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Shared Humanity

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #150 on: September 27, 2014, 04:52:18 PM »
City of Miami Beach, Florida:  New water pumps are being installed as part of a new storm water infrastructure.
"City officials say the annual king tides are expected to be almost three inches higher than last year. Extreme high tides in the fall and spring push seawater up through aging infrastructure, flooding some Miami Beach streets with more than a foot of water even on sunny days, snarling vehicle and pedestrian traffic."

Cost: $400 million to help protect the city for the next "25 to 30 years."

http://www.washingtonpost.com/national/energy-environment/miami-beach-prepares-for-extreme-high-tides/2014/09/17/5926dc16-3e96-11e4-a430-b82a3e67b762_story.html

I have posted this before and skeptics will point out the source as evidence that it should be ignored but the investigative reporting is sound. (It's a shame that the U.S. press is so damaged that we need to rely on the Rolling Stone for accuracy regarding sea level rise.)

http://www.rollingstone.com/politics/news/why-the-city-of-miami-is-doomed-to-drown-20130620

Basically, Miami, much of southeast Florida actually, will be abandoned by the end of the century and the finest engineering companies in the world (from Holland) whose expertise is keeping sea water from penetrating coastal land, says there is nothing that can be done.
« Last Edit: November 25, 2015, 04:14:02 PM by Shared Humanity »

Shared Humanity

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #151 on: September 27, 2014, 05:06:33 PM »
Cost: $400 million to help protect the city for the next "25 to 30 years."
This isn't climate adaptation. This is panic, knee-jerk, band-aidism. Just what do they expect will be necessary in 25 years?!  :o

We, as a species, desperately need to lengthen our planning horizon.

Climate adaptation for this part of the U.S. is going to be quite shocking. By 2100, the populations of Dade and Broward counties (4.4 million) will need to be relocated. This relocation will begin in earnest by 2070, perhaps as early as 2050.

There is nothing that the richest country in the world can do to prevent this.
« Last Edit: September 27, 2014, 05:42:56 PM by Shared Humanity »

Shared Humanity

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #152 on: September 27, 2014, 05:41:34 PM »
Climate Report Details Flood Risk to Sites in Washington
http://www.nytimes.com/2014/09/17/us/climate-report-details-flood-risk-to-sites-in-washington.html?partner=rss&emc=rss

Every city along the coast of Chesapeake Bay is at serious risk by the end of this century. Take a  look at an elevation map of Philadelphia. A person might be mistaken to simply look at the elevations and conclude that the portion 1 meter above sea level or below is fairly small but this is a simplistic way of viewing the risk and impact of sea level rise. The real risk is on infrastructure that is buried below ground, water mains, sewers etc. All or much of this infrastructure could be rendered unusable. Sewers are particularly susceptible to water table rise. Imagine a Philadelphia without working sanitation facilities.

Shared Humanity

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #153 on: September 28, 2014, 05:11:25 PM »
The inevitable future of much of the low lying coastal regions of the U.S.

http://www.theguardian.com/news/datablog/2011/feb/09/louisiana-population-us-census-new-orleans


Shared Humanity

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #154 on: September 28, 2014, 06:40:20 PM »
To get a sense of the size of the exodus, nearly 250K people have moved from the most vulnerable areas of the Louisiana coastline since Katrina. They will not be returning. The exodus will continue through this century and it will spread to adjacent areas of the coastline as sea levels rise.

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #155 on: September 28, 2014, 07:29:44 PM »
This winter and spring the waves were particularly strong on the coasts of France, especially in the south west.
Here is a video that can give an idea of what is going on :


Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #156 on: September 29, 2014, 03:17:58 AM »
Sea level rise is changing the real estate market in Norfolk, Virginia, USA.

Quote
About a quarter of properties in Norfolk - just over 17,000 - are in high-risk flood plains, with values totaling 34 percent of the tax base, according to city figures.

The number of homes that repeatedly flood, so-called "repetitive loss" properties, has increased from about 200 in 2002 to almost 900 today, said Lenny Newcomb, the city's zoning administrator.
http://hamptonroads.com/2014/09/norfolk-sea-level-rise-takes-shine-waterfront-homes
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Shared Humanity

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #157 on: September 29, 2014, 03:54:43 PM »
If we think about the process of relocation of households in this country, the process is by individual choice, regardless of the driving factor. The movement of Americans from urban cores to the suburbs and then exurbs is a perfect example of this. The movement to the suburbs began post WWII and accelerated through the 70's and 80's as residents who could afford to do so left cities to the relative safety of the suburbs and this flight to the suburbs impoverished many of our cities. This migration took decades and for some cities has recently reversed as the urban cores redevelop and attract families.

