• Will it continue? Uncertain, as politics continue
Germany’s War on Fossil Fuel
• “To make matters worse for (conventional fossil
fuel) utilities, their commercial and industrial
customers are increasingly trying to separate
themselves from the grid to avoid government
fees levied to pay for renewable energy
expansion.
• According to the Wall Street Journal, 16 percent
of German companies are now energy selfsufficient -- a 50 percent increase from just a
year ago. Another 23 percent of businesses say
they plan to become energy self-sufficient in the
near future.”
Rapidly Dropping Energy Costs are Making an Impact in
Germany. But subsidies helped, and manufacturing from the
1st world has been rapidly exported to 3rd world, whose
carbon emissions are skyrocketing)
Part 3
Reducing Carbon from Existing Energy
Sources, and Using Plants to Capture
Carbon
Reducing Carbon from Existing
Energy Sources
• We produce 38 billion tons of CO2 per year… ideas for capture:
• Using microalgae to remove CO2 from coal flue gas. Acidic flue gas reduces
CO2 uptake greatly.
• The Economics of CO2 Separation and Capture (Herzog MIT, late ’90’s)
• Other processes have been considered to capture the
CO2 from the flue gas of a power plant -- e.g.,
membrane separation, cryogenic fractionation, and
adsorption using molecular sieves – but they are even
less energy efficient and more expensive than
chemical absorption. This can be attributed, in part, to
the very low CO2 partial pressure in the flue gas.
Therefore, two alternate strategies to the “flue gas”
approach are under active consideration – the
“oxygen” approach and the “hydrogen” or “syn-gas”
approach.
Herzog estimated that by
2012…
• CO2 removal from coal flue gas would cost as
little as 1.5 cents per kWhr (but it hasn’t worked
out that way. At all).
• Gasify’ing coal allows up to 65% of the CO2 to
be captured, according to industry sources. Are
such “industry sources” to be trusted? I don’t
know…
• IPCC Report on Carbon Capture
• Again, strong flavor to “rosy up” the projections
by policy people, vs. energy analyst Vaclav Smil
who estimates scrubbing 20% from our
emissions would take 70% more than the entire
capacity of the petroleum industry flow rate.
Land Use Changes – Carbon
Capture by Plants
• Alan Savory shows how reducing overgrazing by judiciously
confining and moving cattle around on rangeland can make
a healthier grassland, sequestering carbon in the root
systems and helping with desertification.
• But topsoil is on average only 8” deep (and getting thinner),
and once filled with roots, it’s very slow to build new topsoil
(1 to 2 cm per thousand years)
• However, it’s a labor-intensive activity and such costs are
not addressed. There’s nothing brilliant about this sort of
basic cattle raising, and if it hasn’t already been done by
ranchers it’s most likely the cost, especially on a global
scale.
• COST of food is just not addressed, and high cost of food
globally causes revolutions.
Organic Farming and Carbon
Sequestration in Soil
• Soil can hold more carbon in roots, but only
until the topsoil has a climax community
above it, and topsoil is (on average) only 8
inches deep.
• Claims that organic farming can sequester
enough carbon to halt CO2 rise (Rodale
white paper), neglect this key fact. No doubt
a global return to organic farming would
allow a significant (but one-time) increase in
carbon sequestration
Yes, We Need to Do This…
BUT...
• Can we, and still feed 7 billion people affordably? We
have put our soils on steroids, stripping them of natural
nutrients and force-feeding nitrogen chemical fertilizers,
and used today’s massive monoculture Ag practices
precisely because this is the most cost-effective way
to get crops out of the soil with the least labor cost,
• Selling price minus cost means everything to a farmer.
We see riots when basic staple crops rise in price even
by just 20-30%, (e.g. “Arab Spring” revolutions)
• Worse, modern Ag practices are causing topsoil loss of
1%/year, and a recent Scientific American article
estimates we have only 60 years of topsoil left at current
trends.
Crop Yields Peaked a Decade
Ago. However….
• Young scientists (new winners of the Google Science Fair)
appear to have made a breakthrough:
• Irish teenagers Ciara Judge, Émer Hickey and Sophie HealyThow, all 16, have won the Google Science Fair 2014. Their
project, Combating the Global Food Crisis, aims to provide a
solution to low crop yields by pairing a nitrogen-fixing bacteria
that naturally occurs in the soil with cereal crops it does not
normally associate with, such as barley and oats.
• The results were very encouraging: they found their test crops
germinated in half the time and had a drymass yield up to 74
percent greater than usual.
• Maybe we’ll again GMO our way to another few year, further
stripping Nature, before it all catches up with us?
Stop Tropical and MidLatitude Deforestation.
• Deforestation adds carbon to the atmosphere in
two ways – by ending the sequestering happening
in living trees and by letting the carbon they have
already sequestered, slowly or rapidly (slash/burn)
return to the atmosphere
• Also, hurts low cloud formation, and doesn’t alter
albedo enough to compensate for these warming
forcings.
