Transcript Geoengineering

Our Choice: Sacrifice Low-Lying
Island Nations or GeoEngineering*
C. F. Brucker
August 26, 2016
*Large-scale engineering of our environment in
order to combat or counteract the effects of
changes in atmospheric chemistry**
*For low-lying island nations, human control of air
and ocean temperature as a matter of survival
** Natural or anthropogenic.
Cornerstones to Understanding Climate Science
•
•
•
•
•
•
•
•
•
•
CO2, CH4
SO2
H 2O
Planck’s Law
Stefan Boltzmann Equation
Keeling curve
Satellite data
Absorption data
Antarctic ice core data
Reliable sources of data
– IPCC Intergovernmental Panel on Climate Change
– NOAA National Ocean and Atmosphere Administration
– ACS American Chemical Society Climate Science Toolkit
– Refereed technical journals
• MODTRAN and Community Atmosphere Model (CAM3) computer modeling
• Inadvertent geoengineering
• Intelligent geoengineering – what it is and what it isn’t
C.F. Brucker
Radiant Energy
Planck's Law:
2hc 2l -5
Bl T = hc
e lkT -1
( )
B = radiant flux
h = Planck's constant
c = speed of light in vacuum
k = Boltzmann's constant
l = wavelength
T = temperature
Stefan-Boltzmann Equation:
E = sT 4
Sun-Earth energy balance:
(
)
(1- a ) ö÷
S Ave 1- a = s T
æS
TP = ç Ave
çè
s
C.F. Brucker
4
P
÷ø
1
4
SAve = 350 W/m2
α = 0.3
σ = 5.67E-8 W/(m2K4)
Calculate temperature Earth
Tp =
E = radiated energy
(= area under emission curve)
s = Stefan-Boltzmann constant
T = temperature
http://www.acs.org/content/acs/en/climatescience/energybalance.html
Sun-Planet Energy Balance
Planck Distribution
5800°K
Satellite data
reference needed
(http://www.acs.org/content/acs/en/cli
matescience/energybalance.html
C.F. Brucker
Comparison of the experimental solar
emission curve observed outside the
Earth’s atmosphere to the theoretical
(Planck’s Law) emission curve for a
5800 K black body located at the Sun’s
distance from the Earth. The structure
in the experimental curve is the result
of absorption of some wavelengths by
atoms and ions in the cooler layers
outside the sun’s emitting surface.
Calculate CO2 Weight Gain - and Diet Plan
Calculate CO2 Weight Gain - and the Extreme Diet
World Carbon Footprint, 1960 – 2011:
CO2 Emissions, Metric Tons Per Capita
Replot from raw data
C.F. Brucker
http://data.worldbank.org/indicator/EN.ATM.CO2E.PC?end=2011&start=1960&view=chart
Nature’s CO2 Absorption Capacity
C.F. Brucker
http://phys.org/news/2012-08-earth-absorbing-carbon-dioxide-emissions.html
Conservation – Preferred but Probably Not Sufficient
•
•
•
•
•
1750: 280 ppm CO2
(Industrial Revolution)
2015: 400 ppm CO2
CO2 weight gain: 1.1  1012 tons
Natural (forests & oceans) CO2 absorption capacity:
3.7  109 tons per year
• Zero-emissions time to lose all of Industrial Revolution
weight gain: 292 (73) years @ ½ ton (2 tons) reabsorption
• We may will not be able to conserve our way out of this
anytime soon.
C.F. Brucker
Keeling Curve
Average Monthly CO2 (ppm)
at Mauna Loa and South Pole
420
CO2 Concentration (ppm)
400
Mauna Loa website: http://www.esrl.noaa.gov/gmd/ccgg/trends/index.html
Keeling curve: http://www.esrl.noaa.gov/gmd/ccgg/trends/full.htmlCO2
Movie: http://www.esrl.noaa.gov/gmd/ccgg/trends/history.html
Movie: http://www.esrl.noaa.gov/gmd/ccgg/trends/ff.html
380
360
Mauna Loa
trend
340
South Pole
320
300
280
1950
1960
1970
1980
1990
Year
Using the Keeling Curve chart
above, calculate the slope of the
trend line for each decade. Use a
ruler and pencil to improve your
accuracy.