This very large migration (30% of residents) from New Orleans and Jefferson Parish, by contrast, has happened in only one decade and yet it is still the result of individual choices as families who can afford to move leave these regions vulnerable to flooding. We should expect that this ongoing migration will cause a decline in incomes and an increasing rate of poverty in New Orleans and Jefferson Parish. Areas along the waterfront that have traditionally attracted the well to do and had higher property values should see steep declines.

A look at the income trends in New Orleans would suggest that this may be happening.

http://www.deptofnumbers.com/income/louisiana/new-orleans/

While the decline in household incomes since 2007 is due, in part, to the Great Recession, the declines in New Orleans have been more pronounced than the state of Louisiana or the U.S. as a whole. This is a trend that should be closely watched but, if the out migration continues, we should expect this income trend gap to grow.
« Last Edit: September 29, 2014, 04:08:36 PM by Shared Humanity »

Shared Humanity

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #158 on: September 29, 2014, 04:14:42 PM »
If you read the article on the Norfolk, Virginia area above, linked to by Sigmetnow, it is clear that the trend we are seeing in New Orleans and Jefferson Parish will inevitably occur here as well. These tidewater regions have traditionally been some of the wealthiest regions of Virginia. As flooding worsens, the first response will be to strengthen defenses against flooding but, eventually, well to do families will move away from these coastal regions that are prone to flooding and property values and incomes of these regions will fall.

Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #159 on: October 02, 2014, 06:38:02 PM »
"Students to gather on Miami Beach to combat sea level rise apathy on King Tide Day (Oct 9th)."

There is so much denial going on in Florida, particularly south Florida, which makes, I think, this all the more newsworthy.

http://blogs.miaminewtimes.com/cultist/2014/09/king_tide_day_students_gather_on_miami_beach_to_combat_sea_level_rise_apathy.php


Quote of the week:  "Climate change is a really slow, creepy thing."
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Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #160 on: October 02, 2014, 07:20:53 PM »
On the last post there is this website : http://www.eyesontherise.org/
And that video in it.


I like the way professors who are not necessarily climate scientists teach to their students that the situation is dire.
Also some picts about the reality of what is going on around Miami.

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #161 on: October 08, 2014, 09:54:03 AM »

Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #162 on: October 11, 2014, 04:16:20 PM »
Flooding averted -- this time!  Well done.
$15 million down, over $500 million more to go, for perhaps 30 years' worth of sea level rise adaptation in Miami Beach, Florida.

http://www.miamiherald.com/news/local/community/miami-dade/miami-beach/article2633647.html
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Lennart van der Linde

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #163 on: October 13, 2014, 09:06:33 PM »
New SLR-paper by Jevrejeva, Grinsted & Moore:
http://iopscience.iop.org/1748-9326/9/10/104008/article

They estimate a 5% risk of 1.8m of SLR by 2100, based on expert elicitation (Bamber & Aspinall) and physical modeling.

jai mitchell

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #164 on: October 13, 2014, 09:35:05 PM »
New SLR-paper by Jevrejeva, Grinsted & Moore:
http://iopscience.iop.org/1748-9326/9/10/104008/article

They estimate a 5% risk of 1.8m of SLR by 2100, based on expert elicitation (Bamber & Aspinall) and physical modeling.

Interesting, I was just reading:

Quote
To explore these remaining uncertainties, ice2sea has used a less-formal approach of an “expert elicitation.” This method concluded that there is a less than 1-in-20 risk of the contribution of ice sheets to global sea-level rise exceeding 84cm by 2100.

http://www.ice2sea.eu/2013/05/14/from-ice-to-high-seas/

So on this scale, if we plot the 5% expert elicitation results, we will gain 1 meter of SLR every 2 years or so????
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Lennart van der Linde

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #165 on: October 13, 2014, 10:15:28 PM »
Jai,

That's the same expert elicitation: Bamber & Aspinall 2013. Jevrejeva et al use the 5% risk of 84 cm ice sheet contribution by 2100 to get a 5% risk of 1.8m of total SLR by 2100, but then confirmed by the summed maximum contributions of process based models.

wili

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #166 on: October 13, 2014, 10:43:58 PM »
It would be interesting to see an analysis of the experts they elicited and the kinds of results they came up with.

I'm guessing that the experts that have been most active in the field most recently may be on the high end while those who were very familiar with the science and very active in research ten or even five years ago but are now not following it as closely may be less pessimistic (though, of course, the opposite may be true, which would also be important to know).

 Such distributions should be made clear so people can make their own judgments rather than just lumping all 'experts' together.

