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John Hartz at 23:31 PM on 16 July 20152015 SkS Weekly Digest #27
Moderation Comment:
From here on out, please avoid the temptation to respond to Michael Fitzgerald.
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MA Rodger at 19:06 PM on 16 July 20152015 SkS Weekly Digest #27
Michael Fitzgerald @53.
Thank you for this comment @53. Unlike previous offerings, it can be read through and the meaning gleaned in one reading.
170K? "Someone said". This is a bit tenuous. It sounds like somebody is adopting an arbitrary "at -100ºC". But what if it was effectively only -40ºC?
Your basic thesis here is that if ECS=3ºC, feedback has to be contributing two-times the warming of the original forcing. (I note you inflate this to 3.3x but I'm pretty sure that is wrong & let's tackle one thing at a time.) So, very very simplisitically, if there is 150Wm-2 of forcing but the planet has 239Wm-2 of forced warming, at a ratio of 2:1, dropping that level of external forcing we would run out of feedback by 239-(150/2)=164Wm-2=(from Stefan-Botlzmann)232K=-42ºC.
Of course, once the mechanisms that actually create the feedbacks are considered, the simplistic use of a 2:1 ratio will (and the ballpark -40ºC may) prove complete pants. I think it will also demonstrate how much of a theoretical thought experiment it is that you are pursuing.
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PhilippeChantreau at 13:18 PM on 16 July 20152015 SkS Weekly Digest #27
Unless of course said position is lacking merit and has already been considered and found to not deserve further consideration. Then continued repetition will obviously lead to more pointed comments.
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GeoffThomas at 12:59 PM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
I agree with the moderator on jvd particularly noting post 31, thanks Tom, I see Jvd and many other Nuclear exremeists on http://www.energybusinessnews.com.au and it makes it an unpleasant site as they interpret every article and every post on the articles as requiring their strident answer, - I just don't go there anymore.
Years ago we were talking of virtual power stations, - all forms of generation co-operating to get the best power but focussing on just one prevents that.
And btw, I notice that wave and tidal generation is making some big strides so will be able to be added to the mix more and more and Tidal is interesting in that it can be predicted thousands of years ahead.
Moderator Response:[JH] Link activated.
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Dcrickett at 12:05 PM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
I worked in nuclear power engineering and construction for several years back in the 1980's. I was flabbergasted at the costs imposed by excessive requirements of the various codes, and positively impressed with the QA processes. But my gut feeling was (and is) that it was the "Operation Independence" pushed by the government (especially President Nixon) to hurriedly build Nuclear, full-speed-ahead-damn-the-torpedoes, that did irrepairable damage. Arrogance resulted. And the cost-plus contracts that rewarded sloppy inefficiency. Also damaging was the attitude that there was so much in way of safety factors, redundancy etc that there could be no problems... and severe problems came along anyway. Yikes!
Nuclear is a brittle technology. Even so, most problems resulted not from inadequate safety etc factors but from failure to provide for what caused the problems. Like Baldur's mother, told that her son could only be killed by a wood-tipped spear, got him blessed by the spirit of every kind of tree and shrub that grows upon the face of the Earth. So Baldur was killed by the evil Loki with a spear tipped with mistletoe, a parasitic shrub that grows on trees and not on the face of the Earth.
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MIchael Fitzgerald at 11:04 AM on 16 July 20152015 SkS Weekly Digest #27
To All,
I really wish you all would stick to the science. One thing you can learn from co2isnotevil's posts is that he doesn't constantly berate his opponents for having an opposing position, only attacks the position itself and usually quite effectively. Constantly berating those with opposing positions only makes you appear insecure about yours which only serves to weaken your case.
Michael
Moderator Response:[JH] Off-topic and insulting.
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MIchael Fitzgerald at 11:03 AM on 16 July 20152015 SkS Weekly Digest #27
KR,
Actually, it was his post here (#35.1) that inspired my question.
http://joannenova.com.au/2015/07/climate-scientists-more-scared-of-an-inquiry-into-the-science-than-they-are-of-climate-change/
Based on your denial that these questions even have answers, co2isnotevil appears right and the answers clearly dispute the accepted sensitivity, and this scares many who believe otherwise. I'm also a physicist and his descriptions of the underlying physics are spot on. The climate is certainly complex, but in the final analysis, its macroscopic behavior must still obey the laws of physics. The many inconsistencies pointed out in the threads you referenced is astonishing, especially how so many laws of physics must be violated to support a high sensitivity. I still have trouble believing how so many smart people can be so wrong in so many ways about something so important, but the evidence presented is powerfully compelling.One piece of evidence is a plot of monthly average surface temperatures vs. monthly average emissions by the planet, extracted from decades of satellite measurements, where the only possible conclusion is that the Earth is nearly an ideal gray body from space with an emissivity of 0.62 and answers the question about whether an ideal gray body model is sufficient for modeling climate change or at least bounding the sensitivity. The theoretical range of the sensitivity for an ideal gray body model of Earth is in the range of 0.2 – 0.3 and spans most of the estimates from the so called 'consensus of skeptics' and is far from the 0.4 – 1.2 range asserted by the 'IPCC consensus'. There's no room for compromise where both sides can say they were right and that's part of the problem. I predict that a sensitivity significantly less than the accepted lower limit of 0.4 must inevitably be accepted, and when it is, climate science will be disrupted in a way that no field of science has ever experienced and it will be both interesting and scary to watch with many far reaching repercussions.
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MIchael Fitzgerald at 11:01 AM on 16 July 20152015 SkS Weekly Digest #27
MA Rodger, #52
I never denied anything about snowball Earth. Of course I understand the evidence that suggests it may have occurred as many as 3 times, the most recent about 500-800 million years ago and others going back billions of years. All I did was offer a possible hypothesis for why they might arise and why they don't persist, which as far as I'm concerned, anything anyone says about this, published or not, can only be speculative, especially given the how much the Sun, orbit, surface and atmosphere has changed over billions of years.
