Recent Comments

Prev  292  293  294  295  296  297  298  299  300  301  302  303  304  305  306  307  Next

Comments 14951 to 15000:

14951. 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.

14952. 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.)

14953. 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.
14954. 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.

14955. 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.

14956. 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.

14957. 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.

14958. 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.

14959. 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.

14960. 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.)

14961. 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.

14962. 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. 

14963. 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. 

14964. 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.

14965. 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.

14966. 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

14967. 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.

14968. 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'.

14969. 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.

14970. 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.

14971. 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.

14972. 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'.

14973. 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.

14974. 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.

14975. 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?

14976. 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?

14977. 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.

14978. 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.

14979. 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.

14980. 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.

14981. 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

14982. 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!

14983. 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

14984. 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!

14985. 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!

14986. One Planet Only Forever at 07:40 AM on 1 April 2018
       In court, Big Oil rejected climate denial
       

       Glenn Tamblyn@7,

       There is additional understanding related to the devious actions of the delayers of climate action through the past 30 years.

       I shared a version of following on the "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 (unable to find an archive of that interview on the CBC website). His main point was that he, and every other scientist, had a political-minder reviewing what was being written and potentially pushing for a political interest. The only limit on the political push was that the final wording had to be scientifically supportable (scientifically representing the available evidence).

       Political interests that wish to diminish or delay corrective climate action can (and almost certainly did) abuse 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.

       As more information is obtained, as more climate science is performed, it gets harder to push that low. Each subsequent report is highly likely to ratchet up 'how bad things could be', even without a significant development of new learning indicating more negative future results, just an increase of information supporting the previous report's median, rather than best case, scientific understanding of how bad things could be.

       So, the 'legal argument' made by the likes of Chevron 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.

       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 the 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 problem'.

       Efforts to increase awareness and improve understanding are always helpful, compared to the alternative of resistance to correction growing stronger, more damaging, and ultimately unsustainable but doing tremendous harm before it is ended. Not sure what the best answer is, but one good result would be a correction of the systems to apply the highest expectation and requirement for helpfulness to the richest and most influential/powerful. That could be the basis for all legal actions, leading to penalties and other corrective actions being applied to someone who chooses not to behave more helpfully/correctly, even if what they did was not clearly contravening 'currently written laws of the day'. And the highest expectation of proper understanding of how to be helpful would be applied to the richest and most powerful.

       It will be interesting to see just how rapidly the corrections of the incorrectly developed systems occur. The continued unjustified claim-making by the passionate deniers of climate science, exposing what has to change to limit the harm done to future generations, will hopefully fuel a more aggressive development of public support for the need for correction, to the detriment of those who tried to delay such corrections.

14987. michael sweet at 21:22 PM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst,

       "Flexible energy producers" is not baseload.  Learn your terminology.  At 26 your quote describes the system proposed for a 100% renewable energy system that requires no baseload power.  Use quotation marks and indent to show that you are quoting your source.  The OP discusses how much storage is needed in the USA.  Your citations do not support your arguments

       You need to acknowledge that Glen Tamblyn has explained how frequency regulation works and that renewable energy does not have a problem with frequency regulation.

14988. Alchemyst at 20:31 PM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Even the premier manufacurer of electricty storage devices states that a baseload is needed.

       https://www.siemens.com/innovation/en/home/pictures-of-the-future/energy-and-efficiency/smart-grids-and-energy-storage-energy-storage.html

       But the higher the proportion of the energy mix represented by renewable energy sources such as solar and wind power, the greater the fluctuations in electricity generation – varying by the minute, hour, day and season, depending on energy source and region. To offset these fluctuations, the power network needs flexible electricity producers, such as decentralized energy storage systems and gas turbine power plants. These would accumulate electricity when generation exceeds demand, and would release it when renewable sources fail to supply enough.

14989. Glenn Tamblyn at 20:13 PM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst
       
       And there are periods where they generate more power than they need and it is exported, some to Germany, some gets sent to Norway where it is stored in Pumped-hydro in the mountains.
       
       And it's not goodwill, it is an energy system spanning multiple countries.
       
