Post on 16-Dec-2015
Using global climate models to evaluate environmental
problems and potential solutions
Ken CaldeiraDept. of Global Ecology
Carnegie Institution for ScienceStanford CA 94305 USA
kcaldeira@carnegiescience.edu
PIK21 May 2012
Exercises in undisciplined science
Ken CaldeiraDept. of Global Ecology
Carnegie Institution for ScienceStanford CA 94305 USA
kcaldeira@carnegiescience.edu
PIK21 May 2012
Factual statements
Prescriptive and normative
statements
Values, moralityScience
internationalv
Caldeira, Cao, and Bala, submitted
Where did carbon come out of the ground to supply Germany’s CO2 emissions?
Germany
Russia
Norway
Rest ofworld
Caldeira, Cao, and Bala, submitted
Where was CO2 emitted to support consumption in Germany?
Germany
China
Rest ofworld
Caldeira, Cao, and Bala, submitted
Where was the carbon extracted to supply consumption in Germany?
Germany
Russia
Norway
Rest ofworld
What is the international trade in carbon that is extracted from the ground in one country and emitted in another?
Davis, Peters, and Caldeira, PNAS 2011
Extraction Production
Where was CO2 released in one country to produce products that were consumed in a different country ?
Davis, Peters, and Caldeira, PNAS 2011
Production Consumption
What is the international trade in real or “embodied” carbon from the country of extraction to country of consumption?
Davis, Peters, and Caldeira, PNAS 2011
Extraction Consumption
Infrastructural commitment to future climate change
How much climate change are we committed to from existing CO2-
emitting devices?
Steven J. Davis, lead co-conspirator
Assuming normal device lifetime
Infrastructural commitment to future climate change
Approach
Analyze existing stock of power plants, automobiles, etc, and estimate future emissions
from these devices
Apply emissions in a climate models
Project future temperature change
Infrastructural commitment to future climate change
Davis, S. J., K. Caldeira, and H. D. Matthews (2010) Future CO2 emissions and climate change from existing energy infrastructure, Science
Davis, S. J., K. Caldeira, and H. D. Matthews (2010) Future CO2 emissions and climate change from existing energy infrastructure, Science
Infrastructural commitment to future climate change
Davis, S. J., K. Caldeira, and H. D. Matthews (2010) Future CO2 emissions and climate change from existing energy infrastructure, Science
Infrastructural commitment to future climate change
A1G-FI
A2
B1
Climate consequences of energy system transitions
What the climate effects be of specific energy system transitions, taking into account energy-system
life-cycle analysis data?
Nathan Myhrvold, lead co-conspirator
Climate consequences of energy system transitions
Approach
Develop simple low-dimensional climate model-- radiative forcing from greenhouse gases-- time evolution of GHG concentrations
-- thermal inertia of ocean-- radiative fluxes to space
Represent GHG emissions during plant construction and operation
Simulate energy system transitions
Climate consequences of 40 year transition of 1 TW coal system to alternative technologies
Climate consequences of afforestation / deforestation
What are the combined biophysical and biogeochemical responses t
large-scale afforestation or deforestation?
Govindasamy Bala, lead co-conspirator
Climate consequences of afforestation / deforestation
LLNL coupled ocean-atmosphere carbon-climate model
(NCAR PCM2, IBIS, modified OCMIP)
Govindasamy Bala, lead co-conspirator
With deforestation, CO2 is much higher but temperatures are slightly cooler
A2
Atmospheric CO2 TemperatureAdditional contribution from loss of CO2-fertilization of forests
Effect of loss of carbon from forests
Global deforestation experiment: net temperature change (CO2 +
biophysical)
A2
Temperature change predicted in latitude-band deforestation simulations
Boreal
Temperate
Tropical
Predicted role of forests
Tropical forests cool the planetTemperate (mid-latitude) forests do littleBoreal forests warm the planet
Does evaporating water cool global climate?
George Ban-Weiss, lead co-conspirator
Does evaporating water cool global climate?
For each Joule of evaporated water, about ½ Joule additional
gets to space
1 W/m2 of evaporation leads to about ½ K cooling
Geophysical limits on wind power
How much power could civilization get out of winds, considering only
geophysical limits?