If you know of a reasonable quantification for the sensitivity as a function of temperature, please tell me what it is. This is what I've been asking for all along, yet nothing has been forthcoming except arguments that it doesn't apply because feedbacks change as a function of temperature. I completely agree that feedbacks change, but it's completely quantifiable by starting with the slope of SB and increase it when positive feedback arises and decrease it when negative feedback arises. The problem is that there's no version of this form that can lead to a monotonic temperature increase that ends up at a sensitivity of 0.8C per W/m^2 @ 288K. BTW, its perfectly OK to say that the feedback is so negative along the way, that no temperature increase occurs as the input energy increases, but I can't conceive of any negative feedback with this much effect and that can persist over a wide enough range of input power to end up requiring a sensitivity of 0.8C per W/m^2 at 288K, plus there's the T^4 issue to deal with. Denying that the test applies only weakens your case for a high sensitivity.
The 170K comes from something someone said about no GHG effect below this temperature. This means that there is no atmospheric CO2, water vapor, or clouds, thus no feedback. If you can quantify a feedback mechanism below 170K, please tell me what it is, but if its positive feedback, it only makes it more difficult to arrive at a function that ends up at 0.8C per W/m^2 @ 288K.
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bozzza at 10:57 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
@41 and 42, this all comes under the year 11 economics concepts of the problems to do with government intervention into the market place. The more they intervene the more difficult it is to extract themselves.
Government Intervention makes the so-called free-market less efficient: thus picking fossil fuels as the 'winner' all those years ago gave it economies of scale and ,as Bill Gates would say, "Automation of an inefficient process simply increases that inefficiency."
Markets are meant to be robust is another dictum learnt in year 11 economics-> lending the idea that the more governments intervene the harder it is to extract themselves as economies build thmeselves around the initial intervention. If we add the witches wand of Hollywood into the mix we can almost guarantee Americas inability to move away from Nuclear Power due to real-politik which means, of course, it's just not possible from the highest degree of probability at the nuts and bolts level.
People vote and this too counts as government intervention.. it is of course a chicken and egg thing!
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wili at 10:12 AM on 16 July 2015Are we overestimating our global carbon budget?
So what does this mean for the 2018 'hard deadline' for any more production of ff-using devices, vehicles, homes, buildings, and plants just reported on?
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michael sweet at 09:50 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Tom,
I have not been impressed with the material on Brave New Climate in the past.
That said, if SkS had any nuclear thread everyone could post links to the data they thought supported their side and it would all be in one place. Currently we will have to repeat all the posts from the same discussion a month ago again with JvD, since they were posted on a weekly thread and are hard to find (and reargue all the material that JvD posted years ago). Any nuclear thread would allow the data to be consolidated in one place so that we could refer to that thread for all nuclear questions.
I agree that reposting your linked article would be a simple way to get an OP.
Moderator Response:[DB] User JvD had been banned for multiple and repetitive violations of this site's Comments Policy, including sloganeering and inflammatory, to name a few. Since his return in another User ID form (Joris van Dorp) is also a violation (sock puppet), his current User posting rights have been rescinded.
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Tom Curtis at 07:45 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Adding to my comment @41, what might be even better is if Barry Brooks and Dana(?) cowrote an introduction to the topic covering the areas of agreement with each then writing a seperate continuation arguing their respective points of view (ie, that nuclear must be a substantial part of a zero carbon energy mix for Brooks; and that nuclear a zero carbon energy mix can be achieved, and should be achieved with no new construction of nuclear power plants - which I take it is Dana's position.
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Tom Curtis at 07:39 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
michael sweet @40:
"Nuclear has not been demonized, it is uneconomic."
I think it is fairer to say that nuclear has been demonized, but it is also uneconomic. In particular, US reactors built before the Three Mile Island incident (and hence before the dislike of nuclear had any political teeth) were also uneconomic relative to coal in the US.
It may fairly be argued that that is only because it was competing against coal that did not include the social cost; and which could be dug out of the ground cheaply and abundantly with minimal transport costs (and again ignoring considerable social costs). But that also is the cost benchmark solar and wind are expected to exceed, and are on the cusp of exceeding (are exceeding in some cases).
"If you really think that nuclear is worth while, write an OP to support your argument."
It may be worthwhile extending that invitation to Barry Brooks of BraveNewClimate to write that post. If nothing else, he may permit the reposting post to which I directly linked, although it would be better if he fleshed out his arguments. I suspect he would be more than happy to take up the invitation. I am sure this could be made agreeable to the members of the SkS team who strongly disagree with nukes (of which there are at least a few) by noting it would provide a location where discussion of nuclear is on topic, and can be matched by an OP providing the counter argument (giving two locations for such discussion).
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michael sweet at 05:19 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Joris,
Back to SkS for one thread and already the moderator has had to warn you twice. You win no friends for your pet cause when you violate the comments policy.
It is invariably a waste of time to argue Nuclear power in an unrelated thread. That argument has been made many times, you have added nothing new here (I have made this post at least twice in 2015).
If you really think that nuclear is worth while, write an OP to support your argument. Send it to SkS with suitable peer-reviewed data (links to white papers from the nuclear industry are generally not good enough) I have made this suggestion to at least 3 other nuclear supporters but none of them think the argument in support of nuclear is strong enough to warrent the time to write the post. tThis makes me think that even the supporters of nuclear know in their hearts that nuclear cannot be supported. Go ahead, write the op and show I am wrong.
Your posts that bring up old, debunked nuclear arguments like battery storage of renewable power and the "demonization" of nuclear power do you no credit. They make nuclear look worse.
Nuclear has not been demonized, it is uneconomic. The reactors currently being built in the US are 2 years behind schedule and close to double their budget. Georgia taxpayers are paying for power they may never receive. Norway is ten years behind schedule. 3 in four nuclear reactors worldwide are way behind schedule and grossly over budget— and most of the ones that are not behind schedule had no data available.
In the midwest they are getting ready to shut down existing nuclear plants because they cannot compete with wind. How could they afford a new nuclear plant?
In Florida, where I live, we are paying $1.5 billion for a reactor that never broke ground and another $5 billion for a failed upgrade on another reactor. In California, where I used to live, the San Onofre power plant was shut down after a failed upgrade, billions more in losses. You cite future costs from estimations by the same engineers who are 10 years behind in Norway and designed the failed San Onofre upgrade. I certainly trust their estimates--not!!! Nuclear is uneconomic.
We always have to rehash everything when you show up because nuclear supporters cannot be bothered to write an op suporting nuclear. Nuclear should be banned from all other threads until an op is writen so that we do not have to rewrite everything every three months.