C.F. Brucker
2000
2010
2020
“Keeling Curve”
Mauna Loa website: http://www.esrl.noaa.gov/gmd/ccgg/trends/index.html
Keeling curve: http://www.esrl.noaa.gov/gmd/ccgg/trends/full.htmlCO2
Movie: http://www.esrl.noaa.gov/gmd/ccgg/trends/history.html
Movie: http://www.esrl.noaa.gov/gmd/ccgg/trends/ff.html
24
ppm/decad
e
20
ppm/dec
ade
10
ppm/dec
ade
C.F. Brucker
1991 flattening: Pinatubo  enhanced diffuse
scattering  enhanced vegetation growth
•
Climate Progress
–
–
–
–
–
–
•
1988 World Conference on the Changing Atmosphere, Toronto
1992 Rio Earth Summit - United Nations Framework Convention on Climate Change (UNFCCC)
1997 Kyoto Protocol
2009 U.N. Climate Change Copenhagen Accord
2015 Paris Climate Talks
Struggling, sputtering, failing utterly to achieve ANY goals (aside from a rare decline in emissions in 2009 - due
to the financial crisis)
Corporate Globalization Progress
–
–
–
–
–
–
–
–
•
The Past Quarter Century of
International Negotiations
Lowering emissions fundamentally conflicts with unregulated capitalism, the reigning ideology.
It is our collective misfortune that the scientific community made its decisive climate diagnosis at the precise
moment, 1988, when an elite minority holding a stranglehold over our economy was enjoying more
unfettered political, cultural, and intellectual power than at any point since the 1920s, aka GLOBALIZATION.
1988 world’s largest bilateral trade relationship between Canada and the United States, later expanded into
the North American Free Trade Agreement (NAFTA) with the inclusion of Mexico.
1995 World Trade Organization.
Mass privatization of the former Soviet economies.
Transformation of large parts of Asia into sprawling free-trade zones.
Structural adjusting of Africa.
Fossilized free trade never really about trading goods across borders. Rather, about providing maximum
freedom to multinational corporations to produce their goods as cheaply as possible, sell them with as few
regulations as possible, and pay as little in taxes as possible.
It’s a Shut-out for Unregulated Capitalism and the Rich vs. the Planet
C.F. Brucker
Movies
1. Movie: http://www.esrl.noaa.gov/gmd/ccgg/trends/history.html
2. Movie: http://www.esrl.noaa.gov/gmd/ccgg/trends/ff.html
C.F. Brucker
Nation Status: CO2 Emissions 2015
C.F. Brucker
https://scripps.ucsd.edu/programs/keelingcurve/tag/data-analysis/
Our Perilously
Thin Atmosphere
• Earth’s atmosphere
–
–
–
–
Height: 30 miles
Weight: 6 1015 tons
N2 78%, O2 21%, Ar 0.9%, CO2 400ppm (0.04%)
Weight of CO2: 3.6 1012 tons
• Anthropogenic CO2
–
–
–
–
Human population: 7.3 billion
Carbon footprint per person: 4 tons per year
Anthropogenic CO2 : 29 billion tons per year
Anthropogenic fraction of total: 0.8%
• Earth’s CO2 absorption capacity per person:
½  2 tons per year
C.F. Brucker
• Lake Erie or three Lake Tahoes
• Carbon footprint estimator
• Public domain MODTRAN (MODerate resolution
atmospheric TRANsmission)
http://climatemodels.uchicago.edu/modtran/
Greenhouse Gas IR
Absorption Bands
and Lapse Rate
Comparison of experimental (satellite, jagged black) and
theoretical (MODTRAN, jagged red) spectra of infrared
light detected from outer space looking down at the Earth.
The smooth curves are theoretical emission spectra of
blackbodies at different temperatures. The model
demonstrates the effect of wavelength-selective
greenhouse gases on Earth's outgoing IR energy flux.
C.F. Brucker
With increasing CO2
concentration, the lapse
rate (slope) remains
constant, but the energy
balance temperature moves
to a higher altitude. This
results in a warmer surface.
CO2 vs. CH4 MODTRAN Simulations
• Radiative forcing for the
2011 CO2 concentration of
393 ppm: 1.85 W·m–2
• Simulated warming for a
doubling of CO2 from 280 to
560 ppm: 0.9 K.
• Radiative forcing for 2011
CH4 concentration of 1.8
ppm: 0.8 W·m–2
• Simulated warming for an
increase in CH4 from its
current level of 1.8 ppm to
560 ppm: 4.4 K
• CO2 is said to be band-saturated. Additional heat retention per unit increase is small, but
time persistence continues to increase.
• However for CH4, which currently is not nearly band-saturated, we are on a much steeper
part of the curve. As a consequence, compared to CO2, CH4 is a much more potent
greenhouse gas. Fortunately, its concentration is much lower . . . for now.
