Global Climate Models Johannes Feddema Department of Geography The University of Kansas Outline Global Climate Models and Climate Change • (Some) History of climate science • What is a Model? • Basics of the climate system • Climate model components • Climate boundary conditions • Human impacts on climate • Future Climate simulations • Skeptics/deniers and models CLIMATE SCIENCE Conceptual framework for climate studies Global Climate Observing System – Early days Thermoscope Thermometer Greeks (density and energy) 11th Century Avicenna 15?? -1603 Galileo (thermoscope) 1613 – Segredo/Santorio (thermometer)? 1714 Fahrenheit (Mercury) 1742 Celsius (Centigrade Scale) 1853 1st Meteorological Conference Sources: http://en.wikipedia.org/wiki/Thermometer http://inventors.about.com/b/2004/11/16/the-history-behind-the-thermometer.htm www.nature.com http://www.geocities.com/Yosemite/Rapids/7592/Stevenson.jpg Milestones of the WMO 1853 First International Meteorological Conference (standardization of instruments) 1873 WMO's predecessor, the International Meteorological Organization (IMO) established 1882 Launch of the First International Polar Year 1882-1883 1932 Launch of the second International Polar Year 1932-1933 1951 WMO established as a specialized agency of the United Nations 1957 Launch of International Geophysical Year 1957-1958 Source WMO Modeling Concepts Conceptual or Descriptive models Description or understanding of general relationships Physical models Simplified physical replicas of more complex systems e.g. scale models (globe, cars, buildings, rivers etc.) from EPA/RTP WIND TUNNEL Modeling Concepts Conceptual or Descriptive models Description or understanding of general relationships Physical models Simplified physical replicas of more complex systems e.g. scale models (cars, buildings, rivers etc.) Mathematical models Deterministic – exact relationships Parameterized – generalized relationships e.g. correlation and regression Stochastic – contains a random component Can incorporate Feedback systems. Parameterized model: Regression Modeling Concepts This and next three are from A. HUBER, EPA/RTP What is Climate Science What is Modern Climate Science • Understanding of the movement of energy into, through, and out of the Earth System • Based on physics through the processes of: • Electromagnetic radiation • Convective heating of the Atmosphere (sensible heat) • Convective transport of water vapor Global Average Energy Balance Top of Atmosphere Energy Balance: 107 342 342 – 107 = 235 235 Incoming Solar Radiation Outgoing Reflected Shortwave Long-wave Radiation Shortwave radiation Atmosphere Energy Balance: 67 + 350 + 24 + 78 = 324 + 165 + 30 Reflected Shortwave radiation Long-wave Radiation by Clouds from Clouds Aerosols Long-wave Radiation Long-wave Radiation 30 and Gases Atmospheric Window from Atmosphere Absorbed 40 165 77 Shortwave radiation by Atmosphere Latent Heat 67 Longwave Radiationz 350 Absorbed by Atmosphere Sensible Heat Long-wave Radiation Emitted by Reflected Atmosphere Shortwave radiation 24 78 by Surface 30 Longwave Radiation Emmited by Surface 324 Evapo- 168 390 Thermal heating transpiration Absorbed Shortwave radiation Conduction by Surface Surface Energy Balance: 168 = 390 – 324 + 24 + 78 0 Global Climate Models Global Climate Models Global Climate Models Global Climate Models Global Climate Models The NCAR Community Climate System Model (CCSM) Model Resolutions R15 T42 T85 T170 Climate Model Resolution (300 km) (150 km) (75) km (37 km) Climate Models NCAR Community Land Model Biogeophysics Hydrology Momentum Flux Precipitation Wind Speed Evaporation D 0 ua Photosynthesis Latent Heat Flux Heat Latent i Sensible Heat Flux re Interception Canopy Water R c Radiation a t d S Diffuse Solar ia o Longwave Radiation t la io r n Transpiration Reflected Solar Radiation Throughfall Absorbed Solar Stemflow Emitted Long- Emitted Radiation wave Radiation Sublimation Evaporation Infiltration Surface Runoff Melt Snow Soil Heat Flux Soil Water Heat Transfer Redistribution Drainage Snow Catchment Hydrology And River Flow Soil Water Surface Runoff Ground Water Lake Ocean Climate Models Community Land Model Surface Datasets Up To 4 Patches Each patch has unique: • PFT composition glacier • PFT abundance 16.7% BDT temperate • leaf area 25% • height NET temperate • biomass lake vegetated 45% 16.7% 50% C3 grass 15 Plant Functional Types 15% Needleleaf evergreen tree wet- temperate urban land Crop boreal 8.3% 8.3% 15% Needleleaf deciduous tree Broadleaf evergreen tree Additional grid-cell data: tropical • land fraction temperate • soil color Broadleaf deciduous tree • soil texture (% sand, % clay, mineral composition) tropical temperate 2 cm boreal 3 cm Shrub 5 cm Additional data: 8 cm broadleaf evergreen, temperate 12 cm broadleaf