Also note this from the abstract:

Quote
The agreement between the methods may suggest more confidence than is warranted since large uncertainties remain due to the lack of scenario-dependent projections from ice sheet dynamical models, particularly for mass loss from marine-based fast flowing outlet glaciers in Antarctica.

This leads to an intrinsically hard to quantify fat tail in the probability distribution for global mean sea level rise. Thus our low probability upper limit of sea level projections cannot be considered definitive.
« Last Edit: October 13, 2014, 10:49:38 PM by wili »
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sidd

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #167 on: October 14, 2014, 12:51:04 AM »
Lambeck (2014) doi:10.1073/pnas.1411762111

seems like we have pulled the trigger. The figure below shows that SLR was less than 0.1m/kiloyr
for the last couple millennia. Today of course we have 3m/kiloyr, a rate last seen about 7kiloyr ago

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #168 on: October 14, 2014, 12:57:10 AM »
Here is a more complete reference to the article that sidd just posted about:

Kurt Lambeck, Hélène Rouby, Anthony Purcell, Yiying Sun, and Malcolm Sambridge, "Sea level and global ice volumes from the Last Glacial Maximum to the Holocene", PNAS, doi: 10.1073/pnas.1411762111

http://www.pnas.org/content/early/2014/10/08/1411762111

Abstract: "The major cause of sea-level change during ice ages is the exchange of water between ice and ocean and the planet’s dynamic response to the changing surface load. Inversion of ∼1,000 observations for the past 35,000 y from localities far from former ice margins has provided new constraints on the fluctuation of ice volume in this interval. Key results are: (i) a rapid final fall in global sea level of ∼40 m in <2,000 y at the onset of the glacial maximum ∼30,000 y before present (30 ka BP); (ii) a slow fall to −134 m from 29 to 21 ka BP with a maximum grounded ice volume of ∼52 × 106 km3 greater than today; (iii) after an initial short duration rapid rise and a short interval of near-constant sea level, the main phase of deglaciation occurred from ∼16.5 ka BP to ∼8.2 ka BP at an average rate of rise of 12 m⋅ka−1 punctuated by periods of greater, particularly at 14.5–14.0 ka BP at ≥40 mm⋅y−1 (MWP-1A), and lesser, from 12.5 to 11.5 ka BP (Younger Dryas), rates; (iv) no evidence for a global MWP-1B event at ∼11.3 ka BP; and (v) a progressive decrease in the rate of rise from 8.2 ka to ∼2.5 ka BP, after which ocean volumes remained nearly constant until the renewed sea-level rise at 100–150 y ago, with no evidence of oscillations exceeding ∼15–20 cm in time intervals ≥200 y from 6 to 0.15 ka BP."
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sidd

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #169 on: October 14, 2014, 01:51:59 AM »
probably dont need to point out that the graph i posted from Lambeck(2014) indicates very sharp changes in rate of SLR. When it begins to change it is step change ... ie the acceleration (second derivative) of SLR is huge. The graph i posted is of course only the first derivative. However it is probably not possible to recover acceleration from the data, since every differentiation amplifies data noise.

Nice paper tho, reconciles lots and lots of paleo records

sidd

jai mitchell

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #170 on: October 14, 2014, 03:07:04 AM »
Jai,

That's the same expert elicitation: Bamber & Aspinall 2013. Jevrejeva et al use the 5% risk of 84 cm ice sheet contribution by 2100 to get a 5% risk of 1.8m of total SLR by 2100, but then confirmed by the summed maximum contributions of process based models.

http://www.nature.com/nclimate/journal/v3/n4/full/nclimate1778.html

An expert judgement assessment of future sea level rise from the ice sheets
Received  31 July 2012

That means that the assessment was performed in the 3rd and 4th quarters of 2011.

Since then we have had so much work submitted on the subject that has pushed up the estimates.  I believe it was rignot, and the GRACE data for Greenland and WAIS that first gave indication that the 1m SLR by 2100 was now the new minimum.  Now the heat accumulation data from Durack also shows an increase in SLR thermal expansion.   

Any other papers submitted since q3 2011 that have shown a likely increase in the estimates of SLR?
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wili

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #171 on: October 14, 2014, 03:12:16 AM »
From the abstract posted by ASLR: "≥40 mm⋅y−1"

So that's over 40 cm (nearly 16 inches) per decade of sea level rise!

Yikes!

Over 4 meters per century. Ouch!

And our forcings are much larger and faster today than then, right?

