Guest article by Sally Brown, University of Southampton
Let me get this off my chest – I sometimes get frustrated at climate scientists as they love to talk about uncertainties! To be sure, their work thrives on it. I’m someone who researches the projected impacts and adaptation to sea-level rise and gets passed ‘uncertain’ climate data projections to add to other ‘uncertain’ data projections in my impact modellers work bag. But climate scientists do a good job. Without exploring uncertainties, science loses robustness, but uncertainties in combination can become unbounded and unhelpful to end users.
Let’s take an adaptation to sea-level rise as an example: With increasing scientific knowledge, acceptance and mechanisms that would allow adaptation to potentially occur, one would think that adaptation would be straight forward to implement. Not so. Instead of hard and fast numbers, policy makers are faced with wide ranges of uncertainties from different sources, making decision making challenging. So what uncertainties are there in the drivers of change, and can understanding these uncertainties enable better decisions for adaptation?
Prior to considering adaptation in global or regional models, or implementation at local level, drivers of change and their impacts (and thus uncertainties) require analysis – here are a few examples.
Between 1901 and 2010, global sea levels rose by 0.19±0.02m, albeit at varying rates and spatial distribution (Church et al. 2013) – these past values (including their uncertainty) are potentially much smaller than those associated with future projections. Whether this precise trend will continue is uncertain, but scientists are confident that sea-levels will continue to rise and accelerate due to global warming
My background is partly in geology, so I often recall the well-known quote referring to Earth’s history ‘the present is the key to the past’ (Hutton / Lyell). In sea-level science however it might be the other way around: ‘the past is the key to the present’. Kopp et al. (2016) recently found that from the late in the 20th century sea-levels have risen faster than in any of the previous 27 centuries. Further back in time again, sea-levels have risen at much faster rates during the end of the last ice age. Past rates of change, if used wisely, provide potential constraints of future projections, together with the many semi-empirical approaches to project future sea-level rise (e.g. Rahmstorf, 2007) which are typically greater in magnitude than those from process based models. Hybrid approaches have also been undertaken (e.g. Moore et al. 2013, Mengel et al. 2016). Scientific knowledge input into process based models has much improved, reducing uncertainty of known science for some components of sea-level rise (e.g. steric changes), but when considering other components (e.g. ice melt from ice sheets, terrestrial water contribution) science is still emerging, and uncertainties remain high. Still, our understanding has a wide range of projections, particularly for high emissions scenarios as Jevrejeva et al. (2014) illustrates. Given emerging knowledge and changes in uncertainty, this leads me to the question, what are we adapting to, and when could this occur? Is it about 1m of rise by 2100? Or 1.4m?
Planning for sea-level rise does not just depend on how much waters rise, but also how land levels change. Glacial Isostatic Adjustment (GIA) occurs in response to retreating ice from the last glacial period, where around most of the world, land is subsiding at a fraction of a millimetre per year, compounding the problem of sea-level rise. In northern latitudes the reverse is happening – land is rising after being liberated from the mass of the ice sheets, again normally by less than 1mm/yr, but in places over 5mm/yr (Peltier et al. 2015). Land levels also change due to tectonics, natural compaction of soft soils as well as human influences.
I recently researched causes of subsidence in Bangladesh (Brown and Nicholls 2015) and struggled with the uncertainties, data errors, and in some cases, poor science when recording rates of subsidence. In Bangladesh, subsidence can be much higher than GIA – with 10mm/yr being a local norm, rather than an extreme rate. A major cause can be groundwater withdrawal resulting from the needs of a growing population. These factors can be spatially highly variable, even within a short distance. Additionally, rates of subsidence also change with time (Kaneko and Toyota, 2011). Subsidence is common in deltas and projecting relative change (particularly when causes vary or are unknown) remains uncertain.
Relative land level change is extremely important in low-lying delta regions.
When I undertake an impacts assessment, land elevation and population exposed to hazards becomes extremely important. Global elevation levels, such as from the Shuttle Radar Topographic Mission (Rabus, 2003) is an extremely helpful dataset. Elevation data has a resolution of tens of metres, and subject to errors which can mean important coastal features are omitted, such as entire small islands. Similar distribution issues occur with respect to population.
Projecting how population changes – per country and it’s spatial distribution – is an additional uncertainty, particularly as coastal population grows differently to those areas further inland (Neumann et al. 2015). Of course, there are changes in economic growth too – who could have imagined rapid growth seen in Asian cities over the last few decades? Whilst projections of socio-economic change can be made, these still have a wide range of implications in impact assessments and choices over adaptation.
All these factors and many more combine uncertainties resulting in different scenarios of change – each potentially likely to occur. Fed into impacts assessment, further uncertainties arise. But even faced with this, modelling and choosing the type of adaptation itself is uncertain, whether this involves ‘hard’ barriers, such as sea-walls, ‘soft’ protection including sand nourishment, accommodating sea-level rise by raising buildings, or even deliberately retreating from the sea. Furthermore, sea-levels won’t stop rising in 2100 – even under climate mitigation, so adaptation has to be a long-term investment. Nevertheless, engineering reasoning may question the scientific and financial values of adapting newly built infrastructure to sea-level rise over a 100-year timeframe, if the design life is far less than this. Adaptation therefore has to take a flexible modular approach, allowing for uncertainty, rates of change and investment choice. Long-term investment in infrastructure could become a cat-and-mouse game, where monitoring becomes increasingly important leading to reactive adaptation to avoid an unacceptable situation of escalating risk.
With this, adaptation remains a choice or an opportunity which may not be available to all. Better decision making is enabled by making policy makers aware of the wider range of uncertainties, possibilities and options available. This includes how best to apply for and utilise climate change adaptation funds for developing nations, so that intelligent choices can be made to encapsulate uncertainty.
Adaptation is a manner of choice, mixed with local needs
In recent years there has been a push towards climate services to provide forecasts or projections of long-term change to enable adaptation. I think this is a welcome development as it indicates that climate change is becoming more accepted within the international community leading to action. It’s important to remember that climate change is not the only issue and multiple uncertainties exist in other fields that can sometimes be greater than the climate signal alone, leading to deep uncertainty.
