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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #250 on: January 07, 2015, 01:50:18 AM »
With a hat tip to Lennart from the WAIS Collapse thread in the Antarctic folder, the linked reference (with a free access pdf) shows that assuming both cliff failure, and melt-driven hydrofracturing, active the WAIS could contribute from 2m to 3m to SLR by 2100 (note that almost all of my posts in the Antarctic folder support this approximation), per the attached image and associated caption:

Pollard, D., DeConto, R.M. and Alley, R.B., (2015), "Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure", Earth and Planetary Science Letters, Volume 412, 15 February 2015, Pages 112–121, doi:10.1016/j.epsl.2014.12.035

http://www.sciencedirect.com/science/article/pii/S0012821X14007961



Abstract: "Geological data indicate that global mean sea level has fluctuated on 103 to 106 yr time scales during the last ∼25 million years, at times reaching 20 m or more above modern. If correct, this implies substantial variations in the size of the East Antarctic Ice Sheet (EAIS). However, most climate and ice sheet models have not been able to simulate significant EAIS retreat from continental size, given that atmospheric CO2 levels were relatively low throughout this period. Here, we use a continental ice sheet model to show that mechanisms based on recent observations and analysis have the potential to resolve this model–data conflict. In response to atmospheric and ocean temperatures typical of past warm periods, floating ice shelves may be drastically reduced or removed completely by increased oceanic melting, and by hydrofracturing due to surface melt draining into crevasses. Ice at deep grounding lines may be weakened by hydrofracturing and reduced buttressing, and may fail structurally if stresses exceed the ice yield strength, producing rapid retreat. Incorporating these mechanisms in our ice-sheet model accelerates the expected collapse of the West Antarctic Ice Sheet to decadal time scales, and also causes retreat into major East Antarctic subglacial basins, producing ∼17 m global sea-level rise within a few thousand years. The mechanisms are highly parameterized and should be tested by further process studies. But if accurate, they offer one explanation for past sea-level high stands, and suggest that Antarctica may be more vulnerable to warm climates than in most previous studies."

Caption: "Global mean equivalent sea level rise in warm-climate simulations. Time series of global mean sea level rise above modern are shown, implied by reduced Antarctic ice volumes. The calculation takes into account the lesser effect of melting ice that is originally grounded below sea level. Cyan: with neither cliff failure nor melt-driven hydrofracturing active. Blue: with cliff failure active. Green: with melt-driven hydrofracturing active. Red: with both these mechanisms active."

Edit: I note that the values given in the attached image are for a simple Pliocene-like warming scenario, and not for any RCP or SRES pathways.
« Last Edit: January 07, 2015, 10:07:47 AM by AbruptSLR »
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #251 on: January 07, 2015, 04:21:20 PM »
As Pollard, DeConto & Alley 2015 use a simple Pliocene-like initial condition, the real question is how soon will the waters and atmosphere around the Western Antarctic reach these conditions (allowing for both cliff failure and hydrofracturing).  While I do not have time to repeat my posts in the Antarctic folder (look there if you have time), I believe that the PIG/Thwaites basins will reach the cliff failure threshold by 2040 (this is based on both the ozone hole increasing the westerly winds which has increase upwelling of warm ocean water near the grounding line in this area and the increasing frequency of El Nino events in this timeframe), and that hydrofracturing will be more prevalent around the WAIS perimeter (& ice shelves) by the 2060 to 2070 assuming that society stay near an RCP 8.5 pathway through the 2040 to 2050 timeframe.  This could result collapse of the WAIS at the rates cited by Pollard, DeConto & Alley 2015 between 2070 & 2100.
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Lennart van der Linde

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #252 on: January 07, 2015, 07:23:50 PM »
This could result collapse of the WAIS at the rates cited by Pollard, DeConto & Alley 2015 between 2070 & 2100.

ASLR,
Are you thinking about 1m SLR from WAIS between 2070 and 2100? Or complete collapse, so 3m in three decades?

jai mitchell

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #253 on: January 07, 2015, 08:58:14 PM »
This could result collapse of the WAIS at the rates cited by Pollard, DeConto & Alley 2015 between 2070 & 2100.