C.F. Brucker
Radiative Forcing
When other variables are held constant,
emission from the atmosphere is inversely
proportional to the logarithm of the CO2
concentration. The slope of the line in the
figure can be used to find the radiative
forcing for a given CO2 concentration:
radiative forcing = (5.35 W·m–2) ln(C/C0),
Where C0 = 278 ppm (1750 baseline).
The radiative forcing for the 2011
CO2 concentration, 393 ppm, is 1.85 W·m–2,
slightly greater than the barchart value of
1.7 W·m–2 from 2007 (top red bar ).
C.F. Brucker
IPCC Fourth Assessment Report (2007), Chapter 2, Changes in
Atmospheric Constituents and in Radiative Forcing, Figure 2, FAQ 2.1
Climate Sensitivity for CO2 and CH4
• Radiative forcing for CO2 (185 to 265 ppm):
FCO2 = (5.35 W·m–2) ln(265/185) = 1.9 W·m–
Antarctic ice core data
2
• Radiative forcing for CH4 (375 to 675 ppb):
FCH4 = 0.3 W·m–2
• Total radiative forcing due to these two
greenhouse gases: about 2.2 W·m–2
• Predicted change in the average planetary
surface temperature:
ΔT ≈ [0.3 K·(W·m–2)–1] (2.2 W·m–2) ≈ 0.7 K
• Analysis of temperature proxies: Earth’s
average surface temperature increased
3 and temperature
4 K.
• between
Our calculated
change, which includes only the radiative forcing from increases
in greenhouse gas concentrations, accounts for only 20 - 25% of the observed temperature
increase.
• This implies a climate sensitivity factor* perhaps four to five times greater, ∼1.3 K·(W·m–2)–1,
than that obtained by simply balancing the radiative forcing of greenhouse gases.
• Our analysis based only on greenhouse gas forcing has not accounted for feedbacks in the
planetary system triggered by increasing temperature, including changes in the structure of
* Compare Lenton & Vaughn sensitivity factor of 0.9 (W·m–2)–1, p 5541, Atmos.
the atmosphere.
C.F. Brucker
Chem. Phys., 9, 5539–5561, 2009, www.atmos-chem-phys.net/9/5539/2009/
Temperature Rise – Small but Significant
Post WWII sulfate emissions:
https://www.youtube.com/watch?v
=9QpHxLkKYIU (Clark Weaver)
Consensus — All four analyses, shown superimposed in this figure, come to
the same conclusion — the Earth’s land temperature has warmed 0.9 °C in
the past half century.
Temperature Anomaly Measurement (with respect to 1950 - 1980 baseline):
HadCRU: Hadley Centre for Climate Prediction and Research and the University of East Anglia’s
Climatic Research Unit (CRU).
GISS: National Aeronautics and Space Administration (NASA), Goddard Institute for Space Studies
(GISS) at Columbia University.
NOAA: National Oceanic and Atmospheric Administration & National Climatic Data Center (NCDC),
whose results are usually labeled as NOAA or NCDC
UC Berkeley: University of California group, the Berkeley Earth Surface Temperature.
C.F. Brucker
Measured Global Temperature Anomalies
GISS 2011 annual average temperature relative to the reference time period,
1951-1980.
C.F. Brucker
Ocean Warming
Heat energy content of
the World Ocean from
1955 - 2006. The chart at
the bottom represents the
percentage of one-degree
squares that have at least
four values used in their
computation.
• Measured ocean warming from 1955 to 2000: about 0.09°C over the entire 0-2000 m
layer; about 0.18°C over just the upper 0-700m layer.
• As the oceans warm they expand. This thermosteric contribution to sea level rise has
averaged a little over 0.5 mm·yr–1 for 1955-2010 – about 3 cm during this time.
• In addition, melting of glaciers, land snow cover, and land ice sheets has added to sea
level rise for a total of about 10 cm during this period.
• The capital city of the Marshall Islands, Majuro, is about 90 cm above sea level. At the
current rate of sea level rise, Majuro will disappear under the waves in about 500 years.
C.F. Brucker
S. Levitus et al. Geophysical Research Letters 39, L10603 (2012)
One of the First to Go Under
Maldives Buying Land in Australia
in Preparation for Mass Migration
Malé, the capital of the Maldives
•
•
•
•
•
•
The Maldives Archipelago – Pop. 350,000 – one of the most idyllic destinations on the planet;
beautiful tropical islands in the Indian Ocean surrounded by coral reefs and sea life.