So, to answer my question ‘what uncertainties are there in the drivers of change, and can understanding these uncertainties enable better decisions for adaptation?’, perhaps it as apt to quote Albert Einstein: ‘The more I learn, the more I realise how much I don’t know’. The quest to reduce uncertainty (and my frustration!) continues.
Sally Brown is a Senior Research Fellow at the University of Southampton, UK and a member of the Tyndall Centre for Climate Change Research.
References
Anuar, N. (2015). 20 skylines of the world: then vs now. http://www.hongkiat.com/blog/world-skylines-then-now/ Accessed August 2015.
Brown, S. and Nicholls, R.J. (2015). Subsidence and human influences in mega deltas: The case of the Ganges–Brahmaputra–Meghna. Science of The Total Environment, 527-528, 362–374. DOI: 10.1016/j.scitotenv.2015.04.124
Church, J.A., Clark, P.U., Cazenave, A., Gregory, J.M., Jevrejeva, S., Levermann, A., Merrifield, M.A., Milne, G.A., Nerem, R.S., Nunn, P.D., Payne, A.J., Pfeffer, W.T. Stammer, D. and Unnikrishnan, A.S. (2013). Sea Level Change. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (Stocker, T.F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S.K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P.M. (eds.)). Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
Jevrejeva, S., Grinsted, A. and Moore, J.C. (2014). Upper limit for sea level projections by 2100. Environmental Research Letters. 9, 104008. DOI:10.1088/1748-9326/9/10/104008
Kaneko, S., and Toyota, T. (2011). Long-term urbanization and land subsidence in Asian megacities: An indicators system approach. In: groundwater and subsurface environments: Human impacts in Asian coastal cities (Taniguchi, M. (ed.)). Springer, Japan.
Kopp, R.E., Kemp, A.C., Bittermann, K., Donnelly, J.P., Gehrels, W.R., Hay, C.C., Mitrovica, J.X., Morrow, R.D., Rahmstorf, S. and Horton, B.P. (2016). Temperature-driven global sea level variability in the Common Era. Proceedings of the National Academy of Sciences of the United States of America. doi: 10.1073/pnas.1517056113.
Mengel, M., Levermann, A., Frieler, K., Robinison, A., Marzeion, B. and Winkelmann, R. (2016). Future sea level rise constrained by observations and long-term commitment. Proceedings of the National Academy of Sciences of the United States of America.
Moore, J.C., Grinsted, A., Zwinger, T. and Jevrejeva, S. (2013). Semiempirical and process-based global sea level projections. Reviews of Geophysics. 51 (3), 484–522. DOI: 10.1002/rog.20015
Neumann, B., Vafeidis, A.T., Zimmermann, J. and Nicholls, R.J. (2015). Future coastal population growth and exposure to sea-level rise and coastal flooding – A global assessment. PLoS ONE 10 (3), e0118571. DOI: 10.1371/journal.pone.0118571
O’Neill, B.C., Kriegler, E, Riahi, K., Ebi, K.L., Hallegatte, S. Carter, T.R., Mathur, R. and van Vuuren, D.P. (2014). A new scenario framework for climate change research: the concept of shared socioeconomic pathways. Climatic Change, 122 (3), 387-400. DOI: 10.1007/s10584-013-0905-2
Peltier, W.R., Argus, D.F. and Drummund, R. (2015). Space geodesy constrains ice age terminal deglaciation: The global ICE-6G_C (VM5a) model. Journal of Geophysical Research – Solid Earth, 120 (1), 450-487. DOI: 10.1002/2014JB011176
Rabus, B., Eineder, M., Roth, A. and Bamler, R. (2003). The shuttle radar topography mission—a new class of digital elevation models acquired by spaceborne radar. ISPRS Journal of Photogrammetry and Remote Sensing, 57 (4), 241-262. DOI: 10.1016/S0924-2716(02)00124-7
Rahmstorf, S. (2007). A semi-empirical approach to projecting future sea-level rise. Science, 215 (5810), 368-370. DOI: 10.1126/science.1135456
United Nations (2014). Adaptation Fund. http://unfccc.int/cooperation_and_support/financial_mechanism/adaptation_fund/items/3659.php Accessed August 2015.
Torsten Käll @85
You maybe interested in a chart from NOAA. It shows pictorially many sites around the world and how sea levels are trending both up and down.
http://tidesandcurrents.noaa.gov/sltrends/sltrends.html
Take a look around the site and see for yourself if you can find any indications of ‘scary’, ‘unprecedented’ or ‘catastrophic’ rise. I’d be interested to know.
Richard Pauli @96 says: “Sea level rise is not linear, it is exponential.”
Please provide some evidence. I don’t observe it.
Jim Eager @97 says: “the slope of the curve for sea level rise over the last century was concave”
Please provide some evidence. I don’t observe it.
JE @98,
It’s even worse than that. China also wants the Siachen glacier region. And it has nukes, too. Recently, the three powers sat down and signed an agreement to administer the region jointly. Guess how long that will last once the crisis hits?
On SLR–Church & White seems to me to be the most frequently mentioned paper on the topic in recent years. Here is the link:
http://link.springer.com/article/10.1007%2Fs10712-011-9119-1#/page-1
Their ‘bottom line’ is graphed at Figure 7, and does indeed show a slightly concave profile suggestive of overall acceleration–though it is true that there is a lot of variability, and both accelerations and decelerations can be found in the record.
Since then, of course, we’ve seen acceleration, as visible in the sat data from the University of Colorado:
http://sealevel.colorado.edu
But it is true that that is still a short period of time, so it is not yet clear that SLR has definitely ‘increased’ (in the sense of a change in the trend).
On the other hand, it is certainly *much* less likely that it has ‘decreased.’ And as I said previously, consideration of physical processes gives reasons to expect acceleration over time. It’s very possible that that is what we are seeing now.