• New initiatives in tropical Africa may replant trees
on millions of acres of land
Boreal (far North) Re-Forestation:
Not So Clear They Help
• It’s not clear whether deforestation in the far north hurts,
or instead actually helps climate, since deforested land
here reflects more sunlight, even though it doesn’t
sequester the same amount of carbon. Bala et al. 2007
find albedo heating effect of trees dominates their carbon
sequestration effect.
• Remember that carbon can only be removed from the
atmosphere by a tree until the tree reaches full adult size
• But, brighter treeless landscape is a permanent cooling
forcing to climate, by reflecting more sunlight.
… Rebuttal from Nelson et al.
2010
• However, unlike tropical forests, Boreal forests
sequester 85% of their carbon underground, and
tree loss will cause much more carbon release
than just the tree mass Bala assumed.
• Also, climate change is already reducing snow
coverage in spring and summer, when albedo
matters, so albedo changes may not be as
significant.
• They conclude preserving Boreal forests is a
necessary part of combating climate change
If Yours is Goal #1 – To Halt
Climate Change…
• We’ll have to do all of the above, and
much more – we’ll have to quickly undo
the damage we’ve done, and reverse the
existing climate forcing.
• A. Removing carbon from the atmosphere
• B. GeoEngineering strategies to cool the
Earth
• C. Population Control, Other Policy
Strategies
Strategy: Plant Trees – They’ve evolved
over millions of years to extract CO2 and
sequester it as hydrocarbons
• Advantage:
Low tech! Given the political will, millions of people
could be employed immediately to plant trees with
minimal training. This is important – we need
IMMEDIATE solutions in order to avoid long term
disaster
• New initiatives in tropical Africa may replant
trees on millions of acres of land
Planting parties – fun! Build a sense of shared
effort towards our future
But, Tree Planting Looks to be
Too Little and Too Late
• --- Where do we plant them? The reason most of our
forests are gone is that we wanted that land to grow
crops and pave it over for cities and houses. Over 90%
of all arable land on Earth has already been converted to
agriculture and human use.
• --- In a rapidly changing climate, can we plant trees in a
place where they will thrive for decades to come?
• --- Worse, tree planting will only help a little: This IPCC
report, described more digestably in this article, finds
that planting trees will only sequester about 1.4 gigatons
of CO2 per year; vs 38 gigatons of human-generated
CO2 emissions per year as of 2015.
• In other words, only ~4% of current emissions.
• It turns out to be even trickier…..
Trees: Albedo vs. Carbon Uptake
•
•
•
•
•
•
•
•
•
The dark color of forests means they absorb more solar energy than the grasses
that would replace them, and according to one study, actually heat the Earth,
with the effect stronger at higher latitudes. (Bala et.al. 2007)
Especially true in the far north, where winter snow is highly reflective while dark
conifers absorb sunlight. In the tropics, there’s ~no snow so the difference in
albedo is much smaller – thus the dominant effect is the longer term
sequestration of carbon that trees provide.
There are three other effects of trees that both cool climate:
--- 1. Evapo-transpiration; taking water from the ground and evaporating in
leaves into the air absorbs the latent heat of evaporation from the environment
--- 2. This evaporation also promotes the formation of low clouds, which also
cool climate
--- 3. Trees take up CO2 out of the atmosphere to build their tissues
So there are 3 cooling effects, and one heating effect of trees. Finding out the
net of these was the subject of the Bala et.al. study. See summaries here
Lawrence Livermore Labs 2006 study, and also here.
Lee et.al. (2011) claim that the cooling effect of clearing high latitude forests is
not just theoretical, but shown in real data. Still, the issue is very complex and
other studies find losing boreal forests will warm climate, not cool it.
Bottom Line: Reforestation is best in the tropics to lower middle latitudes.
From latitudes of the northern U.S. northward, reforestation’s effect on
climate is controversial
Simulated time evolution of atmospheric CO2 (Upper) and 10-year running mean of surface
temperature change (Lower) for the period 2000–2150 in the Standard and Deforestation
experiments. Warming effects of increased atmospheric CO2 are more than offset by the
cooling biophysical effects of Global deforestation in the Global case, producing a cooling
relative to the Standard experiment of ≈0.3 K around year 2100. Bala et.al. 2006.
(Bala et al. 2007) Simulated cumulative emissions and carbon stock changes in
atmosphere, ocean, and land for the period 2000–2150 in (A) Standard and (B)
Global deforestation experiments. In Standard, strong CO2 fertilization results
in vigorous uptake and storage of carbon by land ecosystems. In the
deforestation case, land ecosystem carbon is lost to the atmosphere. Most of
this carbon is ultimately reabsorbed by grasses and shrubs growing in a
warmer CO2-fertilized climate at year 2100.