ASLR,
Are you thinking about 1m SLR from WAIS between 2070 and 2100? Or complete collapse, so 3m in three decades?

are we talking under RCP 8.5 worst case scenario or RCP 7.0 (I made it up but basically what EXXON recently predicted) or a more aggressive RCP 6.0 with a moderate ECS of 3.0???

or

are we talking about what you, ASLR or I think will actually happen to temperatures and melt dynamics over the next 100 years?

In my understanding, we have significantly underestimated carbon cycle and climate feedbacks of arctic region effects.  We have locked in 2.3C of warming over the next 5 decades at current CO2 forcing.  By the time we are done with our moderately aggressive (near term) and very aggressive (mid term) emissions reductions we will have locked in about 4C of warming by 2065.

At this point natural feedbacks will dominate and we will pass 5C of warming by 2100.

Under this scenario, the massive destabilization of Greenland and the arctic melt will disrupt overturning circulations and lead to a massive increase in Circumpolar deep water temperatures, increased surface melting by 2030 will begin to rapidly destabilize the WAIS and by 2070 the East Antarctic will begin to experience extreme melt effects.  by 2100 we will see 3-5 meters of sea level rise, with an additional 25% increases in the northern mid-latitudes due to gravity effects from losing Antarctic mass.
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #254 on: January 07, 2015, 11:25:30 PM »
This could result collapse of the WAIS at the rates cited by Pollard, DeConto & Alley 2015 between 2070 & 2100.

ASLR,
Are you thinking about 1m SLR from WAIS between 2070 and 2100? Or complete collapse, so 3m in three decades?

Lennart,

If we stay on a BAU to the end of the century then I think that it is reasonable to believe that the WAIS will likely contribute 3m by 2100; however, if we back down to RCP 6 then maybe 2m is reasonable, and if we can get to RCP 4 then maybe 1m is a reasonable contribute to assume from the WAIS.  These are just my opinions; but if you are concerned about The Netherlands, do not forget the fingerprint effect (which I believe is about 1.1 for Holland and up to 1.4 for parts of the USA).

Best,
ASLR
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #255 on: January 10, 2015, 10:41:56 PM »
If the AIS contributes 3m, the GRIS contributes 1m and steric contributes 1m to SLR by 2100 following a BAU scenario then James Hansen's warnings may be supported by Pollard et al 2015's findings.  Therefore, I thought that I would post the four attached images regarding the impacts of a 5m SLR occurrence by 2100; and I would especially like to note that a great main of the great river deltas will all be inundated at the same time and consequently a great about of rice production (e.g. the Mekong, the Jamuna, the Nile, etc.) will be lost abruptly.
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #256 on: January 10, 2015, 10:43:21 PM »
The attached image indicates which country's populations will me impacted by 5m of SLR (eg China, Egypt, Vietnam, Indonesia, Japan, Bangaladesh and India)
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #257 on: January 11, 2015, 05:14:11 PM »
Tried  to post a comment and I believe it got hung up. Tried to repost and it said I had already posted it.     :-[

Neven

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #258 on: January 12, 2015, 12:59:13 AM »
Tried  to post a comment and I believe it got hung up. Tried to repost and it said I had already posted it.     :-[

I'm sorry this happened, SH. I don't think I can retrieve that comment.
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Lennart van der Linde

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #259 on: January 12, 2015, 10:46:14 PM »
New paper on Social Cost of Carbon:
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2481.html

"We implement empirical estimates of temperature effects on GDP growth rates in the DICE model through two pathways, total factor productivity growth and capital depreciation. This damage specification, even under optimistic adaptation assumptions, substantially slows GDP growth in poor regions but has more modest effects in rich countries. Optimal climate policy in this model stabilizes global temperature change below 2 °C by eliminating emissions in the near future and implies a social cost of carbon several times larger than previous estimates."

Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #260 on: January 13, 2015, 02:48:34 AM »
Stanford study: social cost of carbon may be $220/ton, not the previously-estimated $37/ton.
Quote
"If the social cost of carbon is higher, many more mitigation measures will pass a cost-benefit analysis," Diaz said. "Because carbon emissions are so harmful to society, even costly means of reducing emissions would be worthwhile."
http://phys.org/news/2015-01-social-climate-scientists.html
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Lennart van der Linde

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #261 on: January 13, 2015, 08:14:13 AM »
New paper on costs of SLR by Pycroft et al 2014:
http://rd.springer.com/article/10.1007%2Fs10640-014-9866-9

