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Comments 15051 to 15100:

15051. Philippe Chantreau at 05:46 AM on 3 April 2018
       Sea level rise predictions are exaggerated
       

       Meanwhile, our knowledge about what is really happening is increasing:

       www.nature.com/articles/s41561-018-0082-z

       From the abstract: "Between 2010 and 2016, 22%, 3% and 10% of surveyed grounding lines in West Antarctica, East Antarctica and at the Antarctic Peninsula retreated at rates faster than 25 m yr−1 (the typical pace since the Last Glacial Maximum) and the continent has lost 1,463 km2 ± 791 km2 of grounded-ice area."

       This is from Nature Geosciences, so unfortunately behind paywall.

15052. michael sweet at 04:14 AM on 3 April 2018
       Sea level rise predictions are exaggerated
       

       Norrism:

       We can discuss the Nerem paper by comparing it to earlier papers, discussing the methods and reliablity of the authors and reviewing the new data they have discovered.  For important papers (like Nerem) other experts will comment on new papers so that the rest of us can get an idea of what is going on.  Sometimes we have to wait for more papers to come out to decide what is correct.  It took about 5 years for scientists to agree that the "pause" was denier bunk.  Curries claims that it was real have been long proven incorrect.

       This contrasts to your approach.  You said that you had read the IPCC and the 2017 US Climate Change reports as your source of information.  Then you said that you think that everything in those reports is bunk and calculated your own value denovo.  Thus your "estimate" had no relation to either of the reports you claimed to cite.  It is only the wild, unsupported idea of an oil investor. 

       It may be allowed for lawyers to make up any old story they want, but it is not allowed in scientific discussions.  You must support your claims by referring to papers that actually support your position.  Merely reading the IPCC report does not make you an expert comparable to those who have devoted decades of their lives studing the issue. 

       Your inability to discern how the Climate Report reached its new expected values demonstrates that you have little comprehension of what you are reading.  How can you calculate a new value when you have no idea how the existing value was determined?  I could find that information on my own.

       You are welcome to give our opinion in some areas, but it has no place discussing facts on a scientific blog.  You must support your claims with something besides "this is what I thought up on my own after reading a few scientific papers".  Some of the posts are on more subective issues and then all can promote their opinion, athough you still should be able to support your claims with some sort of reference.

       When you have little understanding of a subect you are much better off asking for help on some of the issues you do not uderstand.  People  here are happy to help you undersatnd why scientists are worried that sea level might rise 8 feet when you think 8 inches is a better estimate. A group of top experts recently published a paper warning about the possibility of 17 feet of sea level rise by 2100.

       Making your own novel calculations is a waste of everyones time.  I have a Masters in Chemistry, I have followed AGW closely for 20 years and I have decades of scientific experience. I rely on my personal knowledge less than once a year (and only on chemical behaviour).  If challenged I produce references.   In a scientiic discussion you must find papers that support your claims.  If you cannot find papers to support your claims that tells you that the claim is incorrect. 

       Your claim of 8-10 inches is 50% of the lowest estimate of the IPCC which they say is very likely to be exceeded.  The IPCC is well known to be extremely conservative (low) on sea level rise.  Would a judge allow such a wild claim by a novice to be allowed as evidence in court to argue against expert opinion?

15053. gws at 03:27 AM on 3 April 2018
       How could global warming accelerate if CO2 is 'logarithmic'?
       

       Alchemyst @6 and nigelj @5: The Lambert-Beer Law shows an exponential rise of Absorption with increasing concentration. So Alchemyst's statement is incorrect.

       In the atmosphere, though, the law applies only to infinitesimally small slabs because neither temperature nor pressure are constant with height, thus the results have to be integrated over the whole atmospheric column. Individual absorption lines of GHGs that are "saturated" (e.g. all "strong" GHGs such as CO₂), thus absorb less per concentration change, than lines of "weak" GHGs (e.g. CFCs) that are not "saturated". This is discussed in detail in most atmospheric chemistry textbooks.

       The scientific community worked through the math decades ago and found that weak absorbers produce approximate linear increases in radiative forcing in response to their concentration increases, while those for strong absorbers increase logarithmically. These relationships are empirical, aka they apply to our Earth's atmosphere. The numbers for radiative forcing enter the calculation of Global Warming Potentials.

15054. Philippe Chantreau at 02:46 AM on 3 April 2018
       Arctic sea ice has recovered
       

       Bearling, the sea ice extent has not recovered at all. Although your remark about volume does have some validity, anyone attempting to argue that see ice extent has "recovered" is taking you for a ride. See NSIDC for the latest news.

15055. bearling at 02:18 AM on 3 April 2018
       Arctic sea ice has recovered
       

             So, many people think that the ice has recovered because of the extent of the ice without considering about the volume. The point is that we need to look at the volume to measure how much there really is. According to the thick ice graph, it is great concern that thick ice takes a lot more heat to melt and it is disappearing so fast.
             “Although a thin layer of ice doesn’t tell us much about the overall state of ice loss at the Arctic, it does tell us a great deal about Albedo, the property of ice to reflect heat back into space. When the sea ice diminishes, more heat passes into the oceans. That heat melts the thick ice and speeds up the melting of thinner sea ice, which in turns allows more heat to accumulate in the oceans.” My question is that, does the thickness of the ice really matter to how well it can reflect the heat? If it is thicker will it be better to reflect the heat or not so much difference?

15056. NorrisM at 02:17 AM on 3 April 2018
       Sea level rise predictions are exaggerated
       

       michael sweet @ 62

       There is much to reply to in the responses to date but do not interpret my comments that I do not think AGW is something we have to deal with which will require a move from fossil fuels.  What I am trying to determine is how much time we have to deal with the issue.  There are many potential effects of AGW but obviously one of the most critical is sea level rise.  What I am trying to sort out is how much can we expect and, to a certain extent, how much can be mitigated by a reduction in fossil fuel use.

       But I would like to address one philopsophical point about making contributions to this website.  If your position is that all we can do is exchange academic papers, you would slow any discussion on this blog to a snail's pace.  For example, there could be no references of criticism of the Nerem 2018 paper by other persons until other papers had been published which perhaps disagreed with it.  As you know full well, this could take a year given the process of first writing the paper and then having it go through the peer review process and finally having it published.

       The other philosophical problem I have with your approach is that you then limit any discussion or questions on this website to persons with a technical background.  I highly doubt that the sponsors of this website intend to limit discussion to those persons.  

       If you cannot adequately communicate and discuss these issues with the non-technical public then I have no idea how you expect to get the public onside except on faith.  "Trust me, we know better".  This is obviously a rhetorical statement on my part.

       As promised, I have supported most of my statements in my reply with citations from either the IPCC or peer-reviewed papers. 

       Obviously, my point is that there is more uncertainty in many of these positions than I am fully comfortable with in order to fully accept the projections of the IPCC or the US Climate Report based upon the levels of uncertainty acknowledged, especially when the projection is based upon a statement of "Medium Confidence".  On this point, the US Climate Report was much more "up front" about these uncertainty levels than the IPCC.  I actually did not locate the measurements of Confidence Levels in the early chapter of the Fifth Assessment (I found the probability levels relatively easily but not the Confidence level definitions).

       Glenn Tamblyn has provided me with a paper on the reasons for the increase in the upper level of the sea level rise in the US Climate Report and I intend to read it.

       Moderator Response:

       [DB] Off-topic and argumentative snipped.

15057. NorrisM at 01:51 AM on 3 April 2018
       Sea level rise predictions are exaggerated
       

       Glenn Tamblyn @ 65

       Thanks.  I have printed it and will read it today.  

       One issue which I did not get into in my post given its length already is the cause of ocean warming in the Amundsen Sea which is obviously impacting the melting and calving of the WAIS, or at least parts of it.

       My understanding is that there is geothermal activity at the bottom of the Amundsen sea caused by about 200 fissures of some sort of which some 90 have only recently been discovered.

       If this is a major cause of the warming of the ocean then it obviously is relevant, not as to how much sea level rise we be caused by the melting of the WAIS but how much of that melting can be laid at the doorstep of AGW.

       Have there been any academic papers that have discussed the geothermal warming and its effect on the Amundsen Sea? Either positive or negative.  

       Moderator Response:

       [DB] Off-topic and sloganeering snipped.

       No more.  Period.

15058. billev at 00:11 AM on 3 April 2018
       How do we know CO2 is causing warming?
       

       Is there any measured evidence that the heat energy retention by CO2 and methane has had any measureable effect on the  temperatures shown on the official graphs of yearly global air temperature?

