CLIMATE CHANGE and OIL DEPLETION
RUI NAMORADO ROSA
Évora Geophysics Centre, University of Évora,
Rua Romão Ramalho 59, 7000 671 Évora, Portugal
International Workshop on Oil Depletion
Uppsala, 22-25 May 2002
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KEY ISSUES
• Primary Energy Sources: Past and Present• Climate: Climate Change and Climate variability• Climate Modelling: IPCC and beyond• Anthropogenic climate forcing: UNFCCC, Kyoto
Protocol, EPCC• Energy Efficiency: primary energy saving• Carbon Sequestration: land and ocean• Alternative Energy Carriers: Hydrogen, Synthetic
carbonaceous fuels• Research and Development
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PRIMARY ENERGY SOURCES: PAST AND PRESENT
Consumption of primary energy has worlwide increased at a rate of 2 % per annum for the past century.
Primary energy sources life-cyclesCoal Crude oil Natural gas
One faces a constraint on oil availability right now and a more severe constraint on gas in about twenty five years time. Notice the Decarbonization of the past energy mix Hydrogen appears as a “historically determined” energy carrier but there other options
Synthetic carbonaceous fuels
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Evolution from 1971 to 1998 of World Total Primary Energy Supply by Fuel (Mtoe) [IEA]
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Evolution from 1971 to 1998 of World CO2 Emissions*
by Fuel (Mt of CO2) [IEA]
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EARTH CLIMATIC SYSTEM
• The Earth Climatic System• Climate subsystems: Atmosphere, Ocean, Solid
Crust, Polar and Glacier Ice sheets• Subsystems different reponse/relaxation times• Subsystems interactions (Energy and Mass fluxes)• Solar irradiation• Climate variability and Climate Change
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• Composition of the Atmosphere: gases, aerosols and clouds
• Energy input/output: Solar and terrestrial radiation fluxes
• Water and Carbon cycles
• Energy balance: the GreenHouse Gas effect and the Planetary Albedo
•Modelling Weather evolution and Climate variability and change: forecasts and scenarios
Climate System: how it works
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Climate Variability and Change
•Astronomical forcing (Milankovich cycles)• Space weather: Solar irradiation and Cosmic rays variabilities• Volcanic activity: aerossol emissions•Anthropogenic forcing
• atmospheric emissions of gases and aerosols• land use change, deforestation, urbanization
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THE CARBON CYCLE
• Natural Carbon Fluxes
• Sources Sinks and Fluxes
• Natural Carbon Reservoirs:
• Biosphere: Photosynthesis and respiration
• Atmosphere: CO2 and CH4
• Oceans: Organic/inorganic, dissolved /particulate
• Lithosphere: Sedimentation and weathering, carbonate and organic carbon
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RESERVOIR COMPOSITION Quantity GtonC
Atmosphere Carbon dioxide 720
Oceans (mixed layer and deep water)
Inorganig
Organic (DOC) 39 000
700
Lithosphere Carbonates
Carbonaceous
60 000 000
15 000 000
Terrestrial
BiosphereBiomass
Soil 600
1 600
Aquatic Biosphere Marine organisms 3
Fossil fuelssolid
Coal
Peat 3 500
250
Fossil fuelsfluid
Oil
Gas 230
140
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Absortion of CO2 in rock weathering and sedimentation
• The dissolution of carbonates:
CO3Ca + CO2(aq) + H2O = 2HCO3- + Ca2+
• The dissolution of silicates:
SiO3Ca + 2CO2 + H2O = SiO2 + 2HCO3- +Ca2+
• Carbonate sedimentation:
CO2(aq) + 2 H2O = H3O+ + HCO3
-
HCO3- + H2O = H3O
+ + CO32-
Ca2+ + CO32- = CaCO3(s)
• Carbon dioxide release (high temperature and pressure):
CO3Ca + SiO2 = SiO3Ca + CO2(g)
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Dissolution of carbonates and release of carbon dioxide in fresh and oceanic waters:
MgCO3(s) = Mg2+ + CO32- CaCO3(s) = Ca2+ + CO3
2-
H3O+ + CO3
2- = HCO3- + H2O
H3O+ + HCO3
- = CO2(aq) + 2 H2O
CO2(aq) = CO2(g)
where CO2(aq) denotes both aqueous carbon dioxide and the
carbonic acid H2CO3 .
2H2O = H3O+ + OH-
The first two reactions are slow, all the others are fast.
The chemicl equilibrium and the direction of the prevailing reactions depend upon pH and redox potential.