deciduous, temperate • ½º river network 20 cm 34 cm broadleaf deciduous, boreal 55 cm Grass Soil Profile C , arctic • total depth - 343 cm 3 91 cm C • 10 layers 3 C4 • texture varies with depth Crop 114 cm An Urban Sub-model in the CLM Atmospheric Forcing Tq, uatm atm atm PSatm,, atm L atm Roof HEL,,↑ , S↑ ,τ T Rroof Troof, s roof ,1 T roof ,10 H roof H waste Eroof Tshdwl,10 Tshdwl,1 Tsunwl,1 Tsunwl,10 Canopy Air Space Tsunwall, s Tshdwall, s H Tqu,, H sunwall s ss H shdwall TTmin<<i , build T max Sunlit Shaded Wall Wall Himprvrd H H prvrd E traffic imprvrd Eprvrd R R imprvrd T T prvrd imprvrd ,1 Timprvrd, s Tprvrd, s prvrd ,1 Timprvrd ,10 T Impervious Pervious prvrd ,10 Canyon Floor W Timeline of Climate Model Development Climate Change Climate Change Science What do we need to know? • Is the climate changing • Observations • Reference conditions • Climate change attribution • What is causing it to change • Climate projections • What does theory tell us about the future Background: Human Climate Interactions Natural and human impacts on the climate system Solar Variation Agriculture Natural Vegetation? Atmospheric Composition De/Re-forestation Soil Degradation Urban Grazing WHAT ABOUT SOLAR ACTIVITY? Natural Forcing over the last decades Sources: Globalwarmingart.com Sources: Globawarmingart.com www.globalwarmingart.com/wiki/Image:Sunspot_Numbers_png Hoyt and Schatten (1998a) Solar Physics 179: 189-219. Hoyt, and Schatten (1998b) Solar Physics 181: 491-512. Stott et al. (2003) Journal of Climate 16: 4079-4093. Long term Solar and Temperature trends Sources: Globalwarmingart.com HISTORICAL FORCINGS Climate Forcing (Anthropogenic) Source: World Resources 2000-2001 Time Magazine – 9 April 2001 So what are we worried about? Future? Rate – Depends on: response time? feed backs? 2005 Present 0.7 ºC Rate = +0.7 ºC 100yrs 100 years 1958 Industrial revolution begins 1900 1900 Humans develop as species Rate ≈ +0.036 ºC { 5-8 ºC 100yrs 18,000 years Ice Age Domestication of plants and animals Last Glacial Maximum Relationships between GHGs and Temperature Climate and Greenhouse Gases during the last 650 Kyrs 1700 ppbv 375 ppmv EPICA Dome C Vostok Indermuehle et al (submitted) Pépin et al ( 2001) EPICA project members (2004) Petit et al (1999) Spahni et al (submitted) Delmotte et al (2004) 300 280 260 240 4 (ppmv) 220 2 2 200 CO 0 180 (°C) -2 ΔΤ -4 800 -6 700 -8 600 -10 (ppbv) 500 4 CH 400 700000 600000 500000 400000 300000 200000 100000 0 Age (yr BP) What about the distant past? Sources Globalwarmingart.com www.globalwarmingart.com/wiki/Image:Phanerozoic_Carbon_Dioxide_png Bergman etaal (2004). American Journal of Science 301: 182-204. Berner and Kothavala (2001). American Journal of Science 304: 397–437. Gradstein, FM and JG Ogg (1996). Episodes 19: 3-5. Gradsteinet al. (2005). A geologic time scale 2004. Camb. Univ. Press Rothman (2001) Proc. of the Nat. Academy of Sciences 99 (7): 4167-4171. Royer, et al. (2004) GSA Today www.scotese.com But it was a different world Extinction of Dinosaurs Permian Crash Terrestrial plants WHAT EXACTLY DOES CO2 DO? Effects of CO2 on Energy Balance Sources: Globalwarmingart.com www.globalwarmingart.com/wiki/Image:Atmospheric_Transmission_png Gordley et al. (1994). J. .Quant. Spect. & Rad. Trans. 52 (5). Kiehl and Trenberth (1997) Bull. Am. Meteor. Assoc. 78. Lashof (1989). Climatic Change 14 (3): 213-242. Rothman et al. (2004). J. .Quant. Spect. & Rad. Trans. 96. Peixoto and Oort (1992). Physics of Climate. Springer Global Average Energy Balance Top of Atmosphere Energy Balance: 107 342 235 342 – 107 = 235 235 234 Incoming Solar Radiation Outgoing Reflected Shortwave Long-wave Radiation Atmosphere Energy Balance: Shortwave radiation 67 + 350 + 24 + 78 = 324 + 165 + 30 Reflected 352 79 326 166 Shortwave radiation Long-wave Radiation by Clouds from Clouds Aerosols Long-wave Radiation Long-wave Radiation 30 and Gases Atmospheric Window from Atmosphere Absorbed 40 165 77 Shortwave radiation 39 166 by Atmosphere Latent Heat 67 1 Longwave Radiationz 350 Absorbed by Atmosphere 351 2 352 Sensible Heat Long-wave Radiation Emitted by Reflected Atmosphere Shortwave radiation 24 78 by Surface 30 79 Longwave Radiation Emmited by Surface 324 326 Evapo- 168 390 Thermal heating transpiration Absorbed 391 Shortwave radiation 326 391 79 0 Conduction by Surface Surface Energy Balance: 168 –324= 390 + 24 + 78 + 0 USING MODELS TO GIVE US ANSWERS Climate Simulation: How good are the models? Recent Climate Variable Trends: Observations Sources: Globawarmingart.com www.globalwarmingart.com/wiki/Image:Short_Instrumental_Temperature_Record_png Brohan, et al. (2006) J. Geophaysical Research 111: D12106 Luo etal. (2002 J Clim 15: 2806-2820 Sources: Globawarmingart.com www.globalwarmingart.com/wiki/Image:Solar_Cycle_Variations_png