15059. CBDunkerson at 21:50 PM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       The 'we only just recently figured it out' defence seems to fail both on the grounds that A: it is false and B: several of the denier groups they fund filed amicus briefs insisting it is all a big fraud with the court on this case... so even if it were true that we only figured global warming out a few years ago, the judge is literally holding proof in his hands that they are still funding misinformation to the contrary.

       On the 'shareholder value' front... there is more to it than that. Lying to your shareholders, even if doing so will make them more money, prevents them from making properly informed decisions. It is illegal regardless of the financial outcome... and again, the admission of the truths of climate science in this case does not match well with some dismissive statements these companies have made just in the last year.

15060. Tminus at 20:11 PM on 2 April 2018
       How could global warming accelerate if CO2 is 'logarithmic'?
       

       Though methane‘s direct contribution to sea level rise is small compared to potentional ice melting on Greenland and Antarctica, the point is that the thermal expansion of the sea caused by methane represents stored heat that lasts much longer than the life cycle of methane in the atmosphere that warmed the water. Such methane is like a blow torch heating rocks for only 5 minutes but the rocks then stay hot then warm for 50 minutes. Methane‘s heating of oceans, therefore, contributes to melting ice plugs around Greenland and Anarctica plus on top by contributing to heating the air. Dismissing methane seems misguided.

15061. Glenn Tamblyn at 19:33 PM on 2 April 2018
       Sea level rise predictions are exaggerated
       

       NorrisM
       
       "The US Climate Report increases the upper level of the very likely range from 98 cm to 130 cm but does not explain its reasons for its difference with the very likely range of the Fifth Assessment."
       
       The updated sea level estimate from the most recent reports, since AR5, is primarily due to some key studies that have identified additional mechanisms, poorly considered up till now, that can see ice shelves and marine glacial fronts break up more rapidly than previously considered due to mechanical failures. This could lead for example to 1 meter of sea level rise, just from Antarctica, by centuries end.
       
       Perhaps the key paper is DeConto & Pollard 2016.

15062. Postkey at 18:28 PM on 2 April 2018
       It's global brightening
       

       I presume that 'you' have seen this?

       http://www.bbc.co.uk/sn/tvradio/programmes/horizon/dimming_trans.shtml
       A BBC documentary about how unintentional increased reflectance due to man made pollution has actually hidden the affects of increased carbon dioxide in the atmosphere.

15063. nigelj at 10:53 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming Digest #13
       

       John Hartz, my comments basically do apply to America, but I think China affects other countries in a similar way, and the trump issue is similar to other authoritarian leaders. 

       I should have been clearer. I got the more global story of the week and the editorial on america confused in my head. 

15064. Bob Loblaw at 10:27 AM on 2 April 2018
       It's global brightening
       

       Dpiepgrass et al:

       The aerosol property of interest is the "single scattering albedo". Overall, any reduction in radiation is referred to as "attenuation". What was travelling in a direct line is no longer travelling along that direct line. It can be absorbed, or it can be scattered (now travelling in a different direction).

       Scattering occurs in all directions, For scattering, some is back-scattered (the vector is at least partially opposite to the original direction of travel) and some is forward-scattered  (the vector is at least partially in the same direction as the original direction of travel).

       Things like soot are strongly absorbing. Things like dust are strongly scattering.

       Atmospheric attentuation is easily measured by instruments pointed at the sun (sun photometers). Figuring out how much is absorbed and how much is scattered is a little trickier, but done routinely by international networks such as AeroNet.

15065. Bob Loblaw at 10:16 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       nigelj:

       Well, that's the conundrum. Their strongest defence agains a lawsuit that claims they failed to preserve shareholder value is to show how their actions preserved shareholder value. But that same defence is pretty much an admission of guilt that they preserved shareholder value at the expense of everyone else, even though they knew the damage it would cause.

       Location[self]= insert[between(rock,hard place)]

15066. John Hartz at 09:16 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming Digest #13
       

       nigelj: Fuch's opines about "three threats that could fundamentally endanger American national security". Your comment seems to address more global issues.

15067. DPiepgrass at 09:14 AM on 2 April 2018
       It's global brightening
       

       Correction: some aerosols do absorb solar radiation (which in fact warms up the atmosphere, and I don't know whether this causes more/less warming at ground level than sunlight hitting the ground. "Global brightening" is not a useful concept w.r.t. climate change; it creates a distinction between sunlight warming the ground and solar-induced infrared/warm air warming the ground, which is not an important distinction.)

15068. DPiepgrass at 09:02 AM on 2 April 2018
       It's global brightening
       

       Thanapat, clouds and aerosols do not absorb solar radiation, they reflect it.

       Cloud behavior is complex, and clouds have both warming and cooling effects: clouds traps heat beneath them, but they also reflect light back to space. The main effect of thick, low clouds is cooling; the main effect of high, thin clouds is warming.

       Here, the important thing about clouds is that scientists have determined (after many years of study) that clouds will not change very much as the climate changes. So their effect on climate change will be small (though clouds will most likely act as an amplifying feedback).

       Fossil fuels cause global warming via CO₂ (and NO₂), but fossil fuels also cause aerosols (via SO₂). If humans stop burning fossil fuels, the aerosols will dissipate immediately, but the CO₂ will not. Unfortunately, this may cause global temperatures to increase slightly after we stop burning fossil fuels.

       Infrared radiation is normal. Almost everything on earth emits infrared. The important thing to understand is that greenhouse gases glow in infrared—they send down infrared light from the sky. Reducing greenhouse gases is like removing a blanket, it lets heat escape to space more easily. To reduce greenhouse gases, we can:

       • Use less energy (within reason)
       • Build clean power plants (solar, wind, and nuclear plants such as MSRs).
       • Regrow forests (trees store carbon)
       • Look at drawdown.org for more ideas.
15069. nigelj at 07:47 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming Digest #13
       

       The largest threat to humanity is indeed climate change, because of the level of damage, the range of different effects, and the millenia level time scales and impacts on multiple generations. In comparison, difficult authoritarian leaders are more temporary aberrations although still very troubling.

       Trump has indeed badly handled climate change along with almost everything else, and is distracting attention from the three real existential level threats. The english language simply doesn't have adequate words to describe the situation.

       Surely we also need to be considering other environmental threats, resource scarcity issues and growing inequality and job insecurity in western nations.

       I'm not sure about the alleged existential level threat of China. While China is a dictatorship and this is not ideal, it is relatively benign, and imho the economic threats can be contained with sensible responses by the world more forcefully pushing fair free trade rules in China, etcetera, but this absolutely shouldn't include punative tariffs like Trump is doing. There have to be smarter and less mutually destructive ways than that. But the world cant do nothing either, because China is simply developing in ways that do pose some threats, well analysed on the economist.com.

       I agree threats to democracy are existential, although the issue is not so much democracy itself as a means of electing governments. It is more the threat posed by democratically elected authoritarian leaders, and the mindset that is doing this.

       Many of the current authoritarian leaders seem to currently share the following attributes. They  denigrate scientists and public servants in government, denigrate minority groups and scapegoat them for no good reason, they spread  unfounded fears of immigration and free trade. Some of these authoritarian leaders promote reckless corporate and personal economic behaviour that is short sighted, and pushes costs onto future generations.

       Unfortunately this combination of factors with many of these authoritarian leaders is by its nature toxic to efforts to deal with climate change, so reinforces this existential threat. So the existential threat against democracy posed by excessive authoritarianism and anti science thinking is a huge problem.

15070. nigelj at 06:52 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       Bob Loblow,  well they might try anything, but if the dissinformation campaigns are shown to be fraudulent, I dont think you can use law breaking as a defence.

15071. michael sweet at 06:50 AM on 2 April 2018
       Sea level rise predictions are exaggerated
       

       Norrismm

       Here is the most up to date sea level graph:

       

       I may have misread the graph and the 90% interval for RCP4.5 may be 5.2 instead of 7 feet.   My argument remains unchanged.  Your estimate of 8-10 inches is in contradiction to your sources.

15072. michael sweet at 06:38 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       Bob Loblaw,

       You propose an interesting defense.  I do not know the answer. It seems to me that they could argue they preserved value for shareholders 10 years ago but current shareholders will be left holding the bag.  Those left holding the bag get to sue.

15073. nigelj at 06:30 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       NorrisM @6

       I would have expected the oil companies to be open with the public about what their own internal science was saying, and so also agree with the IPCC findings. This is hard I know, but the oil companies allegedly knew the risks and so had an established  legal duty to acknowledge them unequivocally. The law doesn't make exceptions for products that have benefits, to my knowledge.

       Instead they hid things from the public and got caught, and funded deniers like the Heartland Institute. You pay a price for this sort of corporate behaviour.