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Carbon Dioxide and Climate
•Historical variations of CO2 and surface temperature
•The Carbon fluxes and CO2 redistribution among the Atmosphere, Oceans, the Crust and the Biosphere
•Anthropogenic CO2 emissions: uptake by the oceans and the terrestrial biosphere; the “missing sink”
• Our knowledge of the Climate system is still rather limited and the time span of space observation still short
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Anthropogenic Climate Forcing
•Chemical perturbation of the Atmosphere: gas and aerosol emissions due to Energy, Transportation and Industrial activities
• Thermal pollution due to Energy activities (power plants)
• Changes in land use affecting the surface albedo or the Carbon or the Water cycles
• The emission of CO2 due to burning fossil fuel is considered the most important anthropogenic forcing
• However, the growth of the atmosferic concentration of CO2 lags behind the emitted rate (due to natural sinks)
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CLIMATE CHANGE MODELLING
Climate models are still imperfect and incomplete, on account of the complexity of the climate system, the level of our understanding of how it works and the still limited data available. There are not yet definite conclusions about the actual climate trends, the underlying causes and their future developments. Therefore, climate modelling carries a large uncertainty in the obtained climate projection.
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GHG Emission Scenarios
Socio-economic and technological scenarios:
• Population
• Standard of living (GDP/Pupulation)
• Energy Intensity (Energy/GDP)
• Carbon intensity (Emissions/Energy)
Emissions = (Population) * (GDP/Population) * (Energy/GDP) * (Emissions/Energy)
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Region Population Standard of Living
Energy Intensity
Carbon Intensity
Carbon Emissions
Africa 2.54% -0.58% 0.82% -0.01% 2.77%
Brazil 1.61% 0.76% 1.83% -0.80% 3.43%
China 1.37% 8.54% -5.22% -0.26% 4.00%
Japan 0.41% 2.62% -0.57% -0.96% 1.47%
Europe 0.53% 1.74% -1.00% -1.06% 0.18%
USA 0.96% 2.15% -1.64% -0.21% 1.23%
World 1.60% 1.28% -1.12% -0.45% 1.30%
Emissions = (Population) * (GDP/Population) *
*(Energy/GDP) * (Emissions/Energy) [1980vs1999]
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Intergovernmental Panel on Climate Change
The Intergovernemental Panel on Climate Change was established in 1988 under the initiative of the UNEP and WMO.
Scenarios produced by the IPCC are supported on energy consumption and GHG emission scenarios produced by the International Energy Agency. These assume that the natural resources and the carrying capacity of the environment are both unlimited.
The resource basis of oil and gas does nor support the most extreme emission scenarios formulated.
Climate modelling introduces further uncertainty. The necessity of taking measures to curb the growth of GHG emissions is not universally accepted.
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UN Framework ConventionKyoto Protocol
The UN Framework Convention on Climate Change adopted at the Earth Summit, Rio de Janeiro, June 1992, and the Kyoto Protocol, adopted at the third Conference of Parties to the UNFCCC, December 1997, are the key processes for negotiating international climate policies and the reduction in GHG emmissions (namely CO2, CH4, N2O, HFC, PFC, SF6).
The developed countries thereby accepted binding targets to limit GHG emissions by at least 5% below the 1990, level in the period 2008-12, that is, up to 30% below estimates of the “business as usual” scenario.
The Kyoto Protocol will help curb the demand for fossil energy sources and keep energy price under control.
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The Convention and the Protocol establish financial devices, the “flexibility mechanisms”, that are intended to facilitate the cost-effective implementation of the Protocol, namely Clean Development Mechanisms (CDM), Joint Implementation (JI) and Emission certificate trading (ET).
CDM and JI are project based mechanisms crediting investing developed countries for projects implemented in developing (CDM) and in transition economy (JI) countries.
Emission trading is a scheme whereby governments allocate emissions allowances to emitting entities, which those entities can subsequently trade with each other. Emissions trading converts scarcity (of fossil fuels) into a new business oportunity, to which the energy sector entreprises are particularly disposed.
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European Climate Change Programme
The European Union was a leading negotiator in achieving the Marrakech agreement, November 2001, whereas the USA withdrew from the process on March 28, 2001. The EU committed itself to the Kyoto Protocol target of colectivelly cutting its GHG emissions to 8% below the 1990 level by 2008-12. A “Kyoto package” was adopted comprising three policy tools: the ratification of the Kyoto Protocol, an European Climate Change Programme and a framework directive on GHG emissions trading.
