(philosophy paper) >>Write a five page (or more) paper on the topic of `Risk Assessment and Environmental Ethics'

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EOS VOLUME 90 NUMBER 3 20 JANUARY 2009

Fifty- two percent of Americans think most climate scientists agree that the Earth has been warming in recent years, and 47% think climate scientists agree (i.e., that there is a scientific consensus) that human activities are a major cause of that warming, according to recent poll- ing (see http:// www . pollingreport . com/ enviro . htm). However, attempts to quan- tify the scientific consensus on anthropo- genic warming have met with criticism. For instance, Oreskes [2004] reviewed 928 abstracts from peer- reviewed research papers and found that more than 75% either explicitly or implicitly accepted the consensus view that Earth’s climate is being affected by human activities. Yet Oreskes’s approach has been criti- cized for overstating the level of con- sensus acceptance within the examined abstracts [Peiser, 2005] and for not cap- turing the full diversity of scientific opin- ion [Pielke, 2005]. A review of previous attempts at quantifying the consensus and criticisms is provided by Kendall Zimmer- man [2008]. The objective of our study presented here is to assess the scientific

consensus on climate change through an unbiased survey of a large and broad group of Earth scientists.

An invitation to participate in the sur- vey was sent to 10,257 Earth scientists. The database was built from Keane and Martinez [2007], which lists all geosci- ences faculty at reporting academic insti- tutions, along with researchers at state geologic surveys associated with local universities, and researchers at U.S. fed- eral research facilities (e.g., U.S. Geo- logical Survey, NASA, and NOAA (U.S. National Oceanic and Atmospheric Administration) facilities; U.S. Depart- ment of Energy national laboratories; and so forth). To maximize the response rate, the survey was designed to take less than 2 minutes to complete, and it was admin- istered by a professional online survey site ( http:// www . questionpro . com) that allowed one- time participation by those who received the invitation.

This brief report addresses the two pri- mary questions of the survey, which con- tained up to nine questions (the full study is given by Kendall Zimmerman [2008]):

1. When compared with pre- 1800s lev- els, do you think that mean global tem- peratures have generally risen, fallen, or remained relatively constant?

2. Do you think human activity is a sig- nificant contributing factor in changing mean global temperatures?

With 3146 individuals completing the sur- vey, the participant response rate for the survey was 30.7%. This is a typical response rate for Web- based surveys [Cook et al., 2000; Kaplowitz et al., 2004]. Of our survey participants, 90% were from U.S. institu- tions and 6% were from Canadian institu- tions; the remaining 4% were from institu- tions in 21 other nations. More than 90% of participants had Ph.D.s, and 7% had master’s degrees. With survey participants asked to select a single category, the most common areas of expertise reported were geochemistry (15.5%), geophysics (12%), and oceanography (10.5%). General geol- ogy, hydrology/hydrogeology, and pale- ontology each accounted for 5–7% of the total respondents. Approximately 5% of the respondents were climate scientists, and 8.5% of the respondents indicated that more than 50% of their peer- reviewed publi- cations in the past 5 years have been on the subject of climate change. While respon- dents’ names are kept private, the authors noted that the survey included participants with well- documented dissenting opinions on global warming theory.

Results show that overall, 90% of par- ticipants answered “risen” to question 1 and 82% answered yes to question 2. In general, as the level of active research and specialization in climate science increases, so does agreement with the two primary questions (Figure 1). In our sur- vey, the most specialized and knowledge- able respondents (with regard to climate change) are those who listed climate sci- ence as their area of expertise and who also have published more than 50% of their recent peer- reviewed papers on the subject of climate change (79 individu- als in total). Of these specialists, 96.2% (76 of 79) answered “risen” to question 1 and 97.4% (75 of 77) answered yes to ques- tion 2. This is in contrast to results of a recent Gallup poll (see http:// www . gallup . com/ poll/ 1615/ Environment . aspx) that

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it possible to directly probe some of these properties in situ statically using advanced synchrotron light sources and detecting techniques. Scientists are also gearing up in building new facilities that will help couple dynamic shock wave techniques with syn- chrotron light sources so as to allow in situ probing of these properties under extreme dynamic conditions. Efforts to search for and develop universal pressure and temper- ature scales are also under way to establish consistent results for a coherent picture of the core. The expectation of mineral physi- cists involved with these efforts is that within a decade, these mineral physics missions to the Earth’s core will provide crucial informa- tion to greatly enhance our understanding of the nature of the core.