       Damages will be based on the fact that politicians and the public 'may' have made completely different choices regarding climate change if oil companies had made proper disclosure, and with potentially robust and full mitigation. The plaintiffs do not have to prove they 'would' have made different choices, or what level of mitigation they would have used, because such a thing is impossible to prove either way. Tobacco litigation has shown us these same principles in that it only had to show the smoker may have chosen to give up.

       Damages will be quantified on physical damage caused on the basis of how much damage full mitigation would have prevented. Its complicated to work out but the causative link is there. There may also be punative damages. Again the same principles as tobacco litigation are likely to apply.

       What the IPCC said is irrelevant. Again tobacco litigation showed that what counted was what tobacco companies didn't say, regardless of what the surgeon general said.

       If the oil companies had made full disclosure, the entire denialist movement and influence of fossil fuel companies on politicians would all have probably been much weaker. 

       I also reinforce the point that OPOF makes we cannot assume that oil was the only alternative humanity ever had. Without oil, better progress may have been made with natural forms of energy or nuclear or fission power.

15074. Bob Loblaw at 06:07 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       michael:

       "Additional cases are being investigated because they lied to their stockholders about the likely future value of their fossil holdings in the ground. "

       I wonder if the oil companies would have the nerve to defend themselves against such a lawsuit by arguing that their disinformation campaigns were so successful that they actually preserved shareholder value far above what would have been realized if action to reduce climate change had begun in earnest 30 years ago.

15075. Bob Loblaw at 05:57 AM on 2 April 2018
       Sea level rise predictions are exaggerated
       

       NorrisM:

       I will try to separate three aspects of scientific study: observations, interpretations, and conclusions. Most of what I wll be disagreeing with in your comments falls into the interpretation and conclusion categories.

       I am not sure what gives you the idea that I  am interested specifically in a lawyer's perspective - what I have been interested in seeing from you is a scientific argument that supports your position. That you tend to take a lawyerly approach to the discussion has been apparent, but I tend to see that as a bug, not a feature.

       Michael Sweet has already pointed out how your argument seems to pick the low end of most available data. It has been pointed out to you in the past that this is not good risk management.

       You comment on "the bump" from 1920-1950 in figure 3.14 of the Fifth Assessment. The figure shows results from three studies. The bump is particularly high in one of those studies: Jevrejeva et al. The RealClimate post comments on this, saying

       "The only outlier set which shows high early rates of SLR is the Jevrejeva et al. (2008) data – and this uses a bizarre weighting scheme, as we have discussed here at Realclimate.

       The RealClimate post's figure 3 provides both the sea level rise rates from the IPCC figure, and modelled values. The models tend to underestimate sea level rise, but have been improving (since previous assessment reports).

       

       Please also note that in the IPCC report, figure 13.12, that different semi-empirical studies on sea level projections tend to give higher values if using the Jevrejeva data, and that even work by Jevrejeva gives results within the IPCC range. You need to have a scientific argument as to why you want to pay attention to the Jevrejeva bump, but discount the Jevrejeva projections. It looks like you are just choosing thw answers you like.

       Even if the 1920-1950 "bump" is not well explained, that is not a scientific argument as to why future projections are therefore wrong. We know a good deal less about past inputs than current, and that limits our ability to be sure of what happened historically. This has been discussed with you in the past. Uncertainty in historical sea level rise itself occurs because of the reliance on tide gauges. You allude to this in your post when you discuss  the mid-ocean data that comes available with sateliite monitoring.

       A lengthly discussion on models, data, etc. is hand-waved away with the paragraph:

       "What this tells me is that there is a “theoretical” danger but so far we do not have any evidence of an actual retreat or the time frame over which this could occur. We cannot base our rational responses to AGW based upon theories which have not been supported with observational evidence.

       This is basically a wholesale rejection of science. You basically seem to be rejecting any projections because they haven't happened yet, as there is no observational evidence. I consider this to be irrational. You may wish to reword this or provide further explanation.

       In quoting p1159 of the IPCC report, you neglect to include the closing statement that says:

       From 1993, all contributions can be estimated from observations; for earlier periods, a combination of models and observations is needed. Second, when both models and observations are available, they are consistent within uncertainties. These two advances give confidence in the 21st century sea level projections. The ice-sheet  contributions have the potential to increase substantially due to rapid dynamical change (Sections 13.1.4.1, 13.4.3.2 and 13.4.4.2) but have been relatively small up to the present (Sections 4.4 and 13.3.3.2). Therefore, the closure of the sea level budget to date does not test the reliability of ice-sheet models in projecting future rapid dynamical change; we have only medium confidence in these models, on the basis of theoretical and empirical understanding of the relevant processes and observations of changes up to the present (13.4.3.2, 13.4.4.2).

       I have chosen to bold parts of the quote.

       • Your interpretation that the "biump" in the 1920-1950 period is a game-ender is not in agreement with the IPCC.
       • Your opinion that historical sea-level data are independent of models ("theory") and are purely observational is not in agreement with the IPCC.
       • Your interpretation that there is too much uncertainty to make projections is not in agreement wiht the IPCC.
       • Your opinion that the only reasonable choice it to linearly-extrapolate the historical trends is not in agreement with the IPCC.

       You also comment about "...the average rate of 10 mm/yr during the deglaciation after the Last Glacial Maximum ...". You appear to think that this places some upper physcial limit on rates of sea level rise. The rate of sea level rise is not a function of ice volume, it is a function of the rate of change of ice volume, which depends on the rate of climate change. The temperature rise projected for the remainder of the 21st century is far higher than anything that occurred at the end of the last glacial maximum.

       

       All-in-all, you present little more than an argument from incredulity.

       (Note: in lawyer-speak, I reserve the right to ask further questions regardling NorrisM's posts. This comment is limited by time available today.)

15076. michael sweet at 05:12 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       Norrism:

       Oil companies lied to the public and funded disinformation campaigns about the dangers they knew of.  They have caused billions of dollars of damage since they kept action from being taken to mitigate the harm.  They are now being sued for the damage thay caused by their deliberate disinformation campaign.  

       If you call out fire in a movie theatre and someone is trampled to death in a  stampede to the exits, you are responsible for the death.  If you tell people there is no fire when you know there is a fire you are responsible for the death of those trapped because they stayed when they could have escaped.  Oil companies knew there was a fire and lied when they supported deniers who said there was no fire.  They will have a hard time denying that they funded disinformation since several deniers filed briefs with the court and declared that they were paid by Exxon. 

       Additional cases are being investigated because they lied to their stockholders about the likely future value of their fossil holdings in the ground.  If fossil fuels are limited, as expected to control AGW, their holdings will be worth less.  Fossil companies knew their assets were likely to be stranded but told stockholders they were unlikely to be stranded.  It is fraud to lie to stockholders.

15077. michael sweet at 03:24 AM on 2 April 2018
       Sea level rise predictions are exaggerated
       

       Norrism

       Your very long post at 58 boils down to a claim that you think 8-10 inches of sea level rise from the present is all we should expect.  Therefor we do not need to take any action on AGW.

       If we take no action we would have to consider that at least RCP 4.5 although RCP 6.5 seems more appropriate to me.

       This is a scientiic board.  Arguments are supposed to go like this:

       I say according to paper 1, sea level rise is proected to be 2- 5 feet with a median of 3 feet.  

       You say according to paper 2 sea level rise is 1-3 eet with a median of 2 feet.

       Then we discuss the merits of papers 1 and 2 citing additional papers.  More recent papers have more weight and papers written by reliable scientists have more weight than unreliable scientists.

       Here you say acccording to the most recent US Climate change report for sceniero 4.5 sea level rise is expected to be 1.5-3 feet with the possibility of 5 feet but it is very likely it will not be under 1.5 feet and including recent Antarctic estimates the median estimate may be 7 feet.  You have recalculated their numbers and think that 8-10 inches is the best median estimate!!!!!  Your estimate is no more than 50% of scientists minimum estimate and is less than 15% of the median including the Antarctic.  You appear to claim that if scientists are unsure what the Antarctic contribution will be it should be counted as zero.

       Is this really an argument that a laywer would present in court??  Experts project at least 1.5 feet and when including the Antarctic a median estimate of 7 feet and a laywer who is an oil investor reads the internet for a few weeks and estimates 8-10 inches.   Which estimate should we go for, the lawer or the scientists?  While you have cited your references, they are diametrically opposed to your conclusion.  Are you being serious?

       Your citations proove you are incorrect from the start.  You cannot hope to convince anyone who is scientific.  You appear to be taking us on a wild goose chase. 

15078. NorrisM at 03:04 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       nigelj @ 3

       "The oil companies have resisted doing anything meaningful, so hence people resort to lawsuits."

