Rapid Climate Change: Holocene to Anthropocene (Spring 2005)

GEOL 4700-5 / 5700-8 - Rapid Climate Change Seminar

Theory and observations increasingly point to significant human impacts on modern (and future) climate, particularly through modification of the atmosphere’s composition. Questions remain, however, surrounding the contribution of natural climate variability to recent changes. This course will examine current climate trends in the context of natural Holocene (past 11,500 years) variability. We will cover various modes of climate variability on interannual/decadal (e.g., El Niño-Southern Oscillation, North Atlantic Oscillation) to centennial/millennial (e.g., Medieval Warm Period, Little Ice Age) timescales. Current and emerging theories regarding forcing mechanisms, both natural and anthropogenic, will be discussed.

The course will be primarily conducted in seminar format, with detailed discussions of the current literature. Students will be required to make periodic presentations on assigned readings. A term project, in the form of an annotated bibliography on a relevant topic of the student’s choosing, will also be required.

Term Project description (pdf) (due May 2)
Example of an annotated bibliography (pdf)
Web of Science database
GeoRef link
Various journal links

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Meets: Tuesdays and Thursdays 3:30-4:45, Benson Earth Sciences 355
Professor:Tom Marchitto, tom.marchitto@colorado.edu
Office Hours: By announcement and appointment, Benson 435 or RL1 152
Grading: 40% Presentations, 30% Participation, 30% Project

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Pertinent questions to be addressed

Holocene paleoclimate

Does global climate experience natural oscillations at multi-decadal, centennial, or millennial timescales?
What are the main forcings of such natural variations?
How well are the histories of these forcings known?
How reliable are hemispheric reconstructions of climate over the past 1000 years?
How do the past few decades compare to the past 1000 years?
How skillful are computer models at simulating the climate of the past 1000 years?
Can these simulations tell us if recent warming is anthropogenic?
 

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Class schedule (evolving)

T 1/11: Introduction and class outline

Th 1/13: Lecture: Climate primer


 

Holocene paleoclimate

T 1/18: Holocene millennial-scale climate variability

Mayewski et al., Holocene climate variability, Quaternary Research, 62: 243-255, 2004. (Tom)

Th 1/20: No class


T 1/25: Holocene solar cycles

Hu et al., Cyclic variation and solar forcing of Holocene climate in the Alaskan subarctic, Science, 301: 1890-1893, 2003.PDF (Maureen)

Fleitmann et al., Holocene forcing of the Indian monsoon recorded in a stalagmite from southern Oman, Science, 300: 1737-1739, 2003.PDF (Maureen)

Additional reading:Bond et al., Persistent solar influence on the North Atlantic climate during the Holocene, Science, 294: 2130-2136, 2001.

Th 1/27: Modeling Holocene natural forcing

Schmidt et al., General circulation modelling of Holocene climate variability, Quaternary Science Reviews, 23: 2167-2181, 2004.PDF (Ursula)

Additional reading:Lean et al., The effect of increasing solar activity on the Sun's total and open magnetic flux during multiple cycles: Implications for solar forcing of climate, Geophysical Research Letters, 29 (24): 2224, doi: 10.1029/2002GL015880, 2002.

T 2/1: Little Ice Age

Hodell et al., Climate change on Yucatan Peninsula during the Little Ice Age, Quaternary Research, in press, 2005.PDF (Patrick)

Additional reading:Haug et al., Southward migration of the Intertropical Convergence Zone through the Holocene, Science, 293: 1304-1308, 2001.

Th 2/3: Lecture: El Niño-Southern Oscillation and North Atlantic Oscillation

NAO reading: Hurrell, Decadal trends in the North Atlantic Oscillation: Regional temperatures and precipitation, Science, 269: 676-679, 1995.

NAO reading: Hurrell, Influence of variations in extratropical wintertime teleconnections on Northern Hemisphere temperature, Journal of Geophysical Research, 23: 665-668, 1996.

T 2/8: NAO reconstructions

Appenzeller et al., North Atlantic Oscillation dynamics recorded in Greenland ice cores, Science, 282: 446-449, 1998.PDF (Darren)

Schöne et al., North Atlantic Oscillation dynamics recorded in shells of a long-lived bivalve mollusk, Geology, 31: 1037-1040, 2003.PDF (Darren)

Additional reading:Cook et al., A well-verified, multiproxy reconstruction of the winter North Atlantic Oscillation index since A.D. 1400, Journal of Climate, 15: 1754-1764, 2002.PDF

Th 2/10: ENSO reconstructions

Cobb et al., El Niño/Southern Oscillation and tropical Pacific climate during the last millennium, Nature, 424: 271-276, 2003.PDF (Cynthia)

Adams et al., Proxy evidence for an El Niño-like response to volcanic forcing, Nature, 426: 274-278, 2003.PDF (Cynthia)

