The Global Carbon Cycle Integrating Humans, Climate and the Natural World Island Press – 2004 SCOPE
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
The Global Carbon Cycle
Integrating Humans, Climate and the Natural World
Island Press – 2004
SCOPE
SCOPE 62
COP9, Milan, Dec.8th, 2003,Side EventOutline
• Christopher Field, Carnegie Institution, Stanford, California, [email protected]
• Dorothee Bakker, University of East Anglia, Norwich, UK, [email protected]
• Patricia Romero Lankao, Universidad Autonoma Metripolitana, Mexico City, Mexico, [email protected]
• Josep Canadell, CSIRO Land and Water, Canberra Australia, [email protected]
Revised c budget
Land C budget (1980-2000)
Net land sink 0.6 Pg y-1
Deforestation 1.2 Pg C y-1
Residual land sink 1.8 Pg C y-1
New Understanding
• Inertia
• Saturation
• Vulnerability
• The Energy Gap
• A Common Framework
Inertia
• Many current sinks a result of past actions
• Entrained warming continues for many decades
• Key technologies require fundamental development
Inertia 2• Inertia chart
Vulnerability
• On Land: Several large pools poised for large releases in a warming climate
– C in permafrost soils
– Wildfire
– Tropical forests
WarmingCarbon
release
Tropical forests
Warming
Increased
respiration
Decreased
growth
Increased
fire Low to moderate
Ocean compensation
700 Pg C gain
Becomes
100 Pg C loss
Extra 350 ppm CO2 in Atm
Cox et al. 2000. Nature 408: 184
Vulnerability 2
The Energy Gap
• Scenarios contain optimistic efficiency increases– still fail to stabilize below 750– do not yet account for all sources of
vulnerability
Technology improvement for IS 92a
The oceanic carbon cycle in a changing climate
Blue planet: Oceans and seas cover 71 % of the globe (Tchernia, 1980).
The oceans store 88% of global carbon outside geological reservoirs (IPCC, 2001). (BBC; 6 years of SeaWiFS data, DAAC/GSFC,
ORBIMAGE)
2.0
10.0
0.1
0.01
0.5
50.0
Chlorophyll a (mg/m3)
Oceanic uptake of fossil fuel CO2
(Keeling and Bates)
- BATS (Bermuda)
Tota
l C
O2
(µm
ol/
kg
)
1988 1990 1992 1994 1996 1998
CO
2 c
on
ten
t (µ
mol/
mol)
- Hawaii370
350
310
330
2060
2030
2000
20001970
Oceanic sink for anthropogenic CO2
Based on 40 years of surface pCO2 data (Takahashi et al., 2002)
The oceans absorb 27% of the anthropogenic CO2
emissions or 1.7 +/- 0.5 Pg C/yr (IPCC, 2001).
Quantification of oceanic CO2 sources/sinks puts a constraint on land sources/sinks.
1 CO2 Air-Sea exchange
Sea floor
CO2 (aq) + H2O H2CO3
HCO3-
H+ + HCO3-
H+ + CO32-
H2CO3
Total CO2 1020
~100 m
Lysocline~3500 m
CO2
730
Atmosphere
(in Pg C; after IPCC, 2001, Fig. 3.1)
Surface Ocean
DeepOcean
Sh
elf
CO2 air-sea flux = - K •(pCO2air - pCO2water)Driving force for oceanic uptake of anthropogenic CO2
Sea floor
CO2 (aq) + H2O H2CO3
HCO3-
H+ + HCO3-
H+ + CO32-
H2CO3
Total CO2 38,000
Total CO2 1020
~100 m
Lysocline~3500 m
CO2
730
Atmosphere
(in Pg C; after IPCC, 2001, Fig. 3.1)
Surface Ocean
DeepOcean
Sh
elf
Determines the rate of oceanic uptake of anthropogenic CO2
2 Physical pump
Sea floor
Organic matter
CO2 (aq) + H2O H2CO3
HCO3-
H+ + HCO3-
H+ + CO32-
H2CO3
Total CO2 38,000
CaCO3
Total CO2 1020
~100 m
Lysocline~3500 m
CO2
730
Atmosphere
(in Pg C; after IPCC, 2001, Fig. 3.1)
Surface Ocean
Biota 3
DeepOcean
Sh
elf
<700
3 Physical and Biological pump
Sea floor
Total carbon
Total carbon
~100 m
Surface Ocean
Organic carbon
DeepOcean
Sh
elf
(in Pg C; after Gruber et al., SCOPE)
CO2 system
Warming BiologyCirculationAnthro-pogenic
BufferCapacity Natural
cycle<20% ?