       Leaving aside matters of "causation" and what damages have been suffered by any failure of oil companies to "come clean" on what they really thought, specifically what would you have expected them to do?

       If all you are going to say is that they should have been more honest about their concerns what would this have achieved? 

       Throughout this period, we have had IPCC assessments telling the world as to what the latest science was and politicians (at all levels of government) have listened and done effectively nothing with a few exceptions such as California.  

       So what damages did these cities suffer by not being told by the oil companies that they did have some concerns that had been raised in the public domain by the IPCC and other persons?

       And even today, we still have disagreements as to the relative contributions of AGW and natural causes for our changing climate and how this will impact sea levels. 

       The oil companies sold us something that we not only wanted but needed.  Now they are to pay us for having willingly purchased a product from them? 

       Any idea as to what they should pay for? 

       Even if you were to get past "causation" you still have a major hurdle that the damages were to remote.  In other words, the damages were caused by other factors and cannot be pinned on the oil companies.

       But the US is a wacky place.  There was a major publicly-traded funeral service company based in Vancouver that was consolidating "mom and pop" funeral companies that was bankrupted by a billion dollar jury judgment in Missouri relating to the purchase of one funeral parlour in that state. 

15079. One Planet Only Forever at 02:59 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       Related to my comment@4,

       It is very difficult to provide clear conclusive proof of sustainable helpful developments occurring because people were burning fossil fuels, there being no alternative way that those developments could have occurred.

       It is easy to find clear cases where the ability to burn fossil fuels, and the associated efforts to prolong or increase the ability to personally benefit from those undeniably unsustainable and harmful activities, has delayed the development of sustainable helpful improvements.

15080. NorrisM at 02:34 AM on 2 April 2018
       Sea level rise predictions are exaggerated
       

       michael sweet @ 59

       The US Climate Report increases the upper level of the very likely range from 98 cm to 130 cm but does not explain its reasons for its difference with the very likely range of the Fifth Assessment.

       It does not deal with my main "common sense" concern that the projected rates for the period 2081 to 2100 of up to 16 mm/yr are unrealistically high in comparison to the average 10-11 mm/yr that was experienced at the height of the melting after the Last Glacial Maximum.  According to the US Climate  Report, the  "pulse water" rate of 40 mm/yr lasted for only about 300 years out of thousands of years of melting after the Last Glacial Maximum.

       Can you point me to any academic discussion of my conundrum that these projected rates do not seem realistic given the ice mass differences that existed during the meltdown compared to now?  Surely someone has had to address this.

15081. John Hartz at 01:52 AM on 2 April 2018
       Study: wind and solar can power most of the United States
       

       Recommended reading:

       How energy storage is starting to rewire the electricity industry by Eric Hittinger & Eric Williams, The Conversation US, Mar 22, 2018

15082. One Planet Only Forever at 01:28 AM on 2 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       nigelj@3

       Your response to the spurious claim: "We have fossil fuels to thank for where they have brought us, we do not have cigarettes to thank for anything.", should be expanded.

       It is also spurious because there is no proof that fossil fuel burning has 'directly resulted in helpful sustainable developments that only would have developed because people burned fossil fuels'.

       The root related understanding is that systems that develop unsustainable activities that are harmful to others can be seen to also develop resistance to being corrected. And those systems need to be corrected to become systems that promote the development of sustainable improvements for all of humanity (systems that push to achieve, and improve, all of the Sustainable Development Goals). And the portion of the population that resists correction are understandably 'the core system problem'.

       A related understanding is that 'legal' does not mean 'ethical or helpful or acceptable'. There are undeniably 'Bad Laws' and 'Lousy selective enforcement of laws'. That is an important part of the required increased awareness and better understanding that will develop a beneficial difference for the future of humanity.

       And increasing awareness that popularity and profitability have proven to be lousy measures of acceptability, and have been detrimental to ethics and helpfulness, is also important to limit the damaging popularity of beliefs that good things will develop if people are freer to believe what they want and do as their please, the creed of the promoters/excusers of the 'Neoliberal Free-for-all system that will only really benefit the few Biggest Winners'.

       Naomi Klein's "No is not Enough" is a very enlightening read (borrow it from a library if you can). It is a helpful supplement to understanding the challenges of achieving the Sustainable Development Goals.

15083. One Planet Only Forever at 01:05 AM on 2 April 2018
       Sea level rise predictions are exaggerated
       

       michael sweet@59,

       I shared a different version of the following as a comment on "In court, Big Oil rejected climate denial”. And that comment was an expansion of a comment I made on "Climate scientists debate a flaw in the Paris climate agreement" in response to John Hartz's comment pointing to an article about the IPCC reports already being an outdated understanding when they are published.

       Several years ago I heard a CBC Radio interview of one of Canada's scientist representatives working on writing an IPCC Report explaining that political-minders had influence on what was written by their nation's scientists involved in the IPCC Report process. The only limit on the political push was that the final wording had to be scientifically supportable (scientifically representing the available evidence).

       Political interests wishing to diminish or delay corrective climate action almost certainly abused that process to push for the least disastrous presentation that can be supported by the available information. They pushed as hard as possible toward the 'feel good news' side of how bad things will be. They may have even been the reason for the unclear, able to be abused for political marketing purposes, term 'hiatus' being included in one of the reports.

       As more information is obtained, as climate science is expanded and improved, it gets harder to push that low. An example is that it is harder to exploit the term 'hiatus'. However, much delay of increased public awareness and understanding was achieved. And the trouble-makers care about Winning any extension or increase in their ability to get away with their understandably unacceptable Private Interests.

       I have clarified in other comment threads that it is unacceptable for anyone to benefit from creating challenges/harm/reduced access to resources that Others, including future generations, will have to deal with. The generation that includes people benefiting from creating future challenges owes future generations the neutralization of those damaging unsustainable pursuits, or a building a conservative solution that is almost certain to mean that future generations face no challenge, getting a truly better future (the obligation and expense is on the current generation).

       On the matter of sea ice levels that means the current generation building all of the corrective protective features now, based on a worst case understanding of the possible future result of the unsustainable and harmful activities some people get away with benefiting from. The one way the current generation can reduce that requirement is by reducing activities that generate the need for such a requirement.

       So, 'legal arguments' made by the likes of Chevron in the California case that the earlier IPCC reports were not as adamant about how bad things were, how unacceptable what had developed was, are constructed by abusing the fact that each IPCC Report is subject to political manipulation by the 'powerful likes of Chevron/Exxon/Koch Industries and the elected representatives they can influence' towards down-playing how bad things have developed to be and how much worse they will become. They are trying to manipulate the system to 'not be required to correct the understandably incorrect developments they pursued and benefited from'.

       Increasing awareness that 'legal' does not mean 'ethical or helpful or acceptable' is an important part of the required increased awareness and better understanding that will make a beneficial difference for the future of humanity. And increasing awareness that popularity and profitability have proven to be lousy measures of acceptability, and detrimental to ethics and helpfulness, is also important.

       But the most important increase of understanding is that systems that develop unsustainable activities that are harmful to others also develop resistance to being corrected. And they need to be corrected to become systems that promote the development of sustainable improvements for all of humanity (systems that push to achieve, and improve, all of the Sustainable Development Goals). And the portion of the population that resists correction are understandably 'the core system problem'.

15084. michael sweet at 21:16 PM on 1 April 2018
       Sea level rise predictions are exaggerated
       

       Norrism

       You have decided to go with the lowest estimate that you can find.  You are welcome to choose whatever you want.  

       I compared the projections of the IPCC third assessment (2001), IPCC AR4 (2007), IPCC AR5 (2013) and the 2017 US Climate report.  I notice every 5 years that the estimates go up substantially.  You pick the lowest estimate from the 2013 report, neglecting the 2017 report.  In recent newspaper articles, one of the lead authors of the last two reports testified in court that these reports are writen conservatively ie they give low ball estimates for political reasons.  In 2013 surveys reported at RealClimate reported that a majority of sea level experts estimated likely sea level rise as higher than the IPCC upper estimates. 

       I am surprised that you have decided to ignore the 2017 report and also ignore recent new knowledge about ice sheet instability.  You are allowed to pick and choose as much as you like, but I think we need to consider all knowledge when we make policy choices and we need to apply the Precautionary Principle to preserve a living environment for future generations.  Obviously, you feel no responsibility for the future after you are gone.

       I presume that you do not purchase car, life or house insurance since the chance of you making a claim this year is too small.  No problem there, you are too old to suffer if it turns out that sea level rises 8 feet, an amount that cannot be ruled out with current knowledge.  Perhaps you should study how the Precautionary Principle applies to this type of problem.  I note that in many states engineers are required to design to withstand possible issues like sea level rise so they have to use higher estimates (six feet or more) for their calculations.