Is it ‘scary’? For me, no–but it is concerning. Particularly so when planning authorities spend, or plan to spend, large chunks of cash on long-term infrastructure without considering its effects. For a couple of examples, consider the New Orleans levees, which the Corps of Engineers rebuilt without reference to SLR. Or the Turkey Point nuclear expansion, in which Florida Power & Light toys with the idea of adding two new reactors to their coal/gas/nuclear plant 25 miles outside Miami–even though it is extremely exposed to sea level rise (and potentially hurricane storm surge.)
Victor the troll:
Heh. As our stubborn AGW-denialists can see, their “right” to “speak out” on RC is unabridged under US law. The First Amendment to the US Constitution guarantees they can’t be arrested, fined or imprisoned simply for revealing their incompetence to evaluate climate science. They may be relegated to The Bore Hole for exceeding the limits of the RC moderators’ forbearance, but they can be confident there will be no legal consequences for posting any damn fool nonsense short of libel.
By the same token, the right of all DK-afflicted persons to be told they are incompetent is also unabridged. Just as Titus, Jim Steele or Victor are free to defend long-discredited AGW-denier talking points with false facts and logical fallacies, other commenters are free to challenge them using colorful language. Just as our persistent science-deniers have no legal obligation to recognize genuine competence and are free to reject all attempts to meliorate their own incompetence, their challengers are free to deride them for it. Ain’t free speech grand?
Titus, here you go from Church (2008):
http://www.skepticalscience.com/images/Sea-Level-1.gif
More recent:
https://www3.epa.gov/climatechange/science/indicators/oceans/sea-level.html
Aggregated:
https://www.realclimate.org/index.php/archives/2015/01/a-new-sea-level-curve/
You might want to see an ophthalmologist about your myopia.
‘Titus’ won’t like this answer.
For any new reader coming to the subject, while a knowledge of some statistics will let you confirm this, if you haven’t got that, you’ll have to decide how much trust you place in those who want to help.
I recommend starting here, where Tamino replies to the latest “trust my lying eyeballs I see nothing, nothing” denier blog about sea level change:
https://tamino.wordpress.com/2016/03/20/sea-smoke-and-mirrors/
http://www.eurekalert.org/pub_releases/2016-03/ru-ccg032416.php
Titus #102 “Please provide some evidence. I don’t observe it.”
No.
Victor @99. Thanks for linking an interesting read. It offers a method that could be applied to our current discussion. Quote:
*Here’s my hypothesis.
*Here’s what you’d expect to observe if the hypothesis is true. Here, on the other hand, is what you’d expect to observe if the hypothesis is false.
*Here’s what we actually observed (and here are the steps we took to control the other variables).
*Here’s what we can say (and with what degree of certainty) about the hypothesis in the light of these results.
*Here’s the next study we’d like to do to be even more sure.
And the next list would be very helpful for me to have answers. Quote:
*Here are the results of which we’re aware (published and unpublished) that might undermine our findings.
*Here’s how we have taken their criticisms (or implied criticisms) seriously in evaluating our own results.
Taking this approach could be helpful in answering some of the “uncertainties” that this article refers to.
CSIRO: Watson et al
The graph posted by jimt in a comment at Open Mind is the best I’ve seen.
Barton: China also wants the Siachen glacier region.
Richard: Excellent addition to Jim’s point. I’ll add that the fight is over a death trap. The soldiers are dying, not from bullets, but because glaciers at about 20,000 ft are dangerous places for humans. There is little upside to controlling the area other than to crow about how the lines on a map show an increased area on “your” side.
Now imagine what folks will do when it comes to actually useful land. Coming soon to a planet near you… (However, it’s a remake of a remake of a remake.)
Jim Eager @106. Thanks for the links. I’ll concede that there is a curve, however, we already discussed in previous comments that there was a sea change (pardon pun) in the rate around 100 years ago. We have been discussing the last 100 years and looking at your links they look pretty flat within the bounds of error. In fact the rate looks at bit low. Less than 2mm/yr in all of them.
Richard Pauli @109 says: No
Hmm. Says it all after viewing Jim’s curve…….
It’s been a while since I have checked comments (due to Easter), but it seems as if we are debating exactly the sea-level issue in the articles of ‘how much, how soon’? This is exactly the problem. Whether you are a climate denier of not, the facts from the past century indicates that sea-level risen, and we do not know the exact amount it could rise in the future. We are building cities without sometimes the thought of the long-term consequences of this.
#70 I do not think scientists are exaggerating the sea-level rise threat and did not wish to portray this in any way in the article. Climate scientists’ work is based on scientific knowledge and relationships, which must be respected, but we must take account, as in any area of science, the uncertainties in scientific data.
#36 Loved reading the article about “Native American Tribe Gets Federal Funds to Flee Rising Seas”. I think more instances of this will occur as the social and cultural fabric of the coast is threatened. I listened to a presentation a few years’ ago regarding a coastal town being moved due to port development (I can’t remember exactly where, but it was somewhere cold). Without remember the precise details, the speakers alluded to a few people saying ‘oh, it’s due to sea-level rise’ rather than the real reason. Climate change cannot be the scapegoat for everything.
> Titus … evaluating-scientific-claims-or
> -do-we-have-to-take-the-scientists-word-for-it/
Notice that means YOU do the work of evaluation — you have a good reference librarian near you.
Right now you’re appearing to trust strangers met on the Internet to collect that information for you. See the fail? The chore is for you to look it up, as that article teaches — not taking strangers’ word for what the science says, but reading what’s published. Look at the paper with Scholar. Then look at the subsequent papers that cited the paper.
Or, fail. You can always be a blog commenter without doing any of that work.
Damn: http://gizmodo.com/a-nightmare-is-unfolding-in-the-great-barrier-reef-1767702006
This is addressed to the RC team:
Please delete comments from the likes of “Titus”. He clearly has no idea what he is talking about, and his nonsensical posts cause quality RC contributors to waste a lot of time.
Above at 104, Kevin McKinney mentions the Turkey Point power generating station. At Tamino’s Open Mind, Doc Snow shared a photo link which may be relevant to this thread, since the reactor site seems to be pretty much at sea level, out into the ocean (Pictures can be helpful):
http://www.trbimg.com/img-547f824c/turbine/fl-turkey-point-reactor-20141203
Two nuclear reactors have been in operation at the site for over 40 years, with two more scheduled to be added, starting next year.
