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Advances in Earth's Climate System Modeling

Explore geologic data and modeling partnerships to understand Earth's climate challenges. Discover insights from the International Geophysical Year and implications for human impact on greenhouse gas concentrations. Dive into climate change across scales and the role of climate models in predictions.

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Advances in Earth's Climate System Modeling

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  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

  43. WIPS – The Earth's Climate System

  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

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