       You have decided to go with Curry.   You understand that Curry is held in contempt by the scientiic comunity and that her fame is solely due to her taking a position contrary to world scientific opinion.  I suggest you invest in land near the ocean.  Prices are currently depressed because others think high sea level rise is more likely than you.

       I see no mention of sea level refugees in your post.  Too bad for poor people elsewhere who get screwed, they will just have to move to somewhere that is not near you.

15085. nigelj at 18:28 PM on 1 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       NorrisM @2

       "nigel, do you not think it is rather hypocritical of these cities to be suing oil companies for something that was absolutely critical to their populace? "

       No I don't.

       "Can we not get on with solving the problems rather than pointing fingers and suggesting that these oil companies are like the tobacco companies? "

       Perhaps if the oil companies had actually done something to help solve the problems, but they haven't done anything, apart from a little bit of token feel good window dressing. The oil companies have resisted doing anything meaningful, so hence people resort to lawsuits.

       "Surely any reasoning person understands the difference between the use of a drug for pleasure and the use of a resource for leveraging energy to make our society what it is today."

       Yes, but its not a relavant difference in this instance. The oil companies downplayed a risk and allegedly hid risk, and as a lawyer you know perfectly well that is arguably a tort of negligence. It doesn't matter what the product is, and whether its addictive or not, or has had some use, provided it has the potential to cause harm. People are entitled to proper disclosure of information that can materially affect them.  This is all established law.

       "We have fossil fuels to thank for where they have brought us, we do not have cigarettes to thank for anything."

       Spurious argument  because benefits dont excuse allegedly hiding risks, and this is established law with any products for example pharmaceutical drugs. This is why they are federally regulated. The argument is  wrong anyway on another level, because smokers enjoy their product and get something out of it.

15086. nigelj at 18:01 PM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       NorrisM @34

       "But one thing that has started to "niggle" me is the potential vulnerability that we would create in the US with a grid system reliant on large transmission lines covering the country that are critical to supplying power to areas far away from the source of the wind or solar. We worry about terrorists taking out a nuclear plant but large transmission lines would seem to be sitting ducks for terrorists ..."

       Fair question, however I think the terrorist threat is over stated. Far more people have died each year on average in America from drowning since 911. Property damage from terrorism in America over the last couple of decades has been virtually insignificant in the greater scheme of things. Yes 911 was terrible, and in no way am I downplaying this, but it was one event when America was caught off guard. The psychological impact of terrorism appears to me greater than the real risk of problems, and understandably enough.

       This could of course all change, but it's hard to see why it would. If terrorists haven't been able to launch multiple attacks by now on people or property, and given ISIS is in retreat its hard to see things getting worse, provided the western world does not inflame islamic sentiment.

       And the towers and power lines can be replaced remarkably quickly within about a day. You will see this in articles related to the 2016 Australian event.

       Alternatively cables can be buried underground, however this is expensive at about five times the cost. But then it does insulate the system from stormy weather and tornadoes as well as other risks.

       And climate change is expected to make storms worse.

15087. Glenn Tamblyn at 16:01 PM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst
       
       "Even the premier manufacurer of electricty storage devices states that a baseload is needed."
       
       Hmmm... The word baseload doesn't appear on the Siemens page you link to. They discuss storage which is a recognised part of the mix and also gas. Sure they are promoting the particular flavours of storage they are invested in but we will need all types of storage, again a diverse mix. And we need storage precisely because it is flexible, unlike 'baseload' meaning typically coal which is actually relatively inflexible,
       
       This is what our future energy system will look like. Diverse energy sources, with diverse generation patterns, combined with diverse energy storage options that will balance ALL the variability - supply side and demand side. Add in long distance interconnection to take advantage of differences in weather patterns geographically to reduce the variability on the supply side, with demand-side management to also reduce the variability on the demand side.
       
       The problem with fixating on 'baseload' as an idea, as if it is some Holy Grail, is that it misleads us into totally underestimating how hugely variable our demand is as well. And getting more so as things like hotter weather increases the use of air-conditioners, in summer. Our power demand is becoming less 'base', more 'peaky'.

15088. Glenn Tamblyn at 15:53 PM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst
       
       Tasmnaia is mainly powered by hydro - over 2200 MW of it. Some gas (200 MW) and some wind (300 MW). Then it has a single cable link to the mainland, limited to 500 MW. In the few years before those events, Tasmania had been cooperative selling (remember these are commercial exchanges) to the mainland. Then there were several drought years - the achilles heel of hydro. But they would still probably have been OK with power back from the mainland. Then a fault developed in the cable and it was down for months so they had to take emergency measures.
       
       Too much cooperation? Or not enough? If there had been a second cable or even a third, linking Tasmania to the mainland and also to much more wind assets in NW Tasmania as well as off-shore wind hubs centred around islands in Bass Strait, they wouldn't have had a problem.
       
       This is the thing. You can try to do your power supply from local sources, but if something goes wrong, you have very little fall back. If you interconnect to your neighbours a little, you are vulnerale to failures of your few links. However if you have high interconnectivity, it is hard to knock out lots of links, and the syetm as a whole is stronger.
       
       So Russia cuts off gas? Hydro in Norway and Sweden go to full output, Nuclear in Sweden ramps up, etc. The more diverse your energy sources and connection the better your system. It's like being a little bit pregnant. Being a little bit interconnected is an oxymoron.

15089. Glenn Tamblyn at 15:43 PM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Yes, NorrisN, long transmission lines are a vulnerability, but so too are large centralised power stations, to terrorists or warfare.
       
       Ultimately you need a hybrid mix of everything taking a weighted assessment of all the risks to work out the optimum configuration. These risks are climate change (likely & severe risk), war(unlikely but severe risk), terrorism (more likely but lesser risk), equipment failure (likely but low risk with good design).
       
       If we could get by with local distributed power with storage that would be best, but we must get by with zero-carbon power. The options for this, depend on location. In the tropics, Solar with local storage can probably handle it all. But at higher latitudes solar varies so much more over the seasons amd wind has variability on scales of multiple days so we need to add some long range transmission, particukarly north/south to ease the load that storage alone might try to carry. Local storage is fine for daily variations but not multi-day or seasonal. Nuclear and big hydro may be limited in the sites they can be located at, both can be vulnerable to drought and all of them are sitting ducks to war or terrorism, no escaping that.
       
       We have lots of pieces of the puzzle, all the Lego blocks we need, but we still have to put them together into a sensible design.

15090. NorrisM at 15:30 PM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       nigelj and Glen Tamblyn,

       Interesting discussion.  I read the abstract to the paper and I am surprised that it has generated such a reaction.

       But one thing that has started to "niggle" me is the potential vulnerability that we would create in the US with a grid system reliant on large transmission lines covering the country that are critical to supplying power to areas far away from the source of the wind or solar.  

       We worry about terrorists taking out a nuclear plant but large transmission lines would seem to be sitting ducks for terrorists let alone some country with which we had a conflict (that did not escalate to nuclear war).  When the source of power is more localized we do not have the same risk.

       Maybe this is only theoretical.   Has anyone considered this?

15091. Glenn Tamblyn at 15:21 PM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst
       
       Firstly, the situation in South Australia was an exeptional event. My earlier point about grid collapse was that a grid running under perfectly normal conditions would collapse in seconds without everything matching frequency exceptionally. Consider a grid where half the generators are running at 50 hz, and the other half are running at 50.5 hz. Assume all their waveforms start out synchronised. 1 second later half of them have put out 50 cycles, the other half have put out 50.5 cycles. The second half are now completely out of phase with the first half. They are generating in complete opposition to each other! The final volatage that the end user sees is zero volts. another second later they are in synch again, thena another second totally out of synch. Every 2 seconds the supply voltage to the end used fluctuates between 240 V AC and 0 V Ac. If the the difference was only 0.1 Hz, this would be a 10 second pattern. 0.01 Hz it would be a 1 miniute 40 seconds pattern. Do you see that happening, do the lights dim and return every few seconds?
       
       Now imagine what the supply would look like if each generator deviates by differing amounts from the target frequency. An absolute dogs breakfast of a power supply, visible in seconds. Thats what I mean by collapse.
       
       Now, to the SA black state event. Yes, as others have commented the software setting on the turbines meant that they shut down a bit prematurely. Not intrinsic to wind, but an overly aggressive setting on a software safety switch. But it wouldn't have helped any way on that day. Once those storms did the damage they did, a Black State event was almost inevitable.
       
       Adelaide, the capital city consumes most of the states power. Originally there were two coal poer stations well north of Adelaide at Port Augusta,  orthern and Playford B. They were located there to use coal from the nearby Leigh Creek coal mine. Power from both stations was fed into the large Davenport substation and from their 4 high voltage transmission lines carried the power to Adelaide. Combined with the Heywood Interconnector from Victoria coming up from the south, this is the backbone of the states grid. 
       
