1. Global Climate Simulations Windows on the World of Tomorrow Renewable Energy Summit, Milwaukee, Wisconsin, March 13, 2008 Mark A. Chandler NASA Goddard Institute for Space Studies at Columbia University

2. Fig. TS.2, IPCC 2007 Changes In Greenhouse Gases from Ice Core and Modern Data CO 2 CH 4 N2ON2O

3. Temperature retrievals from satellites now generally consistent with surface-based observations (except for the tropics) Global Temperature Trends 1850-2005 Trend Length Years 25 50 100 150 Surface and TroposphereTrend Maps (1979-2005) 0.75-0.75 °C per decade

4. What are Global Climate Models and what do they project about the future?

5. Wind and Solar Climatologies

6. Computer Simulations of the Earth System

7. The GCM Grid

8. Increased Grid Resolution Requires Increased Computing Power Rule of thumb: 10X more CPU for a doubling of resolution Increased Resolution Requires Increased Computing Power Circa 2000’s Circa 1980’s

9. At every grid cell GCMs calculate: Temperature (T) Pressure (P) Winds (U, V) Humidity (Q) Fundamental Physical Quantities

10. T, P, U, V, and Q calculated and related to each other via: GCM Fundamental Physical Equations

11. Seasonal and Diurnal Cycles Latent and Sensible Heat Fluxes Clouds and Convection Planetary Boundary Layer Greenhouse Gases Aerosols Sea Ice Ground Hydrology Ocean Heat Transport Ocean Circulation Dynamic Vegetation Dynamic Ice Sheets Carbon Cycle Chemistry Physical Processes Simulated by GCMs

12. Global_Warming_Sim2.R Model II 8/24/2000 Owner: Dr. Mark Chandler, chandler@giss.nasa.gov Group: Paleoclimate Group This experiment simulates climate change based on a 1 percent/year increase in CO2 Object modules: MainC9 DiagC9 RadC9 FFTC9 UTILC9 Data input files: 7=G8X10_600Ma 9=NOV1910.rsf_snowball 15=O8X10_600Ma 19=CD8X10_600Ma 23=V8X10_600Ma 26=Z8X101_600Ma 21=RTAU.G25L15 22=RPLK25 29=Snowball_Earth_Regions Label and Namelist: Global_Warming_Sim2 (Transient increase in CO2) &INPUTZ TAUI=10176.,IYEAR=1900, KOCEAN=1, SRCOR=.95485638151, S0X=1.,CO2=.31746031746031, USET=0.,TAUE=35040., USESLP=-12., ISTART=3,KCOPY=2,NDPRNT=-1,TAUE=10177.,TAUP=95616., C** INITIALIZE SOME ARRAYS AT THE BEGINNING OF SPECIFIED DAYS fName = './prt/'//JMNTH0(1:3)//CYEAR//'.prt'//LABEL1( IF(JDAY.NE.32) GO TO 294 JEQ=1+JM/2 DO 292 J=JEQ,JM DO 292 I=1,IM 292 TSFREZ(I,J,1)=JDAY JEQM1=JEQ-1 DO 293 J=1,JEQM1 DO 293 I=1,IM 293 TSFREZ(I,J,2)=JDAY GO TO 296 294 IF(JDAY.NE.213) GO TO 296 JEQM1=JM/2 DO 295 J=1,JEQM1 DO 295 I=1,IM 295 TSFREZ(I,J,1)=JDAY C**** INITIALIZE SOME ARRAYS AT THE BEGINNING OF EACH DAY 296 DO 297 J=1,JM DO 297 I=1,IM TDIURN(I,J,1)=1000. TDIURN(I,J,2)=-1000. TDIURN(I,J,6)=-1000. PEARTH=FDATA(I,J,2)*(1.-FDATA(I,J,3)) IF(PEARTH.GT.0.) GO TO 297 TSFREZ(I,J,1)=365. TSFREZ(I,J,2)=365. 297 CONTINUE So, What Is a GCM Really? A Computer Program Unix ScriptsFortran Code GCMs Require High-Level Programming Skills and Supercomputing Resources

