Arguments
Recent Comments
Prev 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 Next
Comments 33551 to 33600:
-
Smith at 06:54 AM on 11 October 2014What's the role of the deep ocean in global warming? Climate contrarians get this wrong
Shallow ocean = 0-700 meters
Deep ocean = 700-2,000 meters
Abyss = > 2,000 meters
Are the relative volumes of the above depth categories know?
-
PluviAL at 06:36 AM on 11 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
Wonderful summary, I think we are slowly coming around to a new perspective of the way the globe works. From my studies of atmospheric energy budgets, I come to a very unusual perspective, which this studies seem to support. I can't find the reference, but there is a paper showing that the acceleration of the Indian subcontinent into Asia was preceded by climate change.
Here is the unusual perspective: Tectonic plate motion is much easier to motivate with an energy source that is much larger than earth flux; climate. Solar flux onto earth is 3900 times larger. And the mechanics of GIA, glacial isostatic adjustment, transfer much greater, faster, and mechanically more viable energy impetus for tectonic plate movement.
In my mind I see Antarctica pumping with a potential of 60 petatons of energy, on the pulse of climate. In that model, waves from that action have piled the continental masses on the northern hemisphere.
Gravitation waves play nicely into the process too, but that is too detailed here. Although it may be farfetched, the mechanics are much more robust. If there is any truth to this at all, the seismicity implications within immediate human history may be substantial. Such volcanic reactions to climate with feedback mechanisms through carbon seem to be potentially valid. Even the 39 cubic kilometers of water in the Three Gorges Dam affected seismicity, how much seismicity can 72,000,000 km3, suddenly lifted cause?
-
Rob Honeycutt at 06:30 AM on 11 October 2014CO2 effect is saturated
Jonathan Doolin... Just want to get something clear first. You're going to throw your lot in with two computer science guys, who have no special training in any of the science that they're commenting on, over that of 30,000+ actively publishing climate researchers, and all the National Academies, and pretty much every scientific organization who has a statement on AGW.
Have I got that right?
-
Philip Shehan at 06:08 AM on 11 October 20142014 SkS Weekly Digest #36
I received the following reply from Ross McKitrick.
I note that I was incorrect in thinking that he was saying that the "pauses" were statistically significant, but I believe he has incorrectly concluded that when warming ceased to be statistically significant, the "pauses" begin, even though at this point the trends are still warming and the error margins have only just crossed thew zero line.
Dear Phil
I don't know why the UAH result is so different. I don't know what algorithm is used on the SKS website. Also there might have been revisions to the UAH data set since I accessed it.My calculations didn't aim to measure a statistically-significant trend in the neighbourhood of zero, instead I was aiming to measure how far back the hiatus apparently started.
Cheers,Dr. Ross McKitrick
- Professor of Economics and Chair of Graduate Studies
- CBE Fellow in Sustainable Commerce -
Jonathan Doolin at 05:31 AM on 11 October 2014CO2 effect is saturated
I was attracted to this particular article because I think that the causality case can be made most convincingly from the properties of the Carbon Dioxide molecule itself... especially its absorption spectrum.
I have got into the practice of screen-recording things as I learn it, so that three to six months from now when I have the opportunity to pick up where I left off, I might remember some of what I was thinking.Here is a short list of where I think I'm still confused.
•What is the meaning of "Brightness Temperature" Isn't brightness usually measured in Watts/meter^2?
•I didn't fully grasp how the "Pressure and Doppler Broadening" but that may have been for lack of time and effort...
• What I see, though, is that the absorption coefficient doesn't drop off instantaneously... I would think that any absorption coefficient below 1/(10 km) is going to be NOT saturated. I think maybe the problem involves a lot more detailed calculus though because in those 10 km to to the top of the troposphere, there are pretty massive changes in the density and pressure, wouldn't there?
•According to the graph at LINK (which I used in the video above) it appears that Carbon Dioxide absorbs about 2% or more of the light in a continuous spectrum from 1.5 micrometers to 30 micrometers.
