COMBINE: Comprehensive Earth System Modelling for Enhanced Climate Prediction

1. COMBINE – Comprehensive Modelling of the Earth System for Better Climate Prediction and ProjectionM. A. Giorgetta, Max Planck Institute for Meteorology, HamburgIS-ENES kick-off meeting, 30-31 March 2009 Call: FP7-ENV-2008-1, ENV.2008.1.1.4.1 Funding scheme: Collaborative project Partners: 22 Duration: 48 months (plan: 01.05.2009 – 30.04.2013) Status: in negotiation EC sci. officer: Philippe Tulkens

2. Partners in COMBINE, and their involvement in IS_ENES

3. Selected key questions in climate research • Do internal modes of variability exist in the climate system that allow skillful climate prediction on decadal time scales? • What is the nature of these modes? • Initialization methods and data? • In which regions does predictability exist? • For which time scales is a prediction skillful? (5, 10, 20 years?) • What is the role of different processes and related feedbacks for climate sensitivity and climate change on the centennial time scale (until 2100 and longer)? • Carbon and nitrogen cycles (and methane) • Clouds aerosols and chemistry • Stratospheric dynamics • Cryosphere: sea ice and ice shields • How to develop new mitigation scenarios?F( impacts( climate change( RCP scenarios, feedbacks ) )

4. The project in a nutshell CMIP5

5. 2B 1 2A Surface temperature Emissions Concentrations Example: Exploring CMIP5 expts in ENSEMBLES Method proposed for the future CMIP5 experiments, i.e. experiments for the 5th IPCC assessment of climate change (Hibbard et al., 2007): Story lines Impacts in regions and sectors (Mitigation) Scenario Carbon cycle - climate model

6. Well mixed greenhouse gases as prescribed in the E1 scenario.: • [ppm] • [ppb] -1000 ppb • [ppb] • [ppt] • [ppt] • CFC-11* includes the radiative forcing • from all minor CFCs. E1 scenario (Van Vuuren et al., 2007) • Equivalent CO2 concentration stabilizes at 450 ppm • Sulfate aerosol decreases quickly near pre-industrial levels at 2100 less cooling in early 21st cent. • Land use change consistent with assumptions in the IMAGE model

7. Global surface air temperature anomalies • Initially stronger warming in E1 than in A1B because of faster reduction in sulfate aerosol loading, hence less cooling. • Reduce warming in E1 after 2040 • Warming in 2100: ~4°C in A1B and ~2°C in E1 • Climate – carbon cycle feedback will differ after 2050 Global annual mean surface air temperature anomalies w.r.t. 1860-1880 (°C) ECHAM5/MPIOM incl.carbon cycle Historic 1950-2000 A1B 2001 – 2100 E1 2001 – 2100

8. without feedback with feedback Implied CO2 emissions 1950 to 2100 • Implied CO2 emissions of E1 scenario drop sharply after ~2015 (unlike emissions for A1B scenario) • Implied emissions are reduced by climate - carbon cycle feedback2100: -2 GtC/yr in E1 and -4.5 GtC/yr in A1B • Implied emissions of E1 close to 0 in 2100 (still positive). Implied CO2 emissions with and without climate – carbon cycle feedback (GtC/yr) ECHAM5/MPIOM incl.carbon cycle Historic 1950 – 2000 A1B 2001 – 2100 E1 2001 – 2100

9. Summary • In COMBINE we hope to make some interesting science w.r.t. • The role of different processes for feedbacks that regulate climate change • Predictability on the decadal time scale related to the internal variability of the climate system and initialization techniques • Impacts in sectors and regions for RCP scenarios • Iterative improvement of mitigation scenarios. • And we hope for a fruitful interaction with IS-ENES: • Infrastructure support in archiving, and dissemination of large data sets for the full project lifetime (CMIP5 and beyond) • Generally more transparent supercomputing and data processing infrastructure at the European and international level.