Southwest of India and Sri Lanka, it is the planet's lowest country, with a naturally highest point
eight feet above sea level.
The Maldives consist of 1,192 coral islands grouped in a double chain of 26 atolls. About 185
islands are inhabited. About 80% of the islands are less than three feet above sea level, so if sea
levels rise by 23 inches over the next century, as predicted by the Intergovernmental Panel on
Climate Change, the Maldives will largely disappear beneath the waves.
On Dec 26, 2004, the Maldives were devastated by the tsunami following the Indian Ocean
earthquake. 57 islands faced serious damage to critical infrastructure, 14 islands had to be totally
evacuated, and six islands were destroyed.
Maldivian Thoriq Ibrahim chaired an alliance of small island nations on the front lines of climate
change at the 2015 Paris talks. “Is anyone listening?”
Former Maldivian President, Mohamed Nasheed considered India and Sri Lanka, due to cultural
similarities, but has settled on Australia. He has set up a sovereign savings account, funded by
revenue from tourism, with which he has been buying land on high ground down under.
C.F. Brucker
http://www.dreamingofmaldives.com/
http://theislandpresident.com/
The First to Go Under
•
Marshal Islands – pop. 53,000
– About half way between Hawaii and Australia, 24 low-lying coral atolls comprising 1,156
individual islands and islets.
– The capital city of Majuro and other urban centers are 3 feet above sea level. In 2008,
extreme waves and high tides caused widespread flooding. In 2013, heavy waves once
again breached the city walls of Majuro.
– In September of 2013, the Marshall Islands hosted the 44th Pacific Islands Forum summit.
Tony De Brum, Minister of Foreign Affairs, proposed a Majuro Declaration for Climate
Leadership to galvanize concrete action on climate change.
•
Tuvalu – pop. 10,000
– A group of nine tiny islands in the South Pacific. Five of the islands are coral atolls, the
other four consist of land rising from the sea bed.
– All are low-lying, with no point on Tuvalu being higher than 15 feet above sea level.
– Tuvalu (and Kiribati – pop. 100,000) are also approaching the Australian government to
discuss the possibility of immigration assistance
•
Solomon Islands
C.F. Brucker
•
•
•
•
•
•
Also Drowning: Isle de Jean Charles, Louisiana
Isle de Jean Charles is a narrow ridge of land in southern Louisiana, linked to the mainland by a
long straight road. The water is closing in, already lapping at the edges of the asphalt.
It is the historical home to about 60 members of the Biloxi-Chitimacha-Choctaw Indian tribe.
These residents are the first “climate refugees” in the United States.
Exacerbating the rising seal level: levees, which deprive the delta of the very sediments which
made it, and dredging of canals by the oil industry which let salt water into the marsh, killing soilbinding plants at their roots.
About 350 villagers of Newtok, Alaska, are also moving to higher ground, but Isle de Jean Charles
is the first American community to be awarded federal funding – a $48 milllion U.S. Department
of Housing and Urban Development (HUD) grant – to relocate en masse.
The US Geological Society reports that Louisiana is losing a football field’s worth of land every
hour – or, about 75 square kilometers of coastal terrain every year.
1940
C.F. Brucker
O
TODAY
O
O
Arrowheads:
Mitigation
Black – shortwave radiation
White – enhanced natural flows of carbon
Grey – engineered flow of carbon
Grey upward – engineered flow of water
Dotted vertical – sources of cloud condensation nuclei
Dashed boxes – carbon stores
C.F. Brucker
Approaches
T. M. Lenton and N. E. Vaughn, Atmos. Chem. Phys., 9, 5539–5561, 2009
Comparison of Geoengineering Options
Summary of estimates for the radiative forcing potential of climate geoengineering options. Note the logarithmic scale. The potential of
longwave (CO2 removal) options is given on three different time horizons, assuming a baseline strong mitigation scenario: CO2 450 ppm in
2050 and 500ppm in 2100 (2016 update: CO2 could reach 600 ppm in 2050 and 1000 ppm in 2100). The rightward pointing arrows, which
refer to mirrors in space, stratospheric aerosols, and air capture and storage on the year 3000 timescale, indicate that their potential could
be greater than suggested by the diamonds (radiative forcing to be counteracted: 3.71 Wm-2 due to 2⇥CO2 = 556 ppm for the shortwave
options, and 1.43 Wm-2 due to 363 ppm CO2 in the year 3000 under the strong mitigation scenario.