Their high scenario has 1.75m of SLR by 2080 and 0.5% global GDP and 2% welfare loss, with up to 12% in some places, without adaptation. For what it's worth.
« Last Edit: January 13, 2015, 08:19:23 AM by Lennart van der Linde »

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #262 on: January 14, 2015, 05:52:01 PM »
The linked reference indicates that SLR will likely increase parasite trematode-bivalve infections:

John Warren Huntley, Franz T. Fürsich, Matthias Alberti, Manja Hethke, and Chunlian Liu, (2015), "A complete Holocene record of trematode–bivalve infection and implications for the response of parasitism to climate change", PNAS, vol. 111 no. 51,  pp. 18150–18155, doi: 10.1073/pnas.1416747111

http://www.pnas.org/content/111/51/18150.abstract

Significance: "There is growing concern about how parasites will respond to climate change. Previous studies were based on data from short time scales (10−1 to 103 y), but here we present, to our knowledge, the first analysis of the response of parasites to global change on a longer time scale (104 y), utilizing the subfossil record. A 9,600-y record of clams and flatworm parasites from the Pearl River Delta exhibits a significant spike in parasite prevalence during the initial phase of sea-level rise. This increase is not related to changes in salinity or intermediate host availability. Temperature and productivity cannot be quantified and tested as driving factors. These results suggest stark implications for macrobenthos, fisheries, and human health in the context of climate change."

Abstract: "Increasing global temperature and sea-level rise have led to concern about expansions in the distribution and prevalence of complex-lifecycle parasites (CLPs). Indeed, numerous environmental variables can influence the infectivity and reproductive output of many pathogens. Digenean trematodes are CLPs with intermediate invertebrate and definitive vertebrate hosts. Global warming and sea level rise may affect these hosts to varying degrees, and the effect of increasing temperature on parasite prevalence has proven to be nonlinear and difficult to predict. Projecting the response of parasites to anthropogenic climate change is vital for human health, and a longer term perspective (104 y) offered by the subfossil record is necessary to complement the experimental and historical approaches of shorter temporal duration (10−1 to 103 y). We demonstrate, using a high-resolution 9,600-y record of trematode parasite traces in bivalve hosts from the Holocene Pearl River Delta, that prevalence was significantly higher during the earliest stages of sea level rise, significantly lower during the maximum transgression, and statistically indistinguishable in the other stages of sea-level rise and delta progradation. This stratigraphic paleobiological pattern represents the only long-term high-resolution record of pathogen response to global change, is consistent with fossil and recent data from other marine basins, and is instructive regarding the future of disease. We predict an increase in trematode prevalence concurrent with anthropogenic warming and marine transgression, with negative implications for estuarine macrobenthos, marine fisheries, and human health."
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Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #263 on: January 14, 2015, 09:05:01 PM »
« Last Edit: January 14, 2015, 09:15:10 PM by Laurent »

AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #264 on: January 14, 2015, 10:05:43 PM »
Rate of sea-level rise 'steeper'
http://www.bbc.com/news/science-environment-30816143

The tides are changing: Sea levels rising at faster rate than predicted, study finds
http://www.independent.co.uk/environment/climate-change/the-tides-are-changing-sea-levels-rising-at-faster-rate-than-predicted-study-finds-9978390.html

To add some details to your post: The linked reference finds that the acceleration in sea level rise seen in recent decades is more rapid (by about 25% since 1990, see attached plot & caption) than scientists previously thought:

Hay CC, Morrow E, Kopp RE, Mitrovica JX, (2015) "Probabilistic reanalysis of twentieth-century sea-level rise", Nature. 2015 Jan 14. doi: 10.1038/nature14093