10. Thank you

11. COMBINE & IPCC-AR5 time lines

12. Work packages and PIs

13. Text of call FP7-ENV-2008-1 Area 6.1.1.4. Future Climate • ENV.2008.1.1.4.1. New components in Earth System modelling for better climate projections Future climate predictions necessitate development of models which incorporate more complete range of Earth System parameters in comparison to the existing ones, as well as the Earth System feedbacks on future climate change. Incorporation of Earth system components (e.g., chemistry, stratosphere, nitrogen cycle, aerosols and ozone, cryosphere, ocean biochemistry and carbon sink, human dimension) within climate models and applications of these to a number of case studies (e.g. decadal-timescale prediction). Implications of these feedbacks for impacts of climate change on different sectors (e.g. water resources, agriculture, forestry, air quality) through specific simulations. • Expected impact: The project outcome should contribute to the 5th IPCC assessment on climate change and provide solid scientific basis for future policy actions at European and international level …

14. Pert diagram

15. Motivation for this study • United Nations Framework on Climate Change: • Article 2: ‘The ultimate objective of this Convention ... is to achieve, ..., stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.’ • Questions relevant for IPCC AR5 • What anthropogenic CO2 emissions are feasible for a CO2 conc. pathway? • Were are anthrop. carbon emissions stored in the system? • What is the resulting climate change for a given CO2 pathway? • What is the role of feedbacks between climate change and the C cycle: • for climate change? • for feasible carbon emissions? • CMIP5 protocol provides description of experiments for the investigation of these questions in a coordinated multi model ensemble. • European ENSEMBLES project: • Mitigation scenario E1 (Van Vuuren et al., 2007). • Stabilize the anthropogenic radiative forcing to that equivalent to a CO2 concentration at around 450 ppm during the 22nd century. • To match the European Union 2°C target. • Apply E1 scenario and CMIP5 experiments to address questions listed above

16. Pre-industrial control simulation • Climate of undisturbed system stable over 1000 years,no systematic drift in surface air temperature or CO2 concentration Global annual mean surface air temperature (°C) and CO2 concentration (ppmv) Pre-industrial conditions, thick lines: 11-year running means • Surface air temperature(left scale, °C) • Atmospheric CO2 concentration (right scale, ppmv)

17. Global annual mean surface air temperature • Simulated surface air temperature less variable than observed. • Natural sources of variability like volcanic forcing or the 11 year solar cycle are excluded from the experiment. • Simulated warming in 2005 slightly underestimated. Global annual mean surface air temperature anomalies w.r.t. 1860-1880 (°C)5 year running means simulated (5 realizations) observed (Brohan et al., 2006)

18. Global annual mean CO2 emissions 1860 to 2005 • Model allows for relatively higher emissions before 1930. • Minimum in 1940s • Similar emissions in 2000. CO2 emissions from fossil fuel combustion and cement production (GtC/yr)Global annual mean; 11-year running means Implied emissions from simulations Observed (Marland et al., 2006)

19. Carbon release and uptake by land, 1860 – 2005 • Simulated land use emissions smaller than observed, especially in 1960-2000 • Simulated land uptake sationary from 1920 to 1960. Carbon release from land use emissions and uptake by land (GtC/yr), Positive = land-to-atmosphere flux; Model: 11-year running means, Observed land-use emissions (Houghton, 2008) Simulated land-use emissions Simulated net land uptake Simulated land uptake

20. Simulated carbon uptake 1860 to 2005 • Ocean carbon uptake very similar to land uptake • Reduced uptake in 1950s Simulated carbon uptake (GtC/yr)11-year running means Simulated ocean uptake Simulated land uptake(as on previous figure)

21. Carbon cycle – climate model Anthropogenic forcing Natural forcing CH4, N2O, CFC conc. Volcanic aerosol CO2 emissions/conc. Solar variations Land use change X X AtmosphereECHAM5 T31/L19~4° Momentum, Energy, H2O, CO2 LandHD JSBACH OceanMPIOM 3°L40 HAMOCC Carbon cycle climate model

22. 1860 1900 1950 2000 2050 2100 Experiments Control“1860”1000 yr Historic1860-2005 SRES A1B Ensembles of 5 realizations E1 450 ppm

23. Carbon uptake by ocean and land 1960-2000 • 50% of simulated fossil fuel emissons remain in the atmosphere • In 2000: simulated ocean uptake = ~2 x simulated land uptake Fraction of simulated fossil fuel emissions (%) Remaining in the atmosphere Absorbed by ocean Aborbed by land

24. Accumulated C emissions: Coupled – Uncoupled • Climate – carbon cycle feedback reduces implied carbon emissions until 2100 by 180 (E1) to 280 (A1B) GtC. Reduction in accumulated C emissions by climate – carbon cycle coupling (GtC)(11-year running means) Historic 1860 – 2000 A1B 2001 – 2100 E1 2001 – 2100

25. Fig.12

26. Fig.13

27. Surface C uptake: Coupled – uncoupled Regions with negative differences take up less carbon under global warming conditions and contribute to a positive feedback between climate and carbon cycle. Stabilization scenario E1 (2080 to 2100) IPCC SRES scenario A1B (2080 to 2100)

28. Table 1

29. Table 2