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CBDunkerson at 04:33 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Andy Skuce, there will certainly be a limit to intermittent power penetration without storage and/or long distance transmission... but there is no reason that the remainder has to be made up by fossil fuels. There are many countries with large hydro power resources which could be linked to neighboring countries with wind/solar power to provide stable electricity at lower prices. We can see this currently with Denmarks >40% wind power working symbiotically with hydro power in Norway and Sweden. The same could be done with nuclear, but only France really has high enough nuclear penetration to make it feasible (that is, trading their stable baseload for lower cost wind/solar from neighbors).
Thus, it seems plausible to me that most of Europe, and many other places around the world, could completely decarbonize without needing electrical storage... and again, all indications are that the current free-fall in battery storage costs will continue and make large scale grid storage economically feasible soon. Ergo, lots of reason to think that we could see rapid decarbonization, driven purely by economics, in the coming decades.
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Andy Skuce at 03:33 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
I largely agree with Joris that opposition to nuclear power on the grounds of safety is unfortunate and that nuclear fear has been exaggerated. Nevertheless, nuclear fear is a global reality and not one that will go away very easily, certainly not by mocking people who are scared of anything radioactive nor, sadly, by lecturing them on the facts of death counts at Chernobyl, Three Mile Island or Fukushima.
My guess is that many, maybe most, people now have a natural disgust reaction when it comes to nuclear power and that no amount of argument will persuade them otherwise. It's a bit like Americans with their gun culture or my aversion to eating dog. You could tell me how tasty and nutritious dog meat is and that it can be provided without cruelty, but I'm not going to listen to a word you say.
Public rejection of nuclear power is a sad reality and unless the nuclear industry and its friends can find a better way of changing people's minds, it is not going to become a major player in the future. Nuclear proponents are often proud of their hard-headed approach to facts, but they seem to be in denial of the reality that greatly increasing nuclear power in almost any country is going to run into determined public resistance that won't be overcome for a generation or more.
Some of the most strident anti-nuclear sentiment I have encountered is in France, which benefits from cheap(ish), carbon-free electricity, produced for decades without a major accident. In the same country, an estimated 40,000 die every year from diesel pollution.
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Andy Skuce at 03:01 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
While it is true that countries like Denmark sometimes get >100% of their energy from intermittent renewables, they can only do this because they are part of a larger grid that includes coal, gas, bioenergy, nuclear and hydroelectricity. If we are looking at the maximum feasible penetration of solar and wind, I am (mostly) persuaded by Jesse Jenkins' argument that within a grid, the maximum penetration of intermiitents is going to be about 40%. Of course, this would not apply if there were a cheap electricity storage technology.
A place worth watching for renewables penetration is Hawaii. With abundant solar, wind and geothermal potential and with current diesel-powered electricity selling at 31cents per kwh (and a legislated mandate to go 100% renewable), this is a place to watch. Or, rather, places to watch since every island has its own grid.
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wili at 02:09 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
The discussions seems to be getting sidetracked, as happens often in other forums, into another tired, hackneyed discussion about nukes vs renewables.
This paper is important enough, it seems to me, to discuss it's specific claims and take these side-debates elsewhere.
Particularly, I would like to know how Andy Skuce's excellent article just posted on this site intersects with the above study. I assume that it would move the "Hard Deadline" date from 2018 to some even earlier date, but I'm not sure how much earlier. 2017? 2016? Now? Last year? Three decades ago??...
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Rob Honeycutt at 02:00 AM on 16 July 2015There is no consensus
britty5096... Are you looking at the correct tab? The advanced tab specifically states that it's a survey of research papers.
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Joris van Dorp at 01:30 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
CBD, the subsidies report I linked considers both "consumer support" subsidies and production support subsidies, which makes it a little complicated to understand exactly how much money goes to subsidise production, which is what should concern us if we want to evaluate the competitive performance of different energy technologies.
For example, the report considers the fact that oil consumers in many oil exporting countries buy oil products at the domestic cost of production (as opposed to the international market price, which can be several times higher in many cases) as a 'consumption subsidy', and lumps this huge figure (about 400 billion/a) together with actual production subsidies, somewhat obscuring the effective production tax/subsidy situation.
Moreover, both these "consumption subsidies" and tax revenues are highest by far for oil products. This follows logically from the fact that oil products are heavily taxed in most OECD countries, while they are sold at the cost of production in most oil exporting countries.
Ignoring so-called 'consumption subsidies' for oil, the 8 to 1 figure for the ratio between tax revenues and production subsidies (~800 billion to ~100) billion is in fact concluded by this report. The report does not show that coal or gas generally recieve more subsidies than they yield in tax revenues, contrary to your claim above. In fact, the report explicitly states that total coal production subsidies are only 3 billion, on page 5. I assume you are aware that this is virtually nothing when considering the massive amount of electricity provided by coal.
Concerning your PPA figures for recent utility solar in the USA, I have also seen these figures. AFAIK, no details have been provided about the base investment cost. If the solar resource of these projects offers 1700 full load hours of insolation equivalent, if the PPA prices are constant prices, and if the discount factor is 8%, then a PPA price of 0.0553 $/kWh implies a total lifecyle cost of at most 1$/W in present value money, to break even over a 20 year PPA lifetime. This would be very cheap for utility solar. Certainly it is far cheaper than estimates for utility solar from recent literature. It would be good to know how such a low lifecycle cost was achieved.
Of course, none of this is to say that solar is competitive with FF or nuclear. Even if the 0.0553 is in fact fully unsubsidised (which requires more detailed information on the project finances) then this price only matters during times when the sun is shining. Outside of those hours, the value of these solar plants is zero, since they are not dispatcheable. As such, they are only competitive with FF when the sun shines. That makes solar (or wind) power usefull only as a fuel saving technology for traditional fossil fuel power generation. The fuel cost of coal power is about 3 ct/kWh, so the PPA of solar would have to drop to below 3 ct/kWh to be a competitive fuel saving measure paired with a coal power plant.
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KR at 01:14 AM on 16 July 2015There is no consensus
britty5096 - Keep in mind that "unpopular opinions" are absolutely not "null results", but rather the very points that will be noted, especially if they are supported by the evidence.
And the survey (not poll) of abstracts shows very very few items expressing the 'skeptical' "unpopular opinions", and almost none (personally, I can't think of any) that have held up to scrutiny against the evidence.
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KR at 01:09 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Joris van Dorp - "...how solar or wind can ever be cheaper than nuclear on a cloudy, windless day?"
