The Earth’s Climate System Challenges and Advances with Geologic Data and Modeling Partnerships

1. WIPS – The Earth's Climate System

2. The Earth’s Climate SystemChallenges and Advances with Geologic Data and Modeling Partnerships Caspar M. Ammann National Center for Atmospheric Research, Climate and Global Dynamics Divisionammann@ucar.edu WIPS – The Earth's Climate System

3. International Geophysical Year 1957/58“A very successful stimulus package for science” WIPS – The Earth's Climate System

4. IGY : Earth Science WIPS – The Earth's Climate System

5. Geomagnetic and Dating Techniquesopen doors to Geologic Time WIPS – The Earth's Climate System

6. IGY: Weather / Climate WIPS – The Earth's Climate System

7. Weather / Storm forecasts WIPS – The Earth's Climate System

8. Other breakthroughs: Reconstruction of Ocean circulation, … WIPS – The Earth's Climate System

9. Last 10-20 yrs : Abrupt Earth System Change Deep Time Quaternary Holocene WIPS – The Earth's Climate System

10. Initiated / or accelerated by the IGY emerges a much more dynamic picture of the Earth System WIPS – The Earth's Climate System

11. True Global Reach of HumansAtmosphereOceans "Human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future.” Roger Revelle WIPS – The Earth's Climate System

12. Is this still simply a “geophysical experiment”? Greenhouse Gas Concentrations last 600,000 years CO2 - 20,000 years Methane Temperature CO2 Rate of Changeunprecedented for probably millions of years! IPCC 2007 WIPS – The Earth's Climate System

13. IPCC 2007: “Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely (>90% confidence) due to the observed increase in anthropogenic greenhouse gas concentrations.” 3 Decades in Earth Observations and Change WIPS – The Earth's Climate System

14. Why is it not natural? Climate has always been changing, naturally … WIPS – The Earth's Climate System

15. Tools to Study Effect of Change in CO2 • Climate Diagnostics and Analysis:Understand coupled Earth System with best observational data / Data Assimilation • Climate Models:Help to sharpen understanding of geophysical processes • PALEO: Using time perspective to test and corroborate Goal: Seamless understanding of Past-Present to build confidence in projections into the Future WIPS – The Earth's Climate System

16. Changes Across Scales Effect on Extreme Precipitation 1900 2003 Global-wide Glacier Collapse Global Sea Level Rise WIPS – The Earth's Climate System

17. Models are now “Partners” to Data ~150 km Viner (2002) Model Computation: - 15 minute time steps - 1 quadrillion calculations /yr WIPS – The Earth's Climate System

18. Global coupled climate models in 2006 Climate Models circa early 1990s Global models in 5-10 yrs Regional models WIPS – The Earth's Climate System

19. Continuously Improved Models CCSM: Climate Simulations WIPS – The Earth's Climate System

20. Performance of CCSM-3 Surface Air Temperature Model El Niño-Variability Model Observations Observations WIPS – The Earth's Climate System

21. High Resolution Ocean Models WIPS – The Earth's Climate System

22. Climate Modeler's Commandments by John Kutzbach (Univ. of Wisconsin) • Thou shalt not worship the climate model. • Thou shalt not worship the climate model, but thou shalt honor the climate modeler, that it might be well with thee. • Thou shalt use the model that is most appropriate for the question at hand. • Thou shalt not change more than one thing at a time at first. • In making sensitivity experiments, thou shalt hit the model hard enough to make it notice you. • Thou shalt not covet fine-scale results with a coarse-scale model. • Thou shalt follow the rules for significance testing and remember the model's inherent variability. • Thou shalt know the model's biases and remember that model biases may lead to biased sensitivity estimates. • Thou shalt run the same experiment with different models and compare the results. • Thou shalt worship good observations of the spatial and temporal behavior of the earth system. Good models follow such observations. One golden observation is worth a thousand simulations. WIPS – The Earth's Climate System

23. Forcings used in Models • Present-day direct and indirect forcings • Past Geographies • LGM / LIG • Eocene • Cretaceous • Late Permian • Carboniferous WIPS – The Earth's Climate System

24. Simulations of the 20th century: Time Allforcings Naturalonly Meehl et al. 2004 WIPS – The Earth's Climate System

25. Future Climate ProjectionsNote: These are “What If” Scenarios, not predictions A2: 2020s A2: 2090s IPCC, 2007 WIPS – The Earth's Climate System