Sooo, why would we think we are in for anything less, either in terms of magnitude or speed??
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

sidd

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #172 on: October 14, 2014, 03:39:36 AM »
Grant(2014) DOI:10.1038/ncomms6076 points out that the maximum SLR rates over the last 5 glacial cycles show dependence on the ice volume present at the start of deglaciation events or the start of a pulse of SLR. I reproduce fig 4 a,b (the ice volume relative to today at the start of a deglaciation and the start of a pulse respectively on the x axis, and max SLR rate on the y axis, the green point is MWP1A)

Note that the largest SLR rates are only observed at ice volume above  approx twice that of today.

sidd

wili

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #173 on: October 14, 2014, 12:49:20 PM »
Thanks, sidd. That makes sense.
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #174 on: October 14, 2014, 06:15:48 PM »
Thanks, sidd. That makes sense.

wili,

sidd knows well my position on the Grant et al (2014) data/plot that he just referenced, as we have discussed this matter in the Antarctic folder.  First, let me acknowledge that averaged over long periods of time (say 1,000 yrs) sidd is making a very strong point.  For example, during Melt-Pulse 1A when SLR rates were sustained for 500 years at greater than 40 mm per year, there many more marine glaciers in the world than now, and paleo-evidence of debris from icebergs around the Southern Ocean show that during MP 1A many of the marine glaciers (now gone) in Antarctic collapsed to contribute to this pulse.  However, sidd's point does not protect the modern world from SLR rates on the order of 40 mm per year over shorter periods of time (say 100-years), as there are still many marine glaciers in Antarctica (primarily in the West Antarctic, but also in the East Antarctic [say Totten]) that are primed to begin collapsing this century, as are several marine-terminating glaciers in Greenland (say the Jakobshavn Glacier).  The attached image provides paleo-evidence (from O'Leary et al 2013) from relative sea level data for Western Australia that shows that from 119 to 120 kyr sea level rose about 6m in no more than 1,000 yrs (or 6 mm per year) at ice levels essentially at today's levels.  However, as both Grant et al (2014) and O'Leary et at (2013) do not report data at less than 1,000 year resolution, we are left guessing whether, or not, a SLR rate of 30 to 40 mm/yr is going to happen this century; however the National Academy of Science says that such a pulse is plausible.

Best,
ASLR
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #175 on: October 14, 2014, 06:50:14 PM »
wili,

To get a slightly better feel for what type of Russian Roulette risks society is taking with regard to the risk of abrupt SLR this century, I post the attached image from Rohling (2008 data) of paleo-sea level-data with sea level above modern conditions.  While the smoothed curves (averaged over 1,000 year period) paint a less dramatic picture of say 1.6m per century SLR, the data points show sharp peaks that result possible periods of short bursts of SLR, so that Rohling 2008 gives a SLR rate of 1.6 +/- 1.0 m per century, or a reasonable rise of 2.6m of SLR this century based on paleo-evidence without considering the much higher rates of forcing in the modern era.

edit: With regard to modern forcing, please be aware that for SLR contribution from Antarctica the most important forcing is due to the ozone hole over Antarctica that has increased the westerly wind velocities, which have directed warm Circumpolar Deep Water, CDW, to the groundling lines of many key marine glaciers in Antarctica (including: the Pine Island Glacier, the Thwaites Drainage Basin and the Getz Drainage Basin, not to mention the Totten area) already today, so the argument that the beginning of a modern collapse of remaining marine, and marine terminating (like Jakobshavn, whose grounding line is also exposed to warm ocean water), glacier could be a long-time from now is a red-herring as the GRACE and GOCE measurement show that these ice mass loss from these key glaciers is accelerating today.

Best,
ASLR
« Last Edit: October 14, 2014, 07:19:18 PM by AbruptSLR »
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #176 on: October 14, 2014, 09:08:08 PM »
1)Grant(2014) is a 500 yr smooth (datapoints are at 250 yr intervals)
2)note the outlier at approx 1.6 time present ice volume and 2m/yr SLR. Prof. Grant was kind enuf to inform in a personal communication that the outlier is at 9.5 Kyr. From Weber(2014), doi:10.1038/nature13397 this seems to be about the time of the event AID1 (Antarctic Ice Sheet Discharge 1)
3)Most important: Forcing today is very different from Milankovich forcing amplified by other feedbacks. Hansen and others have made a strong case that spring and summer insolation in N. Hemisphere pace the glacial cycles, amplified by feedbacks. But today we have a very different situation indeed.
i)We have manmade greenhouse gas forcing which a)acts all over the globe, not just in N. Hemis. b)acts all the time not just in spring and summer daytime
ii)we have huge deleterious human impact on natural ecosystems and natural carbon reserves
iii)we have huge depletion of freshwater aquifers in coastal areas leading to land subsidence in precisely those populated coastal areas most at risk from SLR
iv)we are in an interglacial already so our forcings exacerbate the ntural forcing that led to this interglacial, and may have already suppressed the next few glacial cycles

The list goes on. So comparison with glacial cycles is only a very rough guide to what awaits. I post these last references to indicate the _low_ end of what we might expect. In this context perhaps the right analogs are the ANDRILL results showing deglaciation of large parts of Antarctica in the Pliocene, before the Pleistocene glacials. See for example Pollard(2009) doi:10.1038/nature07809

sidd

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #177 on: October 14, 2014, 10:45:38 PM »
Thank, both ASLR and sidd. Much to chew on here.
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #178 on: October 14, 2014, 11:13:01 PM »
sidd,

Thanks, I always learn something (or re-learn something I overlooked) from your posts.