Because in reality we aren't talking about single solar or wind stations, but rather networked systems extending over geographic areas. And as demonstrated by Archer et al 2007, Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms, connecting even as few as 20 wind stations in the US MidWest results in a dependable baseload capacity of 33% average power, as weather systems won't cover all of the locations at once. Adding solar to the mix would greatly increase the available percentage, as would extending the geographic region considered.
Overall the papers I've seen indicate that some overcapacity, rather than storage/buffering, is more economic in renewables with current technology. And for the small percent of the time that fossil backup is required, the carbon emissions for that backup amount to only a few percent of the emissions required without renewables.
At this point wind energy is one of the cheapest additions to energy portfolios, with utilities increasing their contract purchases accordingly.
Nuclear power is certainly an option, and IMO needs to be part of the energy mix - but it's rather expensive (for many reasons), requires very long lead/build times, and notably comes in quite large (as in not incremental) chunks, making it hard to plan for and finance.
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britty5096 at 01:08 AM on 16 July 2015There is no consensus
Skeptical Science:
Thank you for this. I would also count myself among those who agree that climate change is impacted by human activities. But can you please consider changing your summary of it to more accurately reflect what the study's abstract says? Firstly, this is not a poll of scientists, but a poll of published scientific papers (so there is probably a lot of representation from a handful of prolific scientists). Also, it says that "66.4% of abstracts expressed no position", and 97% of the abstracts that expressed a position endorsed AGW. In total, only 33% of all abstracts (not scientists) explicitly endorsed AGW. Furthermore, there is often a bias against null findings in any field, which encourages "exciting" results to be published while null findings (especially unpopular opinions) may be suppressed by peer reviewers, journal editors, or lack of funding. So really, if you want to rephrase it, it should say "97% of published abstracts that stated a position on AGW agreed with it".
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ryland at 00:48 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
JvD It will be interesting to see if in the fullness of time, concerns on effects of wind turbines on the human brain are substantiated or not. if they are substantiated and that may well not be the case, wind turbines may have to deal with concerns from the public just as the nuclear industry has had to do. A piece in The Australian states:
"There has been a report from the National Metrology Institute of Germany that concludes exposure to infrasound below the range of hearing could stimulate parts of the brain that warn of danger. It finds that humans can hear sounds lower than had been assumed and the mechanisms of sound perception are much more complex than previously thought.
The researchers do not claim the results are definitive regarding wind turbines and health impacts, and say more work is needed.
But the research builds on recent work in Japan and Iran — and investigations by NASA dating back to the 1980s — that suggests the health science of wind energy is far from decided and would benefit from further inquiry"
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Tom Curtis at 00:24 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
JvD @28:
"the fact that fear of nuclear is universal does not follow from nuclear's performance in terms of safety and environmental effects. Coal based power has killed millions of people, and still kills more people every day, globally, than nuclear has killed in its entire existance."
That establishes only that the risks of coal powered are under appreciated. Not that the risks of nuclear have been overestimated. Of course, it is very probably that those risks have been overestimated by a sizable number of people - but those people have had little influence on regulations. It is therefore entirely uncertain that overdesign of safety features has needlessly increased the cost of nuclear power. Given a priori assumptions about the efficiencies of government, it likely that it has been both overregulated in some aspects and under regulated in others (as chernobyl and fukushima demonstrate).
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Tom Curtis at 00:14 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
JvD @23, I have no intrinsic objection to nuclear power. Indeed, I am happy enough with it that I used to stor a sample of uranium ore in my bedroom as a teen, and still consider it short sighted and stupid that Australia persists in operating diesel/electric rather than nuclear submarines. Having said that:
1) Nuclear power as the primary power supply can only be an intermediate term solution as, if it is considered a long term solution, economic growth will result in waste heat becoming as bad a global forcing as CO2 is currently (and a much worse regional forcing);
2) Given (1), to the extent that we can solve the need for carbon free energy using renewables, that is a step in the right direction;
3) There is no inprinciple reason why renewables cannot supply all our energy needs, even if populations grow to double their current levels, world economic growth continues unabated, and third world per capita GDP catches up with the future levels of western per capita GDP. However, the use of nuclear power, particularly over the next 50 odd years may substantially reduce the cost of going to a carbon free economy;
4) I do not need to determine whether or not a nuclear/renewable mix or a pure renewable strategy will be most cost effective. Rather, we need to ensure there is an appropriate price on carbon and let investors sort it out; but
5) For whatever reasons (rational or irrational), nuclear power is a hard sell in some societies. At the same time for reasons entirely irrational, effective action on AGW is a hard sell in nearly all societies. I do not think it is good policy to shackle the later to the former. Doing so generates a substantial risk that we do not undertake effective action on climate change. It may have the payoff of making available a cheaper mitigation strategy but only at the substantial risk of having no mitigation strategy.
Points (4) and (5) are the key points IMO. I have absolutely no problem with people inclined to do so promoting the use of nuclear power. As a political policy, I would by likely to vote for it given reasonable confidence of certain safe guards (mostly relating to waste disposal). I know that those safegaurds are technically feasible, and probably quite cheap to impliment. But I strenuously object to people attempting to coopt concern for AGW as a mechanism to generate support for nuclear power. (I have similar, but even stronger objections to coopting concern about AGW to push for negative population growth and/or negative economic growth policies by people who think those are intrinsically desirable in any event.)
I want to see support for action agains AGW across all parties, whether green, socialist, centrist or conservative. I am not going to tie support for that action to any secondary issue when they are not essential to solving AGW, even if they would be helpful.
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CBDunkerson at 00:05 AM on 16 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
JvD, the report you link shows that ~94% of those tax revenues come from oil. Conversely, oil accounts for less than 5% of global electricity generation. Basically... you are using gasoline tax revenues, which have nothing to do with electricity generation, to argue that fossil fuel electricity generation is not more expensive when subsidies are removed. Clearly false. The report also shows that ~46% of fossil fuel subsidies go to coal and natural gas, which are primarily used for electricity generation. Rounding that up we could say that roughly half of fossil fuel subsidies go towards electricity generation... while only ~6% of fossil fuel tax revenues come from electricity generation... and suddenly your 'eight times' is going in the opposite direction. That is, fossil fuel electricity generation gets about eight times as much subsidy support as it generates in tax revenues... based on your chosen data.