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14093.html

Abstract: "Estimating and accounting for twentieth-century global mean sea-level (GMSL) rise is critical to characterizing current and future human-induced sea-level change. Several previous analyses of tide gauge records—employing different methods to accommodate the spatial sparsity and temporal incompleteness of the data and to constrain the geometry of long-term sea-level change—have concluded that GMSL rose over the twentieth century at a mean rate of 1.6 to 1.9 millimetres per year. Efforts to account for this rate by summing estimates of individual contributions from glacier and ice-sheet mass loss, ocean thermal expansion, and changes in land water storage fall significantly short in the period before 1990. The failure to close the budget of GMSL during this period has led to suggestions that several contributions may have been systematically underestimated. However, the extent to which the limitations of tide gauge analyses have affected estimates of the GMSL rate of change is unclear. Here we revisit estimates of twentieth-century GMSL rise using probabilistic techniques and find a rate of GMSL rise from 1901 to 1990 of 1.2 ± 0.2 millimetres per year (90% confidence interval). Based on individual contributions tabulated in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, this estimate closes the twentieth-century sea-level budget. Our analysis, which combines tide gauge records with physics-based and model-derived geometries of the various contributing signals, also indicates that GMSL rose at a rate of 3.0 ± 0.7 millimetres per year between 1993 and 2010, consistent with prior estimates from tide gauge records. The increase in rate relative to the 1901–90 trend is accordingly larger than previously thought; this revision may affect some projections of future sea-level rise."


Caption: "Time series of global mean sea level for the period 1900-2010. Figure shows estimates of sea level from the two methods used in this study: 'KS' (blue line) and 'GPR' (black line), and two methods used in the latest IPCC report: 'Ref.4' (purple line) from Church et al. ( 2011) and 'Ref. 3' (red line) from Jevrejeva et al. ( 2008). Inset table shows trends for three different time periods. Source: Hay et al. (2015)"

See also:
http://www.carbonbrief.org/blog/2015/01/global-sea-levels-rising-faster-than-previously-thought-study-shows/
http://in.reuters.com/article/2015/01/14/climatechange-seas-idINL6N0US3IZ20150114
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Steven

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #265 on: January 14, 2015, 10:26:53 PM »
Rate of sea-level rise 'steeper'
http://www.bbc.com/news/science-environment-30816143

Blog post by Stefan Rahmstorf at RealClimate about the new sea level study (Hay et al.):
http://www.realclimate.org/index.php/archives/2015/01/a-new-sea-level-curve



Quote
Hay et al. find that the acceleration of sea-level rise since 1900 AD is larger than in previous reconstructions, but it has been generally questioned whether the quadratic acceleration (derived from a parabolic fit) is a useful number in cases where a parabola doesn’t fit the data well (Rahmstorf and Vermeer 2011, Foster and Brown 2014). Taking a step back, in my view the “big picture” on acceleration is that we have moved from a stable preindustrial sea level to one now rising at 3 mm/year

...

"To sum up, in my view the strength of the method of Hay et al. is that it uses the expected “fingerprints” of the global warming signal, while the strength of Church & White is to take into account the empirical patterns of natural variability. Ideal would of course be a combination of both, and this could be the next step for further research.

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #266 on: January 15, 2015, 01:08:19 AM »
That table says estimates of acceleration over the last period have roughly doubled. If read as exponential (which is a very large assumption) that's a SLR doubling time of a decade or so. The graph at realclimate of acceleration is too noisy to say much, expected when you try to differentiate noisy data.

sidd

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #267 on: January 15, 2015, 01:18:27 AM »
The linked reference (with a free access pdf) presents a relatively conservative briefing on SLR and AIS contributions

Ted Scambos & John Abraham, (2014), "Briefing: Antarctic ice sheet mass loss and future sea-level rise", Proceedings of the ICE - Forensic Engineering, DOI: 10.1680/feng.14.00014

http://www.icevirtuallibrary.com/content/article/10.1680/feng.14.00014

Abstract: "Sea-level rise, one of the most obvious consequences of climate change, has direct impacts on coastal communities and economic infrastructure. It is important to assess current sea-level rise and forecast future rates. These predictions are made difficult because the potential for rapid destabilisation of some of the world's large ice sheets, in particular the west Antarctic ice sheet, remains poorly constrained. In particular, new processes and new mapping and modelling, currently emerging from the science community, may have a radical impact on forecasts. Here, a summary of observations and models of recent west Antarctic ice sheet dynamics are provided. This summary highlights that sea-level rise above the ∼1 m expected by 2100 is possible if ice sheet response begins to exceed present rates. Moreover, ice losses from Antarctica have an amplified impact on the coastlines of North America and Europe, because of the resulting redistribution of water due to the changed gravitational field near the ice sheet."
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #268 on: January 15, 2015, 02:01:44 AM »
Reuters story at The Guardian:  Sea levels rising faster than previously thought says new study; Assessment of 600 tidal gauges across the globe suggests a 25% greater acceleration in the rise over the past 20 years http://www.theguardian.com/environment/2015/jan/15/sea-levels-rising-faster-than-previously-thought-says-new-study

Despite the headline, the story reports on a study published in Nature that says earlier sea level rises were smaller than previously estimated, making the current rate of change more alarming:
Quote
The study said sea level rise, caused by factors including a thaw of glaciers, averaged about 1.2 millimetres (0.05 inch) a year from 1901-90 - less than past estimates - and leapt to 3 mm a year in the past two decades, apparently linked to a quickening thaw of ice.

