Climate%20Uncertainty%20and%20the%20Necessity%20to%20Transform%20Global%20Energy%20Supply%20%20Bob%20van%20der%20Zwaan%20(ECN%20and%20Harvard%20University)%20and%20Reyer%20Gerlagh%20(IVM,%20Vrije%20Universiteit%20Amsterdam)

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Climate Uncertainty and the Necessity to
Transform Global Energy SupplyBob van der
Zwaan (ECN and Harvard University)andReyer
Gerlagh (IVM, Vrije Universiteit Amsterdam)

• International Energy Workshop
• (EMF/IEA(ETSAP)/IIASA)
• International Energy Agency
• Paris
• 22-24 June 2004

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Outline

• I. Introduction
• II. Climate sensitivity
• III. Model
• IV. Results
• V. Conclusions

The EU-funded NEMESIS/ETC project (European
Commission contract No. ENG2-CT-2001-00538) is
greatly acknowledged.
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I. Introduction

• The sensitivity of the global mean temperature on
  Earth to the increasing concentration of
  atmospheric CO2 is currently known to about only
  a factor of three.
• Uncertainty in the climate sensitivity has a
  larger effect than the uncertainty in our
  understanding of the carbon cycle (Caldeira,
  2003).
• This presentation / paper explores the
  relationship between the climate sensitivity
  uncertainty and the claimed necessity to
  transform world energy supply.

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II. Climate sensitivity

• Mankind is already halfway towards an equivalent
  doubling of the atmospheric CO2 concentration,
  from the pre-industrial level of 280 ppmv to 420
  ppmv today.
• A doubling corresponds, via the enhanced
  greenhouse effect, to a global average surface
  air temperature increase, ?T(2X), of 1.5
  4.5 ºC (IPCC, 2001).
• The stabilisation CO2 concentration, P, and
  stabilisation temperature increase, ?T, are
  related through

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III. Model
DEMETER DEcarbonisation Model with Endogenous
Technologies for Emission Reductions

• There are two competing generic energy sources,
  one fossil-based (F), the other one with zero CO2
  emissions (N).
• Old capital is distinguished from new capital, in
  a so-called vintage approach.
• Technological change is modelled endogenously
  through learning curves.
• A substitution elasticity is included between F
  and N, such that the new technology (N) can
  spread before it reaches maturity.

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III. Publications

• van der Zwaan, B.C.C., R. Gerlagh, G. Klaassen,
  and L. Schrattenholzer (2002), Endogenous
  technological change in climate change
  modelling, Energy Economics 24, 1.
• Gerlagh, R. and B.C.C. van der Zwaan (2003),
  Gross World Product and Consumption in a Global
  Warming Model with Endogenous Technological
  Change, Resource and Energy Economics 25, 35-57.
• Gerlagh, R., B.C.C. van der Zwaan, M.W. Hofkes,
  and G. Klaassen (2004), Impacts of CO2-taxes in
  an economy with niche markets and
  learning-by-doing, Environmental and Resource
  Economics, forthcoming.
• Gerlagh, R. and B.C.C. van der Zwaan (2004), A
  sensitivity analysis of timing and costs of
  greenhouse gas emission reductions under learning
  effects and niche markets, Climatic Change,
  forthcoming.

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IV. Carbon stabilisation

• Carbon emissions under various climate
  sensitivities.
• Source van der Zwaan and Gerlagh, 2004.

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IV. Savings vs. decarbonisation

• Relative importance of energy savings and
  decarbonisation in emission reductions.
• Source van der Zwaan and Gerlagh, 2004.

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IV. Emission reduction timing

• Timing of emission reduction efforts.
• Source van der Zwaan and Gerlagh, 2004.

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V. Conclusions

• Allowed carbon emission path is determined to a
  large extent by the climate sensitivity, ?T(2X).
• Even under the lowest value of ?T(2X), the energy
  system must be transformed, from fossil-based
  fuel consumption to the use of non-carbon energy
  resources.
• In the short run, energy savings and
  decarbonisation are both important, while in the
  longer run a transformation of the energy system
  becomes the main means to achieve emission
  reductions, for all ?T(2X).
• The timing of emission reductions is almost
  independent of ?T(2X).