Of the land eco-system carbon in the Standard simulation that is not present in
the land biosphere in the Global case at year 2100, 82% resides in the
atmosphere and the remaining 18% in the oceans.
Let’s Ponder The Implications
of this Debate
• Before thinking about clear-cutting boreal forests, note
that the released carbon goes into the atmosphere and
the oceans
• The resulting greenhouse heating effect in the
atmosphere is slightly less than is the expected cooling
due to the more reflective grasses (and seasonal snow)
that replace trees.
• However, from reading the papers, it’s not clear that they
have included the fact that there is little or no snow to be
reflective in spring and certainly summer, especially as
temperatures soar in the Arctic
• Also, cutting Boreal trees would involve more carbon
going into the ocean, worsening acidification
• Kirchbaum et al. 2011 basically confirm Bala
et al. that albedo wins over carbon
sequestration, so Boreal re-foresting is a
problem.
• They measured the albedo of a pine forest
vs. meadow w/o trees in mid-latitude New
Zealand over time, and find that carbon
capture of trees rises with their age, but still,
the net climate effect is that the warming due
to lower albedo more than compensates for
the climate cooling due to CO2 sequestration
Warming vs. Cooling: Net Climate Effect of Planting
Trees (Gibbard et al. 2005). Only in Tropics does
tree carbon capture and cooling dominate
Natural Vegetation Changes due
to Rising CO2 Levels
• Port et al. (2012) model expected rising
CO2’s effects on vegetation for 300 years
• Find fertilization due to rising CO2 causes
boreal forests to spread north, deserts to
slightly shrink.
• By including the rise in carbon
sequestered by CO2-fertilized plants, the
reduced greenhouse warming is 0.22 C
• 0.22C is only a tiny fraction of the net ~7 C
rise in global temperatures
From Port et al. 2012
U.S. forests are currently taking up carbon in excess of releasing
it. This is as expected on land that has had most of its forests
already cut. Halting further tree cutting would sequester carbon
even more than currently. This is even more true in the tropical
rain forests where clear cutting has been rampant
Deforestation and the Ocean
• Other vegetation change simulations give similar results
• Note in the previous graph that in the global deforested
case, the ocean takes up much more CO2 than in the
‘standard’ case. While global temperatures may not
change much by 2150 between the ‘standard’ and
‘global deforested’ cases, the oceans suffer much
more by deforestation, and that CO2 must further
acidify the ocean.
• Planting mid and high latitude trees to take up carbon
should perhaps be seen more as a strategy for
minimizing ocean acidification and its dire
consequences, and not as much a direct global warming
solution, because it darkens the landscape and so
absorbs more sunlight.
Part 4
Artificial Capture of CO2 from
the Atmosphere – “Air Capture”
of GHG’s
Air Capture Units – Currently an evolving
research project whose goal is to remove CO2
from the atmosphere
Some Early Resources on this
Idea
• Klaus Lackner video lecture on our Carbon
dilemma (53 min) at SUNY Stonybrook
• Video interview (5 min)
• Good quantitative overview of the carbon
dilemma, from DOE and Lackner
• Demonstration video of artificial tree, BBC
2009
• NovaScienceNow video 2008 (12 min)
• Yale Environment 360 op/ed
As of 2014, newer conception of Air
Capture Installations from Lackner
Some Bullet Points on the CO2
Capture ideas of Lackner et al.
• Need 7 typical (real) trees just to pull out of
the air the CO2 generated by one breathing
human being (476 lb/yr)
• We’re injecting the equivalent of 130 billion
people’s worth out-breathing of CO2 into the
atmosphere
• Pulling CO2 by Lackner’s resin is very energy
intensive. This is why I suggest nuclear may be
the way to power them.
• Since CO2 rapidly moves through air, can pull it
out from anywhere. The resin idea works poorly
at low temperature and in high humidity;
Therefore, site them in deserts at mid latitudes
for best results.
Pack the “trees” around nuclear
power plants above carbon
sequestration sites?
• …if that’s feasible or possible (no info on that)?
• Now – the American Physical Society’s
evaluation (2011) and a summary: Bottom line,
uneconomical until all large point-source carbon
emitters are already thoroughly scrubbed.
• What about instead using BECS = BioEnergy
with Carbon Sequestration?
• The idea is to grow trees specially for burning as
power sources, but doing the burning in such a
way as to capture the carbon
Bio-Char as Sequestration?
• Lenton & Vaughn 2009 : “In the most optimistic
scenarios, air capture and storage by BECS,
combined with afforestation and bio-char production
appears to have the potential to remove 100 ppm of
CO2 from the atmosphere…”. (seems extremely
optimistic?)
