[asa] Scientific Reticence

From: Rich Blinne <rich.blinne@gmail.com>
Date: Fri Mar 30 2007 - 09:08:04 EDT

The false comparison between AR4 and TAR has caused global warming
deniers to say sea level rise is a smaller problem than it really is.
This is even when a comparison of the 1990 predictions going forward
correctly predicted CO2 and correctly predicted global temperature
but was 50% low on sea level rise! (Rahmstorf et al 2007 http://
www.sciencemag.org/cgi/content/abstract/1136843v ). Current ice
models assume that ice move slowly (mm or cm/yr). Yet, the Amundsen
Sea Embayment in West Antarctica is moving on the order of km/yr!
This is why the models need to be completely revised. (Note this has
nothing to do with the much maligned GCMs which are pretty much dead
bang on.) How does this happen? Jim Hansen theorizes it is due to
"scientific reticence". See here: http://xxx.arxiv.org/pdf/physics/
0703220 for a preprint.

> I suggest that a ‘scientific reticence’ is inhibiting
> communication of a threat of potentially large sea level
> rise. Delay is dangerous because of system inertias that could
> create a situation with future sea level
> changes out of our control. I argue for calling together a panel of
> scientific leaders to hear evidence and
> issue a prompt plain-written report on current understanding of the
> sea level change issue.

Hansen provides massive evidence that the conservatism in the IPCC
report is seriously low-balling the problem. Here's just the
references for the paper.