Is that graph accurate? And if so, wouldn't you say that Carbon Dioxide does *not* saturate the spectrum in the wavelengths where it is absorbing 2% of the light?
Finally, have you thought about trying to put together some kind of quantifiable problem... Could you give a functional representation of the absorption coefficient of CO2, as a function of wavelength and concentration?
Then a representation of the power-distribution emitted by the surface of the earth, as a function of wavelength (Planck distribution, yes, I know)
Then a calculation of the heat capacity of the atmosphere at large, with 70% nitrogen, 29% oxygen, etc.
And maybe a description of whether heat flows at the boundaries of air and water, and between troposphere and stratosphere... What kind of models are used in predicting heat conduction between the layers. I guess convection between air and water is completely halted, since clearly the water doesn't flow into the air, and the air doesn't flow into the water... But what about conduction? Is the phase change just as dramatic between the troposphere and the stratosphere?Moderator Response:[RH] Hot linked urls.
-
michael sweet at 05:31 AM on 11 October 2014The Wall Street Journal downplays global warming risks once again
Judith Curry has an op-ed in the WSJ down playing the problem of AGW. It is paywalled so I could not see the date. I am sure Dana will have a reply soon.
-
michael sweet at 03:01 AM on 11 October 2014How did the UK grid respond to losing a few nuclear reactors?
Cosmicomics:
Can you provide links to these claims?
-
StBarnabas at 02:42 AM on 11 October 2014What's the role of the deep ocean in global warming? Climate contrarians get this wrong
The thermal expansion coefficient of water is very temperature dependent; warm water expands a lot more than cold for a given heat input, so this is very worrying and a double whammy so to speak. It's interesting that global sea level rise has been nearly constant at c 3mm per year for the past few decades. I worry that there will be a rapid acceleration sometime soon
-
cosmicomics at 01:38 AM on 11 October 2014How did the UK grid respond to losing a few nuclear reactors?
A few minutes ago I heard that the French government has decided to reduce France's consumption of electricity from nuclear power from 75% to 50%. At the same time, France will be reducing its consumption of fossil fuels.
Last week the new Swedish government announced policies that will lead to the shutdown of the aged reactors 1 and 2 at Oskarshamn, 1 and 2 at Ringhals, and stop Vattenfall's plans to build additional reactors there.
Sweden has been building up its renewable infrastructure, and this year the nameplate capacity of Swedish wind power will exceed Denmark's.
-
Hank11198 at 23:47 PM on 10 October 2014The Wall Street Journal downplays global warming risks once again
Tom I think I understand what you are saying. I need to go over it in detail ASAP. Thanks for you help.
-
billthefrog at 23:36 PM on 10 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
Thanks for another illuminating and thought provoking post Howard.
You really know how to spoil somebody's day, don't you?
Cheers BIll F ;)
-
howardlee at 23:01 PM on 10 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
Ianperrin - I addressed Wright and Schaller's study in this post (under 'timing matters' about half way down, and see comments at the end)
I think we can say for now that their study was refuted in a series of replies (towards the end of this page) on the basis of:- (a) the heat capacity of the oceans required centuries to warm to the PETM extent, (b) an instant release of carbon in the atmosphere would produce a carbon isotopic shift far larger than observed, and (c) that microfossils ruled out the sedimentary rates claimed. There was also a claim that the apparent varves were drilling artefacts but Wright and Schaller pointed out varve-like layers in land exposures of the same clay unit - so they can't be just drilling artefacts.
The Marlboro Clay that they studied will I'm sure provide valuable insight to the PETM, but as things stand more work is needed to bridge the apparently-varved clay record with the longer term but coarser-resolution records.
-
howardlee at 22:47 PM on 10 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
Correction to the post above the ...rhythm IS recognized...