Kate Marvel, lead co-conspirator
Geophysical limits on wind power
Approach
Perform simulations using NCAR’s CAM3.5 atmosphere model coupled to mixed-layer
ocean with specified heat transport.
2⁰ lat x 2.5⁰ lon , 26 horizontal layers
100 year simulations, 60 years used
Geophysical limits on wind power
Simulations
Drag added to (i.e., momentum removed from)SL: bottom two Surface Layers
WA: Whole Atmosphere
Effective drag area from 1 to 104 m2 km-3
Geophysical limits on wind powerAdisk = Disk area
η = Fraction of kinetic energy (momentum) removed from flow
Geophysical limits on wind powerAdisk = Disk area
η = Fraction of kinetic energy (momentum) removed from flow
Effective areaAeff = η Adisk
Amount effective drag area and kinetic energy extracted
Amount effective drag area and kinetic energy extracted
Global power demand
Climate effects: Temperature change
Suggests civilization-scale zonal mean temperature changes of ~0.1 K
Climate effects: Precipitation change
Suggests civilization-scale zonal mean precipitation changes of ~1 %
429 TW
428 TW
Atmospheric kinetic energy
Atmospheric kinetic energyproduction (loss)
Slope = 0.8
Atmospheric polewardheat transport
Atmospheric polewardheat transport
Conclusions: wind powerGeophysical limits to global wind power greatly exceed global power demand.
Global power demand ~ 18 TWNear surface winds > 429 TWWhole atmosphere > 1873 TW
Climate effects of uniformly distributed wind turbines appear to be minor at civilization scale (0.1 K temperature , 1% precipitation)
Distribution of corals andocean acidification
Long Cao, lead co-conspirator
0 1 2 3 4 5
Corrosive OptimalΩAragonite
Carbon dioxide level,
Coral reef distribution
,
and chemical
conditions helping
drive reef formation
Cao and Caldeira, 2008
0 1 2 3 4 5
Corrosive OptimalΩAragoniteCao and Caldeira, 2008
Carbon dioxide level,
Coral reef distribution
,
and chemical
conditions helping
drive reef formation
0 1 2 3 4 5
Corrosive OptimalΩAragoniteCao and Caldeira, 2008
Carbon dioxide level,
Coral reef distribution
,
and chemical
conditions helping
drive reef formation
0 1 2 3 4 5
Corrosive OptimalΩAragoniteCao and Caldeira, 2008
Carbon dioxide level,
Coral reef distribution
,
and chemical
conditions helping
drive reef formation
0 1 2 3 4 5
Corrosive OptimalΩAragoniteCao and Caldeira, 2008
Carbon dioxide level,
Coral reef distribution
,
and chemical
conditions helping
drive reef formation
0 1 2 3 4 5
Corrosive OptimalΩAragoniteCao and Caldeira, 2008
Carbon dioxide level,
Coral reef distribution
,
and chemical
conditions helping
drive reef formation
One Tree Reef, Queensland, Australia
Kenny Schneider, lead co-conspirator
Study area at One Tree Reef
About 4 km x 2 km
Water ponds at different levels in different lagoons at low tide.
Some flow over sills.
One Tree Island Research Station
Our study area
Depth transect along experimental site
Observed reductions in
alkalinity concentrations as water flows over reef and
reef builds CaCO3 skeleton
If added alkalinity was taken up by reef, we should have seen a decrease in alkalinity-to-dye ratio as water flowed over reef.
We did not detect any increase in calcification as a result of alkalinity addition.
Time scale of response?
We did not control for formation (dissolution) of Mg(OH)2.
Ken CaldeiraDept. of Global Ecology
Carnegie Institution for ScienceStanford CA 94305 USA
kcaldeira@carnegiescience.edu
Post-doc positions available for brilliant, creative, and productive scientists
who have recently completed or will soon complete their PhD.
If you fit this category and the kind of stuff in this talk interests you, please email your CV to me with “post-doc application” in the header line.
Ocean chemical consequences of ocean iron fertilization
Can ocean fertilization help with the ocean acidification problem, as has sometimes been claimed?
Long Cao, lead co-conspirator
Consequences of CO2 removal from the atmosphere
What is the relationship between CO2 removal from the atmosphere,
atmospheric CO2 concentrations, and temperature?