Adapting to potential sea-level rise for the existing plants must be challenging enough (think of another Katrina, or Ike, or Sandy stirring up that shallow Florida water). Construction of a couple more nuclear plants at this same site would seem to demand prior resolution of the pesky uncertainties Sally Brown discusses here.
Maybe we have magicians in the world of tech solutions:
Sky hooks? A few miles of that 35 ft wall Mr Trump would build on the Mexican border? Adding a new moon or two, to provide compensatory gravity forces that could suspend the new plants above the water – should we consult the director of Avitar for technical assistance?
Perhaps election of a presidential candidate with closer ties to spiritual forces, to pray away this pesky notion of climate change and sea level rise.
Or, maybe the science of this one is a pretty compelling logical construct rather than an alternate religious belief, and solutions require more than magic thinking or BAU “distract and redirect” techniques?
Here’s a shore guard and carbon sink that repositions itself as the sea rises. It also gets better as it goes. At least in Baja. ‘Blue’ carbon (March 28):
http://www.climatecentral.org/news/tiny-mangroves-hold-vast-stores-carbon-20182
“What this new [Scripps, PNAS] paper says is that even the scrawniest of mangroves are important for carbon sequestration,” Kirwan said.
I second Mike Roddy’s comment, #117.
Ruh oh
http://www.nature.com/nature/journal/v531/n7596/full/nature17145.html
https://www.washingtonpost.com/news/energy-environment/wp/2016/03/30/antarctic-loss-could-double-expected-sea-level-rise-by-2100-scientists-say/?hpid=hp_no-name_no-name%3Apage%2Fbreaking-news-bar
Ruh oh:
https://www.washingtonpost.com/news/energy-environment/wp/2016/03/30/antarctic-loss-could-double-expected-sea-level-rise-by-2100-scientists-say/?hpid=hp_no-name_no-name%3Apage%2Fbreaking-news-bar
I didn’t see this new paper, Contribution of Antarctica to Past and Future Sea-Level Rise, mentioned in this thread, yet. Since the models applied there may contribute to a refined theoretical understanding for ice melting processes on Antarctica, it seems appropriate in a topic on sea-level rise uncertainty.
There are a number of popular articles about this new report, as well. For example, this one at the NY Times: Climate Model Predicts West Antarctic Ice Sheet Could Melt Rapidly.
Just added as a footnote. I haven’t gained access to the primary article yet (will need to write the authors), and I’m not so willing to rely on “interpretations” in the news, so I can’t really offer any thoughts about it.
I’d been poking at this over at Stoat’s but wonder — could we get a followup to this thread from 2008?
https://www.realclimate.org/index.php/archives/2008/04/moulins-calving-fronts-and-greenland-outlet-glacier-acceleration
especially viewed in the light of, e.g., this:
http://dx.doi.org/10.1038/nclimate2161
http://www.climatecentral.org/news/new-greenland-ice-melt-fuels-sea-level-rise-concerns-17187
I assume every glacier is different, so there’s no single answer whether meltwater is successfully penetrating through cracks to the base and staying melted, and whether stresses in the ice are opening cracks further, and which glaciers have beds sloping downhill going inland
The final paragraphs from that Climatecentral page:
DeConto and Pollard on Antarctic contributions to sea level rise
doi:10.1038/nature17145
Sally Brown @114 says: “seems as if we are debating exactly the sea-level issue in the articles of ‘how much, how soon’? This is exactly the problem”
Thanks for the article Sally, which does a good job summarizing the many challenges of planners.
I started here by commenting that the alarmism from media, activists, politicians and the like was making the job difficult to at times impossible. Some of the comments here have demonstrated this very well.
Reading Mike Roddy @117 looks like I have outstayed my welcome:(
Thanks again for creating a good read and discussion….
More grist to the mill, just flashed up on the Beeb:
” ‘Drastic’ Antarctic melt could double global sea-level rise”
Link is here:
http://www.bbc.co.uk/news/science-environment-35926694
I suspect my colleagues working down in Antarctica are not that surprised, nor those working on the glacio-isostatic WAI models.
Hank: Notice that means YOU do the work of evaluation — you have a good reference librarian near you. Right now you’re appearing to trust strangers met on the Internet to collect that information for you. See the fail?
Richard: I don’t. Extrapolating your contention hints that no student should ever listen to a teacher. Far better technique is to analyze prospective analyzers and choose who to trust. Given that Titus, and perhaps 99% of other folks simply CAN’T do what you suggest, (as if he could unravel an equation, let alone fathom the implications), your suggestion is ludicrous at best. See the fail?
To Titus et al: my suggestion is to pick your intellectual leaders without bias. Check their publishing records, check out what others say about them, check their academic credentials. A meteorologist from Podunk U should be at the bottom of your list of folks to follow. Remember, you CAN’T do the work, so your primary task is to suppress every single impulse and preconception and desire you have. Make your motto, “I was wrong before, ergo I currently WIN!”
Note that my suggestion to rate scientists according to their classification (alarmist, mainstreamer, lukewarmer, denialist) and comparing their relative accuracy would tremendously help Tutuses (and everybody else) should they want to find the truth. Your suggestion is just plain bunk. (Though useful for intellectuals who also have training in math and science and also consider the massive amounts of time required “fun”.) The incredible amount of human-years required to edumacate the public via your suggestion is both mind-numbing and impossible. When one CAN’T do the work (or when you don’t have the time/inclination), ad hominem is NOT an error, but by far the best technique to use. Just be sure to do ad hominem correctly, which includes placing a mental asterisk labeling the contention as a hypotheses as opposed to a theory or fact.
Of course, since the result of the above will inevitably come full-circle, this begs Titus’ question: do-we-have-to-take-the-scientists-word-for-it?
Yes, with error bars suggested by analyses such as I suggested. That such analyses don’t exist (AFAIK) is a crime against humanity and the planet.