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #269 on: January 15, 2015, 10:08:51 AM »
An other point of view on the matter :

New Research May Solve Puzzle in Sea Level’s Rise
http://www.nytimes.com/2015/01/15/science/earth/new-research-may-solve-a-puzzle-in-sea-levels-rise.html?partner=rss&emc=rss

Quote
Instead of rising about six inches over the course of the 20th century, as previous research suggested, the sea actually rose by approximately five inches, the team from Harvard and Rutgers Universities found. The difference turns out to be an immense amount of water: on the order of two quadrillion gallons, or enough to fill three billion Olympic-size swimming pools.

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #270 on: January 15, 2015, 02:46:06 PM »
From the abstract:

"sea-level rise above the ∼1 m expected by 2100 is possible if ice sheet response begins to exceed present rates"

What are the chances that ice sheet response will not begin to exceed present rates??
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #271 on: January 16, 2015, 12:54:22 AM »
As it is never possible to over cite the excellent research by Purkey et al, the linked paper discusses regional differences in SLR, and indicates that this topic merits still further research:

Purkey, S. G., G. C. Johnson, and D. P. Chambers, (2014), "Relative contributions of ocean mass and deep steric changes to sea level rise between 1993 and 2013", J. Geophys. Res. Oceans, 119, 7509–7522, doi:10.1002/2014JC010180.

http://onlinelibrary.wiley.com/doi/10.1002/2014JC010180/abstract;jsessionid=EB0B6BE46C64753DF09932ACAE4AC179.f01t04

Abstract: "Regional and global trends of Sea Level Rise (SLR) owing to mass addition centered between 1996 and 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 to 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."
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #272 on: January 18, 2015, 05:48:49 PM »
With a hat-tip to Lennart van der Linde in the Greenland folder, the following extract from Applegate et al 2014 indicates that the future contributions to SLR from the Greenland Ice Sheet, GIS, is approximately exponential with increasing Greenland surface temperature change (see first attached associated image).   Furthermore, I point-out that the Pollard et al 2015 findings (see second attached associated image) indicate that this consideration is even more true for the Antarctic Ice Sheet, AIS, than for the GIS, in the coming 100 to 200 years.  These findings imply that if modern society had any meaningful willpower then decision makers could buy future generations a lot more "... time to design and implement improved strategies for adapting to sea level change" by reducing GHG emission sooner rather than later.  Alternately, as societal willpower w.r.t climate change appears to be lacking at the moment, future generations may need to get use to climate shock (including abrupt SLR, with possible increases in sea level of up to 5m by 2100) beginning no later than 2050 following a BAU pathway.

Also, I include the third and fourth attached images of the GIS & AIS elevations and latitudes, respectively, to illustrate that while the WAIS is located further pole-ward than the GIS, its elevation is already lower than that for the GIS; which supports the position that major portions of the WAIS may likely be subject to surface ice melting (which leads to hydrofracturing and cliff failures) starting sometime between 2050 and 2100 when following a BAU pathway.

Patrick J. Applegate, Byron R. Parizek, Robert E. Nicholas, Richard B. Alley & Klaus Keller, (2014), "Increasing temperature forcing reduces the Greenland Ice Sheet’s response time scale", Climate Dynamics, DOI: 10.1007/s00382-014-2451-7

http://link.springer.com/article/10.1007/s00382-014-2451-7

Extract: "We speculate that near-term reductions in greenhouse gas emissions could pay large dividends in terms of avoided sea level rise. Our results suggest that the relationships between temperature change, GIS response time scale, and GIS equilibrium sea level contribution are approximately exponential (Fig. 2). Thus, the benefit, in terms of avoided sea level rise contributions from the GIS, of a unit of avoided emissions is greatest if emissions reductions are begun before much temperature change has already happened. Alternatively, one could say that mitigation becomes less effective in preventing or delaying sea level rise contributions from the Greenland Ice Sheet as temperature rises. Near-term reductions in greenhouse gas emissions may also buy time to design and implement improved strategies for adapting to sea level change."