Best, ASLR

Also, if anyone wants to correlate the iceberg data provided by Weber (2014) with the past retreats of the Amundsen Sea Embayment, ASE, marine glaciers, then the following linked reference provides paleo data (see attached plot [where GL = grounding line]).  Such a correlation might give some rough idea about how fast future grounding line retreats could be for the remaining marine glaciers in the ASE:

James A. Smith , Claus-Dieter Hillenbrand, Gerhard Kuhn, Johann Phillip Klages, Alastair G.C. Graham, Robert D. Larter, Werner Ehrmann, Steven G. Moreton, Steffen Wiers, & Thomas Frederichs, (2014), "New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum", Global and Planetary Change, DOI: 10.1016/j.gloplacha.2014.07.015

http://www.sciencedirect.com/science/article/pii/S0921818114001489


edit: For anyone needing the reference information for Weber et al (2014) it is as follows:

M. E. Weber, P. U. Clark, G. Kuhn, A. Timmermann, D. Sprenk, R. Gladstone, X. Zhang, G. Lohmann, L. Menviel, M. O. Chikamoto, T. Friedrich & C. Ohlwein, (2014), "Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation", Nature, 510, 134–138, doi:10.1038/nature13397

http://www.nature.com/nature/journal/v510/n7503/abs/nature13397.html

Abstract: "Our understanding of the deglacial evolution of the Antarctic Ice Sheet (AIS) following the Last Glacial Maximum (26,000–19,000 years ago) is based largely on a few well-dated but temporally and geographically restricted terrestrial and shallow-marine sequences. This sparseness limits our understanding of the dominant feedbacks between the AIS, Southern Hemisphere climate and global sea level. Marine records of iceberg-rafted debris (IBRD) provide a nearly continuous signal of ice-sheet dynamics and variability. IBRD records from the North Atlantic Ocean have been widely used to reconstruct variability in Northern Hemisphere ice sheets, but comparable records from the Southern Ocean of the AIS are lacking because of the low resolution and large dating uncertainties in existing sediment cores. Here we present two well-dated, high-resolution IBRD records that capture a spatially integrated signal of AIS variability during the last deglaciation. We document eight events of increased iceberg flux from various parts of the AIS between 20,000 and 9,000 years ago, in marked contrast to previous scenarios which identified the main AIS retreat as occurring after meltwater pulse 1A and continuing into the late Holocene epoch. The highest IBRD flux occurred 14,600 years ago, providing the first direct evidence for an Antarctic contribution to meltwater pulse 1A. Climate model simulations with AIS freshwater forcing identify a positive feedback between poleward transport of Circumpolar Deep Water, subsurface warming and AIS melt, suggesting that small perturbations to the ice sheet can be substantially enhanced, providing a possible mechanism for rapid sea-level rise."
« Last Edit: October 14, 2014, 11:21:48 PM by AbruptSLR »
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #179 on: October 15, 2014, 12:19:21 AM »
As a point of reference, the attached NOAA plot of global mean sea level, GMSL, with Jason-2 data through October 3 2014, indicates that during the satellite recorded indicated, sea level has been rising at a rate of 3.17 +/- 0.4 mm/yr, and during this non-El Nino year GMSL is currently following that trend line:

ftp://podaac.jpl.nasa.gov/allData/merged_alt/preview/global_mean_sea_level/GMSL_TPJAOS.jpg
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #180 on: October 16, 2014, 10:27:56 PM »
The forward to the linked (free access) US Department of Defense report on Climate Change Adaption, includes the following statement:

extract: "In places like the Hampton Roads region in Virginia, which houses the largest concentration of US military sites in the world, we see recurrent flooding today, and we are beginning work to address a projected sea-level rise of 1.5 feet over the next 20 to 50 years."

http://www.acq.osd.mil/ie/download/CCARprint.pdf

http://www.newscientist.com/article/dn26379-pentagon-warns-the-us-military-of-climate-change.html#.VD7h_KPn_IU

This statement by the US Secretary of Defense Chuck Hagel indicates that at the upper end, the US military is planning to deal with 1.5 ft of sea-level rise over 20 yrs; which is an average of 22.9 mm/yr; however as currently, SLR is 3.17 mm/yr, and using a linear approximation, this implies that the military is planning for a SLR of about 43 mm/yr by 2034 offshore of Virginia.  This is only possible if the US military is acknowledging that it is plausible that key parts of the West Antarctic Ice Sheet, WAIS, could begin collapsing within the next approximately 5 years.
« Last Edit: October 17, 2014, 12:25:09 AM by AbruptSLR »
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opensheart

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #181 on: October 17, 2014, 06:26:15 PM »
I would take this to mean a local Sea Level Rise, which is different and can be greater than the global sea level rise.