       None of which is relavent to the point that highlevels of wind don't endanger frequency management just because it is wind.

14990. Alchemyst at 20:08 PM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Glen at 1606 

       The Danes have 40% wind powr generation and rely on other nations goodwill for when the wind doe not blow.

14991. Glenn Tamblyn at 17:18 PM on 31 March 2018
       In court, Big Oil rejected climate denial
       

       Interesting point from the Vox article.
       
       "But as Boutrous (for Chevron) detailed the history of how climate scientists like Svante Arrhenius and John Tyndall developed their theories, he also noted that previous IPCC reports weren’t always so certain. The 1990 report said that “the observed increase could be largely due to natural variability.” The 1995 report said that signals were emerging that there is human influence on the climate. The 2001 report said that warming was “very unlikely” due to natural causes alone.

       The point he was making was that the consensus took time to build, and as the science got better, Chevron moved with it. Past rhetoric from oil companies reflected this uncertainty in the science, and Chevron now has a comprehensive strategy for managing climate risks, including cutting greenhouse gas emissions."
       
       Thats what a smart fossil fuel company (Chevron), with a bright Board and good lawyers does. Agrees, says we can't be blamed for the past because, well, because, and we are being 'really really good now'.
       
       Exactly which of the other FF majors thought sending in the clowns instead was a better strategy?
       
       This will be the next strategy, "its real, we accept that, and we are being really good". I expect funding from the mainstream, publicly listed FF companies to the denier institutes to start to dry up. It will only be the Koch's etc who keep funding them.
       
       And the next battle in the inside business wars around climate change? What happens when the FF majors adopt this strategy realise and the the Kochistas are undermining their next step? We may not be able to do much to the Koch's, but what happens to them when Exxon, Chevron & Total come after them with all legal guns blazing - and insider information about how the denial machine works?
       
       This would be a perfectly reasonble PR tactic. "We accept climate change and we are really, really doing .... something ... about it - see we built a wind farm. But these evil climate deniers and these evil billionaires, they are just so bad. It's unAmerican! Don't worry, we won't stand for this, the people of America can depend on us to protect them from evil money".

14992. Glenn Tamblyn at 16:07 PM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Just some points to nore about Amethyst's links. The first is a paper dated 2013, so 5 years ago, and an eternity in the fast developing world of wind power, And it deals with managing power output from individual turbine and management of individual wind farms. No mention of frequency whatsoever.
       
       The second link, a PhD thesis, is from 2014, still some time ago. It discusses voltage stability and response to transient events, but does not discuss basic frequency management at all. As the thesis notes many older turbines were designed for fixed rotor speeds but that has largely been superseded now - new designs manage rotor speed, blade angle of attack etc to maximise energy extraction from the wind. This has been an  important part of the cost reductions in wind recently, turbines that are more efficient,
       
       On the subject of frequency, everything on a grid has to synch frequency very accurately. If each machine's frequency deviates by even fractions of a percent, the overall supply becomes totally chaotic in seconds. But this frequency isn't exactly constant. As loading on the grid varies there ia a natural small variation of frequency - most grids are designed to stay within +/- 0.5 hz of their nominal frequency. Under higher loads for example frequency typically dips a fraction of a hz. But importantly, everything on the grid stays sufficiently synched together, even as they all fluctuate. If the frequency deviates too far too fast generators are often required by the operating rules of the grid to disconnect to protect themselves and the grid.
       
       And wind power systems participate in this successfully. Look at places with high wind penetration. South Australia has around 50% wind, and at times wind is supplying around 1/2 the states power. And there are no problems with wind not synching with everything else. If there were, with that level of wind, the grid would collapse in seconds.
       
       There are some issues with higher levels of wind (and solar) reducing the supply of synthetic inertia to the grid that the fossil fuel (and hydro) generators need to stay in synch.
       
       Essentially Coal, Gas & Hydro plants need the grid to help them stay synched, providing inertia for the spinning machines to work against to help stabilise their speeds and thus output frequency. And some participants on the grid actually supply frequency control services, rapidly adding or removing demand on second timescales to vary the loads that the FF & Hydro generators work against to prevent them varying in speed to much as demand varies. This allows the control systems in the FF & Hydro plants enough time to change the flow rate of the steam for example to adjust the power output of the generator. Essentially the FF generators can't maintain grid frequency stability on their own, their response times are too slow. So instead of them stabilising the grid, they are actually stabilised by it, by other systems.
       