• BUT – the biochar must be very pure or it’ll give
back it’s carbon to the atmosphere in a century or
two, or less. We don’t yet have the technology to
make such pure bio-char, especially at scale
• Another problem – producing bio-char means
heating the carbon in the ABSENCE of oxygen – but
it’s the oxidation which produces the power. So not
clear how efficient BECS really is, and I remain
skeptical of the promotions at this time.
Lackner’s early and (now clearly)
overly optimistic quantitative
evaluation of the artificial tree idea…
• Claimed can remove CO2 a thousand
times faster than real trees (!)
• Emits only 200g of CO2 for every kg of
CO2 removed from the air
• Each “tree” costs about the same as a
new car, and removes 90,000 tons of
carbon per year.
Compare Lackner’s Artificial
Trees to Real Trees (as of 2009)
• Real trees: 7 trees to remove 1 human’s
worth of CO2 production (476 lb/yr)
• Lackner’s “tree”: claim - 1000x more
efficient than real trees.
• Would need 100 million Lackner trees to
remove as much CO2 as we are emitting
at current rates
• Would need 100 billion real trees to do the
same.
• Source for these figures is here
Let’s Run Some Simple Figures…
• 100 billion additional trees (spaced 33 ft apart for a large tree,
seems reasonable in average climate) would require:
• At 33 ft x33 ft = 1000 ft2 per tree as a ballpark rough number,
means
• 1000 ft2 /tree x 100x109 trees = 1014 ft2
• = Area of United States = 1.06 x1014 ft2
• In other words, we’d need to plant additional real trees on a
tree farm as large as the United States to soak up all our
CO2 emissions. That sounds very hard to do
• If Lackner’s claims are correct, we’d need only 1/1000 of this
area, or about ¾ of the area of Los Angeles County, if we still
allow 1000 ft2 per artificial tree. This sounds do-able… IF
Lackner’s claims are correct
• Note that his business venture in this direction folded up in
2012.
2014 Update on Air Capture
• MUCH less rosy estimates of air capture are
now being acknowledged…
• Lackner now estimates the cost at $1,000/ton
of CO2 captured (much higher than his
original estimates of a few years back).
• Still, it’s ~15x more efficient than real trees at
CO2 capture. (His early estimate was 1000x
more efficient) And we need efficiency!
• What’s a planet worth, after all? Infinity, isn’t
it?
Let’s do the Math…
• Each part-per-million of CO2 in the atmosphere
is 7.81 gigatons of CO2
• So even assuming 350.org’s goal of 350 ppm is
where we should aim (climate scientists say it
should be lower), that’s…
• 50 x 7.81 Gt = 390 Gt CO2, and at $1,000 per
ton, that’s $390 trillion, which is…
• $56,000 for every man, woman, and child on the
planet… the vast majority of whom don’t have
anywhere near that kind of cash
UCSC’s Greg Rau Has Another
Idea, Using Bicarbonate Chemistry
• Combine silicate minerals in electrolysis with salt water and CO2
• From (Rau et al. 2013) …
• “Using nongrid or nonpeak renewable electricity, optimized systems at
large scale might allow relatively high-capacity, energy-efficient (<300
kJ/mol of CO2 captured), and inexpensive (<$100 per tonne of CO2
mitigated. [RN: $172/ton w/o re-selling CO2] removal of excess air
CO2 with production of carbon-negative H2. Furthermore, when added
to the ocean, the produced hydroxide and/or (bi)carbonate could be
useful in reducing sea-to-air CO2 emissions and in neutralizing or
offsetting the effects of ongoing ocean acidification.”
• Using wind energy, they calculate that to power the process would
require the wind energy from 7% of the Earth’s surface to remove 40
gigatons CO2/year
• A typical basalt can convert 1/3 of its weight of CO2 into bicarbonate,
so roughly 120 billion tons/yr of basalt would be needed.
But, the Oceans and Soils Already Take up
CO2 so that will help with the job, right?
• True, except that CO2 into the ocean lessens its alkalinity
and ability to absorb CO2, as does today’s hotter ocean
temps. Rising ocean temp does the same, compounding
that problem
• Also, recall that even if we end all CO2 emissions, the
thermal inertia of the oceans and the radiative imbalance
we’re already at, will prevent global temperatures from ever
going back down, for millennia
• So we do indeed need to force it down, quickly, before
more permafrost melts, more runaway polar melt happens,
etc. Perhaps not at $56,000 per capita, but even at ~1/4th
of that the effect on the global economy would be
devastating (but ultimately, worth it).
