Earth’s Climate Past and Future

1. Earth’s ClimatePast and Future Prof. Z. Liu Dept. Atmospheric and Oceanic Sciences

3. Text Book Earth’s Climate, Past and Future, W.F. Ruddiman 2nd edition, W.H. Freeman and Company Reading Material IPCC AR5: Chapter 5: Information from paleoclimate archives Grading Quiz: 1/3 Presentation: 1/3 Term paper: 1/3

4. Syllabus for AOS528 Part I: Basics of the Climate System Lecture 1: Introduction: Overview of the climate system (Ch.1) Lecture 2: Climate Archives and Data (Ch.2) Lecture 3: Climate Modeling (Ch.2) Part II: Tectonic-Scale Climate Change Lecture 4: CO2 and long term climate: last 4.5 Byr (Ch.3) Lecture 5: Plate tectonics and climate: last 550 Myr (Ch.4) Lecture 6: The greenhouse earth (Ch.5) Lecture 7: Back into the icehouse: last 55 Myr (Ch.6) Quiz 1 Part III: Orbital-Scale Climate Change Lecture 8: Orbital variations and Insolation Change (Ch.7) Lecture 9: Orbital control of Monsoon change (Ch.8) Lecture 10: Orbital control of Ice sheets (Ch.9) Lecture 11: Glacial cycles and greenhouse gases (Ch.10) Lecture 12: Carbon pumping into the deep ocean (Ch.10) Lecture 13: Orbital-scale interactions (Ch.11) Quiz 2

5. Part IV: Deglacial and Millennial Climate Changes Lecture 14: The Last Glacial Maximum (Ch.12) Lecture 15: The last deglaciation (Ch.13) Lecture 16: Climate changes in the last 10,000 years (Ch.13) Lecture 17: Millennial changes (Ch.14) Quiz 3 Part V: Historical Climate Changes Lecture 18: The Little Ice Age (Ch.15) Lecture 19: El Nino, La Nina and Southern Oscillation (Ch.15) Lecture 20: Impacts of climate on early humans and civilizations (Ch.16) Lecture 21: Anthropogenic inputs of gases (Ch.16) Part VI: Future Climate Changes Lecture 22: The greenhouse debate (Ch.17) Lecture 23: Climate change in the future 100-1000 years (Ch.18) Student presentations: IPCC paleo chapter

6. Lecture 1: Overview of the Climate System(Chapter 1)

7. Global warming?

8. Global Temp Trend 1.Continetnal warming, even some cooling, 2. surface more Why?

9. Global Prep Trend(?) Less coherent change, Why dryer? Caution: 50-present only!

10. Local Climate Change Melting Lake Ice ! Lake Mendota

11. Global Warming?!

12. Different Time Scales in the Past

13. Different Time Scales in the Past

14. Atmospheric CO2 Evolution

15. Tectonic Impact

16. Abrupt Changes

17. The Cold Climate

18. The Dry Climate

19. Deep Ocean Changes Modern LGM

20. Last 21,000 years Fig. 1. Paleoclimate time series spanning the last deglaciation and Holocene. From left to right, June insolation at 60ºN (Berger, 1978). Far field relative sea level records (Fleming et al., 1998; Clark et al., 2009b) (black squares) and Laurentide Ice Sheet volume (Carlson, 2008; Clark, 2009c). Antarctic Dome C CO2 (Monnin et al., 2001). Antarctic Dome C dD (EPICA, 2004). Greenland GISP2 d18O (Grootes et al., 1993). Hulu (black) and Dongge (gray) Caves speleothem d18O (Wang et al., 2001; 2005). West African terrigenous dust (deMenocal et al., 2000). ENSO frequency (Moy et al., 2002). Tropical sea surface temperatures (SST): dark blue eastern equatorial Pacific (Lea et al., 2006); blue Cariaco Basin (Lea et al., 2003); Red western equatorial Pacific (Stott et al., 2007). Bars denote events discussed in text.

21. Complex System and Interactions

22. Climate Model for Prediction and Mechanism Earth System Model

23. Decadal (10-30-yr) Prediction Climate Model and Climate Projection IPCC, 2007

24. Test Climate Model Against the Past Obs

25. Test Climate Model Against Past Obs 21 ka – 0ka

26. Proxy CCSM3 Salinity AMOC Δ 13C 0ka 21ka Fig.3: Observation of d13C (left), and model Atlantic salinity (zonal mean) (middle) and the AMOC overturning streamfunction (in Sv.) (right) at 0ka (upper) and LGM (lower). Model salinity compares well with the d13C reconstruction in the deep ocean, with a 1-km shallowing of the NADW and AMOC.

27. Observation AMOC in Models (PMIP2) Δ 13C CCSM HadCM MIROC ECBILT_CLIO 0ka 21ka Otto-Bliesner et al., 2007, GRL

28. Fig.2: Data-model comparison for benchmark time series. (a) June insolation at 60 N (red) and atmospheric CO2 concentration. (b) Sea level from the reconstruction (triangle) and model (equivalent sea level for meltwater). (c) Meltwater fluxes in the model. (d) Pa/Th ratio at Bermuda as a proxy for AMOC strength, and model AMOC transport at 30oS. (e) GISP2 annual surface air temperature in (d18O) reconstruction and model. (f) Vostok annual surface air temperature in (d18O) reconstruction (ref) and model. (g) Annual SST in Iberian Margin in reconstruction and model. (h) Annual SST in Cariaco basin in reconstruction and model. (i) Annual rainfall in Cariaco Basin in reconstruction and model. In (c-i), reconstruction is in grey, and model simulations are in color (red for DGL-A , blue for DGL-B.). (see Liu et al., 2009 for more details).

29. Climate Variability Tropical Pacific SST

30. El Nino

31. 1935 Texas (Dustbowl) 1997 Kansas

32. Climate Change and Climate Variability IPCC, 2007

33. Sahel Rainfall Human effect (trend) or/and variability? July Charney??? Charney Giannini et al., 2003: Science

34. Climate Change: Global to Regional Global US Wisconsin Madison

35. and North Atlantic Oscillation ? NAO Wisconsin Climate Change Temp Z. Liu

36. Wisconsin Temperature: Seasonal Annual Winter Dust Bowl Summer http://www.aos.wisc.edu/~sco/divisions/WI-00-temp-djf.gif

37. Decadal (10-30-yr) Prediction Climate Projection and Decadal Prediction IPCC, 2007

38. End of Lecture 1