       Wind hasn't detracted from basic frequency management but at high penetrations levels it has reduced the level of synthetic inertia available on the grid. It hasn't directly destabilised the grid, but it has made it harder for the actual stabilisers to stabilise the FF plants. This issue is well recognised, and there are technologies to address this, adding extra components to increase synthetic inertia.
       
       Alchemysts's point about 'baseload' stabilising wind isn't true. Baseload (meaning things like coal) actually need to be stabilised by other systems.
       
       Modern wind turbines have completely decoupled the rotational speed of the turbine from the frequency of the power they put out onto the grid. Two methods used are:

       • Doubly Fed Induction Generators. Essentially using an AC-DC-AC converter to manipulator the energisation of the windings so the power output from the turbine has the right frequency, independent of the speed of the blades.
       • Direct AC-DC-AC conversion. Instead of messing with the windings, the complete AC power output from the turbine, at whatever voltage and frequency, is fed into a converter. First the conversion to DC removes any consideration of the rotor speed. Then the second DC-AC stage creates the desired voltage and frequency, 60 hz say. And the control system for these can then vary this output frequency to follow the variations in the frequency on the grid. Solar power from PV's, being DC, is fed onto the grid in a similar manner, with a DC-AC conversion that handles managing output voltage and frequency. Similar technologies are used in High Voltage DC Transmission lines to convert AC to DC, transmit DC, then convert from DC back to AC at the other end.

       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!

14993. scaddenp at 14:29 PM on 31 March 2018
       Explainer: The polar vortex, climate change and the ‘Beast from the East’
       

       Alchemyst, given your earlier comments expressing doubts about modelling, I am surprized at you pushing a modelling paper. I am a little curious as to how you found it but yet missed any the 2014 reviews of arctic influence. No matter – the paper in question (Ineson et al, 2011) was written showing some modelling support for hypothesis of low solar activity contributing to the then recent cold winters. The corollary of this view is that anomalous jet stream behaviour (present in those events) should have eased when the sun returned to active mode. It did not – anomalies continued right up to this year. Furthermore, if the solar is the dominant influence, (as opposed to a contributing factor), then the 2018 tree ring study of jet stream behaviour should be also revealing the link – it does not. 

       Overland et al 2015 has a discussion of arctic – jet stream linkages which I found very helpful. It notes solar (citing Ineson et al) among other possible influences (ENSO, QBO, AMO etc). However, the evidence is increasing pointing towards the loss of ice in the arctic basins as the dominant cause of recent anomalous jet stream variability. The tree ring study by itself put any "Its just a natural cycle" explanation in doubt.

       Interestingly, the model effect from solar changes in Ineson et al affecting the jet stream variability is the decrease in equator-polar temperate gradient.

       "This temperature change is directly attributable to the decrease
       in ozone heating associated with ultraviolet irradiance, which
       is important at these levels11. This signal peaks in the tropics
       and corresponds to a relative decrease in the pole-to-equator
       temperature gradient. This response is reproduced in our model
       (Supplementary Fig. S1) with significant cooling of about 2 K near
       the tropical stratopause. Geostrophic balance requires that the
       diminished polewards temperature gradient is matched by a weak
       easterly wind anomaly in the subtropical zonal mean circulation
       in the upper stratosphere"

       Sea-ice loss does exactly the same thing.

       As this article clearly states, the science is still young but it certainly cannot be dismissed. 

14994. Philippe Chantreau at 13:22 PM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       As Nigel has noted, the thesis linked by Alchemyst does not point to any fundamental problem. In fact, the introduction of the thesis states that it is of interest because of increased contribution from a specific type of wind generator into the grid and an even greater anticipated future contribution.