Acknowledgments

We acknowledge S. D. Jacobsen for con- structive comments. Leonid Dubrovin- sky is supported by Deutsche Forschungs- gemeinschaft (DFG) and European Science Foundation EuroMinSci programs. Jung- Fu Lin is supported by the U.S. National Sci- ence Foundation Geophysics Directorate ( EAR- 0838221), Carnegie/ Department of Energy Alliance Center ( CDAC), and Con- sortium of Materials Properties Research in Earth Sciences ( COMPRES).

References

Antonangeli, D., F. Occelli, H. Requardt, J. Badro, G. Fiquet, and M. Krisch (2004), Elastic anisot- ropy in textured hcp- iron to 112 GPa from sound wave propagation measurements, Earth Planet. Sci. Lett., 225(1- 2), 243–251.

Badro, J., G. Fiquet, F. Guyot, E. Gregoryanz, F. Occel- li, D. Antonangeli, and M. d’Astuto (2007), Effect of light elements on the sound velocities in solid iron: Implications for the composition of Earth’s core, Earth Planet. Sci. Lett., 254(1- 2), 233–238.

Belonoshko, A. B., N. V. Skorodumova, A. Rosen- gren, and B. Johansson (2008), Elastic anisot-

ropy of Earth’s inner core, Science, 319(5864), 797–800.

Dubrovinsky, L., et al. (2007), Body- centered cubic iron- nickel alloy in Earth’s core, Science, 316(5833), 1880–1883.

Lin, J.- F., W. Sturhahn, J. Zhao, G. Shen, H.-K. Mao, and R. J. Hemley (2005), Sound velocities of hot dense iron: Birch’s law revisited, Science, 308(5730), 1892–1894.

Vočadlo, L. (2007), Ab initio calculations of the elasticity of iron and iron alloys at inner core conditions: Evidence for a partially molten inner core?, Earth Planet. Sci. Lett., 254(1- 2), 227–232.

Vočadlo, L., D. Alfè, M. J. Gillan, I. G. Wood, J. P. Brodholt, and G. D. Price (2003), Possible ther- mal and chemical stabilization of body- centred- cubic iron in the Earth’s core, Nature, 424(6948), 536–539.

Author Information

Leonid Dubrovinsky, University of Bayreuth, Bay- reuth, Germany; E-mail: Leonid . Dubrovinsky@ uni - bayreuth . de; and Jung- Fu Lin, University of Texas at Austin

TRANSACTIONS AMERICAN GEOPHYSICAL UNION

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Editors Anny Cazenave: Laboratoire d’Etudes en Géophysique et Océanographie Spatiales, Toulouse, France; [email protected]

John W. Geissman: Department of Earth and Planetary Science,University of New Mexico, Albuquerque, USA; [email protected]

Wendy S. Gordon: Texas Parks and Wildlife Department, Austin, USA; wendy.gordon@tpwd .state.tx.us

Manuel Grande: University of Wales, Aberystwyth; [email protected]

Hassan Virji: START, Washington, D. C., USA; [email protected]

Editor in Chief pro tem Judy C. Holoviak: AGU, Washington, D.C., USA; eos_ [email protected]

Editorial Advisory Board M. Lee Allison Earth and Space Sciences Informatics

Roni Avissar Global Environmental Change

Roland Bürgmann Tectonophysics

Noah S. Diffenbaugh Atmospheric Sciences

John E. Ebel Seismology

Michael N. Gooseff Hydrology

Stephen Macko Education

Stefan Maus Geomagnetism and Paleomagnetism

Jerry L. Miller Oceanography

Peter Olson Study of the Earth’s Deep Interior

Michael Poland Geodesy

Paul R. Renne Volcanology, Geochemistry, and Petrology

Jeffery J. Roberts Mineral and Rock Physics

John B. Rundle Nonlinear Geophysics

Susan E. H. Sakimoto Planetary Sciences

Sarah L. Shafer Paleoceanography and Paleoclimatology

David G. Sibeck Space Physics and Aeronomy

Maribeth Stolzenburg Atmospheric and Space Electricity

Jeffrey M. Welker Biogeosciences

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Mineral Physics cont. from page 21

Fig. 2. Representative phase diagram of iron and iron- nickel alloys at high pressures and temperatures. The hcp iron is stable over a wide range of pressures and temperatures, while bcc iron is predicted to exist in the inner core (blue dashed line) and bcc iron with 10% nickel alloy is experimentally observed at 225 gigapascals and 3400 K (blue hexagon). Melting curves of iron measured from shock waves (red diamonds) are much higher than static diamond cell results (black dashed line). Shaded area indicates current survey of the melting temperatures of iron at core pressures; inset shows hcp iron with 10% nickel alloy at 195 gigapascals and 2150 K.