Or should we be planning for a 2 meter rise by the end of the century? http://www.nature.com/nature/journal/v531/n7596/full/nature17145.html
#128–That’s the same paper mentioned by Jon K. @ 123 and also by sidd @ 126. The best news, perhaps, is that if you follow the Beeb link, it will land you in the complete paper via automatic follow-on from the Nature abstract page.
“Polar temperatures over the last several million years have, at times, been slightly warmer than today, yet global mean sea level has been 6–9 metres higher as recently as the Last Interglacial (130,000 to 115,000 years ago) and possibly higher during the Pliocene epoch (about three million years ago). In both cases the Antarctic ice sheet has been implicated as the primary contributor, hinting at its future vulnerability.”
“Antarctica has the potential to contribute more than a metre of sea-level rise by 2100 and more than 15 metres by 2500, if emissions continue unabated. In this case atmospheric warming will soon become the dominant driver of ice loss, but prolonged ocean warming will delay its recovery for thousands of years.”
> with error bars suggested by analyses such as I suggested.
Please show your work. Just a single example on a single analysis, calculating the error bars for just one scientist according to _your_ classification of that person (alarmist, mainstreamer, lukewarmer, denialist).
You don’t have a scale, you don’t have a method, and you’re accusing people of crimes against humanity because they don’t do what you say.
This is disappointing. Good luck with it, but please don’t start dragging people off to your Gulag just yet. You could be wrong about this.
#121 that’s exactly my point…another possible scenario of SLR…a bit more uncertainty!
#118 Nuclear reactors….that’s another topic. As sadly seen in the Japanese tsunami, one can never be sure how high is safe enough (even though the wave of destruction there was not to do with SLR).
I wrote a paper on this a few years’ back: Implications of sea-level rise and extreme events around Europe: a review of coastal energy infrastructure doi:10.1007/s10584-013-0996-9
At the time there were still new nuclear power stations being built in Europe, but after the tsunami some countries rethought about locating nuclear power stations on the coast. In the paper, I wrote that due to the tsunami, ‘Germany decided to phase out nuclear power by 2022’. I am not sure what is German policy now. With nuclear power plants though, it’s not just about SLR, but for inland plants, the availability of cooling water from rivers. In the heat wave of 2003, power stations in France had problems due to river levels / temperatures. This meant that nuclear power station could be more likely to be located on the coast in the future.
One of the greatest concern for coastal infrastructure is the growing need for energy is Asia. The number of plants is China has significantly increased in recent years, and 21 are under construction at the moment. See: http://world-nuclear.org/information-library/facts-and-figures/reactor-database.aspx
Long-term changes may have less uncertainty (relative to the total change) than short term changes. The largest uncertainties are about near-term rates of sea-level rise (including regional issues), and about what emissions scenario the global community chooses – those decisions will control the long-term impacts. Although on-the-ground adaptations may necessarily focus on the short term scales of economic cost/benefit, it would be best if they were cognizant of the more certain long-term outcomes. This awareness is important because it will help to avoid short-term maladaptations that may inadvertently increase long-term risks (for example by encouraging development of coastal zones that must eventually be abandoned). The long-term perspective is essential for designing policies that produce major investments in tech development, and provides motivation for aggressive CO2 mitigation. http://www.nature.com/nclimate/journal/v6/n4/full/nclimate2923.html
re:131
What I’m interested more, regarding this particular paper, is the addition of ideas to help provide more complete quantitative modeling… and much, much less about the specific predictions they make in the paper itself. It’s not so much the conclusions, I guess, but more about how to think about the world around us that is important. And this paper may be helpful, here. Too bad I don’t have a full copy to read, right now. I’d enjoy it. (My fault… I still need to ask for a copy.) I care more about how improved models sharpen our blurry “vision” and allow us to see still further and deeper ahead. To the degree this article helps there, that’s far more important than any specific value they calculate today or next week.
For those who don’t entirely understand this point I’m making (many here will, I suspect), the following may help:
Imagine predicting the period of a pendulum... In the simplifying theoretical case, where x = sin(x) is a useful approximation within the precision and accuracy limits of the various experimental measurements (length, time, mass) of the swing angle, then quantitative models based upon theory predicts that the period will be 2*pi*sqrt(L/g), where L is the length of the pendulum from the pivot point to the center of mass of the bob and where the mass of the pendulum "string" can be usefully ignored. (Well, also ignoring the effects of air.)
Now build thousands of variations of these to test the quantitative derivations from the above model and find that so long as the length L is within reasonable limits of construction (where 'g' remains the same constant throughout its length) and so long as the angle is sufficiently small, the quantitative model holds up well (within known experimental error.) Even as new and better timing instrumentation is created over time, let's say it still seems to hold. Nice.
But now build a new kind of pendulum, where some significant portion of the mass resides in the pendulum arm itself. A stick with a sliding weight on it, for example. What happens? The first step in the experimental design is to involve theorists, who may analyze this situation by applying more existing theory to create a better model. A new important concept, the "center of oscillation," now occurs to take into account the moment of inertia for the entire plumb bob and arm structure (and assumed frictionless pivot point.) This replaces the older "center of mass" concept used earlier for length L. Now go out and build thousands more of these and test the new quantitative derivations to circumstances (test the new model.)
At first, when instrumentation (stop watches, for example) aren't yet quite so accurate, the newly applied model holds well and is supported by the experimental results. But, as better timing arrives (removing the human element and also improving inherent precision and cross-instrument repeatability, for example), then let's say we now find that the improved model applied to experimental results no longer holds so well. The variations are too large to be fully explained by the new model. And at first, no one knows why as there is substantial unexplained error which cannot be entirely assigned to known experimental error.
But someone considering the problem has a new thought. What about that pivot point? A lot of effort was applied in every case to reduce friction and in any case analysis of the experimental results took that into account. But the thought arises about the possibility of the diameter of the hole in the pendulum arm and the diameter of the pin upon which it rocks as the pendulum swings are different (the pin diameter is smaller than the hole in the arm.) If the hole in the arm isn't exactly the size of the pin (and it may not be, because this was one way by which the friction was reduced) and if the various experiments didn't previously control for these two related factors, then this could be one possible uncontrolled factor allowing the results to vary more widely than the model and experimental results would otherwise permit. So, in examining this hypothesis, it is indeed found that there was uncontrolled variation here.