Your other claims are similarly flawed. Many countries have been able to install massive amounts of renewable electricity generation (up to 100%) without any storage or long-distance transmission. These things will certainly be required in many countries, but not until the transition to renewable electricity is well underway (say ~50% of electricity generation)... by which point even the combined costs of renewable power and improved grids are expected to be significantly lower than fossil fuels.
As to solar getting 75% subsidies in the US. Not even close. It's a 30% investment tax credit (dropping to 10% at the end of next year). At either $0.0387/kWh (with subsidies), or $0.0553/kWh (without), the lowest solar PPA prices in the US are now both lower than the national average price. That's more than 'competitive'. Indeed, the subsidized price is lower than any other power generation in the country... except the cheapest wind farms.
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Joris van Dorp at 23:58 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
To the moderator,
It is no controversy that adding electricity storage to solar or wind adds at leasts 10 to 20 ct/kWh, making it grossly uncompetitive even with FF having fully internalised costs.
http://www.sandia.gov/ess/docs/other/Grid_Energy_Storage_Dec_2013.pdf
By the way, you can always just ask for a source for anything I claim. I never write anything not backed-up by solid evidence. I don't have time for such nonsense. I'll give evidence for all my claims freely, if asked. No need for threats! :)
Moderator Response:[JH] If have neither the time nor inclination to document the sources of your statements, then this website is not for you.
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Joris van Dorp at 23:42 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
@CBD: the fact that fear of nuclear is universal does not follow from nuclear's performance in terms of safety and environmental effects. Coal based power has killed millions of people, and still kills more people every day, globally, than nuclear has killed in its entire existance.
My point is that the extraordinary fear of nuclear power is an irrational barrier to having nuclear solve AGW efficiently, which scientists should have spent some time removing in decades past. Instead, scientists have devoted all their attention to urging co2 emission reductions. In the upcoming climate talks in Paris, the focus will again be entirely on agreeing on reduction of global co2 emissions. No effort will be spent on agreeing to reduce global antinuclearism. I think this way of approaching climate policy has failed in the past and it will continue to fail in Paris and beyond.
You repeat that solar and wind are cheaper than nuclear. Could you explain briefly how solar or wind can ever be cheaper than nuclear on a cloudy, windless day?
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Joris van Dorp at 23:16 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
CBD: "If even just the overt subsidies, to say nothing of the massive 'external costs' from their health and environmental effects, were withdrawn fossil fuels could not compete with solar and wind power now."
That is incorrect. Fossil fuel tax revenues dwarf fossil fuel pre-tax subsidies in a ratio of 8 to 1.
http://www.oecd.org/env/49090716.pdf
In other words, fossil fuel usage brings in eight times as much tax revenue (in OECD countries) as it takes in subsidies. It is only the external costs (mostly climate impact costs) which can push the cost of fossil fuel energy above the cost of unbuffered(!) solar and wind power.
That said, buffered wind and solar power (buffered as in: made fully dispatcheable by adding electricity storage and long-distance transmission) is still far more expensive than unmitigated FF, even including FF external costs. That is a serious issue not to be ignored. It implies that relying on solar or wind to replace global FF use will require their permanent financial subsidies, globally, so better make sure the money for that is made available - globally - if we intend to go that route.
Finally, recent record-breaking PPA's for solar and wind in the US still benefit from exorbitant tax benefits and subsidies, equivalent to up to 75% of their base cost, so these impressively low PPA's do not nearly imply that solar or wind are competitive with FF.
Moderator Response:[JH] Youcontinue to make unsubstantiated global asertions, e.g.,
That said, buffered wind and solar power (buffered as in: made fully dispatcheable by adding electricity storage and long-distance transmission) is still far more expensive than unmitigated FF, even including FF external costs.
Unsubstantiated global assertions such as the above are nothing more than sloganeering which is prohibited by the SkS Comments Policy. Please cease and desist immediately.
Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Moderating this site is a tiresome chore, particularly when commentators repeatedly submit offensive or off-topic posts. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
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wili at 23:11 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Are there any proposed bills in any government body anywhere in the world calling for a halt to all production of ff-burning machines, vehicles, buildings and plants by the year 2018?
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CBDunkerson at 23:10 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
JvD, yes the high cost of nuclear power is largely due to safety measures... which are required due to fear of meltdowns... which exists because the nuclear power industry cut corners and continued using outdated plant designs (e.g. Chernobyl) and old reactors (e.g. Fukushima) long after they should have been abandoned.
However, the only thing that matters is that they are expensive. Why that is the case would only be relevant if there were some realistic way of changing it in the immediate future... which there isn't. Yep, without Three Mile Island, Chernobyl, and Fukushima the whole world would very likely be running on relatively cheap nuclear power by now. But that isn't the reality we live in. Every time nuclear power could have really started to take off and become competitive there has been a disaster and the technology has instead fallen further behind.
Now that it has reached the point that wind and solar are both cheaper than nuclear there is no chance that current commercial nuclear power designs will ever become a major contributor. None. Maybe some new technological breakthru will make some form of nuclear financially viable again in the future, but until then nuclear isn't going anywhere.
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CBDunkerson at 22:48 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Tom Curtis, I disagree that 'we have not seen any major turnaround in the US'. US CO2 emissions per capita peaked at 22.51 metric tons in 1973 and were down to 16.3 in 2012. Yes, that is still higher than most countries (though not Australia), but a 28% reduction (most of it in the past several years) seems like a "major turnaround" to me. Similarly, total US CO2 emissions peaked at 5.928 billion metric tons in 2007 and were down to 5.181 billion in 2012... a 13% reduction in five years.
The world record for lowest cost solar power purchase agreement has been broken twice in the past month... both for new plants in the US southwest. Wind and solar power generation have tripled in the US since Obama became president. Average fuel efficiency of US vehicles is rising rapidly. Et cetera. There are a lot of different indicators showing that the United States has turned the corner on carbon pollution. Certainly still a long way to go, but the US has been heading in the right direction for several years now.
