[asa] Scientific Reticence

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.

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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