Additional reading: Mann et al., Volcanic and solar forcing of the tropical Pacific over the past 1000 years, Journal of Climate, in press, 2005. PDF

T 2/15: US aridity reconstructions

Cook et al., Long-term aridity changes in the western United States, Science, 306: 1015-1018, 2004. (Benjamin)

Schubert et al., On the cause of the 1930s Dust Bowl, Science, 303: 1855-1859, 2004. (Benjamin)

Th 2/17: Regional/hemispheric/global temperature reconstructions (past 500-2000 yr)

Mann and Jones, Global surface temperatures over the past two millennia, Geophysical Research Letters, 30 (15): 1820, doi: 10.1029/2003GL017814, 2003. (Kelly)

Luterbacher et al., European seasonal and annual temperature variability, trends, and extremes since 1500, Science, 303: 1499-1503, 2004. (Kelly)

Additional reading (long!):Jones and Mann, Climate over past millennia, Reviews of Geophysics, 42: RG2002, doi: 10.1029/2003RG000143, 2004. (PDF)

Additional reading:Mann RealClimate blog entry rebutting "myths" about the "hockey stick"

T 2/22: 1000-yr Northern Hemisphere temperature reconstruction: Preserving low frequencies I

Cook et al., Extra-tropical Northern Hemisphere land temperature variability over the past 1000 years, Quaternary Science Reviews, 23: 2063-2074, 2004. (Saedis)

von Storch et al., Reconstructing past climate from noisy data, Science, 306: 679-682, 2004. (Saedis)

Additional reading:Esper et al., Low-frequency signals in long tree-ring chronologies for reconstructing past temperature variability, Science, 295: 2250-2253, 2002.

Th 2/24: 1000-yr Northern Hemisphere temperature reconstruction: Preserving low frequencies II

Pollack and Smerdon, Borehole climate reconstructions: Spatial structure and hemispheric averages, Journal of Geophysical Research, 109: D11106, doi:10.1029/2003JD004163, 2004. (Zack)

Moberg et al., Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data, Nature, 433: 613-617, 2005. (Zack)

Additional reading:Huang et al., Temperature trends over the past five centuries reconstructed from borehole temperatures, Nature, 403: 756-758, 2000.

T 3/1: No class


Th 3/3: Modeling Northern Hemisphere temperatures over past 1000 yr

Hegerl et al., Detection of volcanic, solar and greenhouse gas signals in paleo-reconstructions of Northern Hemispheric temperature, Geophysical research Letters, 30 (5): 1242, doi:10.1029/2002GL016635, 2003. (Darren)

Bauer et al., Assessing climate forcings of the Earth system for the past millennium, Geophysical Research Letters, 30 (6): 1276, doi:10.1029/2002GL016639, 2003. (Darren)

Additional reading:Crowley, Causes of climate change over the past 1000 years, Science, 289: 270-277, 2000.

T 3/8: Paleo synopsis discussion


 

Documenting recent climate change (instrumental)

Th 3/10: Land surface air temperatures (Patrick)

GISS (Hansen et al.) surface temperature analysis webpage. Read this like you read a paper, including links that seem useful. Printing the main webpage in landscape orientation will give 4 pages.

Jones and Moberg, Hemispheric and large-scale surface air temperature variations: An extensive revision and an update to 2001, Journal of Climate, 16: 206-223.

T 3/15: Ocean temperatures (Maureen)

Rayner et al., Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century, Jornal of Geophysical Research, 108 (D14): 4407, doi:10.1029/2002JD002670, 2003. Long, but parts can be skimmed.

Levitus et al., Warming of the World Ocean, 1955-2003. Geophysical Research Letters, 32: L02604, doi:10.1029GL021592.

Th 3/17: Tropospheric (and stratospheric) temperatures (Ursula)

Vinnikov and Grody, Global Warming Trend of Mean Tropospheric Temperature Observed by Satellites, Science, 302: 269-272, 2003.

Fu et al., Contribution of stratospheric cooling to satellite-inferred tropospheric temperature trends, Nature, 429: 55-58, 2004. See also Comments by Tett & Thorne, and by Gillett et al. (2004) (pdf) and Reply by Fu et al. (2004) (pdf)

Additional light reading on the stratosphere:Baldwin et al., Weather from the stratosphere?, Science, 301: 317-319, 2003. (pdf)

T 3/22 & Th 3/24: Spring Break


T 3/29: Melting ice and rising sea levels (Kelly)

Thomas et al., Accelerated Sea-Level Rise from West Antarctica, Science, 306: 255-258, 2004.

Miller and Douglas, Mass and volume contributions to twentieth-century global sea level rise, Nature, 428: 406-409, 2004.