26. Simulation 20th and 21st Century Climate Models reasonably reproduce changes in: • Global and continental scale evolution of temperature • Vertical temperature profile • Atmospheric moisture • Heat content of oceans • sea ice retreat in all seasons • … NCAR CCSM: Gary Strand WIPS – The Earth's Climate System

27. 2000 ~2040 Sea Ice : Observations and Model Projections September Sea Ice Extent: Abrupt change potential! WIPS – The Earth's Climate System

28. Are we over-blowing the problem? • … most likely not …: • emissions faster than projected • carbon cycle and nutrients • speed of sea ice retreat? • melting on ice sheets? • weaker trends in models in some responses (precip)? • models in paleo applications: never quite the amplitude … Canadel et al. 2007 WIPS – The Earth's Climate System

29. Goal of seamless understanding Past-Present-Future Ammann et al., 2007 WIPS – The Earth's Climate System

30. Last Interglacial (~130 ka): +6m sea level WIPS – The Earth's Climate System

31. Importance of a “Seamless” Integration of Paleo into Climate Change Research • How well do we understand the cause and magnitude of past changes? • What effect on the Earth System did past changes have? • Identify and study analogues to future Climate Change (PETM?, Cretaceous, …) • Can we develop rigorous benchmarks for climate models on global and regional scales? • … Goal: Further improve confidence in models projections regarding magnitude, spatial extent, hydrologic - environmental impact WIPS – The Earth's Climate System

32. Paleo Analogs for future temperatures?Future climates might resemble the past >40 Mio yr ago WIPS – The Earth's Climate System

33. What’s Next? (AR5 ~2013?)Key Role for PALEO! ( 1 ) Long, multi-century projections to study Carbon Cycle Feedbacks, Sea Level Change ( 2 ) Very high-resolution simulations of the next 20-30 years for regional climate change prediction WIPS – The Earth's Climate System

34. Possible new CCSM Components for AR5 • Aerosols • Direct and indirect effects • Chemistry • Radiative and air quality issues • Dynamic Vegetation • Regrowth following disturbance, human landuse • Carbon & Nitrogen Cycle • Ocean & land biogeochemistry • Anthropogenic (transient) land use/cover • Land Ice Sheets • Sea level Rise & Abrupt Climate change WIPS – The Earth's Climate System

35. Future Sea Level and New Orleans (+1m) WIPS – The Earth's Climate System

36. New Focus on Regional Water Colorado School of Mines: Sustainability

37. Changes in Seasonal Cycle of Snowmelt (T)and shifts in Jet-stream with change in Precip (P)Water from Snowpack in dry summer season? Barnett et al. 2008 WIPS – The Earth's Climate System

38. North American Precipitation and Hurricanes • 36, 12 and 4 km domains nested into CCSM • Multi-member ensembles for each period • Dedicated time on NCAR IBM Power 6 (Bluefire) since July: • ~300 Tb of data (to date); 450 Tb total (including earlier runs) WIPS – The Earth's Climate System

39. CCSP 2.1a Mitigation Simulations WIPS – The Earth's Climate System

40. A modern science revolution with Models as Partners in Earth System Analysis: What important answers do we need from the past! • What can be learned about sensitivity of polar ice sheets? • How quickly can sea level rise? • How effective is the carbon cycle feedback? • How much did the tropics or subtropics change? • How does high atmospheric carbon affect ocean acidity, and how does acidity influence the ocean food chain? WIPS – The Earth's Climate System

41. Climate Change in Perspective • Climate has always been fluctuating, and we generally “know” why : Seamless perspective • Ongoing Climate Change is real and due to increase in Greenhouse Gas concentrations • Models have become partners to field-data and observations. Open questions could provide a platform for enhanced interaction and collaboration providing very important constraints and predictions for decision making • There is an urgent need for a constructive dialogue to address the “Great Global Challenge” between Energy Needs and Climate Change WIPS – The Earth's Climate System

42. The Great Challenge:Balancing Climate and Energy Needs Thank you! WIPS – The Earth's Climate System

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44. Paleocene-Eocene Thermal Maximum: A possible “analog” to study future impact on Earth System? Zachos et al. 2005 WIPS – The Earth's Climate System

45. Challenge: Polar Temperatures during Warm Climates(Equator - Pole Gradient : High latitude warm but tropics cool?A data or a model problem?) ProxyRecord Models Future Present Huber and Sloan, 2001 WIPS – The Earth's Climate System

46. Subtropical drying in with large scale warming?Can this fundamental concept be confirmed in past climates? WIPS – The Earth's Climate System