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #182 on: October 17, 2014, 08:18:37 PM »
opensheart,

I concur this 43-mm/yr RSLR rate by 2034 offshore of Virginia, is clearly a local SLR value.  That said even if one accounts for the local subsidence and the local steric SLR, and other local corrections; in order to get anywhere near 43-mm/yr one must assume a partial collapse of the WAIS by that date.

Best,
ASLR
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

opensheart

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #183 on: October 21, 2014, 06:51:30 PM »
In this age of budget cuts, one must demonstrate superior need to get funding approved.  If one is going to ask for funding, one only wants to ask once.   Cost overruns can be scandalous.   In such environments, spinning the need in the most urgent language possible is normal. 

If turns out to be the one chance to raise the land or build sea walls, etc, at such densely used area, one would want to make sure it was enough to last a good long time.   If one is going to do something, it might as well be big.    Politicians like to approve Big projects for their districts.

Once they ask to address the issue, their solution has to cover everything.   If 20 years from now a Superstorm Sandy storm surge makes a direct hit on the highest tide of the year, Congress is going to ask why they didn’t foresee that when the work was done.    This leads to inflating the best reasonable guesstimate by a healthy fudge factor, just to be safe.

Likewise the published timeframe may be more of a budgetary, resource planning target for getting the work done, than a scientific forecast of what will happen by when.

I would believe their request is worded to have the most chance of approval without it ever coming back to haunt them, rather than what they believe will actually happen.       As such, I highly doubt it was formulated from a vision that a specific event like the West Antarctic Ice Sheet will collapse X amount by Y year.

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #184 on: October 21, 2014, 11:33:56 PM »
opensheart,

While the DoD did not say that the WAIS would collapse X amount by Y year; its partial collapse is the only way that I can see that the DoD could estimate the possibility of 1.5 ft of relative sea-level rise at Norfolk by 2034.  As to the scientific plausibility of such a partial WAIS collapse this century, please see the following document (and associated extract):

National Research Council, NRC, (2013), Abrupt Impacts of Climate Change Anticipating Surprises, The National Academies Press, Washington D.C.

Extract: "Because large uncertainties remain, the Committtee judges an abrupt change in the WAIS with this century to be plausible, with an unknown although probably low probability."

Best,
ASLR
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Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #185 on: October 26, 2014, 05:58:06 PM »
Two Years After Sandy’s Surge, New York City Shifts Toward a Softer Relationship with the Sea.
http://dotearth.blogs.nytimes.com/2014/10/26/two-years-after-sandys-surge-new-york-city-shifts-toward-a-softer-relationship-with-the-sea/?partner=rss&emc=rss

Nice video ! informative about the consequences of "Sandy".

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #186 on: October 27, 2014, 10:43:56 PM »
While the authors of the linked paper are very conservative (and thus ignore any possible contribution to SLR from a possible collapse of the WAIS this century); nevertheless, the paper (see associated images and caption) does indicate that SLR will be noticeable by 2030 for most parts of the world for all RCP scenarios:


Kewei Lyu, Xuebin Zhang, John A. Church, Aimée B. A. Slangen & Jianyu Hu, (2014), "Time of emergence for regional sea-level change", Nature Climate Change, doi:10.1038/nclimate2397


http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2397.html


Abstract: "Determining the time when the climate change signal from increasing greenhouse gases exceeds and thus emerges from natural climate variability (referred to as the time of emergence, ToE) is an important climate change issue. Previous ToE studies were mainly focused on atmospheric variables Here, based on three regional sea-level projection products available to 2100, which have increasing complexity in terms of included processes, we estimate the ToE for sea-level changes relative to the reference period 1986–2005. The dynamic sea level derived from ocean density and circulation changes alone leads to emergence over only limited regions. By adding the global-ocean thermal expansion effect, 50% of the ocean area will show emergence with rising sea level by the early-to-middle 2040s. Including additional contributions from land ice mass loss, land water storage change and glacial isostatic adjustment generally enhances the signal of regional sea-level rise (except in some regions with decreasing total sea levels), which leads to emergence over more than 50% of the ocean area by 2020. The ToE for total sea level is substantially earlier than that for surface air temperature and exhibits little dependence on the emission scenarios, which means that our society will face detectable sea-level change and its potential impacts earlier than surface air warming.

