Posted on 06/25/2012 9:32:12 AM PDT by Ernest_at_the_Beach
From the Potsdam Institute for Climate Impact Research (PIK) another Stephan Rahmstorf scare projection, so important they couldn’t even wait for it to be put on the NCC website before sending off this press release to Eurekalert (see weblink at end of story which is DOA as of 10PM PST 6/24).
Significant sea-level rise in a 2-degree warming world
Sea levels around the world can be expected to rise by several meters in coming centuries, if global warming carries on
The study is the first to give a comprehensive projection for this long perspective, based on observed sea-level rise over the past millennium, as well as on scenarios for future greenhouse-gas emissions.
“Sea-level rise is a hard to quantify, yet critical risk of climate change,” says Michiel Schaeffer of Climate Analytics and Wageningen University, lead author of the study. “Due to the long time it takes for the world’s ice and water masses to react to global warming, our emissions today determine sea levels for centuries to come.”
Limiting global warming could considerably reduce sea-level rise
While the findings suggest that even at relatively low levels of global warming the world will have to face significant sea-level rise, the study also demonstrates the benefits of reducing greenhouse-gas emissions. Limiting global warming to below 1.5 degrees Celsius and subsequent temperature reductions could halve sea-level rise by 2300, compared to a 2-degree scenario. If temperatures are allowed to rise by 3 degrees, the expected sea-level rise could range between 2 and 5 metres, with the best estimate being at 3.5 metres.
The potential impacts are significant. “As an example, for New York City it has been shown that one metre of sea level rise could raise the frequency of severe flooding from once per century to once every three years,” says Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research, co-author of the study. Also, low lying deltaic countries like Bangladesh and many small island states are likely to be severely affected.
Sea-level rise rate defines the time for adaptation
The scientists further assessed the rate of sea-level rise. The warmer the climate gets, the faster the sea level climbs. “Coastal communities have less time to adapt if sea-levels rise faster,” Rahmstorf says.
“In our projections, a constant level of 2-degree warming will sustain rates of sea-level rise twice as high as observed today, until well after 2300,” adds Schaeffer, “but much deeper emission reductions seem able to achieve a strong slow-down, or even a stabilization of sea level over that time frame.”
Building on data from the past
Previous multi-century projections of sea-level rise reviewed by the Intergovernmental Panel on Climate Change (IPCC) were limited to the rise caused by thermal expansion of the ocean water as it heats up, which the IPCC found could reach up to a metre by 2300. However, this estimate did not include the potentially larger effect of melting ice, and research exploring this effect has considerably advanced in the last few years. The new study is using a complementary approach, called semi-empirical, that is based on using the connection between observed temperature and sea level during past centuries in order to estimate sea-level rise for scenarios of future global warming.
“Of course it remains open how far the close link between temperature and global sea level found for the past will carry on into the future,” says Rahmstorf. “Despite the uncertainty we still have about future sea level, from a risk perspective our approach provides at least plausible, and relevant, estimates.”
Article: Schaeffer, M., Hare, W., Rahmstorf, S., Vermeer, M. (2012): Long-term sea-level rise implied by 1.5° C and 2° C warming levels. Nature Climate Change [doi:10.1038/NCLIMATE158] (Advance Online Publication)
Weblink to the article when it is published on June 24th: http://dx.doi.org/10.1038/NCLIMATE158
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UPDATE: The link above is as published at Eurekalert. The bolding of “when” is mine. Harold W points out in comments:
Correct link to the article is http://dx.doi.org/10.1038/NCLIMATE1584 [Published link lacked the final digit], or alternatively http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1584.html
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Gonna try reading thru the linked paper tonight.
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I’m absolutely no expert but surely the seasonal variation in sea ice shows that its extent and volume can change very rapidly so that a small decline in global temperatures would lead to a fall in sea levels invalidating the statement that:
“Due to the long time it takes for the world’s ice and water masses to react to global warming, our emissions today determine sea levels for centuries to come.”
I think I trust Mark Twain more:
“In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.
- Life on the Mississippi”
From the comments:
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tonyb says:
A few months ago I wrote Part 1 of ‘Historic variations in sea levels-from the Holocene to the Romans.’ It is here
A much more comprehensive version is here.
http://curryja.files.wordpress.com/2011/07/document.pdf
It is clear that there are considerable variations in levels which may coincide roughly with warm/cool periods. We are currently around 20cm or more BELOW the levels that occurred during the Roman optimum. There are a couple of useful graphs in the article towards the end that show this. As our current temperatures are somewhat below that period it seems unlikely we will reach it (unless temperatures continue to rise strongly) although there is the considerable wild card of the pumping of water from underground sources which may affect levels in a manner that hasn’t happened in previous sea level changes
tonyb
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Graph from the first link:
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Ray Boorman says:
June 24, 2012 at 11:44 pm
“The press releases from organisations wedded to the AGW gravy train become more sensational over time. The money must be good, because they seem to have no idea how ridiculous they appear to thinking members of the community.”
Yes the money in CAGW “science” is VERY good right now…even the WUWT trolls don’t argue with that.
My climate “projection” for 2012? Expect to see a rapid increase in the frequency and hysterical tone of climate “science” press releases (like this one) as we approach the U.S. elections in November.
Did it ever occur to those involved in the study that the east coast land mass just might be sinking a bit. Like is being shown to be the case on parts of the Louisiana coastline.
I wouldn’t want to have to play “moving chairs” with these folks. Surely I would loose big time. :)
Global Warming on Free Republic
I'll bet there's a place - maybe close by - where the water is dropping 3 times faster than normal - and that it's NOT being reported.
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I’ll ask again, where is that dangerous SLR coming from? Check out the graphs of “all the models” for Greenland positive and Antarctica negative for the next 300 years.
http://rsta.royalsocietypublishing.org/content/364/1844/1709/F4.expansion.html
We’ve covered 99% of the planet’s ice and 89% ( antarctica) will be gaining ice until the year 2300.
So where’s that SLR to come from again?