Long Cao, lead co-conspirator
Consequences of CO2 removal from the atmosphere
Approach
Remove all CO2 from the atmosphere of a carbon-climate model and see what happens.
(Uvic model)
Consequences of CO2 removal from the atmosphere
Cao, L., and K. Caldeira. Atmospheric carbon dioxide removal: long-term consequences and commitment. 2010, Environmental Research Letters. doi: 10.1088/1748-9326/5/2/024011
Consequences of CO2 removal from the atmosphere
Cao, L., and K. Caldeira. Atmospheric carbon dioxide removal: long-term consequences and commitment. 2010, Environmental Research Letters. doi: 10.1088/1748-9326/5/2/024011
Ocean chemical consequences of ocean iron fertilization
Approach
Take the extreme case where we assume that ocean iron fertilization is able to cause all ocean mixed-layer
phosphate to be utilized.
Perform simulations in the UVic carbon-climate model and see what happens.
Cao, L., and K. Caldeira. 2010. Can ocean iron fertilization mitigate ocean acidification? Climatic Change, 99. DOI: 10.1007/s10584-010-9799-4
Ocean chemical consequences of ocean iron fertilization
No iron fertilization(A2 CO2 emissions)
Fertilize ocean to mitigate atmosphere CO2
8.18
7.74
7.80
7.74
3.53
1.54
1.71
1.52
pH Aragonite saturation
Year
210
0
Fertilize ocean to generate carbon credit
Without human interference
Ocean chemical consequences of ocean iron fertilization
No iron fertilization(A2 CO2 emissions)
Fertilize ocean to mitigate atmosphere CO2
8.18
7.74
7.80
7.74
3.53
1.54
1.71
1.52
pH Aragonite saturation
Year
210
0
Fertilize ocean to generate carbon credit
Without human interference
Ocean chemical consequences of ocean iron fertilization
No iron fertilization(A2 CO2 emissions)
Fertilize ocean to mitigate atmosphere CO2
8.18
7.74
7.80
7.74
3.53
1.54
1.71
1.52
pH Aragonite saturation
Year
210
0
Fertilize ocean to generate carbon credit
Without human interference
Ocean chemical consequences of ocean iron fertilization
No iron fertilization(A2 CO2 emissions)
Fertilize ocean to mitigate atmosphere CO2
8.18
7.74
7.80
7.74
3.53
1.54
1.71
1.52
pH Aragonite saturation
Year
210
0
Fertilize ocean to generate carbon credit
Without human interference
Solar Geoengineering
Julia Pongratz, lead co-conspirator
Temperature effects of doubled CO2
ΔTemperature Statistical significance
Caldeira and Wood, 2008
Temperature effects of doubled CO2
Temperature effects of doubled CO2
ΔTemperature Statistical significance
Caldeira and Wood, 2008
with a uniform deflection of 1.84% of sunlight
Precipitation effects of doubled CO2
Caldeira and Wood, 2008
Temperature effects of doubled CO2
Caldeira and Wood, 2008
with a uniform deflection of 1.84% of sunlight
Caldeira and Wood, 2008
Deflecting 1.8% of sunlight reduces but does not eliminate simulated temperature and precipitation change caused by a doubling of atmospheric CO2 content
But what about the effect ofdecreased sunlight food?
Probability of 2080-2100 summer being hotter than hottest on record
Maize yield in a high-CO2 world without and with
deflection of sunlight
Benefit of CO2-fertilization without the
costs of higher temperatures
Pongratz et al 2012
From Pongratz, Lobell, Cao &-Caldeira, Nature Climate Change, 2012.
Crop yields in a high-CO2 world without and with deflection of sunlight
Benefit of CO2-fertilization without thecosts of higher temperatures
92From Pongratz, Lobell, Cao &-Caldeira, Nature Climate Change, 2012.
Crop yields in a high-CO2 world without and with deflection of sunlight
93
Crop yields in a high-CO2 world without and with deflection of sunlight
Pongratz et al 2012
94From Pongratz, Lobell, Cao &-Caldeira, Nature Climate Change, 2012.
% increase in crop yields in a high-CO2 world
without and with deflection of sunlight2xCO2 minus pre-industrial
2xCO2 + geo minus pre-industrial
2xCO2 + geo minus 2xCO2
Maize -3 11 14Wheat 6 26 21
Rice 19 28 8