       Alchemyst, I suggest  that you read more carefully the materials you link. Also, you need to argue on topic. The topic of this thread is 100% wind/solar generation and the geographical are and overgeneration capacity to achieve that goal. The paper in the OP discusses that topic, that's what you need to argue about here on this thread. Your comment at 18 indicates that you did not carefully read the OP paper.

       The instability caused by increased contribution of intermittent sources in a grid prinarily fed by conventional sources is a different enough topic to warrant looking for a more appropriate thread.

14995. nigelj at 12:24 PM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst @17

       Your claims don't appear to be sustained. These appear to be problems about wind power maintaining an even voltage and frequency.

       The abstract of the thesis in your link is about the problems of fixed speed generators in terms of stable voltages, and notes these are common in existing wind farms. However it notes that direct drive variable speed generators are feasible, although  more expensive. However it did not say prohibitively more expensive, and its not clear why they would be given the nature of generators.

       I couldn't see any obvious reference to frequencies or problems with this.

       I really don't see that the thesis found some fundamental unsolvable problem with anything.

       If you meant problems with functionality of storage technology, I'm not sure where you get that from. Have a look at the huge Tesla battery instillation working in southern australia.

       Clearly batteries are still expensive, but numerous options are under investigation in prototype that use relatively cheap materials including alluminium, carbon, sodium sulphur etc. And note my post above on how much lithium batteries have dropped in price in just a few years.

14996. nigelj at 11:51 AM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Alchemyst @15

       "You are correct at the moment we can only use wind power to supplement other generating systems. "

       I only said that in the sense that wind and solar can provide 80 - 90% of power with the remainder as biofuels, nuclear or hydro. (or gas as a last resort). This system provides a stable baseload according to the article, and is also economically viable right now.

       Storage options are however dropping fast in price and could replace the need for biofuels, nuclear etc. This would be preferable to me.

       Your science daily link didn't say anything about baseload power requirements.

14997. DPiepgrass at 11:44 AM on 31 March 2018
       How could global warming accelerate if CO2 is 'logarithmic'?
       

       William, tipping points do exist and imply that the long-term warming curve isn't quite logarithmic. I believe that the usual estimate of ECS of 3°C (when CO₂ doubles) does include some tipping points having been reached.

       You mentioned clathrates—it is considered "very unlikely" that clathrates will release methane in a "catastrophic" manner during this century; in fact it appears the threat is many centuries away (see this video or this SkS article); I think it's safe to say we can stop worrying about clathrates unless new evidence comes in showing the threat has been underestimated.

       I believe the most notable tipping point is ice sheet melting. According to one estimate, "the tipping point for eventual total melting of the Greenland ice sheet could be a global temperature of around 1.6°C above preindustrial"—or even lower due to uncertainty (this corresponds to more than 1.6°C of warming in northern Greenland, since the arctic has warmed much faster than the global average. In southern Greenland, maybe not, due to the cold blob.)

       Uncertainty—contrary to what the dismissives say—is one of the scariest things about global warming. Due to uncertainty, the ECS could be as low as 2°C or as high as 4.5°C. The latter would be catastrophic for human civilization, especially as it corresponds to more than 4.5°C of warming on land. (Based on Sutton et al 2007's low-lattitude warming ratio of 1.51, that would be 5.9°C/11°F hotter on land and 3.9°C at sea. If you've ever lived in a tropical climate, you know the last thing we need is more heat!)

14998. Philippe Chantreau at 11:40 AM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Storage technology has been proven.

14999. Alchemyst at 11:37 AM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       Sweet for point 15

       To reliably meet 100% of total annual electricity demand, seasonal cycles and unpredictable weather events require several weeks’ worth of energy storage and/or the installation of much more capacity of solar and wind power than is routinely necessary.

       I think you are going to need a back up

       your report missed

15000. Alchemyst at 11:28 AM on 31 March 2018
       Study: wind and solar can power most of the United States
       

       My claims are sustansiated.

       http://shodhganga.inflibnet.ac.in/bitstream/10603/79069/1/jeeva%20jothi%20thesis%20final.pdf

       Moderator Response:

       [GT] Link corrected. Please use the linking tool in the toolbox

Prev  292  293  294  295  296  297  298  299  300  301  302  303  304  305  306  307  Next