(not sure how 'not' got in there)
-
howardlee at 22:35 PM on 10 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
Wili and WheelsOC - yes I meant beat as in heartbeat, sorry if that was confusing. The point is that this 100,000 year and 405,000 year rhythm is not recognized throughout most of the geological record, operating as an oscillation about a background climate state. In the Eocene the climate state was already hot so the orbital oscillations made hyperthermals.
-
ianperrin at 20:29 PM on 10 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
How does this fit with the Wright and Schaller study of last year that has the PETM push occuring within just 13 years. Though at first it seems unlikely, the study has not been refuted as far as I know.
-
Tom Curtis at 12:20 PM on 10 October 2014The Wall Street Journal downplays global warming risks once again
Hank, your correspondent seems to be taking the view of the greenhouse effect I discussed @9 above, rather than Coonin's actual view. As such, the relevant figures are:
Total greenhouse effect c.1980: 150 W/m^2
CO2 contribution: 20% (30 W/m^2)
(Figures from Schmidt et al 2010)
CO2 concentration c 1980: 340 ppmv
Projected CO2 concentration for mid century with BAU (RCP 8.5): 550 ppmv
Relative forcing: 2.55 W/m^2
Change in CO2 forcing: 8.5%
Assuming that CO2 is responsible for 25% of the total greenhouse effect reduces that to 6.8%. Assuming the forcing change is from 2013 reduces it to 5.6%, or 4.5% assuming the 25% figure.
The only way to reduce it to the 1% figure is calculate it as a percentage of the total greenhouse effect, ignoring the anthropogenic increase over the last 33 years, and ignoring the increase in the total greenhouse effect from water vapour related feedbacks. That is, it requires first fudging the figures, and then making an apples to oranges comparison.
The scenario as described, by the way, deliberately excludes all other well mixed greenhouse gases from the equation; and is chosen to ignore the fact that we are not in temperature equilibrium, and that consequently temperature changes from past forcings (including prior to 1980) are still "in the pipeline".
-
wili at 10:13 AM on 10 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
Doh! Of course you're right, Wheels. I missed the metaphor. But they do use that throughout, now that I look again.
-
Hank11198 at 08:21 AM on 10 October 2014The Wall Street Journal downplays global warming risks once again
First time post. Hope someone sees this and it not too late.
As an engineer I'm able to follow a lot of the math but not the details. Living in east texas I’m among a lot of deniers. Even other engineers who I would think would understand some basic science. Anyway a friend of mine often sends me articles that criticize climate change science and I try to respond but often don’t understand the details as I said. When I responded to his email he sent me regarding Noonin’s article using one of the comments here, he sent me the following reply.
He is dead on accurate Hank. Koonin said the HUMAN additions to atmospheric CO2 are expected to shift the greenhouse effect by only 1% to 2%. That is perfectly in agreement with the fact that the totality of CO2 in the atmosphere contributes 25% of the total greenhouse effect in the atmosphere. What he's saying is that the 25% is going to increase to be 26% to 27% by the middle of this century.
Your science sources are blooming idiots.”
I was hoping someone could help me with a reply because I don’t understand what that reply is talking about.
-
foolonthehill at 06:12 AM on 10 October 2014GWPF funder Lord Leach – relying on unreliable sources of global warming information
I quite like the image but they're not actually seals...
www.theguardian.com/environment/2014/oct/03/walrus-alaska-beach-climate-change-arctic-ice
-
WheelsOC at 05:32 AM on 10 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
Pretty sure "beat" is the right word, referring to the rhythmic recurrence of the warming even though the suspected sources for it had dried up. Hence the term "heartbeat" after the block quote.
-
wili at 04:39 AM on 10 October 2014The long hot tail of global warming - new thinking on the Eocene greenhouse climate
In the second sentence after "New Thinking": " But Turner et al refute this, showing that the Hyperthermal beat continued long after reserves of methane hydrates and permafrost must have been emptied..."