The theorists are consulted once again, now with this newly arrived idea to contend with, and they develop a further improved quantitative model upon which to make predictions into specific experimental design circumstances. Applying this still better model to prior experimental designs (where possible) finds that, indeed, the variation now comes back within experimental error again!
This is part of a healthy process by which science knowledge advances. New instrumentation, better instrumentation, etc., can provide an improved "view" into experimental results. With this new "sight," new unexplained anomalies can become "visible" where they weren't, beforehand. These may lead in many directions: a refinement of some earlier concept, the discovery of some new force or concept, etc.
The thrust of the above story is simple. Better quantitative models let you see more clearly and to also see, and then identify and better model, additional effects. These effects also may at first appear “2nd order” or lower, but will be the dominant effect soon enough. So it is very important to develop the sight to see them and then to better model them, as early as possible.
That’s why I think this article may be important. Not because of a specific prediction about “twice as much.” But because, if their work helps improve our quantitative modeling then we see much more clearly and better. And that added sight’s value accumulates over time and is worth more than some isolated, early prediction. I like to see papers that look like this one. And I hope one of the authors will do me the boon of sending me a copy, shortly. I’d like to see how they think about things!
Hank: You don’t have a scale, you don’t have a method, and you’re accusing people of crimes against humanity because they don’t do what you say.
Richard: I didn’t accuse anybody of anything. I said the lack of data was a crime. How you warped that into accusations against individuals and the advocating of gulags to place them in, even virtual, is beyond me. I stand by my words solidly. Remember, my call was for some random grad student to do a study and gave suggestions as to one possibility how it could be organized. It ain’t my work, it ain’t my methods, and it ain’t my scale. Your insistence that I restrict s)he who chooses this topic is just plain wrong. My suggestion was productive, clearly reasonable, and directed towards some unknown student who might be looking for a topic to dive into. Perhaps somebody will choose to do the work. If not, yes, it is a crying shame. Feynman said it best, “The real problem in speech is not precise language. The problem is clear language. The desire is to have the idea clearly communicated to the other person. It is only necessary to be precise when there is some doubt as to the meaning of a phrase, and then the precision should be put in the place where the doubt exists. It is really quite impossible to say anything with absolute precision, unless that thing is so abstracted from the real world as to not represent any real thing.” Since you seem to have doubts, I’ll clarify: I’m talking about the effect of a lacking, not intent behind an action.
That I found your suggestion to be ludicrous isn’t reason to leap off the logic trail completely, dude. Perhaps you would have done better by explaining how Titus could actually do what you told him to do? I still maintain that you essentially admonished him for not sprouting wings and flying to Venus.
Since the rate of the sea level raising is around 1 inch a year in sort of a “bursts” – the long-term will definitely be the one who poses less uncertainties, unlike the short-term. While scientists try to eliminate uncertainties methodically – removing all of them is almost next to impossible.
Adaptation: Floating Cities, moored to the sea bed. Rather than retreat, just lengthen the anchor cable as sea level increases. On-the-sea adaptation avoids the need for on-the-ground adaptations.
Hard-headed civil engineers might have objections: Power? Water? Sewage disposal? Transportation?
Meteorologists would wonder how they would fare in a major storm.
But these are trivial concerns compared to continually building/rebuilding new cities farther and farther inland.
Mal Adapted asks “Jim, just how did you “find” that natural climate variability is more important than anthropogenic forcing?
First realize that the consensus that CO2 has driven recent climate change is based on the inability of climate models to detect natural variability associated with recent changes. But that is an argument based on a fallacy. Absence of evidence is not evidence of absence! The argument rests on the belief that climate models accurately represent natural variability. But that is contradicted by model results such as presented in Gillett et al (2008). The models failed to simulate the natural Arctic warming spike in the 1930s and 40s, with or without greenhouse gases. In fact when CO2 was added the simulated temperatures were even colder. I suspect many modelers become too infatuated with their own creation, even when contradicted by observation.
Second consider the evidence for natural variability.
1. Regards rates of sea level rise the IPCC graph ( https://goo.gl/C9NoQR ) shows multidecadal rates of change. Most tide gauges show rising trends since the Little Ice Age suggesting natural causes have dominated.
2. There is debate about Antarctica’s contribution to sea level rise as evidenced by Zwally 2015.
3. Antarctic ice loss due to basal melting has been noted before any significant greenhouse effect. As RC’s Eric Steig commented, “I think the evidence that the current retreat of Antarctic glaciers is owing to anthropogenic global warming is weak. The literature is mixed on this, about 50% of experts agree with me on this.”
4. Sea level dropped during 2010, and GRACE results suggest it was due to heavy precipitation falling in Australia. Since then sea level has continued to increase, but that event illustrates how changes in rates retention of water on the land can dramatically affect sea level rise. In Past And Future Contribution Of Global Groundwater Depletion To Sea-Level Rise, Wada 2012 discusses why by 2050 0.87mm/yr of SLR will be due to ground water extraction. In addition my research in the Sierra Nevada led to restoring a watershed because channelized streams were also depleting ground water. Hydroloigst suspect over 99% of the streams have been degraded and channelized. Runoff is now exceeding retention from dams.
5. Like the early warming in the Arctic, my 30 years of research on wildlife and regional climate change also observed a warming spike in northern California. Relative to the 30s, maximum temperatures in most of California are cooler in the most recent decade as illustrate by the graph in Rapacciuolo (2014) http://goo.gl/lauHYm Regional variations suggest dynamics that overpower any CO2 effect
6. In Atmospheric Controls On Northeast Pacific Temperature Variability And Change, 1900–2012, Johnstone 2014 showed the Pacific Decadal Oscillation can explain climate change in the Pacific northeast without invoking greenhouse gases.
7. Kahl 1993 found no warming in the Arctic from 1950 to 1990. Dramatic Arctic warming began after the natural Arctic Oscillation shifted the wind direction and sub-freezing winds blew thick ice out into the Atlantic as reported by Rigor 2002, 2004, and agreed upon by the consensus.