Pollard, D., DeConto, R.M. and Alley, R.B., (2015), "Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure", Earth and Planetary Science Letters, Volume 412, 15 February 2015, Pages 112–121, doi:10.1016/j.epsl.2014.12.035

http://www.sciencedirect.com/science/article/pii/S0012821X14007961

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #273 on: January 19, 2015, 05:48:07 PM »
Given the future contributions to SLR from Greenland is exponential, do we have any sense of what the doubling time period is?

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #274 on: January 19, 2015, 06:18:50 PM »
Between (around) 2000-2005 : 600 Gt
                                  2005-2010 : 1100 Gt
                                  2010-2015 : 1400 Gt
 
It is hard to tell yet, I would say a doubling between 5 to 10 years. Recent numbers seem to slow.
« Last Edit: January 19, 2015, 06:25:31 PM by Laurent »

sidd

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #275 on: January 20, 2015, 10:39:45 PM »
Prof. Kopp, one of the authors of Hay(2015,  doi:10.1038/nature14093 ) , writing at realclimate, points out one of the strong achievements of the paper:

"I should note one element of the paper not highlighted in this write-up: the closing of the 1901-1990 sea-level rise budget."

He goes on:

" ...  no net contribution from polar ice sheets is needed over 1901-1990. By contrast, there is of course a significant contribution over the past 20 years, observed directly ... "

So the polar ice sheet destabilization unequivocally began and accelerated over the last twenty five years. We are at roughly 500 GT mass waste today (360 GT = 1 mm SLR) from AIS and GIS, beginning from zero in 1990.

sidd

Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #276 on: January 29, 2015, 07:07:03 PM »
Update on the story of the Kirabati refugee who applied to stay in New Zealand because his family home on the tiny island is threatened by sea level rise.  He has become the test case for climate change refugees.
http://foreignpolicy.com/2015/01/28/the-making-of-a-climate-refugee-kiribati-tarawa-teitiota/
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #277 on: January 29, 2015, 08:33:26 PM »
I thought that I would post the three attached images all illustrating how quickly groundwater levels are dropping around the world, and to point-out that as the groundwater level is being drawing down quickly in many coastal areas, it will become more and more difficult to stop seawater from flowing into the depleted coastal groundwater level areas with continued SLR increasing the amount of the pressure head gradient from the ocean to the depleted groundwater level areas.

Edit: I point-out that: (a) the Sacramento Delta is at sea level and represents a major avenue for seawater to enter the groundwater in California's Central Valley, and (b) Bangladesh represents a major avenue for seawater to enter the groundwater beneath the northern plains of India.
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Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #278 on: January 30, 2015, 03:32:50 PM »
Slope on the ocean surface lowers the sea level in Europe
http://phys.org/news/2015-01-slope-ocean-surface-lowers-sea.html

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #279 on: January 31, 2015, 12:02:27 AM »

sidd

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #280 on: January 31, 2015, 05:09:05 AM »
The USA presidential directive linked in the previous post is big. Now USA fed planning has to take SLR into account, regardless of state level morons. This will affect fed spending in a big way.

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #281 on: January 31, 2015, 10:04:36 PM »
Outbreak of the plague in Madagascar.  The plague is caused by Yersinia pestis, a bacteria found in rodents and spread by fleas.

Recent flooding in Madagascar has displaced tens of thousands of people and an "untold numbers of rats," leading to fears the disease could spread further.

http://www.cnn.com/2015/01/31/health/madagascar-plague/index.html
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #282 on: February 01, 2015, 04:57:14 AM »
Not to detract from the significance of the outbreak of the plague in Madagascar, but per the linked article the flooding that displaced the poor and "untold" rats that can transmit the plague, was caused by rainwater from Tropical Storm Chedza on January 16 2015 (not due to SLR):

http://thewatchers.adorraeli.com/2015/01/19/severe-tropical-storm-chedza-flooded-madagascar-and-affected-more-than-50-000/

Extract: "Severe Tropical Storm "Chedza" made landfall north of Morondava, Madagascar between 15:00 and 16:00 UTC on January 16, 2015 bringing heavy thunderstorm rains across much of the country."