"beat" should, presumably, be "heat." -
dklyer at 04:19 AM on 10 October 2014It's cooling
Simpleton here with a dumb question. This has probably been answered multiple times but I'm not finding any reference in the main posts. There are 6 long pages of comments that I haven’t read through.
Much has been made of the hiatus in warming. It seems like it is (at present) small compared to the cooling in the 40’s to 70’s. This seems apparent from your graph on the PDO post. I read that the cooling seen from the 40’s to the 70’s was due to aerosols from industrial pollution and volcanism (see New Scientist) and that the temperature began ramping up after clean air legislation in England and Europe followed by similar legislation in the US.
Is there any new data on aerosols from Asia and India and how those may be affecting global average temperatures? Is the aerosol affect still thought to be the main culprit in the post WWII dip? Didn’t I also read that the aerosols were thought to be a factor in shifting rainfall patterns that created multi-year drought conditions in North Africa? Are people looking at how aerosol pollution from Asia may be affecting the drought in the American Southwest?
-
jja at 03:20 AM on 10 October 20142014 SkS Weekly News Roundup #41A
The IPCC AR5 report is written as an update to the 2007 AR4. The information used to update the previous report was gathered between 2005 and 2009. Then that information was collected, analyzed and a peer review paper was submitted. The newest paper utilized in the AR5 was published in 2010.
Since 2010 we have learned that the West Antarctic Ice Shelf is losing mass at twice the rate published in the AR5. We have also learned that the topography of the WAIS valleys will allow a steady increase in melt rates leading to eventual, unavoidable, collapse (Rignoit et. al). We have also found that the arctic sea ice is set to be ice free in September sometime closer to 2030, not "as early as September 2050". This means that by 2050 the arctic will be largely ice free in June, during the summer solstice when the arctic receives a higher daily solar insolation than occurs at the equator. This will produce significantly higher temperatures and regional melting of arctic permafrost and the Greenland ice sheet than is currently projected by the AR5.
Additionally, the AR5, while showing permafrost area decomposition in the graph of this article, it does not include permafrost emissions as a contributor to global warming. The closest that the AR5 comes to including these is by showing a graph that indicates carbon feedbacks will reduce the amount of future emissions that are captured by the earth and sea (taken from the atmosphere) by 6%-29%. This means that an additional 160 Billion tons of CO2 will be effectively rejected by the earth and sent into the atmosphere by 2100. (IPCC AR5 WGI Fig. 6.27)
If the emissions from thawing permafrost were included, especially with the new understanding of arctic feedbacks (ice loss) and the rapid rise of arctic temperature that it will bring was then applied to the thawing of permafrost in the arctic we would find that the arctic permafrost, on its own, has a very high likelihood of emitting between 200 and 600 billion tons of carbon (not CO2) into the atmosphere between now and 2100. This is enough to raise the global atmospheric CO2 burden by between 90 and 270 ppm, on its own.
Finally, Lawrence Livermore Lab just released its study of the southern hemisphere oceans and found that the current warming rates are underestimated, by a vast amount. This means that global current warming rates have been underestimated by 9.4% to 30.3%, with the vast majority of that heat going into the oceans.
This means that our current understanding of the basic heating effect of CO2 in our atmosphere has been underestimated, significantly. This makes worst-case projections much more likely.
In summary, this current CO2 abundance of 402 ppmv in our atmosphere will likely lead to 4C of warming by 2100, even if all emissions were halted today. We have no more time to waste in our efforts to repair our broken biosphere.
-
bill4344 at 21:56 PM on 9 October 2014GWPF funder Lord Leach – relying on unreliable sources of global warming information
Though the mental image is great, you may want to modify 'actual seal level experts'
-
Firgoose at 13:33 PM on 9 October 2014GWPF funder Lord Leach – relying on unreliable sources of global warming information
@Alexandre: Why allow that these people may have made a mistake when blatant lying fits their consistent behaviour far more accurately?