13. Distributed Computing Climate Experiments DOE GISS Model E NASA GISS Model E NSF GISS Model E National Lab Supercomputing Resources Personal Computers EdGCM Model E School Labs EdGCM Model E University Clusters EdGCM Model E GSFCGISSLangley Scientific Community Simulation Distribution Simulation Results Collection Primary Server Perturbed Physics Ensembles Desktop Client Computing Resources NASA MAP Climate Scientists “Big Iron” Computing

14. Scarsdale Teachers Institute Workshop, March 3 and 4, 2006 Climate Computing @ Home and School

15. What are the model inputs and where do they come from? Population Prospects Economic Development Energy Demand Resource Availability Technological Change Future Energy Systems Land Use Environmental Policy Google: IPCC SRES IPCC Special Report on Emissions Scenarios (SRES)

16. Figure SRES 5-1 An Example of the Greenhouse Gas Emissions Scenarios Carbon Dioxide Scenarios

17. Figure SPM-5

19. Figure SPM-6 IPCC 2007 Atm-Ocn GCM Projections of Surface Air Temperatures 0.08.0 °C IPCC 2007 Atm-Ocn GCM Projections of Surface Air Temperatures

20. Fig. TS.29 Continental Temperature Anomalies: Observations and Projections

22. IPCC, WG1, 2007 Model Ensemble Changes in Temperature, Precip, Storminess

23. Carbon Dioxide Change Over Geologic Time

24. Mid-Pliocene The Last Global Warming vs. The Coming Global Warming

25. Pliocene Sea Surface Temperature Anomaly (January) ∆T = +2.09°C

26. Simulated Change in Surface Air Temperature (Annual Average) ∆T = +2.1°C

27. 3 Mya 2005

28. Pliocene Temperature Change: 3 MYA +2.13 °C +2.33 °C 2050s

29. The Last Global Warming vs. The Coming Global Warming The North Atlantic Conundrum Pliocene DATA IPCC AOGCM

30. Impacts at ∆ Global Mean Temperature (R. Warren, in “Avoiding Dangerous Climate Change” 2006) 1°C: world ocean and arctic ecosystems damaged 1.5°C: Greenland ice sheet melting starts; ecosystems damaged in many regions 2°C: Agricultural yields fall, 1-3 billion experience water stress, sea level rise displaces millions, malaria risks spread, Arctic ecosystems collapse, extinctions soar, 97% of coral reefs gone, global ecosystems lose 5-66% of their extent; 2-3°C: Amazon and other forests and grasslands collapse, adding to CO 2 increase 3°C: Millions at risk to water stress, flood, hunger, dengue and malaria increase, few ecosystems can adapt, losing 7-74% of extent 4°C: whole regions forced out of agriculture (Australia), thermohaline circulation could collapse, West Antarctic Ice Sheet melting may begin, increases in extreme weather, 60% loss of tundra

31. http://data.giss.nasa.gov/cgi-bin/cdrar/do_LTmapE.py

32. 21 st Century Global Warming Climate Simulations for IPCC 2007 Report ► Climate Model Sensitivity 2.0-5.0ºC for 2xCO 2 (consistent with paleoclimate data & other models) ► Simulations Consistent with 1880-2003 Observations Source: Hansen et al., to be submitted to J. Geophys. Res.

33. IPCC MAIN FINDINGS Working Group I – The climate is warming and humans are causing it. (90% Certainty) Working Group II – Impacts are occurring now as a consequence of human-caused climate change. Specific future impacts have been identified. A portfolio of adaptation and mitigation measures can diminish the risks associated with climate change. Working Group III – There is substantial potential for mitigation. Projected costs are ~3% of global GDP in 2030. All sectors, as well as changes in lifestyle and behavior patterns, can contribute to climate change mitigation.

34. Pliocene Global Warming: Main Findings Global warming was 2-3°C higher than modern, similar to projected temperatures in the latter half of the 21st century. Sea level was approximately 25 meters higher than today, indicating probably complete loss (collapse?) of Greenland and West Antarctic ice sheets. North Atlantic ocean was a key area of warming in past global warming scenarios in contrast to the IPCCC AOGCM estimates of future climate change. If model ’ s are underestimating the climate change impact in the N. Atlantic global warming could proceed more rapidly than our current projections.