       Various wind farms have been built in SA, mainly in that Adelaide/Port Augusta corridor, taking advantage of those 4 power lines to connect to the grid. And the two coal stations have been closed and are currently being demolished.
       
       So what happened on that day? Storm roared through the region between Adelaide and Port Augusta, including some tornadoes. Over about 1.5 minutes they ripped up 3 of those 4 high voltage lines. Literally towers smashed, one tower sucked out of the ground, concrete footing and all. And the power lines lying on the ground, shorted out.
       
       When it frst started and faults started to occur on those lines, the controllers started to react and shut down the lines. Yes, some of the wind farms shut down needlessly early due to the software settings. But they would still have had to shut down soon any way since the transmission lines they were connected to had failed. With this loss of power from the north, the rest of the system to the south struggled to meet demand in Adelaide over the next few seconds and freqquency started to drop as turbines slowed under the excess load. So frequency was running out of control, and the grid rules meant that everything would have to disconnect fairly soon anyway.
       
       They Heywood interconnector rapidly ramped up the power being drawn from Victoria to try and meet the load. So the interconnector reached overlaod and was disconnected. SA now had hardly anthing still on-line. The remaining generators, mainly gas, couldn't cope and slowed radically, dropping frequency and eventually they disconnected. In fact the last couple of seconds of voltage and frequency gyrations was due to the erratic behaviour of the gas plants under overload.
       
       Now, what if the wind farms had kept operating, without their safety switches tripping out? Well most of them couldn't have, their transmission lines were lying on the ground so even without the software setting they would have been forced to disconnect seconds later anyway. Only the 1 or 2 farms connected to the remaining operational line, to the west, might have been able to keep running. But the frequency would still have been swinging wildly, possibly causing them to have to disconnect.

       Importantly, the remaining farms weren't large enough to carry enough load, so the Heywood interconnector would still have overloaded. Then those remaining frms, with the gas stations, would still have been inadequate to meet the load and the frequency slew would have forced all of them to disconnect anyway, so the sam result. And all of this happenbed too quickly for the system controllers to institute controlled load shedding, blackouts in some regions to stop the whole system going down.
       
       The collapse wasn't caused by wind, or even software settings. It was caused by tornadoes tearing power lines down.
       
       Now a hypothtical scenario. No wind and those two coal stations were operating instead. Most of their power would have been going to Adelaide, down those 4 power lines. Then the storms ripped up 3/4 of their transmission capacity. Operating at high output, with now only 1/4 of their transmission capacity, a race would have started over a few seconds. With high output but unable to get the power out, the generators in those power stations would have started running away, driving frequencies up rapidly, equally something where they are required to trip out and disconnect from the grid. No way in the world could an old coal power station throttle it's output back by 75% in a few seconds and still keep running. And the one remaining powerline would have overloaded and the safety systems on the powerline would shut it down as well, tripping circuit breakers at the substations. The race would have been which would trip out first in those few seconds but either way, the same thing would have occurred - power from the north died, Heywood collapses and the system goes down.
       
       On that day, given the layout of SA's power grid, given where it's generation assets were, both old and new, and where the storms did their damage, the Black State was almost inevitable. Nothing to do with it being wind per-se. How many networks can survive loosing 75% of their transmission capacity?

15092. NorrisM at 14:52 PM on 1 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       nigelj @ 1

       nigel, do you not think it is rather hypocritical of these cities to be suing oil companies for something that was absolutely critical to their populace?  One sardonic comment from someone else on another website asked: "Do you blame the ladies of the night for having customers?"

       Can we not get on with solving the problems rather than pointing fingers and suggesting that these oil companies are like the tobacco companies? 

       Surely any reasoning person understands the difference between the use of a drug for pleasure and the use of a resource for leveraging energy to make our society what it is today. 

       We have fossil fuels to thank for where they have brought us, we do not have cigarettes to thank for anything.

15093. nigelj at 12:29 PM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst

       You have made a number of claims on this page  1) that wind, solar and storage wont work without base load power (nuclear, gas etc) 2)wind voltages are unreliable and 3)wind frequencies are unreliable and 4) wind, solar and mass storage is too expensive.

       These are just assertions without any details. The sources you quote dont support your assertions. People have refuted your assertions with technical detail and / or real world examples in comments above as pointed out by MS.

       Heres something more on costs of battery storage in this article: "Plunging costs make solar, wind and battery storage cheaper than coal" Please note theres no baseload power in this instillation either.

       In all fairness its not a massive instillation, (500 mw) but it shows how fast things are growing and how competitive costs are becoming.

       You say "But the South Australia grid has collapsed! Sept 2016, due to a storm that forced most of the windfarms to shut down and black out the whole state!"

       The primary cause was actually an exceptionally severe storm and multiple transmission line failures. It appears the wind farms shut down automatically when the transmission lines failed, (in other words it wasn't that the wind turbines couldnt handle the wind)). This shut down in turn was due to the software settings of the wind farm systems,  and appears to be an issue that can be changed. This wikipedia article has the details.

       And more here in this article :"Overly sensitive protection mechanisms in some South Australian wind farms are to blame for the catastrophic statewide blackout in September last year, the Australian Energy Market Operator (AEMO) says."

       "AEMO said changes made to turbine control settings shortly after the event has removed the risk of recurrence given the same number of disturbances."

       So yes the system had some problems not unexpected with new technology, but they were not intractable sorts of failings, and have been fixed.

15094. michael sweet at 11:56 AM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst,

       I am sorry for the confusion, apparently one of your offensive posts was deleted so the posts were renumbered.  I referred to your post now numbered 14.

       Your primary false claim was about renewable energy upsetting the grid frequency which Glen Tamblyn has shown was false.  You then make false claims about storage of energy and the necessity of baseload energy on the grid which you have not supported.  

       Alchymist has been posting for a long time here at SkS without providing citations to support his/her arguments.  Many posters have pointed out false claims that (s)he has made.

15095. Alchemyst at 11:46 AM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Glen at 20 13,

       It is goodwill should we have an europe wide energy crisis eg Russia stopping the natural gas flow, I have a feeling that certain countries will put their own needs above others. It is already happening with the UK breaking away.  similar things have been happening in Australia where I understand that other states are not as helpful as they could on the energy scene with Tasmania and south australia.

       http://www.abc.net.au/news/2016-02-23/tasmanias-energy-crisis-explained/7194234

       "Hydro is sourcing 200 diesel generators which could supply up to 200 megawatts by April."

       Its sad really , if human nature should see that cooperation works, but when the chips are down self interest comes first.

15096. Alchemyst at 11:34 AM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Glen Tamblyn 16 07

       "If these approaches didn't work, then places like South Australia or Denmark with high penetrations of wind would have totally collapsed grids. They don't!"

       But the South Australia grid has collapsed!   Sept 2016, due to a storm that forced most of the windfarms to shut down and black out the whole state!

       Is Elon there now on a rescue mission? 

       https://www.smh.com.au/national/state-in-the-dark-south-australias-major-power-outage-20160928-grqmn2.html

15097. Alchemyst at 10:47 AM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       Sweet, I think I should remind you of your past reasoning with regards to the passage and that you offenviveness to anyone who disagrees with you

       It doesn’t take a stretch of the imagination to suppose that losing half the Arctic sea-ice cover in only 30 years might be wreaking havoc with the weather, but exactly how is not yet clear. As a research atmospheric scientist, I study how warming in the Arctic is affecting temperature regions around the world. Can we say changes to the Arctic driven by global warming have had a role in the freakish winter weather North America has experienced?

       michael sweet at 07:43 AM on 2 February, 2018
       Alchymst
       Idle claims that the sea ice expert who wrote this article was incorrect are easily dismissed with actual data.
       To answer your question: "could someone please explain this disepancy [sic] or is it due to inflation and projection?"
       The discrepancy is due to the asker being uinformed of the actual data. The linked article was a summary article and did not detail all the sea ice data.

       michael sweet at 11:33 AM on 2 February, 2018
       Alchymist,
       You are cherry picking your start year as 1979. That is when satalite records start, but not when scientific records start. This graph from Cryosphere Today

       Michael just a reminder of your logic, now the author stated 30 years that is from 2017 is 1987, not 1979.
       I’m sorry but I have great difficulty in accepting your comments seriously (ps 1979 makes 38 years not 30)
       And yes the author has retracted her comments!