-
Joel_Huberman at 08:41 AM on 9 October 2014Bart Verheggen Interview: Scientists’ Views About Attribution Of Global Warming
Very nice article. But, just like the preceding three words, "Despite the overwhelming evidence in the scientific literature showing that we’re causing global warming" is not a sentence. I hope that the author will correct this problem in both his original post and in the Skeptical Science re-post. Correction should be simple--replace the preceding period (stop) with a comma, and change "Despite" to "despite".
-
mancan18 at 08:21 AM on 9 October 2014Bart Verheggen Interview: Scientists’ Views About Attribution Of Global Warming
Sadly, the balance of 97% agreement by climate scientists re Anthropogenic Global Warming and Climate Change versus the only 55% of agreement by the public relects the reality of getting a message across using modern media. Having publicists, media advisors and proper marketing is just as important as having climate scientists agreeing. While Internet sites like Skeptical Science and Real Science deliver a pro-AGW/CC perspective, and the related Internet forums do allow those who understand the issue to discuss it and provide information to interested lay people, the vast majority of people still get their information from traditional mainsteam media outlets like newspapers, TV and radio. Because of the recent decline in investigative journalism due to the economic realities of running traditional media outlets today, there has been an increase in spin by the competing political entities who provide copy to fewer and fewer journalists. It is this spin that is being reported mostly, not proper investigative journalism. This means that the reporting of this issue has been biased by the the effectiveness of the media and marketing advisors on the each side of the debate, a debate that the contrarian side is winning due to the powerful vested interest backing it and because they can afford the media and marketing advisors to properly promote it. This may be one of the reasons for the consensus imbalance between the science and the public.
A study of traditional media with the respective market shares of each outlet and how it reflects the scientific consensus should be quite informative. Quite simply, Climate Change is not currently winning the marketing war. It's a sad reality that having a 97% consensus among Climate Scientists is not simply enough to turn around public opinion. To do that will require simplifying the CC message with the science presented to the public in terms that can be more easily understood; using professional media advisors providing appropriate copy to journalists; and marketing advisors providing a proper marketing strategy of to convey the science. Scientific discussions between climate scientists and just expecting journalists to properly convey the balance of those discussions will not translate the balance of the scientific consensus into a similar media consensus and hence a similar public consensus.
-
Paul D at 04:27 AM on 9 October 2014How did the UK grid respond to losing a few nuclear reactors?
tcflood@66 AFAIK the only limitation regarding storage time is 'leakage' of heat from the hot store and gain of heat from the surroundings in the cold store and that is down to how good the insulation is insulation. The storage medium is gravel and the gas used is Argon.
This video might help:
http://youtu.be/sIxt6nMf-IQ
-
Alexandre at 01:00 AM on 9 October 2014GWPF funder Lord Leach – relying on unreliable sources of global warming information
Lindzen also claims that high climate sensitivity comes from models, whereas low ones come from observations. Odd that an active climate researcher could make such a mistake. Didn't he bother to read the papers from his colleagues, perhaps?
-
JARWillis at 23:02 PM on 8 October 2014Bart Verheggen Interview: Scientists’ Views About Attribution Of Global Warming
Any sensible person who really believes that 55% (never mind the actual 97%) of experts are telling us that we must cut carbon emissions to avoid the risk of catastrophe would surely want to play safe. 'Prepare for the worst while you hope for the best' and that sort of old fashioned wisdom. The problem seems to be that people are not behaving sensibly over this arguably most urgent of all issues. Too big to comprehend, perhaps.
-
Zeboo at 19:47 PM on 8 October 2014How did the UK grid respond to losing a few nuclear reactors?
Some reflections: 1) Finland is highly technical developed and stable democratic society with a long history of running nuclear plants. If they can not build one nuclear plant on time and within budget, who will do it? Both investors and governments are likely to divert their money to other areas. 2) Are there any life cycle assesment of real (carbon) costs of nuclear energy, which includes mining, building (a lot of concrete) and long term waste disposal? A new study seems to be very favorable for renewables 3) The discussion here focus very much on production side of energy. As much as there is a need to vary energy production, what are technologies for smart changes in demand? If the wind is low during a day, how much can a combination of smart utilities and smart grid adsorb the need to lower demand? I think more out of the box thinking is needed.