8. Heimback and Wunch show the upper 700 meters of the Arctic Ocean have cooled in the past decade. That suggests warm Arctic air temperatures is largely due to ventilation of the abundant subsurface heat that resides between 100 and 900 meters below the surface.
9. In Greenland Warming Of 1920–1930 And 1995–2005 Chylek 2006 reported that the rate of warming was greater between 1920-1930.
10. Esper 2012 tree ring studies suggest the 1940s was the warmer than recent decades concluding “The record provides evidence for substantial warmth during Roman and Medieval times, larger in extent and longer in duration than 20th century warmth.
11. In Pacific Ocean Heat Content During The Past 10,000 Years Rosenthal 2013 found Pacific water masses that were ~0.65° warmer than in recent decades.
There is a lot of “smart people” providing evidence that much of the changes we are observing could be attributed to natural climate change.
The one thing all the “smart people” will agree on is, when you try to denigrate the arguers instead of debating the arguments you are no longer debating science. Mal Adapted you have offered no science just rhetoric and empty attempts to denigrate my skills. You deride my 30 years of literature and field research on the topics, yet you offer no skills other than a blogger hiding behind a pseudonym bent on attacking skeptics. I suggest you read more of the scientific literature. There is lots of room for debate.
JS @137: First realize that the consensus that CO2 has driven recent climate change is based on the inability of climate models to detect natural variability associated with recent changes. But that is an argument based on a fallacy. Absence of evidence is not evidence of absence!
… etc.
BPL: Do an analysis of variance. When I do it, I find that CO2 accounts for 82% of temperature variance from 1850 to 2015. That means that all other causes together–including other anthropogenic ones–can only account for 18%.
You seem to neglect how _small_ the global warming signal is expected to be compared to natural variation.
The climate scientists were working on this long before a climate warming signal could begin to be detected statistically.
Yes, there’s a lot of natural variation we’re learning how to measure.
What’s the likelihood of being able to detect a trend in a noisy signal?
It depends.
Your broad generalization would include all the climate scientists I’ve read.
Then your list — notably lacking cites and dates for people to check what you claim — is spun toward emphasizing one side of your argument.
Go for both.
P.S.: for more, see, e.g.:
https://www.google.com/search?q=tamino+natural+variation+noise+climate+signal+warming
10. Esper 2012 tree ring studies suggest the 1940s was the warmer than recent decades concluding “The record provides evidence for substantial warmth during Roman and Medieval times, larger in extent and longer in duration than 20th century warmth.
Assuming you are talking about this Esper 2012, it’s in a region… Scandinavia… in the summer.
Try finding a statement in the various studies you cite that shows they have concluded natural variation could have caused both ocean heat content and surface air temperature and sea level to go up at the same time as they are at present. It cannot be as important if it is not a significant contribution to causing them to all be going up at the same time. You are asserting these authors are in agreement with you. I sincerely doubt that many of them, if any at all, actually are in agreement with you.
Jim Steele, #139–“First realize that the consensus that CO2 has driven recent climate change is based on the inability of climate models to detect natural variability associated with recent changes.”
Er, no, it’s not. It’s based upon multiple lines of evidence including (in no particular order) the paleoclimate record, experimental evidence, well-established physical theory, and observational evidence.
As to your instances of natural variability, that list might be impressive if anybody were actually arguing that natural variability doesn’t exist, or isn’t significant.
But as far as I know, the ‘natural variability denier’ is as yet a purely hypothetical creature.
Jim Steele:
Jim, I have offered no science for a couple of reasons:
The first is that while I’ve had training in the natural sciences to the doctoral level, I’m quite willing to acknowledge that I’m not an expert in climate science. It’s not what I do for a living, so it’s not my job to make point-by-point rebuttals of every Gish gallop by drive-by AGW-deniers.
The second reason is that it’s not me you’re arguing with, it’s the people who do make their living as climate specialists. Though I’m not comprehensively literate in the multiple lines of evidence supporting the consensus of climate specialists for AGW, I’m sufficiently meta-literate in the culture and practice of science to recognize genuine expertise when I see it. I spend time at RC trying to fill in the gaps in my knowledge. If I don’t understand an explanation offered by the experts here, I don’t assume it’s because the explanation is wrong. And if I’m a little unclear on the details, when 97 out of 100 working climate specialists say one thing and 3 say something else, the same scientific meta-literacy inclines me to accept the overwhelming consensus, at least absent a more compelling argument than you’ve made.
Despite your insistence otherwise, you evince at best a shallow understanding of basic principles of climate science (hint: while radiative forcing is known to be at least partially controlled by atmospheric CO2, no “natural”, i.e. internal source of variability has been demonstrated that could drive a global temperature trend for half a century), as well as an inability to recognize genuine expertise. These are tell-tale indicators of the Dunning-Kruger effect:
To the climate realists here, you clearly manifest the first three characteristics. So far, you show little sign of the fourth, but in any case it’s not up to me to provide the required training. For that I recommend starting with any of the excellent textbooks by David Archer, Ray-Pierre Humbert and others on the RC Books page. They are written by genuine experts, Jim, and you can learn a great deal from them and their colleagues in the peer community of climate specialists, if you’d only acknowledge your own lack of skill.
Lack of skill by itself is nothing to be ashamed of, and can often be corrected by training. Unfortunately, in your case the very nature of the DK effect makes that unlikely ever to happen. If nothing else, I recognize a lost cause when I see one.
Hello Jim @ 139. I will always agree with comments like “I suggest you read more of the scientific literature. There is lots of room for debate.” Yes there is always room for debate. Then there is the science and the data itself. So I’ll pose a few queries anyone could ponder, debate or check fro themselves.
1) Most tide gauges show rising trends since the Little Ice Age suggesting natural causes have dominated. – Yes, and yet the industrial age and major increases in population and expansion into new territories all began at the end of the little ice age as well. Co-incidence? Humans are a part of the “natural world” too so “suggesting xyz” is a very long bow and a debating point.
2) There is debate about Antarctica’s contribution to sea level rise as evidenced by — every paper about antarctica.
