1. Socio-Economic Scenarios Roberto Roson University of Venice, FEEM & ICTP Richard S.J. Tol Hamburg, Vrije and Carnegie Mellon Universities

2. RT7 Team FNU, Hamburg University and ZMAW –Richard Tol FEEM, Venice –Roberto Roson CIRED, Paris –Jean-Charles Hourcade IIASA, Vienna –Brian O‘Neill RIVM, Utrecht –Tom Kram CICERO, Oslo –Asbjorn Aaheim LSHTM, London –Sari Kovats

3. Tasks Ensembles of emissions scenarios Ensembles of emission reduction scenarios Scenarios of land use and adaptive capacity Feedback of climate change on emissions scenarios through impacts of climate change on economy and human health Towards the construction of the economic component of an earth system model

4. Emissions scenarios Events have overtaken this task GCMs have started running the SRES scenarios, and there have always been ensembles of scenarios available We can extend this in the light of the recent critique on SRES and IPCC and recent model developments We can add a fifth, politically incorrect scenario But only if you intend to run it...

5. Emissions scenarios ENSEMBLES Objective Needed

6. Emission reduction scenarios USDoE, EMF and ENSEMBLES RT7 decided to join forces in developing emission reduction scenarios Emission reduction scenarios need to specify four things –No control scenario (SRES) –Stabilisation target (450, 550, 650, 750 ppm CO2, CO2eq, rad. forc., temperature) –Reduction target allocation over space and time –Implementation Aim is to find a small, representative number of cases

7. Land use Run IIASA and RIVM models for the above scenarios Work towards LPJ - Land use Adaptive capacity Is needed for impacts Add further detail to the population and economic drivers of the emissions scenarios

8. Conventional, scenario-based analyses… Socio-economic systems Climate systems emissions

9. Conventional, scenario-based analyses… Socio-economic systems Climate systems emissions …miss one important feedback!

10. Assessing the economic impact of climate change: some key concepts Multiplicity of effects –e.g., sea level, health, tourism, energy demand, water availability, extreme events, land use, agricultural productivity… Market interdependence –General equilibrium –Computable general equilibrium models (CGE)

11. Computable General Equilibrium Models: Pros and Cons + a unifying framework for the consistent analysis of heterogeneous impacts; + a widely accepted assessment tool; + general-purpose and flexible; - data demanding; - rarely used on long-term horizons; - national accounting, market based parameter estimation; - calibrated, cannot readily take into account non observable technologies.

12. Simulation experiments of climate change impacts

13. Some further remarks Others, more significant impacts Dynamics