Edit: Here is a map of the storm track for Tropical Storm Chedza.
« Last Edit: February 01, 2015, 12:23:15 PM by AbruptSLR »
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #283 on: February 02, 2015, 05:36:19 PM »
The linked research could result in a relatively inexpensive means to estimate the contribution of ice calving to SLR:

Glowacki, O., G. B. Deane, M. Moskalik, P. Blondel, J. Tegowski, and M. Blaszczyk (2015), Underwater acoustic signatures of glacier calving, Geophys. Res. Lett., 42, doi:10.1002/2014GL062859.

http://onlinelibrary.wiley.com/doi/10.1002/2014GL062859/abstract

Abstract: "Climate-driven ice-water interactions in the contact zone between marine-terminating glaciers and the ocean surface show a dynamic and complex nature. Tidewater glaciers lose volume through the poorly understood process of calving. A detailed description of the mechanisms controlling the course of calving is essential for the reliable estimation and prediction of mass loss from glaciers. Here we present the potential of hydroacoustic methods to investigate different modes of ice detachments. High-frequency underwater ambient noise recordings are combined with synchronized, high-resolution, time-lapse photography of the Hans Glacier cliff in Hornsund Fjord, Spitsbergen, to identify three types of calving events: typical subaerial, sliding subaerial, and submarine. A quantitative analysis of the data reveals a robust correlation between ice impact energy and acoustic emission at frequencies below 200 Hz for subaerial calving. We suggest that relatively inexpensive acoustic methods can be successfully used to provide quantitative descriptions of the various calving types."
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AbruptSLR

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #284 on: February 06, 2015, 09:59:41 PM »
The linked open access reference investigates the economic impact of rapid SLR, and examines up to 1.75 m of SLR by 2085 (see the attached image and the associate extract showing that Southeast Asia would be impacted the most, followed by China).

Jonathan Pycroft, Jan Abrell, Juan-Carlos Ciscar, (2015), "The Global Impacts of Extreme Sea-Level Rise: A Comprehensive Economic Assessment", Environmental and Resource Economics, DOI: 10.1007/s10640-014-9866-9

http://download.springer.com/static/pdf/503/art%253A10.1007%252Fs10640-014-9866-9.pdf?auth66=1423255498_13cf655ea315d2e24fcd392571319f47&ext=.pdf


Abstract: "This paper investigates the world-wide economic cost of rapid sea-level rise of the kind that could be caused by accelerated ice flow from the West Antarctic and/or the Greenland ice sheets. Such an event would have direct impacts on economic activities located near the coastline and indirect impacts further inland. Using data from the DIVA model on sea floods, river floods, land loss, salinisation and forced migration, we analyse the effects of these damages in a computable general equilibrium model for 25 world regions. We consider three sea-level rise scenarios that correspond to 0.47, 1.12 and 1.75 m by the 2080s. By incorporating a wider range of damage categories, implemented in an economy-wide framework and including very rapid sea-level rise, the study offers a new contribution to climate change impact studies. We find that the loss of GDP worldwide is 0.5 % in the highest sea-level rise scenario, with a loss of welfare (equivalent variation) of almost 2 % world-wide. Within these aggregates, there are large regional disparities, with the Central Europe North region and parts of South-East Asia and South Asia being especially prone to high costs (welfare losses in the range of 4–12 %). The analysis assumes that there is not public adaptation, which would substantially lower the costs. In this way, the analysis demonstrates what is at risk, and could be used to justify adaptation expenses."

Extract referring to Figure 1: "In the High scenario, Rest of South-East Asia shows a huge 12.91% loss, followed by China (5.63%) and South Asia (5.20 %).  The less affected regions are South Africa, Mexico and Russia, who experience equivalent variation losses in a range between 0.1 and 0.3%."
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jai mitchell

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #285 on: February 06, 2015, 10:59:15 PM »
1.  The word "rice" is not found within the entire document.  Nor are the compounding effects of higher wave-height and storm surge functions as a result of higher sea surface temperatures in the future warming scenarios.   These kinds of compounding secondary damage functions are totally absent from the paper (see below)

2.  Instead of attempting to model actual secondary effects of SLR, say, a loss of 27% of south east Asian rice cultivation in 20 years (high scenario).  With the resulting regional political instability caused by famine and mass migrations.  They look to a "damage to capital" indicating, I suppose the reduction in capital stock for the increase of GDP. 