Examining the Scientific Consensus on Climate Change

Fig. 1. Response distribution to our survey question 2. The general public data come from a 2008 Gallup poll (see http:// www . gallup . com/ poll/ 1615/ Environment . aspx). Climate Change cont. on next page

EOS VOLUME 90 NUMBER 3 20 JANUARY 2009

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Recent observations show that ice sheets can respond to climate change on annual to decadal timescales and that the Green- land and West Antarctic ice sheets are losing mass at an increasing rate. The current gen- eration of ice sheet models cannot provide credible predictions of ice sheet retreat, as underscored by the Intergovernmental Panel on Climate Change ( IPCC) in its Fourth Assessment Report (2007). The IPCC pro- vided neither a best estimate nor an upper bound for 21st- century sea level rise because of uncertainties in the dynamic response of ice sheets.

In response to this need, a workshop was held at Los Alamos National Laboratory ( LANL). The workshop was sponsored by the LANL Institute for Geophysics and Plan- etary Physics, with additional support from the U.S. Department of Energy and National Science Foundation. The workshop’s goal was to create a detailed plan (including commitments from individual researchers) for developing, testing, and implementing a Community Ice Sheet Model ( CISM) to aid in predicting sea level rise. This model will be freely available to the glaciology and climate modeling communities and will be the ice sheet component of the Community Climate System Model ( CCSM), a major contributor to IPCC assessments.

The workshop was attended by 35 scien- tists from U.S., U.K., and Canadian institu- tions. The discussion was organized around

four focus areas: (1) ice sheet dynamics and physics, (2) ice shelf/ocean interac- tions, (3) software design and coupling, and (4) initialization, verification, and validation. Because of the short timescale for includ- ing ice sheet forecasts in the next IPCC assessment, participants prioritized model improvements according to their impor- tance for sea level prediction. The following improvements were deemed critical:

a higher-order flow model with a uni- fied treatment of vertical shear stresses and horizontal- plane stresses;

improved models of basal sliding over hard and soft beds, with explicit ice sheet hydrology;

a well-validated parameterization of melting and refreezing beneath ice shelves;

an accurate, semiempirical law for ice- berg calving; and

an accurate, numerically robust treat- ment of grounding-line migration.

Workshop participants also agreed that CISM should be modular, portable, and user- friendly, with transparent source code sup- plemented by data sets for initialization, forcing, and validation. The model should scale efficiently to hundreds or thousands of processors, using existing parallel solvers (e.g., Portable, Extensible Toolkit for Scien- tific Computation (PETSc); http:// www - unix . mcs . anl . gov/ petsc/ petsc - as/) and infrastruc- ture from other Earth system models (e.g., CICE; http:// climate . lanl . gov/ Models/ CICE/).

Because warm- water intrusions beneath ice shelves could drive rapid ice sheet retreat, new methods are needed for coupling ocean models to ice sheet models, attendees noted. Software development is proceeding from the GLIMMER model ( http:// forge . nesc . ac . uk/ projects/ glimmer/), which has already been coupled to CCSM.

Six focus groups have formed to guide ongoing CISM development. These groups are working on hydrology, calving, ice- ocean coupling, software development, data sets, and climate assessment. In the near term the assessment group will use the best available current models to provide

quantitative upper bounds for sea level rise; these assessments will inform longer- term model development. CISM source code and tools will be posted on a public Web site.

For more information, including work- shop presentations, focus group reports, and the full workshop report, please visit http:// oceans11 . lanl.gov/ trac/ CISM.

—WILLIAM LIPSCOMB, Group T-3, Los Alamos National Laboratory (LANL), Los Alamos, N. M.; E-mail: lipscomb@ lanl . gov; ROBERT BINDSCHADLER, NASA Goddard Space Flight Center, Greenbelt, Md.; ED BUEL- ER, University of Alaska Fairbanks; DAVID HOLLAND, New York University, New York; JESSE JOHNSON, Univer- sity of Montana, Missoula; and STEPHEN PRICE, LANL

A Community Ice Sheet Model for Sea Level Prediction Building a Next-Generation Community Ice Sheet Model; Los Alamos, New Mexico, 18–20 August 2008

suggests that only 58% of the general pub- lic would answer yes to our question 2. The two areas of expertise in the survey with the smallest percentage of partici- pants answering yes to question 2 were economic geology with 47% (48 of 103) and meteorology with 64% (23 of 36).