C.F. Brucker
T. M. Lenton and N. E. Vaughn, Atmos. Chem. Phys., 9, 5539–5561, 2009
• movie (2 min)
– sulfate emissions post WWII
– https://www.youtube.com/watch?v=9QpHxLkKYI
U
• In 1980, students at Princeton noticed a thin layer of ash
accumulating on their window sills.
• It came from Mount St. Helens in Washington State, 3000
miles away.
• Hic-cups like Mount St. Helens and coal-fired plants inject
sulfur dioxide into the troposphere, the atmospheric layer
closest to earth. It lingers there for a week or so before
falling back to earth as acid rain.
• In 1815, the gargantuan eruption of Mount Tambora in
Indonesia produced “The year without a summer” that
brought snow to New England as late as June and killed
crops, prompting widespread starvation and food riots.
• Major volcanic eruptions like Tambora, Krakatoa (1883), and
Pinatubo (1991) inject SO2 particles into the stratosphere,
10miles up (five miles at the poles), where they circulate for
a year or more, with strong climatic effect - in particular, a
drop in global temperature.
• Based on measurements before and after Pinatubo, there is
no doubt that stratospheric SO2 cools the earth.
• Enhanced diffuse insolation following Pinatubo and El
Chichon (1982) produced enhanced vegetation growth.
• Wouldn’t it be nice, though, not to have to rely on volcanoes
to do the job?
C.F. Brucker
Volcanoes to
the Rescue!
June 1991
August 1991
View from the Space Shuttle over South
America, showing Pinatubo aerosol cloud
(dark stripes) high over culumonimbus tops.
2011
Natural SSI
The eruption of Mount Pinatubo in the Phillipines, 1991. The cloud of ash and
pumice was deadly. The roughly 11 megatons of sulfates initially injected into the
stratosphere cooled the entire earth about 0.5°C (0.9°F) between 1991 and 1993.
Cyclone frequency found to be inversely proportional to volcano frequency:
https://eos.org/research-spotlights/fewer-tropical-cyclones-form-after-volcaniceruptions
C.F. Brucker
CAM3 Globally Uniform Insolation Reduction
Simulated temperature profiles assuming (left) a twice pre-industrial CO2 level of 560
ppm without geo-engineering intervention, and (right) a geo-engineered globally
uniform 1.84% reduction in solar insolation over a 40-year period. This idealized
climate engineering simulation suggests that relatively simple climate engineering can
diminish temperature changes in most of the world.
The Community Atmosphere Model (CAM3) represents the sixth generation of atmospheric general circulation models
developed by the climate community in collaboration with the National Center for Atmospheric Research (NCAR).
Collins, W. D. et al.: The formulation and atmospheric simulation of the Community Atmosphere Model version 3 (CAM3),
J. Clim. 19, 2144–2161. (doi:10.1175/JCLI3760.1), 2006
CAM3 simulation by Caldeira, K. and Wood, L.: Global and Arctic climate engineering: numerical model studies,
Philosop. T. R. Soc. A, 366, 4039– 4056, 2008
C.F. Brucker
CAM3 Arctic-localized Insolation Reduction
Simulated temperature profiles assuming a twice pre-industrial CO2 level of 560 ppm
with insolation reduction constrained to latitudes 61° N – 90° N, with insolation
reduction factors of (left) 10% and (right) 50% over a 40-year period. The global
average insolation reduction corresponding to the right hand plot is 1.84%, the same
as in the right hand plot in the previous figure.
A disadvantage of Arctic injection is that the aerosols would last a few months rather
than a couple of years for tropical injection (the height of the troposphere is only ~8
km in the Arctic vs. ~16 km in the tropics). An advantage is that injection would only
be needed in the spring (there is no sunlight to reflect in the dark winter).
C.F. Brucker
CAM3 simulation by Caldeira, K. and Wood, L., “Global and Arctic climate engineering:
numerical model studies,” Philosop. T. R. Soc. A, 366, 4039– 4056, 2008
Polar Ice Cap
Simulated arctic sea ice extent corresponding to (left-to-right)
pre-industrial CO2 (280ppm), twice pre-industrial CO2 (580
ppm), twice CO2 with a global insolation reduction of 1.84%,
and twice CO2 with 50% insolation reduction above 61° N
latitude (Arctic Circle is at latitude 66° 33´ 39”).