-
Michaelf at 14:58 PM on 8 October 2014Tackling global warming will improve health, save lives, and save money
Ingvar, your post shows absolute ignorance of the actual consequences of global warming and the associated climate changes. More likely though you are deliberately misleading, and yes I agree that should be a criminal offence. In summary, the issue is not a slight change in temperature in one area but the effects of an increase in global temperature on the climate, sea levels, ocean warming and acidification. Your understanding, if true, indicates zero knowledge of the science, the real world and lacks common sense.
-
Rob Honeycutt at 14:11 PM on 8 October 2014Increasing CO2 has little to no effect
Skinny_Pete...
And here is your experiment performed (for all intents and purposes).
-
Rob Honeycutt at 13:55 PM on 8 October 2014Increasing CO2 has little to no effect
Skinny_Pete...
1) You should read all 3 levels of the article you're commenting on first.
2) You should understand the difference between a greenhouse and the greenhouse effect.
3) You should read the comments policy for SkS before you make another comment.
Now, to answer your question. Yes. Greenhouse 1 will get hotter than greenhouse 2.
-
Skinny_Pete at 13:00 PM on 8 October 2014Increasing CO2 has little to no effect
Let's take a look at a small scale model. As everybody knows if you cover a greenhouse frame with clear plastic it quickly gets much hotter inside than outside the greenhouse on a sunny day. Yet if you cover the frame in shade cloth which is perforated, the temperature in the greenhouse goes down in full sunlight. The cloth helps retain some warmth during the night, thus helping to stabilize the extremes. This is a typical greenhouse effect model and is in fact the reason why greenhouses and shadehouses are so popular in backyards. It is also the reason why shade cloth is so popular in large car parks.
Now, consider the following experiment. I have two greenhouses completely covered with clear plastic and both are in full sunlight, out in the open, and side by side, on the same day. I extract all of the air out of the first greenhouse and then pump it full of CO2. I do nothing to the air inside the second greenhouse. Question: Will greenhouse 1 get any hotter than greenhouse 2?
-
DSL at 12:27 PM on 8 October 2014Tackling global warming will improve health, save lives, and save money
Ingvar, where has anyone said that living in a world that's on average 2C warmer is the primary threat from global warming. You're building a strawman. How's about you actually read some of the research from the scientists out in the field--out in the "the world out there." Here's a good place to start. Perhaps when you can actually articulate what it is you wish to attack, you'll be taken more seriously.
-
wili at 11:30 AM on 8 October 2014Bart Verheggen Interview: Scientists’ Views About Attribution Of Global Warming
Somewhat related: Psychologists Are Learning How to Convince Conservatives to Take Climate Change Seriously
I had heard that pointing out the scientific consensus was one of the more successful approaches, but this article suggests other kinds of reframing.
-
Ingvar at 11:24 AM on 8 October 2014Tackling global warming will improve health, save lives, and save money
Of course warmth will possibly be a cause to health problems. But climate change theory is not that terrible. For example living in a temperate climate I moved into a tropical environment where the average temperature was 11C higher. That situation lasted for 4 years in the late 1970s. The alarmist view displayed here for a puny 2C increase by year 2100 as mentioned by IPCC indicates to me that researchers have little or no experience of the world out there.
Emotional drivers work well on the uninitiated population. But to deliberately mislead should be a criminal offence. We do not owe anything to environmental scientists, because nature, common sense and honesty should be the main purpose in our lives. Maybe I should add a better ethical standard.
Moderator Response:[PS] you have been warned previously about sloganeering and this is dangerously close. All you are really indicating is that you have not bothered to read the science and are happy to accept other's distortions instead. If you want to play that game, find quote in paper or IPCC report and then present data or papers that you think contradict it. Take some time to understand what is being claimed before you dismiss it. Further nonsense like this will be summarily deleted.