15098. Alchemyst at 10:23 AM on 1 April 2018
       Study: wind and solar can power most of the United States
       

       "Your claims at 15 are also false. You have provided no references to support your wild claims. It is sloganeering to make unsupported claims. The moderators wil start to delete your posts if you continue to refuse to support your wild claims."

       before I go on please state exacly which claims that a wrong in para 15. 

       It is extrememly difficult to understand what you are against, 

       Please elucidate, thank you

15099. NorrisM at 09:47 AM on 1 April 2018
       Sea level rise predictions are exaggerated
       

       Bob Loblaw, Eclectic and michael sweet,

       This has been an interesting journey, exploring what I will describe as the “conflicting views” on the future sea level rise “predicted” for the remainder of the 21st century. Let me say that I appreciate that my use of the term “predict” is used in a general sense and that many of what I refer to as “predictions” are in fact “projections” because they are predictions based upon certain assumptions relating to a number of things but most importantly, the level of CO2 emissions based upon the various pathways assumed by the IPCC.

       The relevance of the views of a lawyer are on such a technical subject as “sea level rise” is certainly questionable but I suspect the interest of Bob Loblaw is simply because there are a number of legal cases that will be coming before the courts of the United States over the next few years and these cases will be adjudicated by lawyers and not physicists or other scientists. Having said that, there are many lawyers who have an engineering or scientific background before entering law so there may be some hope of having a scientist hear the case. In my case, my undergraduate degree was in the “dismal science”.

       In researching this topic, I have largely focused on Chapter 13 of the IPCC Fifth Assessment (Fifth Assessment) and those portions of Chapter 3 dealing with sea level rise as well as blog information contained on this website on the subject as well as blog information on one other website (which does not carry much weight from most of the commentators on this website). I have also read the US Climate Science Special Report published in late 2017 (US Climate Report) as well as the very good RealClimate article on the Fifth Assessment (suggested by Bob Loblaw).

       But before I delve into my impressions from these sources, I would also like to reference the discussion of “uncertainty” both in the Fifth Assessment and the US Climate Report. In both reports, the extent of understanding (and certainty or uncertainty about that understanding) is based upon levels of confidence (dealing with the consistency of the evidence and degree of agreement within the literature) and likelihood expressed probabilistically (based upon the degree of understanding or knowledge).

       What I want to focus on are the levels of “Confidence”:

       “Medium Confidence” means suggestive evidence (a few sources, limited consistency), competing schools of thought.

       “High Confidence” means moderate evidence (some sources, some consistency) medium consensus

       “Very High Confidence” means strong evidence (established theory, multiple sources) high consensus.

       All of the definitions for uncertainty are found in the US Climate Report in the “Guide to this Report” which is easily located.

       I think it is very important to keep these measurements in mind when analyzing the findings of the Fifth Assessment. When they use “Medium Confidence” they do not mean “medium consensus” because that term is reserved for “High Confidence”. Unless the term “Very High Confidence” is used then there is considerable uncertainty remaining.

       So to commence this research the most logical place to begin is the Fifth Assessment projections found at Section 3.7.6:

       "It is very likely that the global mean rate was 1.7 [1.5 to 1.9] mm yr–1 between 1901 and 2010 for a total sea level rise of 0.19 [0.17 to 0.21] m. Between 1993 and 2010, the rate was very likely higher at 3.2 [2.8 to 3.6] mm yr–1; similarly high rates likely occurred between 1920 and 1950."

       Figure 3.14 of the Fifth Assessment shows the “bump” in sea level rates in the period 1920 to 1950. Given that the accepted view is that the rapid increase in the use of GWG’s only started after 1950, it seems incumbent on scientists to explain the “bump”. The only explanation I could find in the Fifth Assessment was that this “bump” was ”likely related to multi-decadal variability”. See Section 3.7.4. However, the natural question is if “multi-decadal variability” caused the increase in rates in the 1920-1950 period then why cannot the increase in rates found since 1993 of approximately 3.2 mm/yr also be attributed to multi-decadal variability? Or should not at least a portion be attributed to this internal variability, if only a portion, then how much?

       So the Fifth Assessment found that it was “very likely” (read 90-100%) that the average rate of sea level rise since 1901 was 1.7 mm/yr. But before we get into the 3.2 mm/yr rate, we now have a number of papers since the Fifth Assessment that have suggested that the Fifth Assessment’s 90-100% assured estimate is all wrong and the real rate for 1901 to 1990 is 1.1 to 1.2 mm/yr. (Hay 2015 Dangendorf 2017). When asked by others how the IPCC could have got this so wrong, the answer seems to be that everyone is entitled to be wrong, that is science. I fully agree but it does not necessarily engender confidence in other “Very Likely” predictions or projections of the IPCC in the Fifth Assessment.

       Perhaps the IPCC will, in the Sixth Assessment actually maintain its 1.7 mm/yr rate which I understand was similar to the AR4. Why do I say this? Because my understanding is that these “new” lower estimates are largely based upon a reanalysis of VLM. But here is what the Fifth Assessment has to say about VLM adjustments:

       "High agreement between studies with and without corrections for vertical land motion suggests that it is very unlikely that estimates of the global average rate of sea level change are significantly biased owing to vertical land motion that has been unaccounted for. {3.7.2, 3.7.3, Table 3.1, Figures 3.12, 3.13, 3.14}"

       So now on to the $64,000 question as to whether the observed acceleration in sea level rise since 1993 is an increase in the long term rate or is reflective of decadal variability or only reflects “apples and oranges” measurement issues with satellite altimetry compared to tide gauges.

       We have disagreements both on the rate of acceleration and the causes of the acceleration.

       Firstly, we have a disagreement between the Fifth Assessment estimates of what the acceleration rate is and the recent Nerem 2018 paper. From the Fifth Assessment, the acceleration is quite small with Ray & Douglas (2011) at -.002 to .002 mm/y, Jeverejeva (2008) at .012 mm/yr and Church & White (2011) at .012 mm/yr. Then we have Nerem (2018) re-evaluating things and coming up with .084 mm/yr. I do not propose to get into the technical disagreements that I have read on the Nerem (2018) paper but even extrapolating his acceleration, his projected 2100 sea level rise is somewhere around 65 cm close to the low range of the IPCC RCP8.5 estimate. Although I am not qualified to make any judgments, I suggest that anyone who is qualified should at least read the comments made by FrankClimate on the other website under the Part IV discussion on sea level acceleration. Without question, FrankClimate is technical. His comments have now been incorporated into the Part IV discussion. Would be interested to hear from Eclectic as to whether he disagrees with FrankClimate.

       Secondly, we have questions of what is the cause of this recent acceleration since 1993. I had to ask myself why 1993 and not 1990? The obvious answer is that it is in 1993 that satellite altimetry came into the equation with the launch of the TOPEX satellite. Although I think there is general agreement that there are serious questions about whether the data from TOPEX for the first six years should be used at all (or for that matter even the remaining period for that satellite), my sense from looking at the NASA website is that the satellite altimetry is pretty well matching the tide gauges. I think there are a number of people who disagree with me on this but the average rates seem to match. But it is curious that where we see this very large increase in SLR is not at the land-based tide gauges but out in the middle of the oceans. It at least led me to ask myself whether this significant difference between the tide gauge measurements and satellite altimetry measurements in the middle of the oceans would have always been there if we could have measure it with satellites much earlier. I fully appreciate that the tide gauge measurements have shown an upward trend since 1980 (Section 3.7.4) but my understanding is that the large average increase during the satellite era can be attributed to the large increases found in the middle of some of the oceans, especially the Indian Ocean.

       But back to attribution. A number of authors have suggested that the way to reconcile the “bump” in 1920-1950 and the increases since 1990 is to link these climate changes to multi-decadal variability, and specifically the AMO or the PDO. Here is what the Fifth Assessment has to say about this at 3.7.4:

       "Several studies have suggest­ed these variations may be linked to climate fluctuations like the Atlan­tic Multi-decadal Oscillation (AMO) and/or Pacific Decadal Oscillation (PDO, Box 2.5) (Holgate, 2007; Jevrejeva et al., 2008; Chambers et al., 2012), but these results are not conclusive."

       Others have said that the increase in SLR since 1990 is not “statistically relevant” when looking at the long term sea level rise. In that respect, the Fifth Assessment does make the following statement immediately following the above quotation:

       "While technically correct that these multi-decadal changes represent acceleration/deceleration of sea level, they should not be interpreted as change in the longer-term rate of sea level rise, as a time series longer than the variability is required to detect those trends."