Other EU instruments to support this programme are the EUMETSAT, the European Space Agency (namely through the recently approved GMES Programme) and the VI Framework Programme and VI Environment Action Plan
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Identified research needs to be supported by the VI Framework Programme and VI Environment Action Plan:
• Impact of GHG emissions on climate and carbon sinks
• Water cycle
• Biodiversity, protection of genetic resources, ecosystems
• Mechanisms of desertification and natural disater connected with climate change
• Socio-economic and integrated research for mitigation, adaptation and sustained development
• R&TD; technological and social innovation:
• Renewable energy sources; Intelligent transport, interoperability and intermodality
• Fuel cells ;Hydrogen; New concepts in PV technology
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Fiscal measures, a carbon-energy tax and tax reduction on energy efficiency are planned. Ten measures wrere identified whose cost efficiency will be better than 20 Euro/tonCO2 and may attain a reduction of 180 Mton CO2 [COM(2001)580].
Further policies and measures are being identified, aiming at cutting GHG emissions and implementing an emissions trading scheme. A framework for emissions trading [COM(2001)581], due to come into effect by 2005, relates to the energy sector and large industrial plants: electricity and heat production, iron and steel, refining, chemicals, glass, pottery, cement and building materials and paper pulping and printing.
A critical issue is the initial allocation of allowances. Optional typologies are “auction” (allowances provided by the state through auctioning), “grandfathering” (allocation on the basis of historical data) and “update” (allocation to sources on information updated over time).
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CARBON SEQUESTRATIONCarbon management is a concept expressing the use of fossil primary energy sources with the implementation of sequestering technologies.
Electrical power plants are the most obvious target. Capture of CO2 in the flue gases although requiring expensive
investment is feasible. The required technologies - recovery, concentration, compression or liquefaction and disposal - are available from the experience of the petroleum and petrochemical industries.
Carbon management might comprise CO2 capture from the
atmosphere plus sequestration in large natural reservoirs by specialized sequestration plants.
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CO2 could be stored by deep ocean injection below the
thermocline, taking advantage of sinking oceanic currents. Liquid CO2 is stable at the pressure and temperature found
at high depths and denser than sea water.
In the lithosphere, the most obvious opportunity for sequestration is in impermeable geological reservoirs. In natural gas fields, CO2 is being reinjected and, in oil fields,
used to enhance oil recovery.
The biosphere might be instrumental in sequestering CO2 ,
but forestation is not a solution unless soil accumulation of organic matter really takes place. Enhanced aquatic photosynthesis - ocean fertilization - followed by biomass sinking below the mixing layer, would lead to permanent sedimentation of the captured CO2 .
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ENERGY EffICIENCY
First and Second Principles Efficiencies
Thermal efficiency in energy conversion
Combustion technology
Combined cycle power plants (CCGT),
Combined heat and power plants (CHP)
Heat pumps: low temperature applications and heat recovery
Combined Heating and Cooling
Process integration and Integrated Energy systems
Material recycling.
Direct energy conversion
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ALTERNATIVE ENERGY CARRIERS Prospective energy system scenarios consider a mix of energy carriers of wich Hydrogen and Synthetic carbonaceous fuels deserve further attention.
Synthetic carbonaceous fuels (SCF) have been proposed. Coal is the most available source of carbon. Coal conversion could provide all fluid carbonaceous fuels and feedstocks. Efficiente sequestration of CO2 would be required.
Synthetic carbonaceous fuels could have zero carbon emission in their lifecycles, by carrying out the synthesis with Hydrogen obtained by splitting water and Carbon extracted from the atmosphere or from the ocean. CO2 incorporated in a
SCF would be reemitted when burnt, maintaining a zero net balance of CO2 in a cycle akin to photosynthesis.
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Hydrogen has been proposed as ideal energy carrier. Its obvious advantage is the zero CO2 emission at the end point and its high heat of combustion. However, an hydrogen energy economy raises problems: storage, safety and global energy efficiency of the primary energy source.
Hydrogen is generated and used in certain chemical industries. It can be obtained from natural gas, petrochemical feedstocks, coal and biomass.
Efficient Water splitting can be attained with the supply of high temperature heat, either directly, or in thermally assisted electrolysis of steam or in thermocatalytic cycles.
Advanced high-temperature nuclear reactors and solar furnaces were proposed as the high-temperature heat source.
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The energy cost of synthetic fuels is mainly due to the H2
extraction. Once hydrogen production becomes energetically and economically interesting, it can be used as feedstock to the SCF economy. The existing transportation, distribution, storage and end-use systems can go on being used, while investments required by the hydrogen economy might be set up.
SCF might provide a gradual transition from today’s range of fuels towards a single hydrogen rich fuel for the whole transport sector.
Further R&D is required on alternative energy sources, energy carriers, energy storage and energy conversion concepts and technologies.