3.  The damage to capital is modeled under 3 tenuous assumption regimes and their effect assume functional markets and the maintenance of regional infrastructure, and the absence of regional conflict.

I find this to be a wholly inadequate methodology, though, to give them some credit, they appear to be using the models with some effective results (for measuring direct impacts).
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #286 on: February 18, 2015, 06:57:18 PM »
here are a couple pieces on slr:

An oldie-but-goodie lecture by Jeremy Jackson that recently came to my attention again:



Something recent from the main stream-ish press, Rolling Stone:

http://www.rollingstone.com/politics/news/the-pentagon-climate-change-how-climate-deniers-put-national-security-at-risk-20150212
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #287 on: February 18, 2015, 09:25:52 PM »
I have issues with the Pycroft paper.

1) It uses Tol's methodology from 2006 for damage estimates. Better estimates are available today.  To take just one feature, following Tol, damages due to forced migration are taken to be three times GDP per capita of the affected population. This is laughable. Consider that after 1971,displaced persons camps in India which housed refugees from Bangladesh were still in operation after a decade, accruing huge costs to both India and Bangladesh.

2)Pycroft assumes  capital depreciation (the quantity D in the only equation in the paper) are unaffected. This is dubious, see for example, Moore(2015)  doi:10.1038/NCLIMATE2481 arguing that both capital depreciation and total factor productivity growth are adversely affected, increasing cumulative cost.

3)There are other arguments in Moore(2015) indicating higher damage estimates than the conventional DICE model, I do urge everyone to read the paper, especially the supplementary material.

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #288 on: February 18, 2015, 10:52:03 PM »

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #289 on: February 19, 2015, 08:05:31 PM »

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #290 on: February 19, 2015, 08:06:33 PM »

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #291 on: February 24, 2015, 08:35:25 PM »

Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #292 on: February 24, 2015, 09:25:45 PM »
US sea level north of New York City 'jumped by 128mm'
http://www.bbc.com/news/science-environment-31604953

Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #293 on: February 25, 2015, 03:01:15 PM »
US sea level north of New York City 'jumped by 128mm'
http://www.bbc.com/news/science-environment-31604953
That's just over 5 inches!, for the metrically-challenged. ::)  And it happened within two years.  :o
« Last Edit: February 25, 2015, 03:06:44 PM by Sigmetnow »
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Laurent

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #294 on: February 25, 2015, 03:33:23 PM »
Well that's obvious that the trend is not good at all...wake up people... (either to late or not something has to be done...come back to 300 ppm CO2eq... )

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #295 on: February 25, 2015, 03:34:51 PM »
As I understand it, the only thing that could change sea level that fast in one location is a shift in ocean currents. Does anyone have a good bead on what has been happening with the AMOC recently?
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Re: Sea Level Rise and Social Cost of Carbon
« Reply #296 on: February 25, 2015, 04:16:00 PM »

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #297 on: February 25, 2015, 06:02:42 PM »
US sea level north of New York City 'jumped by 128mm'
http://www.bbc.com/news/science-environment-31604953
That's just over 5 inches!, for the metrically-challenged. ::)  And it happened within two years.  :o
:o indeed!

Things seem to be rapidly escalating in rate of change. The split weather pattern we are experiencing here in the US is really concerning. Out here in California, there's no rain in the forecast. Still. Maybe Boston can send us some snow cones? When you start putting all the pieces together in these threads into one picture, it's hard to not hide under the bed!

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #298 on: February 25, 2015, 06:10:50 PM »
As I understand it, the only thing that could change sea level that fast in one location is a shift in ocean currents. Does anyone have a good bead on what has been happening with the AMOC recently?

You go, Wili! From Sleepy's link:
Quote
Co-author Jianjun Yin, UA assistant professor of geosciences, said, "We are the first to establish the extreme sea level rise event and its connection with ocean circulation."

Sigmetnow

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Re: Sea Level Rise and Social Cost of Carbon
« Reply #299 on: February 25, 2015, 08:19:56 PM »
Given the anomalous warmth of the seas off the northeast U.S. coast, a change in the Gulf Stream flow would certainly fit.
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