       For those who say that the acceleration should be attributed to AGW, they largely point to the increased rates of melting in the glaciers and the Greenland ice sheet and potentially catastrophic impacts relating to the West Antarctic Ice Sheet (WAIS). I cannot obviously get into discussing these topics without clearly being “snipped” for too long a post. In my view, having read the Fifth Assessment, the risk of “dynamic changes” in WAIS (there is virtually no risk with the topography of Greenland bedrock) are minimal. Here is what the Fifth Assessment has to say about the MISI hypothesis relating to WAIS at 13.4.4.3:

       "In summary, ice-dynamics theory, numerical simulations, and paleo records indicate that the existence of a marine-ice sheet instability asso­ciated with abrupt and irreversible ice loss from the Antarctic ice sheet is possible in response to climate forcing. However, theoretical consid­erations, current observations, numerical models, and paleo records cur­rently do not allow a quantification of the timing of the onset of such an instability or of the magnitude of its multi-century contribution."

       As to the evidence of a retreat of WAIS, see Chapter 13 at 13.5.4.1:

       "Although the model used by Huybrechts et al. (2011) is in principle capable of capturing grounding line motion of marine ice sheets (see Box 13.2), low confidence is assigned to the model’s ability to cap­ture the associated time scale and the perturbation required to ini­tiate a retreat (Pattyn et al., 2013)."

       What this tells me is that there is a “theoretical” danger but so far we do not have any evidence of an actual retreat or the time frame over which this could occur. We cannot base our rational responses to AGW based upon theories which have not been supported with observational evidence.

       As for the Greenland ice sheet, we know that the major warming was caused by warm waters appearing around Greenland and the impact that this has had on the melting of the ice sheet in the peripheries around the ocean at least from 1990 to 2012. My understanding is that this has been attributed to a decrease in cloudiness associated with the NAO which would mean that it was the increased insolation which caused the increase in the melting. Here is the discussion in FAQ 13.2 regarding the Greenland ice sheet:

       "Although the observed response of outlet glaciers is both complex and highly variable, iceberg calving from many of Greenland’s major outlet glaciers has increased substantially over the last decade and constitutes an appreciable additional mass loss. This seems to be related to the intrusion of warm water into the coastal seas around Green­land, but it is not clear whether this phenomenon is related to inter-decadal variability, such as the North Atlantic Oscillation, or a longer term trend associated with greenhouse gas–induced warming. Projecting its effect on 21st century outflow is therefore difficult, but it does highlight the apparent sensitivity of outflow to ocean warming. The effects of more surface melt water on the lubrication of the ice sheet’s bed, and the ability of warmer ice to deform more easily, may lead to greater rates of flow, but the link to recent increases in outflow is unclear."

       With the above information, the question that has been posed to me is where would I place the estimate of GMSL at 2100 compared to the Fifth Assessment (RCP 8.5) projection of .59cm to .98cm?

       Firstly, it seems to me that during the 20th Century we had an almost linear rise in sea level as is acknowledged by the Fifth Assessment at 13.3.6 at p. 1159:

       "GMSL rise during the 20th century can be account­ed for within uncertainties, including the observation that the linear trend of GMSL rise during the last 50 years is little larger than for the 20th century, despite the increasing anthropogenic forcing (Gregory et al., 2013b)."

       Here is a larger quote from the same Gregory paper:

       “The largest contribution to GMSLR during the twentieth century was from glaciers, and its rate was no greater in the second half than in the first half of the century, despite the climatic warming during the century. Of the contributions to our budget of GMSLR, only thermal expansion shows a tendency for increasing rate as the magnitude of anthropogenic global climate change increases, and this tendency has been weakened by natural volcanic forcing. Greenland ice sheet contribution relates more to regional climate variability than to global climate change; and the residual, attributed to the Antarctic ice sheet, has no significant time dependence. The implication of our closure of the budget is that a relationship between global climate change and the rate of GMSLR is weak or absent in the twentieth century. The lack of a strong relationship is consistent with the evidence from the tide gauge datasets, whose authors find acceleration of GMSLR during the twentieth century to be either insignificant or small.”

       This is consistent with the “Munk enigma” that he saw a near linear increase in GMSL during the 20th Century notwithstanding the impact of AGW only in the second half.

       The Fifth Assessment RCP 8.5 assumes that in the second half of the 21st Century we will have what at least are “quadratic increases” if not “exponential increases” in the GMSL rate. I have no understanding of how a “quadratic curve” differs from an “exponential curve” and I do not have to notwithstanding all of the debate that I read on this issue on the “other website”. What I do know is that it is much steeper than a linear increase.

       From Table 13.5 the Fifth Assessment has acknowledged that in the case of RCP 8.5 that in the period 2018 to 2100 they project an average sea level rate of 11.2 mm/yr for the mid-case and for the high case of .98 m the projected average rate is 15.7 mm/yr. See Section 13.5.1 at page 1180:

       "The rate of rise becomes roughly constant in RCP4.5 and RCP6.0 by the end of the century, whereas acceleration continues throughout the century in RCP8.5, reaching 11 [8 to 16] mm yr–1 in 2081–2100."

       Notwithstanding this projection, the Fifth Assessment acknowledges that this would exceed the average rate of 10 mm/yr during the deglaciation after the Last Glacial Maximum when there were massive ice caps over North America and Europe and Asia to supply the melt water (Chp13 pg. 1205):

       "For the RCP8.5 scenario, the projected rate of GMSL rise by the end of the 21st century will approach average rates experienced during the deglaciation of the Earth after the Last Glacial Maximum."

       The IPCC clearly understood this but did not explain how this could be achieved given the lack of such volumes of ice now (Chp 13 pg. 1185):

       "The third approach uses paleo records of sea level change that show that rapid GMSL rise has occurred during glacial terminations, at rates that averaged about 10 mm yr–1 over centuries, with at least one instance (Meltwater Pulse 1A) that exceeded 40 mm yr–1 (Section 5.6.3), but this rise was primarily from much larger ice-sheet sourc­es that no longer exist."

       Grammatically, the phrase “but this rise ….” modifies the reference to 10 mm/yr and not 40 mm/yr.

       The IPCC projection of sea level rise attributes the largest rise to thermal expansion, secondly to glaciers, and thirdly to the Greenland ice sheet mass balance loss and with a negative contribution by the Antarctic ice sheet.

       As to the IPCC’s ability to adequately model dynamic changes to the Greenland and Antarctic ice sheets here is what the Fifth Assessment says at 13.5.4.1 pg 1187:

       "As discussed in Sections 13.4.3.2 and 13.4.4.2, there is medium con­fidence in the ability of coupled ice sheet–climate models to project sea level contributions from dynamic ice-sheet changes in Greenland and Antarctica for the 21st century. In Greenland, dynamic mass loss is limited by topographically defined outlets regions."

       Note the use of the term "Medium Confidence".

       With all of the above research, given that I could not accept some of the projections of the IPCC for RCP8.5 (leaving alone the fact that RCP 8.5 is probably unrealistic given the changes we see in a move to renewable energy sources at least in the developed world) the question came down to what would I guesstimate the GMSL for 2100 if for some reason I was asked my opinion (which I was by Bob Loblaw).

       For me, I would go back to the observations and look at where the sea level has moved since 1900 and assume that it will follow along the same largely linear path that it has pretty well followed since we have kept records in tide gauges. Taking Figure 13.27 of the Fifth Assessment and applying a ruler to the line, it projects out to about .4m by 2100. In other words, whatever impact CO2 emissions have had they are “baked in the cake”. What we see is what we will get.

       Using the most recent date online at NASA, as of December 2017, we have had an 87.5 mm rise since 1993 representing an average rate of 3.2 mm/yr according to the NASA website. If we multiply this figure of 3.2 mm times 82 years, we arrive at around 26.24 cm of further rise if the rise continues to be linear. If you add this 26.24 to the .19 cm for the period 1900 to 1990 it totals 45.24 cm.

       So my guess is that we probably will have a further 21 to 26 cm from now until 2100 representing somewhere around 8 to 10 inches of sea level rise. Unfortunately, I will not be around to see if I am right!

15100. nigelj at 08:20 AM on 1 April 2018
       2018 SkS Weekly Climate Change & Global Warming News Roundup #13
       

       "From what I can tell, Chevron’s lawyer intimated that the oil companies’ defense will be that the science of anthropogenic causes was not clear until a few years ago and now that it is clear, the industry isn’t denying it......"

       The science was clear enough at least 20 years ago, so thats quite a few years. Apparently the oil companies own internal ducuments were telling them there was a problem back then.

       Covering up problems, or denying them, undermining science,  or being equivocal can be a case for claims of negligence. Just look at the history of tobacco litigation, and the millions awarded in damages.

       At least the oil companies have accepted the basics of the science. The oil companies are now in conflict with the extreme denialist groups like Christopher Moncton who deny basically everything. With some luck they will all start fighting each other, like the different groups of Orcs in Lord Of the Rings!

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