As to when we will see a global transition... I don't think it will have as much to do with the '100th monkey' as with the financiers. At this point, the only reason fossil fuels are still hanging on is that they've got powerful financial lobbies behind them. If even just the overt subsidies, to say nothing of the massive 'external costs' from their health and environmental effects, were withdrawn fossil fuels could not compete with solar and wind power now. By 2020 they won't be able to compete even with the benefit of subsidies. That situation is not sustainable. The political favor which is propping up the fossil fuel industry is purchased via campaign contributions and lobbiests. As fossil fuel profits continue to get squeezed (as oil profits are currently being squeezed like never before) the money available to buy that political favor will decline... just as the money available for wind and solar companies to do the same increases. Renewables have already started to receive some of the favorable treatment previously enjoyed by fossil fuels. That will only snowball as each benefit to renewables pushes fossil fuels further and further behind. In the end, I expect a rapid collapse of fossil fuel financial and political influence. At which point, the misinformation campaign will also stop and the '100th monkey' will realize that they believed in global warming all along... because the people telling them what to think will then be getting their money from 'big renewable'. No way we aren't in the midst of full scale global conversion to renewable power before 2030 unless some major new technological breakthru comes along with a less expensive alternative.
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Joris van Dorp at 22:03 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Tom, are you suggesting that solar and wind power are more likely to eliminate global coal burning than nuclear power, and hence that scientists have been right to focus on the need to reduce co2 emissions rather than the need to remove irrational barriers to nuclear deployment?
I'm not sure I understand what overarching point you are trying to make here.
Concerning wind in Europe, it is clear that onshore wind in Europe tends to be costly, not so much due to the cost of the technology itself, but due to the cost of NIMBY and the high cost of land, which is getting worse because many of the best locations have already been tapped. But yes, there has been a kind of 'demonisation' of onshore wind energy growing in Europe. The concern is not so much the result of a misunderstanding of safety issues as with nuclear (although there have been a few horrific fatalities in the wind industry in recent years, which briefly made headlines), as it is the high cost of subsidies, the spoilage of views, the bird and bat mortality, the emerging issue of the financial and environmental cost of the additional powerlines needed, and the particular noise polution caused by the turbines. A number of European countries have recently shut down subsidies for onshore wind for this reason. All in all, I don't think it is difficult to understand why onshore wind is a bit more expensive in Europa than in the Asian pacific region. It's probably not about irrational demonisation as is the case with nuclear.
Moderator Response:[JH] Please tone down the rhetoric and avoid unsustantiated global assertions.
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MA Rodger at 21:59 PM on 15 July 20152015 SkS Weekly Digest #27
Michael Fitzgerald @47.
I concur with your first sentence. However, addressing these three logical outcomes from your '239-Steps' test is made difficult by your apparent denial of the snowball Earth mechanism ('apparent' in that I am left to interpret the moderation "(snip)" @47).
And in addition to that apparent difficulty, I do not concur with your second sentence. Why do you write that I "seem to believe that no reasonably supportable function consistent with a sensitivity of 0.8C per W/m^2 at an average surface temperature of 288K exists."? My comment @40 surely suggests the exact opposite.
In the round, your comment @47 simply re-states your problematical 239-Steps test in a different form. I'm not sure how that would be any help to 'man nor beast'.
Within all your inconsequential/nonsensical blather @47, I note you tell us "170K ... below which the feedback is zero". On what do you base that assertion?
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Tom Curtis at 21:08 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
JvD @20 & 21, I notice from page 17 of the report that onshore wind costs more in Europe than in the Asian countries. Is this also because of the "demonization" of renewables in Europe? Apparently that is "the only credible explanation" in this sort of case.
What is noteworthy is that while the values I quoted are for studies of historical, actually operating plants, the values from the various bar charts are for Gen III nuclear plants; and include a carbon price of $30 a tonne for coal. The report feels it is necessary to report that " that there are great uncertainties concerning
the cost of carbon capture, which has not yet been deployed on an industrial scale" but feels no need to report similar uncertainties on the price third gen nuclear reactors, which have also "not yet been deployed on an industrial scale". The important point, however, is that the bar charts you are rellying on do not reflect historical values and hence are irrelevant to the point I made. -
Joris van Dorp at 20:19 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Page 19 of this IEA publication clearly shows that nuclear is far cheaper in asia-pacific countries than in the USA.
https://www.iea.org/publications/freepublications/publication/projected_costs.pdf
The only credible explanation is the high cost of rabid antinuclearism in the USA and other countries.
My point is that scientists have spent too much time urging humanity to stop emitting co2, while failing to urge humanity to stop being antinuclear.
Moderator Response:[JH] Unsubstantiated and argumentative assertion stricken. Please cease and desist including statments like this in your posts.
Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
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Joris van Dorp at 20:14 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Tom, I believe you are mistaking cause for effect. Demonisation undermines public acceptance of nuclear, which increases the cost of nuclear (the extreme 'negative learning curve' of nuclear as seen in antinuclear countries). In China and other non-antinuclear countries, the exact same nuclear power plant costs only half as much as in antinuclear countries like the USA. Public acceptance is the cause of this difference. Cost is merely a symptom of public acceptance.
By the way, the 'nuclear is too expensive' argument seems contrived, because solar and wind energy are even more expensive than expensive nuclear. Yet popular 'green' mythology holds that we can solve the climate crisis with wind and solar, never mind the cost. It seems one can't disparage nuclear over cost issues while hailing far more expensive solar and wind as the end-all and be-all of climate protection, no can one?
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Tom Curtis at 20:05 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
JvD @18, what has kept the world from nuclear has not been demonization but the simple fact that its levelized cost is greater than that of coal (see table 11.1a):
Nuclear
LCOE $/MWh 74 56-67 44 51-77 33-74 71
Pulverised coal
LCOE $/MWh 47 45 51 36-44 28-75 51-53 -
Joris van Dorp at 18:02 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
If nuclear power hadn't been demonised so successfully, the world could have had a decarbonised electricity supply by now.
http://www.researchgate.net/publication/270572988_Global_zero-carbon_energy_pathways_using_viable_mixes_of_nuclear_and_renewables
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0124074
http://conservationbytes.com/2014/12/15/an-open-letter-to-environmentalists-on-nuclear-energy/
SKS is a very popular climate science website, and rightly so, but in all the years I've followed this website, I've seen a lot of talk about renewables as a solution to AGW, but almost nothing about nuclear. Indeed, whenever nuclear has come up, it has been attacked and disparaged. That is a pity, because as this article shows, it is now almost too late to prevent 2C of warming.
I wonder if the decades of antinuclearism which has prevented nuclear power from achieving global hegemony instead of coal could not have been prevented if scientists had spent a little less time advocating for people to reduce co2 emissions, and a little more time on explaining to the public that nuclear power is in fact a bona fide and effective way to achieve credible climate protection, let alone elimination of air pollution from electricity generation.
