EAS 4801/8801: Abrupt Climate Change Seminar
Fridays 12:30-2pm, ES&T L1175
Kim Cobb
ES&T 2234, 404-894-1992
Course web-site: http://shadow.eas.gatech.edu/~kcobb/abrupt
Course Objectives:
Widespread evidence for dramatic climate changes that occurred in as little as 10 years during the recent geologic past has fueled efforts to predict how anthropogenic radiative forcing will cause future abrupt climate changes. An abrupt change in global precipitation patterns under continued greenhouse forcing would carry steep societal costs, given that water plays such a fundamental role in public health and economy. There is some evidence that such changes are currently underway, yet detecting them against a backdrop of rich natural variability remains a challenge, and presents an obstacle to robust long-range forecasts of regional precipitation. The paleoclimate record presents many opportunities to investigate the causes and effects of abrupt changes that in many cases eclipse those of the anthropogenic era, while providing a backdrop against which to detect anthropogenic trends.
In this seminar we will review the evidence for large, abrupt changes in sea ice, atmospheric circulation, and precipitation during the recent geologic past, and the mechanisms that have been proposed to explain these anomalies. The second part of the seminar will focus on the immplications of paleo-abrupt changes for anthropogenic climate change, using modern-day observations and IPCC model runs as discussion tools.
Course requirements:
Graduate students are required to present weekly papers to the class (30 minute max powerpoint). A second student (either graduate or undergraduate) will be appointed by the instructor to facilitate discussion after the presentation. All students should read the papers carefully and come prepared with 2 comments and/or questions for group discussion.
Grades:
50% Presentations (presenter and facilitator)
50% Participation
Schedule & Papers:
Section I: Views of abrupt climate change during the LGM & deglacial
August 29 It's the MOC, stupid: Alley 2007 (Jake and Jacky) (Jake's presentation)
Sept 5 Don't discount the tropics: Seager and Battisti, 2007 (Laura's presentation)
Sept 12 Plus or minus the winds: Wunsch, 2006; Brauer et al., 2008 (Kelli's presentation)
Sept 19 With a dash of sea ice: Masse et al., 2008; Li et al., 2005 (Intan and Colin)
Section II: Paleo-records and mechanisms of abrupt change in the Holocene
Sept 26 Wang et al., 2007; Liu et al.,, 2007 (monsoon regions)
Oct 3 Cook et al., 2004; Graham et al., 2007 (western US drought)
Section II: Abrupt change in the Anthropocene
Oct 17 Holland et al., 2006 (sea ice); Walter et al., 2006 (methane)
Oct 24 Seager et al., 2007 (western US drought); Held and Soden, 2006 (global precip)
Dec 5 IPCC AR4