-
tcflood at 05:42 AM on 8 October 2014How did the UK grid respond to losing a few nuclear reactors?
Glenn @63
Thanks. That helps a lot.
Still, it looks like both the hot and cold storage reservoirs need a narrow region of thermal gradient bwtween the two isothermal zones. This seems to imply that 1) the system must be discharged as some point short of complete temperature conversion of a reservoir (limiting its storage time) and 3) prevention of widening of the gradient region might be a problem through numerous partial cycles.
I realize this is getting off topic for this thread, but I don't know a proper thread and it seems important to me to have some idea of the reality of solutions to storage that are presented on the web.
-
How did the UK grid respond to losing a few nuclear reactors?
Gustafsson - I suspect that's because the topic, nuclear power, provided an opening for the general topic of nuclear power in a reduced carbon economy. As far as I know there aren't any specific threads for that.
Personal opinion: nuclear will certainly have its place. But given the failure of nuclear power to seize a large worldwide share over the last half century, and the general lack of solutions (economic and political) to nuclear ash and plant end-of-life, I have some doubts as to whether nuclear can present a really large scale alternative. We'll see...
-
Gustafsson at 18:31 PM on 7 October 2014How did the UK grid respond to losing a few nuclear reactors?
I find it surprising that apart from KR @25 nobody seems to stress the fact that the data is from such a short timescale and doesn't really answer the question of wether wind can cover for reduced nuclear. (Although the people stating that wind stepped in when nuclear failed is apparently wrong it's a very small question in the scope of it all, isn't it?)
The market reaction to a short term energy shortage is not the same as the long term reaction to a long term energy shortage. If we shut down nuclear plants the short term market response might be the same, given insufficient time to adapt in advance but the long term response is given by which new form of energy is considered the most economically viable at the time.
For a better (more relevant) analysis i recommend looking at using a tool like MARKAL (http://www.iea-etsap.org/web/Markal.asp), developed by the IEA, or simmilar and looking at the long term changes. An analysis like that would be truly worthy of SKS ;)
-
Glenn Tamblyn at 13:37 PM on 7 October 2014How did the UK grid respond to losing a few nuclear reactors?
tcflood
The Isentropic system is based on the Brayton Cycle.
Note particularly the sections on Closed and Reverse Brayton cycle. So the basic process is fairly standard. Also read the FAQ at Isentropic — this covers the question of the applicability f the Carnot Efficiency.
During the discharge cycle the Carnot Efficiency applies to the conversion of heat to work. However during the charging cycle it is acting as a heat pump, a Carnot Refrigerator
Carnot Efficiency for the discharge phase is (Thot - Tcold)/Thot
So some of the heat flowing is extracted as work, the rest flows through to the cold store. Efficiency is less than 1.
Whereas during the charging phase the Carnot Coefficient of Performance applies Thot/(Thot - Tcold)
Work in plus some heat from the cold store is transferred to the hot store. CoP is greater than 1.
It is because this is a cycle. If the system were perfectly reversible then they would get 100% of the energy they put in back out again. But because of irreversibilities they get less than this. Their performance claims are about the quality of the equipment and thus how close to true reversibility they can get. Carnot does not apply to that calculation
This diagram might illustrate this:
If all the processes are perfect, reversible processes then Win = Wout.
It is only the irreversibility of the processes that leads to any losses.
So yes, it does pass the smell test.
-
chriskoz at 12:01 PM on 7 October 20142014 SkS Weekly Digest #40
From the policy frontlines, I think recent selective misquoting of wikipedia by current Australian env minister Greg Hunt, proving him as totaly unfit for his job, did attract the attention os SkS readers.