P.S. (I have been banned from this website (which I greatly value) for years now, for being a determined pro-nuclear advocate. My first account was "JvD". I hope that re-registering under a new account is acceptable, since I've spent so much time being banned in penance. If not acceptable, please excuse me and just ban this account as well. Thank you.)
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sidd at 14:02 PM on 15 July 2015Global warming is causing rain to melt the Greenland ice sheet
Another paper linking the 2012 event to an atmospheric river (among other causes) is Neff(2014) doi:10.1002/2014JD021470 -
GeoffThomas at 13:46 PM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
Whilst I agree with the article and it's undoubtedly gloomy and likely conclusions, there is a form of Carbon Capture which is gaining traction all over the world which I have never seen on this forum, - not that I read the majority of articles, - however, I am referring to Terra Preta, now usuallly called Biochar, which is the practice of mixing charcoal with compost and using this as compost.
The charcoal part of this mix remains in the soil with the nutrients from the compost and makes the goodies available to plants (becomes 'Permanent Compost' whilst also acting as nurseries for huge populations of soil biota, which also stimulate the plants.
This has two major effects, one the carbon is sequestered for huge periods of time,- Terra Preta paddocks in South America have had the charcoal measured to be there 7000 years- those paddocks contain 30% charcoal down to 1 metre, in fact it has been calculated that if all the tropical areas of our planet went over to Biochar we would remove all the carbon dioxide added by industrial development since 1800 whatever, - although I have not seen how long estimated.
Nontheless it is a significant thought.
The second major effect is the increased, often spectacularly increased soil fertility, which adds a significant element/motivation, economics, ie you make money with it, very hard with CCS
Less major effects include greatly increasing the water retention ability of the soil, and locking up most toxins in the soil.
The point is that the Biochar movement is significantly growing all over the world, almost all using waste carbon, which would otherwise have returned to the air and much of it happening at grass roots level and it is a message of hope, whereas requiring the rich and powerful to make the required sacrifices seems to me to be a hopeless.
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KR at 12:08 PM on 15 July 20152015 SkS Weekly Digest #27
Moderators - Take note, there may be a sockpuppet in action.
Michael Fitzgerald, you are either co2isnotevil/George White, whose views on this site were shown to be nonsense years ago, or you are parroting his views without credit.
Your last post with "..1.6 W/m^2 of surface emissions per W/m^2 of net solar input..." directly echos many co2isnotevil SkS posts both in phrasing and in claims about short climate response, and both your phrasing "...incremental solar input..." and arguments here directly match a July 3rd 2015 co2isnotevil post at WUWT.
---
Your math is IMO utter and complete nonsense - 4.4*239 is a meaningless and unphysical multiplication, 255K is only of interest as the emissions of a perfect blackbody radiating 239 W/m2 (ie in Gedankenexperiments), while the Earth is a real graybody where emissivity throttles radiative output to space, you confuse cause and effect (TOA imbalances from emissivity or albedo changes lead to changed surface temperatures that can once again radiate the same as incoming - you have the temperature change coming first), Snowball Earth is a red herring in regards to current climate change, etc etc. Nonsense on top of nonsense, complicated arguments without basis that seem (IMO) intended to dazzle and confuse, not science.
Moderator Response:[RH] Looking into it.
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MIchael Fitzgerald at 11:36 AM on 15 July 20152015 SkS Weekly Digest #27
Moderator (RH)
You should also remove 2) from post 41) where snowball earth was originally brought up.
Thanks.
Moderator Response:[RH] The issue is that you're making up your own theory how snowball earth events play out, on the fly. Tom's reference is well substantiated by a great deal of research on the subject.
Update: Specifically, your explanation doesn't explain cap carbonate deposits. There's a whole website dedicated to snowball earth science at snowballearth.org.
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MIchael Fitzgerald at 11:33 AM on 15 July 20152015 SkS Weekly Digest #27
Moderator (RH)
Thanks for the reference. One error is defining the current steady state as the zero feedback result. The 1.6 W/m^2 of surface emissions per W/m^2 of net solar input must be after feedbacks have been accounted for, otherwise more than 1 W/m^2 per W/m^2 of input violates COE. This is also a multi-decade to multi-century average that varies little from year to year going as far back as we have accurate records, so certainly any feedback that operates on time scales of decades to centuries must alreadly be accounted for in the steady state average and this includes GHG, cloud and weather related feedback.
It's also interesting that the steady state average includes seasonal transitions which, relative to surface reflectivity from ice and snow, emulates the transitions in and out of ice ages, albeit on a much shorter time scale. Another test could be crafted to more precisely calculate the most predominant non GHG related component of temperature changes between ice ages and interglacials based on seasonal differences in the response to solar input (i.e. feedback from growing/melting ice/snow).
The incorrect quantification of feedback didn't seem to affect the specific analysis (I didn't dig too deep), but the sensitivity claimed was 3 W/m^2 per K, which in the units used by the IPCC is a sensitivity of 0.33 K per W/m^2 which is below the IPCC's lower bound of 0.4C per W/m^2 and approximately equal to the SB sensitivity at the planets emission temperature of 255K.
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denisaf at 11:32 AM on 15 July 2015A Hard Deadline: We Must Stop Building New Carbon Infrastructure by 2018
The essential point is that the exisiting infrastructure of industrialized civilization irreversibly uses fossil fuels at a high rate, so produces greenhouse gases at a high rate. That is the situation now. Policies to reduce the usage of fossil fuels can only slow down the rate of emissions slowly. The current atmospheric concentration level is 400 ppm and this will continue to increase even as the rate of emissions decreases. The continuing absorption of emissions in the oceans will only slow down the global atmospheric warming but at the expense of the damaging acidification of the oceans. Limiting the warming to 2 deg Celsius is not feasible even if policies are adopted to reduce the rate of fossil fuels as rapidly as practical.
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MIchael Fitzgerald at 10:34 AM on 15 July 20152015 SkS Weekly Digest #27
PhilippeChantreau, #43
There's no double standard. I expect the same degree of rigor from others about anything having to do with science that I expect of myself. Anyone can assert a hypothesis, but scientific rigor is all about asking questions and testing those hypotheses.