Ah! But You Recall from Garrett’s work
on the Thermodynamics of Civilization
• …that an economic collapse is what we need if
we are to keep CO2 levels from climbing
further and forcing temperatures higher
• An engineered massive global depression of
indefinite length, engineered by diverting
money away from goods and services and
instead to funding atmospheric CO2 removal –
cleaning up after our century-long Carbon party
• Highly unlikely to be politically acceptable until
climate pain has progressed till far too late
Where to sequester
the carbon is still
an issue…
Injecting CO2 into underground porous spaces
• Norwegians have been putting 1 million tons of CO2 per year back
into the ground undersea. (Recently, that halted)
• The Utsira Sand has pore-space volume of ~600 km3. 6 km3 would
be sufficient to store 50 years emissions from ~20 coal-fired or ~50
gas-fired 500 MW power-stations. Not remotely enough for global
….But…
• Remember that China alone had been stoking up 1
coal-fired power plant PER WEEK (albeit slowing
here in 2015)
• "Global Coal Risk Assessment: Data Analysis and
Market Research," released on 11/20/2011,
estimated there are currently 1,199 proposed coal
plants in 59 countries. China and India together
account for 76 percent of these plants.
• The United States is seventh, with 36 proposed new
coal-fired power plants.
• Update 2015: most of these are now shelved,
thanks to new requirements for cleaner emissions
affecting the economics
The industry buzz about natural gas as the new
energy source (“thanks” to fracking) in 2011.
Thankfully looking pretty wrong these days
Artificial photosynthesis
An electrochemical cell uses energy from a solar
collector or a wind turbine to convert CO2 to
simple carbon fuels such as formic acid or
methanol, which are further refined to make
ethanol and other fuels.
• Very energy intensive, but recent discovery of a
catalyst – an ionic liquid electrolyte (Rosen et.al.
2011) may make it energetically viable
• Process involves converting CO2 into carbon
monoxide (lethal!) as a first step. Safety issues?
Capturing CO2 by way of
Accelerated Weathering of
Limestone
• Rau et.al. find this a viable process for capturing CO2 from fossil fuel
power plants (flue gas), converting it to calcium bicarbonate through
the reaction…
• Cost estimated at ~$25/ton of flue gas CO2 sequestered (YouTube
promo seeking funding)
• http://aftre.nssga.org/Symposium/2004-09.pdf
• If these costs can be realized, this looks relatively economical
• What to do with the calcium bicarbonate? It only exists as an
aqueous solution at standard atmospheric conditions, so the volumes
required mean it would have to go into the oceans, presumably. How
would this affect ocean chemistry?
Rau method w/ outflow to the ocean results in minimal pH
and pCO2 effects vs. letting atmospheric CO2 directly
diffuse into surface waters
Rau’s Process is the Most Promising CO2
removal mechanism I’ve yet found for
scaling up to GeoEngineering scales
• Requires ready source of limestone, so could only be
done on large scale from certain coastal locations?
• Results in equilibrium pH change in ocean, after 1000
years, of -0.0014 per 35B tons CO2 processed. (35B
tons/yr was current rate (at publication) that we’re injecting
CO2 into atmosphere) (my calculation), and this is
acceptable in terms of its effect on ocean life (compare to
our ocean slide show on pH rate of change today)
• More figures and power requirements should be done, but
the basic paper provides enough to do this – it’s worth a
careful examination, if/when we get serious about
removing atmospheric CO2 before it’s too late.
• In 2012 I contacted Greg Rau (he’s a
professor right here at UCSC) and
suggested he consider ways to apply his
chemical process not only to flue gas, but
to the atmosphere.
• He has since teamed with Klaus
Lackner…
• Rau and Lackner – together! (but behind
paywall!)
• Here’s a YouTube with Rau
Related: Add CaCO3=Calcium Carbonate
Powder Directly to the Ocean?
• Harvey et al. 2012 suggest this, although it would take
decades to have an effect on fighting acidification, and
it would be tiny
• Would (marginally) help the ocean absorb CO2 from the
atmosphere, but plenty of limestone is already in contact
with the oceans along many shorelines worldwide
• 10% of the Earth’s surface is covered by limestone.
• Add CaCO3 to upwelling areas, sequester an additional
0.3 billion tons of CO2 per year (1% of what we add to
air by fossil fuel burning).
• Would seem to be a pretty minimal effect, and Stanford’s
Ken Caldeira agrees
• Bottom line – doesn’t look promising
Drawing CO2 out of the atmosphere and using it to
make carbonates - limestone rock (Belcher et al.
2010)
• … a process which happens naturally by ocean
life (but too slowly, and cannot happen at all in a
too-acidic ocean such as rapid CO2 rise is
creating).
• Major problems to be overcome; the amount of
energy required in the process, scaling up to the
levels needed to affect our atmosphere,
sourcing calcium, and cost, among others.
• Given that humans have injected an additional
1.2 trillion tons of CO2 over the past 250 years,
the Belcher et.al. process would require ~2.4
trillion tons of CaCO3, and at 2.71 g/cc density
of calcium carbonate,
Mt Everest-sized Block of CaCO3
to get back to Pre-Industrial
Atmospheric CO2 Levels
• This would require building 8x1017 cc's of rock,
or a cube 1 million centimeters on a side, which
is a Limestone block higher than Mt. Everest
(30,500 ft on a side) from sea level.