It seems that the debate on the authenticity of global warming and the

role played by human activity is largely nonexistent among those who under- stand the nuances and scientific basis of long- term climate processes. The challenge, rather, appears to be how to effectively communicate this fact to policy makers and to a public that con- tinues to mistakenly perceive debate among scientists.

References

Cook, C., F. Heath, and R. Thompson (2000), A meta- analysis of response rates in Web- or Internet- based surveys, Educ. Psychol. Meas., 60, 821–836.

Kaplowitz, M., T. Hadlock, and R. Levine (2004), A comparison of Web and mail survey response rates, Public Opin. Q., 68, 94–101.

Keane, C. M., and C. M. Martinez (Eds.) (2007), Directory of Geoscience Departments 2007, 45th ed., Am. Geol. Inst., Alexandria, Va.

Kendall Zimmerman, M. (2008), The consensus on the consensus: An opinion survey of Earth

scientists on global climate change, 250 pp., Univ. of Ill. at Chicago.

Oreskes, N. (2004), Beyond the ivory tower: The scientific consensus on climate change, Science, 306, 1686–1686.

Peiser, B. J. (2005), The dangers of consensus sci- ence, Can. Natl. Post, 17 May.

Pielke, R. A. (2005), Consensus about climate change?, Science, 308, 952–953.

—PETER T. DORAN and MAGGIE KENDALL ZIMMER- MAN, Earth and Environmental Sciences, University of Illinois at Chicago; E-mail: pdoran@ uic . edu

Climate Change cont. from page 22

Honors AGU executive director Fred Spilhaus

and Joseph Burns, Cornell University, Ithaca, N. Y., have been made honorary fel- lows of the Royal Astronomical Society

(RAS), a U.K. society for professional astron- omers and geophysicists. The Society, on 9 January, also honored other AGU mem- bers: Eric Priest of the University of St. Andrews, United Kingdom, received the Gold Medal for Geophysics for his work in the fields of solar and solar- terrestrial phys- ics. Malcolm Sambridge of the Australian National University, Canberra, received the

Price Medal for his major contribution to algorithms in geophysics. In honoring David Kerridge of the British Geological Survey in Edinburgh with the Award for Services to Geophysics, RAS noted the Survey’s effort at leading a multiagency study to assess the tsunami risk to the United Kingdom.

Wallace Broecker of Columbia Univer- sity’s Lamont- Doherty Earth Observatory,

Palisades, N. Y., has received the 2008 BBVA Foundation Frontiers of Knowledge Award in the climate change category. The award certificate notes that Broecker’s research into the oceans’ biological and chemical processes “pioneered the development of Earth system science as the basis for under- standing global climate change, both past and present.”

G E O P H Y S I C I S T S

MEETING

4–6 May 2009 First U.S. Atlantic Meridional Overturning Circulation Annual Meeting, Annapolis, Maryland, USA. Sponsor: U.S. Cli- mate Variability and Predictability Program Of- fice (U.S. CLIVAR) (J. Reisdorf, E-mail: reisdorf@ ucar . edu; Web site: http:// www . atlanticmoc .org/ AMOC2009 .php)

The meeting will focus on initial, near-term ob- jectives outlined in a 5-year implementation strat- egy for a new interagency program that together with activities from the U.S. Climate Change Sci- ence Program and international partnerships, will develop components of an Atlantic meridi- onal overturning circulation (AMOC) monitor- ing system and AMOC prediction capability. The meeting also will discuss overarching issues

including the current state of the AMOC, what governs AMOC changes, and what the impacts of AMOC variability are.

13–18 September 2009 2009 South African Geophysical Association (SAGA) Biennial Technical Meeting and Exhibition, Swaziland, South Africa. Sponsors: SAGA; Society of Explora- tion Geophysicists; European Association of Geo- scientists and Engineers. (Conference Secretar- iat, Tel.: +27-0-11-728-8173; Fax: +27-0-11-728-1675; E-mail: events@ rca .co .za; Web site: http:// www . sagaonline .co .za/ 2009Conference/ index .htm)

The conference, whose theme is “Ancient Rocks to Modern Techniques,” welcomes papers on many geophysical topics. Abstract deadline is 30 June.

M E E T I N G A N N O U N C E M E N T S