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MIchael Fitzgerald at 10:25 AM on 15 July 20152015 SkS Weekly Digest #27
MA, Tom #40 #41
It seems that both of you understand the contradiction this test exposes which can be resolved by either finding a way to disqualify the validity and applicability of the test, identifying a function of sensitivity that when the test is applied, produces the correct results or accepting a lower sensitivity. You both also seem to believe that no reasonably supportable function consistent with a sensitivity of 0.8C per W/m^2 at an average surface temperature of 288K exists. Let me address the potential issues you've raised towards disqualifying the applicability of this test.
Snowball Earth is not a stable state, for if it was, we would still be in it. The most likely events to initiate it would be a large impact event or the explosion of a super volcano that happened to coincide with a natural ice age. Once the dust settles, the planet will warm back up. Of course, this requires that the Earth respond to changes in solar input much faster than currently accepted, as the dust will only persist for a decade or so. A less likely cause would be a dramatic decrease in solar output.(snip)
Hysteresis is not evident in the response to more than a 100 W/m^2 difference in total forcing between summer and winter. If it was, we would see different delays between min/max solar input power and min/max temperature and/or different average temperatures as the planet warms vs. as the planet cools. Delay can masquerade as hysteresis, but the two are not the same. To mitigate the effects of delay on the test, after each step of input, a long enough time must pass for the planet to be in LTE with respect to the total input power. To the extent that feedback from increasing or decreasing reflection changes the input power, the pre-reflected input power will need to be adjusted until 1 W/m^2 of input after reflection (forcing) is received in LTE. This isn't a problem since forcing, per the IPCC definition, already excludes input power reflected away by the dynamic actions of surface ice/snow and clouds.
The ice cores show that entering an ice age is somewhat slower than exiting one which could be an indication of a small amount of hysteresis. This is more likely the consequence of less snow consequential to reduced evaporation as the planet cools and more rain consequential to increased evaporation as the planet warms, resulting in asymmetric rise/fall delays. As an avid mountaineer and back country skier, I can assure you that nothing erodes surface ice and snow faster than rain. If enough time is allowed to pass and TSI remained constant, the same LTE surface temperature will eventually arise whether TSI was increasing or decreasing prior to being held constant, although the time it takes to achieve LTE may be different. Keep in mind that the LTE surface temperature is the time weighted average of all possible metastable states consistent with the current accumulated forcing.The relative temperature range that the Earth experiences is quite large when you consider seasonal variability in monthly average temperatures which are about 250K at the poles and about 320K in the deserts. The only gap is between 170K and 250K, below which the feedback is zero and we can reasonably assume a linearly interpolated temperature dependence of unit (zero feedback SB) sensitivity at 170K up to the required sensitivity at 250K. We can also reasonably assume a monotonically decreasing sensitivity with temperature unless positive feedback as a function of temperature can be shown to increase at a high enough rate to provide significantly more than the 4.5% additional emissions consequential to a 1.1% increase in temperature arising from a 1% increase (3.9 W/m^2) in total forcing (baseline 390 W/m^2 @ 288K with a sensitivity of 0.8C per W/m^2).
The assertion that there's no baseline reference for the sensitivity as a function of temperature is not correct. The slope of the SB Law precisely quantifies the sensitivity for the zero feedback case, positive feedback increases the sensitivity above this and negative feedback decreases it below. By extending the ideal black body analysis we can establish hard bounds for an ideal gray body where the absolute effect can vary based on the specific physics describing how a layer between the surface and space reduces the emissivity. This range has an upper limit quantified by the slope of SB at the radiating temperature of the planet and a lower limit quantified by the slope of SB at the radiating temperature of the surface whose emissions are attenuated by the emissivity. The accuracy and precision of the ideal black body result is limited by the precision of the SB constant, while that for an ideal gray body is limited by the precision and accuracy of the emissivity.
If Earth behaved as an ideal gray body, we could bound the sensitivity at 0.25 +/- 0.05 C per W/m^2 (0.3C per W/m^2 is the sensitivity at the radiating temperature of 255K and 0.2 C per W/m^2 is the sensitivity of a surface at 288K). This represents only 20% uncertainty as compared to the 50% uncertainty of the currently accepted estimate of about 0.8 +/- 0.4C per W/m^2. Unfortunately, there's no overlap in these two estimates, so more testing is required.
Determining if the planet behaves like a gray body and how close to ideal this behavior is can be ascertained by plotting the average surface temperature on one axis vs. the average power emitted by the planet the other. From this, we can establish how close the real behavior is to the ideal behavior of a gray box quantified by Stefan-Boltzmann with an emissivity of about 0.61 (239 W/m^2 @ 255K / 390 W/m^2 @ 288K). This seems like a simple enough test, does anyone have an idea about what it will tell us when applied to satellite data? Has anyone done this?
Moderator Response:[RH] Unsubstantiated snowball earth theory removed as sloganeering until such time you provide a published citation supporting it.
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MIchael Fitzgerald at 10:10 AM on 15 July 20152015 SkS Weekly Digest #27
KR #42
I've already considered the analysis based on current conditions and the situation doesn't get any better. If 1 W/m^2 of forcing (incremental solar input after reflection) results in a 0.8C temperature increase, the Planck emissions increase by 4.4 W/m^2 from 288K to 288.8K. All of the W/m^2 of input are subject to the same conditions, thus each W/m^2 of input must also result in 4.4 W/m^2 of Planck emissions (how can it tell which watt is which) and results in a total of 4.4*239 = 1051.6 W/m^2 which corresponds to a temperature of about 96C. Clearly this can't be true.
Didn't Milankovitch postulate that the asymmetric response to forcing by the hemispheres interacting with the precession of perihelion had the effect of variable gain, thus apparent amplification?It also seems to me that the sensitivity has a discontinuity at 0C, since the negative feedback from incremental reflection by clouds is absent because surface ice/snow has about the same average reflectivity as clouds, thus below 0C the net feedback is more positive. This would imply that as more of the surface is covered by ice and snow, as it is during ice ages, the average sensitivity is higher.
Moderator Response:[RH] If you're interested, SoD has a very good three part series on measuring climate sensitivity that you might find interesting.
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John Hartz at 08:57 AM on 15 July 2015Global warming is causing rain to melt the Greenland ice sheet
Recommended supplemental reading:
Greenland is Experiencing a Sudden and Rapid Melt Season Onset by Pakalolo, The Daily Kos, July 9, 2015
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