• That's also going to require a lot of calcium.
Calcium is common, but mostly it is found as calcium carbonate! Destroying CaCO3 in order
to make CaCO3 is questionable, except that we
might hope to use low-carbon energy (nuclear)
to make this round trip(?)… that’s frankly very
speculative at this point.
• Bottom Line: This is not the most promising
strategy
Start Smaller?
• To instead immediately drop current CO2
atmospheric levels from 400 ppm to 350 ppm
would required a cube of calcium carbonate of
only 22,180 ft on a side; still higher than any
mountain in the Western Hemisphere.
• At current production rates of ~40 billion tons of
CO2 per year, it requires an additional cubeshaped mountain 8,000 ft on a side every year.
• Is it possible to build "scrubbers" for the
atmosphere that could accomplish such a vast
task? Where do we put it all - the ocean? We'd
better make sure ocean acidification levels don't
reach levels (as they will this century, on our
current trajectory) that begin to dissolve existing
oceanic calcium carbonate. When that happens,
the problems we have been presenting so far will
pale by comparison.
Maybe besides putting it in the ocean, we could take a clue from
the ancient Egyptians… Visualize oil company executives
conscripted to toil under the hothouse conditions on 21st Century
Earth building the Great Carbonate Pyramids - pyramids of
calcium carbonate (or containers of calcium bicarbonate, as the
case may be) miles high, sufficient to clean up our atmosphere.
And, at wages comparable to those of the poor souls who built
the pyramids of Egypt. Likely we’d find people who would
donate the necessary land just for the satisfaction of watching
them toil.
Creating carbon fuels on-the-fly,
rather than mining ancient carbon
Gasoline and gasoline substitutes are attractive because…
• --- transportation vehicles (trucks, cars, trains) require very high energy
density power sources, and gasoline is hard to beat.
• --- we have existing infrastructure to deliver
• --- require little modification to existing vehicles to utilize
• But….
• Corn-based biofuels make little sense. They consume 30% more energy in
growth/manufacture than they give. Other problems:
• --- commandeer valuable farmland which could go to food
• --- vast acreage of tropical forests are cleared to produce sugar cane, palm
oil, and cereal grains destined for ethanol. Clearing tropical forests adds
both heat and CO2 to the atmosphere
• --- biofuels leave soils poorer, are supplemented with artificial fertilizers,
which add nitrous oxide and other pollutants to the atmosphere in their
manufacture, and are heavy water users.
• --- they nevertheless are being pursued, incentivized by government
subsidies for growers, who grease the pockets of the appropriate
government decision-makers
• --- accounting for carbon flows is deeply flawed on the part of the
proponents of corn and sugar ethanol biofuels. This strategy is not carbon
neutral
Good: Cellulosic Ethanol
• A Berkeley study published in Science
(Farrell et al. 2006) finds the cellulosic
ethanol has significant advantages over
fossil fuel in the making of gasoline
• Cellulosic ethanol many times more
efficient and lower carbon footprint than
corn-based or other ethanol’s.
(A) Net energy and net greenhouse gases for gasoline, six studies, and
three cases. (B) Net energy and petroleum inputs for the same.
Small light blue circles are reported data that include incommensurate
assumptions, whereas the large dark blue circles are adjusted values that use
identical system boundaries. Conventional gasoline is shown with red stars, and
EBAMM scenarios are shown with green squares. Adjusting system boundaries
reduces the scatter in the reported results. Moreover, despite large differences in
net energy, all studies show similar results in terms of more policy-relevant
metrics: GHG emissions from ethanol made from conventionally grown corn can
be slightly more or slightly less than from gasoline per unit of energy, but
ethanol requires much less petroleum inputs. Ethanol produced from cellulosic
material (switchgrass) reduces both GHGs and petroleum inputs substantially.
Better: Microbe-based fuel producers?
• Bio-engineered bacteria at MIT produce isobutanol – a
burn-able fuel. It appears it may be feasible to scale this
up to industrial scales.
• Algae-based diesel production. The company Algenol
claims to be able to produce over 6,000 gallons of
ethanol per acre per year, compared to corn’s rate of
370 gallons per acre per year. That’s 15 times more!
• In 2015, Algenol plans to open their first commercial
facility, for producing ethanol from algae
• Algae-based fuels may be viable, as judged in this paper
on alternative energy economics and investments
• However, energy analyst Vaclav Smil thinks biofuels are
completely cost/energy absurd (but I have no figures to
give here, yet)
Biodiesel from Algae
From Algenol’s website
Vertical hangers better utilize space,
but lose some incoming sunlight
We have TOO MANY people competing for
TOO FEW resources on this finite planet
• However, a major point is that ANY method of
producing significant quantities of biofuels are
going to have a major impact on raising prices
for competing resources. For ethanols, the
dilemma is “food-vs.-fuel”, and for cellulosic it is
(to some extent) “everything-vs.-fuel”…
• Cellulosic ethanol led to price rises in pulp such
that Mexicans were unable to buy tortillas, and
wood pellet factories pricing dairy farmers out of
the market for sawdust.