See also:NSIDC (Dyurgerov et al.) global glacier recession webpage

Scary additional reading:Gregory et al., Threatened loss of the Greenland ice-sheet, Nature, 428: 616, 2004.

Th 3/31: Ecological shifts (Cynthia)

Parmesan and Yohe, A globally coherent fingerprint of climate change impacts across natural systems, Nature, 421: 37-42, 2003.

Edwards and Richardson, Impact of climate change on marine pelagic phenology and trophic mismatch, Nature, 430: 881-884, 2004.

Additional reading:Root et al., Fingerprints of global warming on wild animals and plants, Nature, 421: 57-60, 2003.

Attribution, feedbacks, and ancillary effects

T 4/5: Heat islands (Zack)

Kalnay and Cai, Impact of urbaniurbanization and land-use change on climate, Nature, 423: 528-531, 2003. See also Comments by Trenberth, and by Vose et al., and Reply by Kalnay and Cai (2004) (pdf)

Parker, Large-scale warming is not urban, Nature, 432: 290, 2004.

Additional reading:Peterson, Assessment of Urban Versus Rural In Situ Surface Temperatures in the Contiguous United States: No Difference Found, Journal of Climate, 16: 2941-2959, 2003.

Th 4/7: Clouds (Saedis)

Stephens, Cloud Feedbacks in the Climate System: A Critical Review, Journal of Climate, 18: 237-273, 2005. This paper is VERY long. Skip/skim over the technical parts if you like, but try to get the author's main points.

Additional reading, short News & Views:Penner, The cloud conundrum, Nature, 432: 962-963, 2004. (pdf)

Additional reading, if you're interested:Lindzen et al., Does the Earth have an adaptive infrared iris?, Bulletin of the American Meteorological Society, 82, 417-432, 2001. (pdf)

T 4/12: Earth's albedo (Benjamin)

Hansen and Nazarenko, Soot climate forcing via snow and ice albedos, Proceedings of the National Academy of Sciences, 101: 423-428, 2004.

Palle et al., Changes in Earth's Reflectance over the Past Two Decades, Science, 304: 1299-1301, 2004.

Th 4/14: Reduced evaporation?

Wild et al., On the consistency of trends in radiation and temperature records and implications for the global hydrological cycle, Geophysical Research Letters, 31: L11201, doi:10.1029/2003GL019188, 2004. (pdf) (Ursula)

Liepert et al., Can aerosols spin down the water cycle in a warmer and moister world?, Geophysical Research Letters, 31: L06207, doi:10.1029/2003GL019060, 2004. (pdf) (Benjamin)

T 4/19: Fate of anthropogenic CO2

Sabine et al., The Oceanic Sink for Anthropogenic CO2, Science, 305: 367-371, 2004. (pdf) (Cynthia)

Feely et al., Impact of Anthropogenic CO2 on the CaCO3 System in the Oceans, Science, 305: 362-366, 2004. (pdf) (Kelly)

Additional reading:Archer RealClimate blog entry entitled "How long will global warming last?"

Predicting future climate change

Th 4/21: Heat waves and "committed" warming

Meehl et al., More Intense, More Frequent, and Longer Lasting Heat Waves in the 21st Century, Science, 305: 994-997, 2004. (pdf) (Darren)

Meehl et al., How Much More Global Warming and Sea Level Rise?, Science, 307: 1769-1772, 2005. (pdf) (Patrick)

Additional reading:Wigley, The climate change commitment, Science, 307: 1766-1769, 2005. (pdf)

T 4/26: Future simulation uncertainties

Murphy et al., Quantification of modelling uncertainties in a large ensemble of climate change simulations, Nature, 430: 768-772, 2004. (pdf) See also the News & Views commentary by Stocker. (Saedis)

Stainforth et al., Uncertainty in predictions of the climate response to rising levels of greenhouse gases, Nature, 433: 403-406, 2005. (pdf) (Zack)

Th 4/28: Synthesis discussion
 

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Some interesting climate websites

IPCC Intergovernmental Panel on Climate Change, the world's leading voice on anthropogenic change
ClimateScience.gov US Government site dedicated to "integrating federal research on global change and climate change"
GlobalChange.gov US Global Change Research Program's "gateway to global change data and information"
CDIAC Climate Trends Oak Ridge National Laboratory database of CO2 and other climatic measurements
GISS Surface Temperatures NASA's Goddard Institute for Space Studies compilations of global surface temperature data
IRI Forecasts Short-term climate forecasts by Columbia University's International Research Institute for Climate Prediction
DOE Climate Change US Department of Energy site on climate change initiatives
ClimateWire.org International news stories and editorials about climate change
Prometheus: Climate Change CU science policy blog
RealClimate.org Climate change blog "to provide a quick response to developing stories and provide the context sometimes missing in mainstream commentary"