<3% ?[<20%] 50% ?[30%]
CaCO3
Climate changeAnthropogenic CO2 uptake
50% ?
Relative to 600-700 Pg C of cumulative oceanic uptake of anthropogenic CO2 for 2000 - 2100.
4 Feedbacks on oceanic CO2 uptake
A reduction of calcification by oceanic uptake
of anthropogenic CO2
(Greenblatt and Sarmiento, SCOPE book; Jeremy Young, Natural History Museum, London; Steven Cook, Florida Keys National Marine Sanctuary)
Calcifying algaeEmiliania huxleyi;A bloom in the English Channel.
Brain coral and sea fan,Florida Keys
North Atlantic Carbon Observing System
90°W 50°W 10°W
Greenland-Denmark
New York–Halifax-
Hamburg
Caribbean –
Portsmouth
Sou
th-A
meri
ca-S
pain
Cruise tracks CAVASSOO 2001 – 2003 EU project
Greening the oceans
Courtesy Sue Turner (UEA)
by iron fertilisationto combat global warming?
High nutrients
[after Conkright et al., 1998]
µM0 5 10 15 20 25Nitrate
Low chlorophyll
2.0
10.0
0.1
0.01
0.5
50.0
Chlorophyll a (mg/m3)
(6 years of NASA SeaWiFS data, DAAC/GSFC, ORBIMAGE)
Only the Southern Ocean has a potential for long term CO2 storage by iron fertilisation (circulation).
DMS and climate
AlgaeDMS
Degradation/Loss
DMS
SO2
Sulphate AerosolH2SO4 Radiation
Budget
DMS = dimethyl sulphide
Greening the oceans to combat global warming?
Poorly known efficiency of CO2 storage.
Warming by the production of the greenhouse gases N2O and CH4 could outweigh cooling by CO2 storage (Jin and
Gruber, 2002).
Climate feedbacks by the production of DMS, halocarbons and alkyl nitrates.
Unknown, major shifts in the marine ecosystem.
The oceans absorb 27% of anthropogenic CO2 emissions.
Strong feedbacks in the marine carbon cycle will reduce oceanic CO2 uptake relative to the increase in atmospheric CO2 for 2000-2100.
Net oceanic CO2 uptake will reduce calcification and coral reef formation.
The oceanic carbon cycle in a changing climate
Drivers of GHG, Kaya identity*
CO2 =(CO2 /E) x (E/GWP) x (GWP/P) x
where• P = Population growth• GWP/P = Per capita gross world product• E/GWP = Energy requirement per unit
of gross product
• CO2 /E = CO2 emissions per unit of energy
Historical and future trends of drivers
• CO2 emissions grew 1.7% (1900), double next 3 decades
• Population grew 1.3% (1900), double ≥70 years
• GWP grew 4% (1950), 3.5 to ≥32 times in 2100• Weak relation population / economic growth• Primary energy consumption 2% (1900), will
growth 1.3% • E. growth => capital turnover => less energy
intensity; decarbonization
Key common trends
1. Exponential increase in LUC 2. Shift from biomass to fossil fuels3. From LUC to fossil fuels as main
proximate cause4. Urbanization became major global
driver of GHG (urban sprawl)5. Key driver globalized trade
dominated by few countries
Diverse regional pathways of development (1)
Developed countries• Highest share of trade, production,
energy use and emissions• Slow urban growth • High ecological footprint (8-15 times)• Decreased LUC • Higher ability to deal with
mitigation/adaptation?
Diverse regional pathways of development (2)
Two clusters:1. During 1970-90 increased share of trade,
production, energy and emissions, high urban growth, aggressive states
2. Industrialization, still dependant primary commodities, high urban growth, weak states, recurrent crisis
Could first cluster have increased capacity for mitigation/adaptation strategies?
Diverse regional pathways of development (3)
High primary commodity-export economies in Africa, Latin America and Asia with:
• Insignificant participation in production, trade, energy and emissions
• Vulnerable to vagaries of international markets and to climate vulnerability and change
• Economic crisis and stagnation, segregation hamper promotion of carbon relevant policies
Hydrogen Fuel Cell Vehicles
Zero Net Emission Buildings
Nuclear Power Generation IV
Renewable Energy Technologies
Vision 21: Zero-Emission Power Plant
Bio-Fuels and Power
Carbon (CO2) Sequestration
• Deep cuts in emissions require
advanced technologiesSOON
• No single technologycan do it all
• Some constraints
Portfolio ofTechnological Solutions
Plant New Forests
Ocean Fertilization
Reduced deforestation
Sequestration in Ag. soils
Reduced methane production
• Can be implementedimmediately
• Not long term solutions
•Potential for ancillary
costs and benefits
Portfolio ofBiological Solutions
Multiple constraints on C mitigation options
• Economics.• Social factors.• Institutional factors.• Institutional and timing aspects of technology
transfer.• Demography.• Environmental requirements for other resources.