All Biofuels Share a Common
Problem
•
•
•
•
They emit CO2 back into the atmosphere!
As such, they are at best “carbon neutral”.
That’s not good enough. However…
If it becomes possible to scrub the CO2 emissions
from burning biofuels, this is another way to net
remove atmospheric CO2
• One idea is to convert the burned biofuel into biochar, which would hold the carbon for centuries (but
the amounts would be vast to affect atmospheric
CO2)
So, we’ve had alternative fuels employed now for going on
20 years. How are we doing on reducing CO2 emissions?
Answer: CO2 is not going down, not staying level, nor
merely increasing linearly… rather, it continues to
accelerate upward as of 2016.
Maybe we need more Drastic
Measures…
Part 5
Geo Engineering
• (No, not the conspiracy buff’s “spraying
the populace” nonsense.
• The word “GeoEngineering” first came into
being to refer to engineering efforts which
would affect the entire globe; here, for
climate)
• Example: Launch billions of “butterflies” to
the L1 point between Earth and Sun, to
block sunlight. Must be actively controlled
to keep them there. (Angel et al. 2007)
Or… Move one or more asteroids to the L1
Lagrangian point between us and Sun, and sputter
dust off of it to attenuate sunlight
Tug an asteroid to the L1 Lagrangian
Point, keep it there and blast off dust to
block sunlight from Earth?
• But the L1 point is an unstable gravitational equilibrium point.
When you run out of fuel to actively keep it there, the odds are
50/50 it’ll head downhill and smash into Earth.
• This would seem quite dangerous to attempt and far too
difficult to engineer right now (we need something NOW!). But
you can read the paper (Bewick et al. 2012) and see what
you think. You can read more opinions here.
• There is precedent, in that there is a great deal of
circumstantial evidence that comet impact(s) / debris
associated with the Taurid Meteor Shower may have been the
culprit which initiated the Younger-Dryas cooling 12,900 years
ago which reversed the exit from the last great Ice Age and
cooled the Earth for an additional 1000 years (Napier 2010
and references therein)
Injecting Reflective Aerosols into
the Stratosphere?
• This would mimic the effect of large volcanic
eruptions in their climate effect, and so we are
confident they would indeed cool the planet
• My (cynical) thought – why not just encourage
through direct Big Coal Corporate subsidies, the
construction of more coal mines, coal plants, with
very tall smoke stacks??
• Let’s make the whole world’s air look like China’s!
• Oh, I forgot – we already subsidize fossil fuel
corporations in the amount of $1,000,000,000,000
in 2012 alone (source)
Are These Sun-Shade Strategies Really a
Long Term Solution?
Big Problems
• 1. Sulfate aerosols are toxic (sulfuric acid) and would come down out of
the stratosphere on a ~few years time scale at most. So need constant
injection, which becomes a long term major expense.
• Continuous acid rain on our surface water. I’ve got no figures on how
significant this would be, but likely significant.
• These aerosols would also accelerate loss of stratospheric ozone, so that
it would affect not only the poles, but all over the globe.
• 2. Energy required to get the sulfates up there. Dozens or hundreds of
cubic kilometers of material raised into the stratosphere very energycostly.
• They cool only daytime, not night time temperatures (in fact, hurt radiative
cooling!)
• 4. Astronomers would not be happy (but, they’re not a significant voting
block, so who cares?)
• 5. Aesthetics – permanently smoggy hazy skies everywhere. Anyone
who’s lived in a smoggy city like I have, wheezes just thinking about it,
and finds this pretty depressing.
• 6. Most serious – ALL shade strategies at best only cool the planet,
they do nothing to help the problem of CO2-induced ocean
acidification if we continue to burn carbon
• But as a desperation measure to halt temperature rise and therefore
ice loss and sea level rise, they should continue to be investigated.
Enhance carbon capture by the
ocean phytoplankton by enhanced
upwelling through pumps/pipes
• Looked at by Lovelock and Rapley (2007)
and discussed here
• And also in this promotional video by
Atmocean Inc. here
• Early evaluation: Too slow to matter (see
next page), and quite possibly very
dangerous to ocean ecosystems
Radiative Forcings of GeoEngineering
Strategies (Lenton & Vaughn 2009)
Bottom Line as of Now…
• Nothing looks like a good GeoEngineering
strategy, except CO2 removal from the
atmosphere, which will almost certainly be
required to avoid a catastrophic future.