Caption first image: "The blue curve shows projected sea level, the red curve shows the same projections once year-to-year variations have been removed. The grey and black lines show the range of natural variability. The asterisk denotes the time of emergence when sea level moves beyond the realm of natural variability.

Caption for second image: "The likely Time of Emergence (year) for regional sea-level change for a business-as-usual scenario. The warm (cold) colours represent rising (falling) sea level."
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #187 on: October 29, 2014, 01:05:32 AM »
In stark contract to the findings of the paper (Lyu et al 2014) that I posted about in may last post: In the extract form the linked article, ODU = Old Dominion University's Center for Sea Level Rise; and working for the US military, ODH calculates that sea level could raise by 1-ft (0.3m) by 2030; which is an average annual rate of increase of about 20mm/year:

http://www.military.com/daily-news/2014/10/27/hampton-roads-military-bases-brace-for-climate-change-sea-level.html

Extract: "Sea levels have risen 14 inches since 1930, according to the ODU center. That's a rate of more than five millimeters per year and is accelerating, Kreidel said. Some calculations show it will rise a foot by 2030 and 2 feet by 2050. By 2100, it could rise 7.5 feet."
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Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #188 on: October 29, 2014, 05:01:22 PM »
Life on a Louisiana island slowly disappearing into the sea
http://www.bbc.com/news/magazine-29796842

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #189 on: October 30, 2014, 04:29:38 PM »

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #190 on: October 30, 2014, 05:38:55 PM »
As a follow-on to Laurent's post: What Purkey et al (2014) do not point-out is that while the mass contribution to sea level rise has stayed nearly constant at 1.5 +/- 0.4 mm/yr from 1996 to 2013, the contribution from glaciers and ice caps has started to decline while the contribution from ice sheets has started to accelerate (see attached image).  Therefore, we appear to be in a period of relatively calm transition to a more rapid acceleration of SLR (assuming that the contribution from ice sheets continues to accelerate):

Sarah G. Purkey, Gregory C. Johnson and Don P. Chambers, (2014), "Relative contributions of ocean mass and deep steric changes to sea level rise between 1993 and 2013", Journal of Geophysical Research: Oceans, DOI: 10.1002/2014JC010180

http://onlinelibrary.wiley.com/doi/10.1002/2014JC010180/abstract

Abstract:  "Regional and global trends of Sea Level Rise (SLR) owing to mass addition centered between 1996–2006 are assessed through a full-depth SLR budget using full-depth in-situ ocean data and satellite altimetry. These rates are compared to regional and global trends in ocean mass addition estimated directly using data from the Gravity Recovery and Climate Experiment (GRACE) from 2003–2013. Despite the two independent methods covering different time periods with differing spatial and temporal resolution, they both capture the same large-scale mass addition trend patterns including higher rates of mass addition in the North Pacific, South Atlantic, and the Indo-Atlantic Sector of the Southern Ocean, and lower mass addition trends in the Indian, North Atlantic, South Pacific, and the Pacific Sector of the Southern Ocean. The global mean trend of ocean mass addition is 1.5 (±0.4) mm yr-1 for 1996–2006 from the residual method and the same for 2003–2013 from the GRACE method. Furthermore, the residual method is used to evaluate the error introduced into the mass budget if the deep steric contributions below 700, 1000, 2000, 3000, and 4000 m are neglected, revealing errors of 65%, 38%, 13%, 8% and 4% respectively. The two methods no longer agree within error bars when only the steric contribution shallower than 1000 m is considered."

The attached figure is from
https://www.ccin.ca/home/ccw/glaciers/current


edit: here is a link to a free access pdf of the Purkey et al paper:

http://www.pmel.noaa.gov/people/gjohnson/Ocean_mass_trends_v2.pdf
« Last Edit: October 30, 2014, 06:57:22 PM by AbruptSLR »
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #191 on: October 30, 2014, 10:58:37 PM »
The following link leads to an article that provides a reasonable summary of reasons why the IPCC's SLR projections are too low:

http://www.washingtonpost.com/blogs/wonkblog/wp/2014/10/30/climate-scientists-arent-too-alarmist-theyre-too-conservative/
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Bruce Steele

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #192 on: October 31, 2014, 05:10:00 PM »
If you extend the trend lines in the Glaciers and Ice Sheet contribution to SLR chart it looks like the Ice Sheets may already have passed the Glaciers in their contribution to SLR. Totals look to be in excess of 3 mm annually . Does anyone have info on when in the past this happened last? Quite the transition to transpire without note.
 