Now, it turns out Greg not only proved to be ill-informed science denier, but also deliberate obfuscator, because according to smh, BOM warned Greg Hunt about climate change before he cited Wikipedia. So Greg did not just forget to seek the scientific truth on the matter, he deliberately ignored the given truth, replacing it with his agenda. As a scientist, I can only follow Kerry Emmanuel's lead and say I am ashamed to be an Australian but I do precisely qualify that my shame is because we have such env minister.
-
chriskoz at 11:47 AM on 7 October 20142014 SkS Weekly Digest #40
Agree, Bojan, one of the best cartoons I've seen for a while. Deserves special mention.
-
tcflood at 11:04 AM on 7 October 2014How did the UK grid respond to losing a few nuclear reactors?
Talking about "pumped heat energy storage" @53 and 54.
Take a close look at the video in the link @54. It seems to me there is something seriously wrong with the thermodynamics in these two (charge and discharge) cycles. In charging, the upper cylinders engage in adiabatic compression heating of the fluid, while the lower cylinders undergo an expansion/cooling power stroke. When the device is discharged, the upper cylinders undergo an expansion/cooling power stroke, while the lower cilinders must consume power to compress and heat the cold fluid. I don't think this adds up.
In addition, while a working fluid temperature change between 773 K and 113K (claimed in the video) would give a Carnot efficiency of 85%, the real temperature differences are between "ambient" (say 300 K) and 773 k for the hot fluid and 300 k and 113 K for the cold fluid, one being a compression and the other an expansion simultaneously. I don't think this can possibly work, let alone give an efficiency of 90%.
Does any of this pass the smell test?
-
michael sweet at 10:32 AM on 7 October 2014How did the UK grid respond to losing a few nuclear reactors?
Glenn,
Budischak also found solar was cost effective for only about 5% of supply. It strikes me that studies like this become rapidly dated and need to be redone. Budischak was only offering a perspective, one that did not include storage. Arguing that storage makes renewables too expensive is not necessarily true.
For our discussion I think we need to keep our minds open to a variety of options. Price on a lot of strategies is rapidly changing and it is difficult to predict the winners now.
If nuclear can lower their costs with pre-approved designs it might become cost effective.
Until renewables are about 40% of supply on a regular basis it makes little difference, storage is not needed and backup is already built. The change from 40% to 100 percent is where these issues become important. Currently Holland uses the EU grid for renewable backup just as France uses the grid to off load excess nuclear at night.
-
Tom Curtis at 08:03 AM on 7 October 2014Scientists find human fingerprints all over Australia's hottest year on record
Ashton @12, you represented me as making a claim that implied MGST would increase monotonically. That was not the case, and transparently not the case from what I wrote. You are not pretending that you made no such claim - which quite frankly makes me even more dubious of your honesty.
-
Composer99 at 06:57 AM on 7 October 2014Tackling global warming will improve health, save lives, and save money
FYI the article "breaks" in preview mode at the end of the blockquote and it's messing up all the following articles on the front page.
-
Glenn Tamblyn at 06:05 AM on 7 October 2014How did the UK grid respond to losing a few nuclear reactors?
Michael
Budischak are using lithium batteries as the form of energy storage in their study and data from 2008. In contrast the links above to Isentropic are giving storage costs for that technology 1/4 the costs used by Budischak.
This is a fast moving area and it would be interesting if they repeated their study for differing storage costs. I wonder how sensitive the over-build ratio is to storage costs?
-
Paul D at 05:59 AM on 7 October 2014Global warming: a battle for evangelical Christian hearts and minds
Non-Scientist@50
I disagree with you. The per capita approach is a good measurement. Taking your example, then a household of 14 people who produce a total CO2 figure that is double of a smaller household (of one) is indeed better and more efficient.
The fact is those 14 people are most likely using fewer resources and use less energy each. If they copied the other household, then they would be producing 7 times as much CO2 (0.5 x 14) as the 14 person household.
CO2 emissions is all about people. It's about how individuals can live whilst minimising their impact.
Prev 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 Next