• The cost looks far beyond sticker-shock
level, but when the planet is dying, at
some point we may finally accept author
Kurt Vonnegut’s address at Stanford’s
commencement some years ago…
• “We could have saved the Earth, but we
were just too damn cheap”
Miscellaneous Pieces
• The later slides here need to be better
placed elsewhere. For now, rather than
‘delete’ them, here they sit…
Pop Quiz Question!
• You’ve seen all the great strides we’re
making in Renewable Energy…
• Now, in the past ~decade, looking at total
global energy consumption…
•
•
•
•
•
Has the fraction from Fossil Fuels…
A. gone down substantially?
B. gone down a little
C. Gone up a little?
D. Gone up substantially?
Can We Get Off Fossil Fuels?
Locally, In Some Countries – Yes
But Fossil Fuel burning is
skyrocketing in the new
manufacturing hubs of Asia
• We’ve only outsourced our
greenhouse gas
generation to Asia, as
they make all the cool
STUFF we crave.
• True 1994 to 2004
(here)
• And true 1965-to2012… (next slide)
U.S., Europe Exporting CO2
Emissions to Asian Manufacturers
World Energy Mix: Fraction
from Fossil Fuels is RISING
• Fossil Fuels made up 81% of global energy
consumption in 2004, and 2009, but 87% in
2013.
• We’re walking down slowly… on a still fast
rising escalator
• Yes, coal has turned and is going down – but
rising nat gas is more than compensating. If
coal-caused aerosols go down, immediate
effect is to RAISE global temperatures
In 2004, 81% of Global Energy
from Fossil Fuels (source)
In 2009, 81% of Global Energy
from Fossil Fuels (source)
In 2013; 87% of Global Energy
from Fossil Fuels
Global Fossil Fuel Use is Rising Faster
than Renewables, although Slowing in
2015 with the Global Economic Slowdown
Initially growing exponentially, after the end
of the ‘Great Recession’ in 2011, global
solar PV deployment has dropped back to a
constant annual deployment rate
The Wildly Celebrated US/China Emissions Pledges… do very
little. Even if entire world follows, CO2 emissions per year at best
stay constant so that atmospheric CO2 continues to climb
Oil exec’s have said current carbon tax
proposals of ~$10/ton of CO2 can be
(reluctantly albeit) incorporated into
their business plans
• $10/ton is nothing. After all, the whole POINT is to
DESTROY these business plans! Because they
are DESTROYING our future!
• The tax must be high enough to be crippling to
fossil fuel use, to radically and immediately
motivate strong change.
• $1,000+ per ton of CO2 is needed in order to fund
atmospheric CO2 removal in amounts significant to
climate, according expert Klaus Lackner
Present: Humans are over-taxing the ability of the planet to support life. The
“green revolution” helped moderate the growing overshoot (red curve
declined) from 1977-2000, but now is being swamped by the rising “standard
of living” of the 3rd World. All the while, our degradation of the land and ocean
is lowering the bio-capacity of the Earth (green curve dropping)
Future: Business-As-Usual can’t continue much longer. In 2008 we
were using resources at a rate of 1.5 Earth’s ability to renew, possible
only by steeply depleting our topsoil, stripping our oceans, and draining
thousands of years of groundwater… This trajectory ends badly.
Reducing the number of people has another aspect…reducing the
size of existing people! Obese people use up excess resources
just like additional people do. Enough corporate-promoted junk
food, please!
This also relates to the Stanford delayed gratification studies
Getting People OFF Junk
Food? Tougher than You May
Think…
• …Since climate change will be turning our
staple crops, the very crops most of the
World needs for food - into “junk food”
• Diabetes-inducing carb content will rise,
while protein and other nutrients will fall, in
C3 crop plants, according to a study
published in Nature by Meyers et al. 2016
K45: Key Points – Strategies: Technology
•
•
•
•
•
•
•
•
•
•
•
•
Shu (2008); Solar PV and Nuclear can provide practical large-scale non-fossil power.
Wind power rising rapidly as well.
Solar requires high quality battery or super-capacitor technology to go “off grid”
Solar has many advantages: know them.
Existing point-source CO2 emitters are more economical to scrub than is the
atmosphere
CO2 and high temperatures are permanent, unless humans actively remove CO2
from the atmosphere, beyond what the land and ocean do naturally
Artificial trees to scrub CO2 from atmosphere – must be sited in mid-latitudes
Artificial trees; rapidly evolving, require high energy input, sequestration still
problematic
CO2 must be removed from atmosphere before it is absorbed by the ocean, else
ocean life in peril and climate change truly permanent
World energy supplied by fossil in ’08 = 86%, rising to 87% by 2013.
Renewable sustainable present technologies can support world’s current
population only at a standard of living equivalent to that of Ethiopia. Or, at current
income distribution, can support about 2 billion people.
Most promising carbon-neutral bio-fuel source appears to be algae-based
Reducing atmosphere CO2 from 400ppm to 280ppm by making calcium carbonate
would require a Mt. Everest sized cube