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #193 on: October 31, 2014, 09:15:03 PM »
If you extend the trend lines in the Glaciers and Ice Sheet contribution to SLR chart it looks like the Ice Sheets may already have passed the Glaciers in their contribution to SLR. Totals look to be in excess of 3 mm annually . Does anyone have info on when in the past this happened last? Quite the transition to transpire without note.

Bruce,

Thanks for all of your observations.  Part of the problem with getting people to recognize the risks associated with sea level rise (beyond the IPCC's behavior of erring on the side of least drama) include such factors as:

(a) The observed data record is so small that short-term rainfall/snow events can hide the contribution that the ice sheets are making to SLR.  For example an Atmospheric River event hit East Antarctica around 2011 which dumped a lot of snow there, which due to the mass balance approach used to report SLR contribution, makes the Antarctic Ice Sheet, ASE, ice melting appear small than it really is.

(b) There is so much ice mass loss occurring in the Amundsen Sea Embayment glaciers that the ground is rebounding so quickly that it is drawing magma beneath the lithosphere, which is adding confusion to the gravity change measurements of the GRACE satellite (see that attached GRACE measurement of ice mass loss from the West Antarctic Ice Sheet, which is already accelerating faster than the ASE rate, even before probable corrections for land rebound [isostatic] corrections); which again masks the true amount of ice melting.

(c) Most importantly ice melting from the ice sheets for the next century will be dominated by ocean water melting of the ice at the grounding line; therefore, even if society gets off of the RCP 8.5 scenario within the next few years, the ice mass contribution from marine terminating glaciers (in Greenland) and marine glaciers (in Antarctica) have already been triggered and we will be now experiencing that SLR no matter what (even if climate sensitivity is smaller than expected).
« Last Edit: October 31, 2014, 09:20:35 PM by AbruptSLR »
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #194 on: November 12, 2014, 12:42:05 AM »
I decided to post the attached recent SLR trend plot from the University of Colorado issued Nov 4, 2014 indicating that even with the ENSO currently being neutral sea-level rise continues to trend upwards.
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wili

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #195 on: November 14, 2014, 01:07:38 AM »
Floating above the rising tides

Keren Bolter



Perhaps more of our scientists need to get this passionate!
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

Lennart van der Linde

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #196 on: November 14, 2014, 08:52:41 AM »
Wow, that's powerful and hurts.

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #197 on: November 19, 2014, 09:47:51 AM »

Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #198 on: December 21, 2014, 10:15:09 PM »
About the Miami Beach inundation:
Quote
Wanless remembers when he first started getting calls for help from local authorities.

"In around 2008 or 2009, one of the first years we had a lot of water in the Miami Beach area, the public works people called me for help and I went into this room in their government building and they were all in their coats and ties and they said, 'We are having a little problem in Miami Beach, we are getting water in the streets. Where do you suggest we put it?'

 "I held my laughter. The ocean had arrived. You can put the water anywhere you want, but it is going to keep coming."

Wanless believes the hundreds of millions of dollars that have already been spent of flood mitigation infrastructure around Miami have been wasted because the sea cannot be held back.

"We are in the position where we think we are going to fight it and win. We are not going to win."

Soon, he believes, insurance companies will stop underwriting homes in the worst affected areas and then owners will be unable to sell.

Money should be saved for moving people away while all levels of government work to reduce emissions, he argues.
http://www.brisbanetimes.com.au/world/warming-worlds-rising-seas-wash-away-some-of-south-floridas-glitz-20141220-129wub.html
People who say it cannot be done should not interrupt those who are doing it.

Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #199 on: December 24, 2014, 08:09:35 PM »
New study says damage this century in U.S. due to sea level rise (SLR) that includes storm surge could be more than twice estimates due to SLR alone.
Quote
The results show that the U.S. is facing what until now has been a hidden financial risk, not unlike the mortgage backed securities that helped blow up the U.S. economy in 2008. Scientists have improved their tracking and projections of sea level rise — but they have not, until now, figured out a way to estimate the combined economic impact of storm surges and sea level rise nationwide.
...
According to the new study, the combined costs from sea level rise and storm surge events, including sea level rise adaptation measures like raising home elevations, abandoning some properties and building new sea walls to defend others, comes to between $930 billion to $1.1 trillion nationally by 2100, which is 84% to 110% higher than the projected costs from sea level rise alone, the study says.
http://mashable.com/2014/12/23/sea-level-rise-storm-surge-1-trillion/
People who say it cannot be done should not interrupt those who are doing it.