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sydney alternative media - non-profit community independent trustworthy
Monday, 21 May 2007
Do the math - 5 metre sea rise in 90 years on a non linear ice shelf collapse
Mood:  lazy
Topic: globalWarming

Picture: Quoting USA Today 12th May 2007 "   Iceberg B-15A, which broke off in March 2000, sits at a right angle to C-19, which broke away from the Ross Ice Shelf last last week."

Sent: Monday, May 21, 2007 10:28 AM

Subject: do the math on NASA's Dr Hansen advice of 5 METRE sea rise in 90 years with non linear ice shelf collapse

(Just another reason to stop forest destruction and land clearing of natural carbon store.)
Regarding your State of the Planet last week, I took the trouble to follow the links to quality Grist news site with Dr James Hansen NASA, (also carry a one to one interview with Rupert Murdoch). Hansen references his recent scientific paper that a more likely scenario than the IPCC predictions on minor sea level rise goes like this (be afraid, very afraid): 15 May 2007  An interview with renowned climate scientist James Hansen |  

 "I've actually written a paper and submitted it called "Scientific Reticence and Sea Level Rise" [PDF], because it just seemed to me that there was a gap between what scientists really thought and what was in the public knowledge in regards to ice sheet stability and sea level rise."

at the pdf  [bold added] dated 23rd March 2007

"Under BAU forcing in the 21st century, sea level rise undoubtedly will be dominated by a third term (3) ice sheet disintegration. This third term was small until the past few years, but it is has at least doubled in the past decade and is now close to 1 mm/year, based on gravity satellite measurements discussed above. As a quantitative example, let us say that the ice sheet contribution is 1 cm for the decade 2005-2015 and that it doubles each decade until the West Antarctic ice sheet is largely depleted.

 

That time constant yields sea level rise of the order of 5 m this century. Of course I can not prove that my choice of a 10 year doubling time for non-linear response is accurate, but I am confident that it provides a far better estimate than a linear response for the ice sheet component of sea level rise."

Dr James Hansen NASA.

 

Last weekend one of the commercial tv channels in Sydney reported footage of another ice huge like 200 sq km block falling into the Arctic sea: USATODAY.com - 124-mile-long iceberg breaks off Antarctica May 12th 2007

 

So do the maths - 1mm a year, 1cm in 10 yrs, 2cm in 20yrs, 4cm in 30yrs, 8cm in 40 yrs, 16cm in 50 yrs, 32cm in 60 yrs, 64cm in 70yrs, 1.28m in 80yrs, 2.56m in 90yrs. Total sea rise - 5.11 metres by 2100. Exponential rate of change is like that - very unforgiving.

 

Tom McLoughlin, editor www.sydneyalternativemedia.com/blog

 


Posted by editor at 12:30 PM NZT
Updated: Monday, 21 May 2007 2:12 PM NZT

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