3) Antarctic ice loss due to basal melting has been noted before any significant greenhouse effect. — which is irrelevant to the existence of the GHE or increases due to AGW drivers. Antarctic ice loss since the end of the last great ice age was not due to AGW drivers either.
4) In Past And Future Contribution Of Global Groundwater Depletion To Sea-Level Rise, Wada 2012 discusses why by 2050 0.87mm/yr of SLR will be due to ground water extraction. – if that turns out to be accurate, it is still an example of ACC, ie caused by human activity. It simply adds to the ice melts and temp expansion of the oceans. So?
5) Regional variations suggest dynamics that overpower any CO2 effect – and yet the CO2 effect, plus other GHGe, plus land use changes, plus deforestation, and cement use, and and and clearly suggests dynamic drivers that overpower natural regional variations – by either mitigating them or accelerating them and at times evening them out. AGW/CC is a global issue that has (theoretically or practically?) downstream affects on every region. Global AGW issues are far more important than the regional / man-made causes of the US Dustbowls of the 1930s. imo.
6) What are the drivers of the Pacific Decadal Oscillation? Has it and will it remain historically a constant?
7) That suggests warm Arctic air temperatures is largely due to ventilation of the abundant subsurface heat that resides between 100 and 900 meters below the surface. – and yet you say the top 700 metres have cooled? Given that the air is above the “surface” how did this purported subsurface heat skip past that cool top 700 meters?
8) Why did the ‘natural’ Arctic Oscillation shift the wind direction in the way that it did when it did? How come that didn’t occur 5 decades earlier, or 3 decades later? What are the fundamental drivers of the Arctic Decadal Oscillation? Are they changing or a constant you think?
9) In Greenland Warming Of 1920–1930 And 1995–2005 Chylek 2006 reported that the rate of warming was greater between 1920-1930. – Was it? Is that land surface air temps, sea temps, or what that was “warming” in all those studies? How does that compare with any studies for 1995 to 2015 and uptodate ice loss records and comparisons?
10) Esper 2012 tree ring studies suggest the 1940s was the warmer than recent decades concluding….. – and where exactly were those trees? and “larger in extent and longer in duration than 20th century warmth” – where you are speaking of global warmth or only the specific region where those trees were in the 1940s?
11) In Pacific Ocean Heat Content During The Past 10,000 Years Rosenthal 2013 found Pacific water masses that were ~0.65° warmer than in recent decades. — Indeed yes he did. http://science.sciencemag.org/content/342/6158/617
And here Rosenthal speaks about that: http://rosenthal.marine.rutgers.edu/index.php/holocene-climate-variability-ocean-heat-content-role-in-past-climate-change
eg “These studies provide new insights on the sensitivity and response of meridional ocean circulation to melt water inputs to the North Atlantic high latitudes (e.g., Bamberg et al., 2010; Irvali et al., 2012; Morley et al., 2011) and their potential role in amplifying small radiative variations into large a climate response through dynamic changes in ocean-atmosphere interactions (e.g., Morely et al., 2011; Irvali et al., 2012; Morley et al., 2014). For example, we recently showed that NADW formation may become unstable under slightly warmer climate, such as occurred during the last integlaciation ~125 kyr B.P. (Galaasen et al., 2014).”
and he also speaks about it here: http://dotearth.blogs.nytimes.com/2013/10/31/10000-year-study-finds-oceans-warming-fast-but-from-a-cool-baseline/?_r=0
Just another great reason why it is I appreciate climate scientists so very much, and the wisdom intelligence and skills they bring to the table. Not to mention the sacrifices of their families and friends not getting to see them as much as the average wood duck. :-)
133 Sally Brown: Germany has the problem of a 3 party political system. The so-called “Green” party has way more power than its numbers justify because the winner is whoever the Greens side with. The new party, AfD [Alternative for Germany]
https://www.alternativefuer.de/europawahl/afd-english-versions-downloads/
is upsetting Angela Merkel’s apple cart.
Your http://world-nuclear.org/information-library/facts-and-figures/reactor-database.aspx
is a list of 663 reactors. Why do we need that list?
How can I get to doi:10.1007/s10584-013-0996-9 without going through a paywall?
http://www.world-nuclear.org/information-library/current-and-future-generation/plans-for-new-reactors-worldwide.aspx
says: “Nuclear power capacity worldwide is increasing steadily, with over 60 reactors under construction in 15 countries.”
Have you counted the dead from the various sources of electricity? From not having electricity? Please do a risk analysis like this one:
http://www.phyast.pitt.edu/~blc/book/chapter8.html
“UNDERSTANDING RISK
LOSS OF LIFE EXPECTANCY (LLE) DUE TO VARIOUS RISKS”
Please compare Fukushima to natural background radiation. Natural background varies a lot.
Caithness Windfarm Information Forum at
http://www.caithnesswindfarms.co.uk/accidents.pdf
provides information on the deaths and injuries to humans caused by wind turbines. The most deaths are from coal, at 3 million per year, globally.
Nuclear power is off topic, but, you are talking about particular designs of reactors that were built years ago. The problems you mention have been designed out.
118 Phil Mattheis: Nuclear is off topic.
#138. Great idea. Could also be a large boat….
We’ve had civil engineering students look at the idea of floating cities in the Maldives. They found it would cost millions and would only be cost effective in situations where there aren’t many alternative left.
re: 139.
Re: denigration. Sorry, what you have described in ludicrous in many ways. Why? Because what you described is not science at all. It is cherry picking and regurgitating things you have heard that you want to believe, regardless of taking them out of context. Scientific debate is done via peer-reviewed papers and conferences, the way it has been done for centuries. The scientific method (something taught in grade school) is the very cornerstone of all science. And the idea that somehow you know something that literally thousands upon thousands of peer-reviewed scientists and every major professional climate science organization (including the National Academy of Science) agree upon is beyond ludicrous. And truly arrogant. Your “30 years” is irrelevant. Please list all of your peer-reviewed climate science papers. (crickets chirping)
Trying to defend yourself as a victim of denigration when you have no clue of subject at hand or the way science is conducted…wow. Just wow. Clue for you: Pointing out how fundamentally wrong you are is not “denigration”.