1. Assessment of contributions to climate change: Results from CICERO UNFCCC Expert meeting, Bracknell, 25-27 September 2002 Bård Romstad, Jan Fuglestvedt and Terje Berntsen CICERO, Norway

2. Model description Simple Climate Model (SCM) (Fuglestvedt and Berntsen, 1999) Incorporates an energy-balance climate/up-welling diffusion ocean model developed by Schlesinger et al. (1992) A CO 2 scheme from Joos et al. (1996) Lifetimes and concentration-forcing relations from IPCC TAR Includes 32 source gases Global radiative forcing is calculated for 35 components Global-mean ΔT and ΔSL from ocean thermal expansion (and melting of glaciers) (Schlesinger et al., 1992)

3. Model description (cont.) The model source code can be obtained by contacting bard.romstad@cicero.uio.no or j.s.fuglestvedt@cicero.uio.no

4. Model setup for attribution calculation SCM Emission database (CDIAC/EDGAR/ SRES) World OECD REF ASIA ALM World OECD REF ASIA ALM World OECD REF ASIA ALM Results (dT,dSL) Attribution calculation

5. Model input (emission perturbations) Emission database (CDIAC/EDGAR/ SRES) World OECD REF ASIA ALM

6. Model output (dT) Attribution calculation World OECD REF ASIA ALM Results (dT,dSL) World OECD REF ASIA ALM SCM

7. Model output (all regions) Results (dT,dSL)

8. Attribution calculation

9. Attribution calculation (α r ) DEFAULT: CO 2, CH 4 and N 2 O perturbations from 1890-2000

10. Attribution from CO 2, CH 4 and N 2 O, 1890-2000

11. Model setup for sensitivity study Time frame Attribution calculation period 18902100 Emission sources+sinks CO2 All GHGs All forcing agents CO2,CH4 N2O Kyoto basket Historical Emissions 1890 Scenario Emissions 210019502000 Gases

12. Time frame sensitivity Emission attribution periods –1890-2000 (default) –1950-2000 –1890-2100 –1950-2100

13. Time frame sensitivity (em start and end) DEFAULT: CO 2, CH 4 and N 2 O attribution from 1890-2000

14. Time frame sensitivity (cont.) Emission attribution periods –1890-2000 (default) –1950-2000

15. Timeframe sensitivity (em start only) DEFAULT: CO 2, CH 4 and N 2 O attribution from 1890-2000

16. Scope sensitivity Sensitivity due to inclusion/exclusion of gases –CO2 only –CO2, CH4 and N2O (default) –Kyoto basket –(all cases with emission attribution period 1890-2000)

17. Gases included DEFAULT: CO 2, CH 4 and N 2 O attribution from 1890-2000

18. Attribution from CO 2 only, 1890-2000

19. Attribution from CO 2, CH 4 and N 2 O, 1890-2000

20. Attribution from all Kyoto-gases, 1890-2000

21. Source sensitivity Sensitivity due to exclusion of LUCF –Attribution period 1890-2000

22. Sources DEFAULT: CO 2, CH 4 and N 2 O attribution from 1890-2000