SustainablyAchievablePotential
Carbon Sequestered or GHG emissions avoided (tCeq)
BaseLine
Cos
t of
car
bon
($/t
Ceq
)
Social and Institutions
EconomicalFactors
Economic Structure
Urbanization
Industrialization
Social:Class structureLife style
AttitudeBehavior
PoliticsFormal policiesInformal rules
Property rights
Demographic:
Density, growthMigration
Spatial distribution
Institutional:
Economic Structure
Mitigation Potential
TechnicalPotential
EnvironmentalFactors
Land, water,Biodiversity,Navigation andFisheries rights
Timing
Generation transfer
Markets
Trade
Effects of economic, environmental and social-institutional factors on the mitigation potential of a carbon management strategy
Potential mitigation with sustainability principles
Land-BasedC Sequestration
Projects
ClimateMitigation
Land-based C mitigation options
BiodiversityConservation
ErosionPrevention
BiomassEnergy
WaterYield
Soil Fertility
Use of Wood
Products
Sustainable
Regional DevelopmentRecreationalValue
Win-winC sequestr.BiodiveresityCombat salinization
C sequestration in Ag.Soil fertility
Multiple-constraints
Theoretical vs. Achievable PotentialGlobally, enhanced terrestrial sequestration and energy cropping for the next 50 years could offset (Gt C yr-1) (Cannell 2003)
15-EU, sequestration in agricultural soils for the first Kyoto commitmentperiod (2008-2012) could offset (Mt C yr-1) (Freibauer et al. 2003)
Achievablepotential
16-19
100% 15%
Theoreticalpotential
~90
Theoretical Potential
2-5
Realistic Potential
1-2
Conservatively Achievable
0.2-1
100% 10-20%
Conclusions• Vulnerability of carbon pools
– The higher the CO2 concentrations the higher the risk of destabilizing vulnerable carbon pools (eg, permafrost, tropical peatlands).
• Inertia of the carbon cycle and energy systems– Even when anthropogenic CO2 emissions begin to decrease,
atmospheric CO2 will continue to go up for up to a century.– Inertia of technology transfer
• Sustainability criteria in sequestration and emission reduct.– Particularly on biological sequestration, realistically achievable potential
is much less than theoretical potential.
• Saturation of sink mechanisms– If NH sinks is largely due to forest regrowth, the sink strength will
disappear within decades. Saturation of the CO2 fertilization effect on plan productivity occurs at around 600 ppm.
Conclusions (ii)
• Likely acceleration of climate change as the century progresses beyond what climate models are currently predicting.
• Early action on carbon mitigation while terrestrial sinks are strong, and positive feedbacks are less likely.
ObservationsIntegrated Global
Observing Strategy
ResearchGlobal Carbon
Project&
Partners
International efforts on carbon cycle research
AssessmentIPCC
International Geosphere-Biosphere Program
IHDP WCRP
Global Carbon Project
World ClimateResearch ProgramInternational Human
Dimensions Program
IGBP
National and regional carbon research programmes
LBA
CarboEurope
China
Australia
North AmericaCarbon Plan
Siberia
Jp
SA
NZ
Canada
GCP Objective
To develop comprehensive, policy-
relevant understanding of the global carbon cycle, encompassing its natural and human dimensions and their interactions.
Research activities
• Urbanization pathways to minimize C emissions.• Attribution of terrestrial sinks to mechanisms.• Full carbon accounting methodologies.• Vulnerability of carbon pools on land and in oceans.• Model-data fusion approaches.• Coordination of ocean cruise programmes.• State-of-the-art synthesis of the carbon cycle.• Capacity building: institutes and summer courses.• Fostering integrated carbon research in LDC.
GCP International Project and Affiliate Offices
CSIRO,Canberra Australia
NIES,TsukubaJapan (April 2004)
USA
CarboEurope, GermanyGHG CA, Italy
IOC/SCOR-CO2 PanelParis, France
Beijing, China
Affiliate Off.Proposed only
Affiliate Off.
Inter.Proj.Off.
Related Documents