C.F. Brucker
CAM3 simulation by Caldeira, K. and Wood, L., “Global and Arctic climate engineering:
numerical model studies,” Philosop. T. R. Soc. A, 366, 4039– 4056, 2008
•
Annual SSI Cost @ 1 Megaton per year
Airplanes
– A small fraction of existing military planes could be retrofitted for
SSI
– Three two-hour flights per day for 200 planes
– Several $B per year.
•
2008 Dollars
Artillery shells
– 40 10-barrel stations, 8000 shots per day, 250 days per year
– Noise, fallback of expended shells
– $30B per year
•
Balloons
– 36,000 balloons per day, 250 days per year
– “Trash rain” of collapsed balloons
– $20/$40 B per year for H2S/SO2.
•
Tall tower
– Single 20 km tower on equator (no strong winds, hurricanes, or
tornados)
– Two backup towers.
• Garden hose with tethered balloons.
– Similar issues as tall tower.
– Probably least expensive option ~$1B per year
Aerosol Research Directions
•
•
•
Injector design for 0.5 μm sulfate particle size.
Agglomerization of sulfate particles.
Marine Cloud Brightening Project in Sunnyvalle/Moss Landing
Mountaintop staging areas,
e.g., Gunnbjorn Mountain,
Greenland, high altitude
locations in the Andes.
– http://www.mercurynews.com/science/ci_28470304/climate-change-controversial-cloudA. Robock, A. Marquardt, B. Kravitz, and G. Stenchikov, “Benefits, Risks, and Costs of
brightening-project-proposed-moss
Stratospheric Geoengineering,” Gephysical Research Letters 36, L19703 (2009)
C.F. Brucker
Garden Hose to the Sky
Nozzle
18 km long
(high) hose
V-shaped
balloon
•
•
•
•
•
Base Station
C.F. Brucker
Sulfur is burned into SO2 and liquefied (just like in the
early 20th century, when SO2 was the major
refrigerant fluid).
A two-inch diameter hose is suspended from high
strength He-filled balloons fastened to the hose at
100- to 300-yard intervals, ranging in diameter from 25
feet near the ground to 100 feet near the top.
Pumps, about 45 pounds each, are affixed to the hose
every 100 yards
Nozzles near the top spritz the atmosphere with a fine
mist of colorless liquid SO2.
1 kg sulfur “balances” 100,000 kg CO2.
Steven D. Levitt and Stephen J. Dubner, Superfreakonomics (Illustrated
Version), Harper Collins, New York (2009).
Athabasca Oil Sands - The Perfect Site?
1000m wide, ultimately
100m high
•
•
•
•
•
One of the most plentiful waste products of oil mining is sulfur, which commands such a
low price that oil companies simply stockpile it.
Like industrial reincarnations of ancient step pyramids, mountains built of waste sulfur
dominate the Athabasca landscape.
One corner of one of these sulfur mountains contains enough sulfur to solve the global
warming problem for the Northern Hemisphere.
Thanks to stratospheric winds that typically reach 100 mph, the spritz would wrap
around the earth in about ten days’ time.
Because stratospheric air naturally spirals toward the poles, and because the arctic
regions are more vulnerable to global warming, it might make sense to spray the sulfur
aerosol at high latitudes - perhaps one hose in the Southern Hemisphere and one in the
Northern.
C.F. Brucker
Steven D. Levitt and Stephen J. Dubner, Superfreakonomics (Illustrated
Version), Harper Collins, New York (2009).
Stratospheric Sulfur Injection (SSI) Benefits and Risks
• Benefits
• Pre-industrial global average
temperature restored
• Sea ice restored
• Land ice restored
• Pre-industrial sea level restored
• Enhanced vegetation growth
• Relatively non-polluting
•
•
•
•
•
•
Risks
Regional climate variations
Ozone depletion
Reduced sunlight for solar power
Skies less blue
Hamper Earth-based optical
astronomy
• Human error
SSI Moral/Ethical/Political/Religious Issues
•
•
•
•
•
•
Proof that SSI is working might reduce the drive for mitigation.
Political and commercial control: whose hand on the thermostat?
Nightmare scenario – a rogue nation or individual takes unilateral action.
Global warming perceived to be good for some, so why SSI?
Do we have the right? Not gonna worry, he’s got the whole thing in his hands.
Geoengineering may be perceived as a weapon – not one of annihilation like
nuclear or bio-warfare, rather one of dominance and control.
• Military implementation/extensions.
C.F. Brucker
A. Robock, A. Marquardt, B. Kravitz, and G. Stenchikov, “Benefits, Risks, and Costs of
Stratospheric Geoengineering,” Gephysical Research Letters 36, L19703 (2009)
The End