> Automobile Manufacturers 2006 Central Valley Chrysler-Jeep v.
> Catherine Witherspoon, California Air
> Resources Board, United States District Court, Fresno, Case 1:04-
> CV-06663
> Barber B 1961 Resistance by scientists to scientific discovery.
> Science 134, 596-602
> Barrett P J, Adams C J, McIntosh W C, Swisher C C and Wilson G S
> 1992 Geochronological evidence
> supporting Antarctic deglaciation three million years ago Nature
> 359 816-8
> Cazenave A 2006 How fast are the ice sheets melting? Science 314
> 1250-2
> Chen J L , Wilson C R and Tapley B D 2006 Satellite gravity
> measurements confirm accelerated melting
> of Greenland Ice Sheet Science 313, 1958-60
> Crowley T J 1996 Pliocene climates: the nature of the problem Mar.
> Micropaleontol. 27 3-12
> Davis C H, Li Y, McConnell J R, Frey M M and Hanna E 2005 Snowfall-
> driven growth in East
> Antarctica ice sheet mitigates recent sea-level rise Science 308
> 1898-1901
> Dowsett H J, Thompson R, Barron J, Cronin T, Fleming F, Ishman R,
> Poore D, Willard D and Holtz T
> 1994 Joint investigations of the Middle Pliocene climate Global
> Planet. Change 9 169-95
> Dowsett H, Barron J and Poore R 1996 Middle Pliocene sea surface
> temperatures: a global reconstruction,
> Mar. Micropaleontol. 27 13-26
> Fahnestock M A, Abfdalati W and Shuman C.A. 2002 Long melt seasons
> on ice shelves of the Antarctic
> Peninsula: an analysis using satellite-based microwave emission
> measurements Ann. Glaciol. 34 127-
> 33
> Hansen J, Johnson D, Lacis A, Lebedeff S, Lee P, Rind D and Russell
> G 1981 Climate impact of
> increasing atmospheric carbon dioxide Science 213 957-66
> Hansen, J 2005 A slippery slope: how much global warming
> constitutes “dangerous anthropogenic
> interference”? Clim. Change 68 269-79
> Hansen J et al 2005 Earth’s energy imbalance: confirmation and
> implications Science 308 1431-5
> Hansen J, Sato M, Ruedy R, Lo K, Lea, D W and Medina-Elizade M
> 2006a Global temperature change.
> Proc. Natl. Acad. Sci. 101 16109-14
> Hansen J et al 2006b Dangerous human-made interference with
> climate: A GISS modelE study Atmos.
> Chem. Phys. Discuss. 6 12549-610
> Hansen J, Sato M, Kharecha P, Lea D W and Siddall M 2007 Climate
> change and trace gases Phil. Trans.
> Royal Soc. A (in press)
> Howat I M, Joughin I R and Scambos T A 2007 Rapid changes in ice
> discharge from Greenland outlet
> glaciers Science 315 1559-61
> Hughes, T 1972 Is the West Antarctic ice sheet disintegrating?
> ISCAP Bulletin no. 1 Ohio State Univ.
> Intergovernmental Panel on Climate Change (IPCC) 2001 Climate
> Change 2001: The Scientific Basis ed
> J T Houghton et al. (Cambridge University Press)
> IPCC 2007 Climate Change 2007: The Physical Basis – Summary for
> Policymakers. Accessed at
> http://www.ipcc.ch/SPM2feb07.pdf
> Johannessen O M, Khvorostovsky K, Miles M W, Bobylev L P 2005
> Recent ice-sheet growth in the
> interior of Greenland Science 310 1013-6
> Kerr R A 1989 Hansen vs. the world on the greenhouse threat Science
> 244 1041-3
> Kerr R A 2007 Predicting fate of glaciers proves slippery task
> ScienceNOW Accessed at
> http://sciencenow.sciencemag.org/cgi/content/full/2007/215/2
> Lisiecki L E and Raymo M E 2005 A Pliocene-Pleistocene stack of 57
> globally distributed benthic δ18O
> records Paleoceanogr. 20 PA1003 doi:10.1029/2004PA001071
> MacCracken, M C 1983 Climatic effects of atmospheric carbon dioxide
> Science 220 873-4
> Mercer J 1978 West Antarctic ice sheet and CO2 greenhouse effect: a
> threat of disaster Nature 271 321-5
> Monaghan A J et al 2006 Insignificant change in Antarctic snowfall
> since the International Geophysical
> Year Science 313 827-31
> Nghiem S V, Steffen K, Neumann G and Huff R 2007 Snow accumulation
> and snowmelt monitoring in
> Greenland and Antarctica Dynamic Planet - Monitoring and
> Understanding a Dynamic Planet with
> Geodetic and Oceanographic Tools: Proc. IAG Symp. (Cairns,
> Australia, 22-26 August 2005) (Intl.
> Assoc. Geodesy Symposia vol. 130) ed C Rizos and P Tregoning (New
> York:Springer)
> Payne A J, Vieli A, Shepherd A P, Wingham D J and Rignot E 2004
> Recent dramatic thinning of largest
> West Antarctic ice stream triggered by oceans Geophys. Res. Lett.
> 31 L23401
> doi:10.1029/2004GL021284
> Rahmstorf S 2007 A semi-empirical approach to projecting future sea-
> level rise Science 315 368-70
> Raymo M E, Grant B, Horowitz M and Rau G H 1996 Mid-Pliocene
> warmth: stronger greenhouse and
> stronger conveyor. Mar. Micropaleontol. 27 313-26
> Rignot E and Jacobs S S 2002 Rapid bottom melting widespread near
> Antarctic ice sheet grounding lines
> Science 296 2020-3
> Rignot E and Thomas R H 2002 Mass balance of polar ice sheets
> Science 297 1502-6
> Rignot E, Casassa G, Gogineni P, Krabill W, Rivera A and Thomas R
> 2004 Accelerated discharge from
> the Antarctic Peninsula following collapse of Larsen B ice shelf
> Geophys. Res. Lett. 31 L18401
> doi:10.1029/2004GL020697
> Rind D and Chandler M 1991 Increased ocean heat transports and
> warmer climate J. Geophys. Res. 96
> 7437-61
> Scambos, T A, Bohlander, J A, Shuman, C A and Skvarka, P 2004
> Glacier acceleration and thinning after
> ice shelf collapse in the Larsen B embayment, Antarctica Geophys.
> Res. Lett. 31 L18402
> doi:10.1029/2004GL020670
> Shepherd A, Wingham D, Payne T and Skvarca P 2003 Larsen ice shelf
> has progressively thinned Science
> 302 856-9
> Shepherd A, Wingham D and Rignot E 2004 Warm ocean is eroding West
> Antarctic ice sheet Geophys.
> Res. Lett. 31 L23402 doi:10.1029/2004GL021106
> Shindell D T and Schmidt G A 2004 Southern Hemisphere climate
> response to ozone changes and
> greenhouse gas increases. Geophys. Res. Lett. 31 L18209 doi:
> 10.1029/2004GL020724
> Steffen K, Nghiem S V, Huff R and Neumann G 2004 The melt anomaly
> of 2002 on the Greenland Ice
> Sheet from active and passive microwave satellite observations
> Geophys. Res. Lett. 31(20) L20402
> doi:10.1029/2004GL020444
> Tedesco, M 2007 Snowmelt detection over the Greenland ice sheet
> from SSM/I brightness temperature
> daily variations Geophys. Res. Lett. 34 L02504 doi:
> 10.1029/2006GL028466
> Thomas R et al 2004 Accelerated sea-level rise from West Antarctica
> Science 306 255-258
> Van den Broeke M 2005 Strong surface melting preceded collapse of
> Antarctic Peninsula ice shelf
> Geophys. Res. Lett. 32 L12815 doi:10.1029/2005GL023247
> Vaughan D G, Marshall G J, Connolley W M, Parkinson C, Mulvaney R,
> Hodgson D A, King J C,
> Pudsey C J and Turner J 2003 Recent rapid regional climate warming
> on the Antarctic Peninsula
> Clim. Change 60 243-74
> Velicogna I and Wahr J 2006 Measurements of time-variable gravity
> show mass loss in Antarctica
> Science 311 1754-6
> Wardlaw B R and Quinn T M 1991 The record of Pliocene sea-level
> change at Enewetak atoll Quatern.
> Sci. Rev. 10 247-58
> Wild, M, Calanca P, Scherer S C and Ohmura A 2003 Effects of polar
> ice sheets on global sea level in
> high-resolution greenhouse scenarios J. Geophys. Res. 108(D5) 4165
> doi:10.1029/2002JD002451
> Zwally H J, Abdalati W, Herring T, Larson K, Saba J and Steffen K
> 2002 Surface melt-induced
> acceleration of Greenland ice-sheet flow Science 297 218-22

So is this true? Is the natural conservatism of the scientific
community giving aid and comfort to those who deny the problem and
delay the solution until it is too late? Or, do we need to be always
be > 90% certain to preserve our credibility like Philip Ball
suggests? See here for his response: http://www.nature.com/news/
2007/070326/full/070326-11.html I started on Ball's side and now am
leading towards Hansen because of an Antarctic Symposium held at UT
Austin this week, entitled "Secrets of the West Antarctic Ice Sheet:
A Panel Discussion About Global Warming, Climate Change and Rising
Seas" (http://www.esi.utexas.edu/walse/) This included the premier
Antarctic experts in the world. They showed how the unlike what TAR
thought was the case the West Antarctic ice is rapidly collapsing.
What they couldn't do was give a proper scientifically-bounded
prediction. When pressed for a ballpark number one participant said
that West Antarctic effects alone would be in the ball park of
doubling the current predictions. Note that this doesn't include
Greenland. To give you a feel the size of the collapsing ice field is
the size of the state of Texas. Dr. Hansen is right. The time for
reticence is over.

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Received on Fri Mar 30 09:07:11 2007

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