Recent Comments

Prev  1600  1601  1602  1603  1604  1605  1606  1607  1608  1609  1610  1611  1612  1613  1614  1615  Next

Comments 80351 to 80400:

80351. Mark Harrigan at 02:19 AM on 6 July 2011
       A Detailed Look at Renewable Baseload Energy
       @Tom 138 I'm sorry Tom but it is totally fallacious to extrapolate from an average figure of deaths for all mining to a figure for uranium mining. All mining profiles are different but perhaps the most important is that the majority of Uranium mining is either open cut (stripping off overburden and refining) or in-situ leaching as opposed to Under Ground (such as in long wall coal mining). Underground mining is inherently more dangerous. So I dispute your figures - they are not logical I agree it's hard to get precise figures but even if you allow a significant increase in the figure I quoted - and say it is wrong by a factor of 100 - it is still two orders of magnitude better than coal. And this doesn't take into account the 100,000's of early deaths the UN attributes each year to the use of extractive fossil fuels. So I do not think you can pretend that Nuclear is a real problem on the basis of its comparative mine safety. As to my statement "The technology is CO2 free in operation" - well - it IS. I meant exactly what I said - the issues you raise of CO2 emissions relate to extraction (which I made clear) so I feel you either misunderstood or are being disingenuous. The Green movement often slanders uranium as somehow producing more CO2 than alternatives over the lifetime of the plant by pumping up figures involved in mining and processing. Really this is a furphy. Of course there are emissions associated with mining and extraction - just as there are associated with the extraction of metals and refining, forging and fabrication of Wind Turbines and Silicon for Solar Panels (which is actually quite energy intensive!). That all depends on what methods you use to power those processes and should really be the subject of a separate comparison. What matters is that once the Nuclear Plant is in place it is essential CO2 emissions free. I agree it is hard to find reliable life cycle emissions data that most would accept life cycle emissions is one source but many would discount it because it's the industry talking. I think it is pretty reasonable though and here is an independent source that suggests nuclear is on a par with Wind emiisions comparisons Regardless I think it is hard to conceive of any logic that would make Nuclear a "bad" CO2 option - I think it's a furphy raised by those who are ideologically opposed to nuclear power - It's the same sort of misrepresentation that denialists use only from a different direction. I prefer to be data and logic driven and not come from an ideological view point of support or oppositiion The real issue with Nuclear as an option is, I believe, as I have stated. On the plus side it's reliable and will contribute to enormous CO2 emissions reduction - It's proven technology and generally able to be implemented in most geographies (excluding those that are seismically at risk) - which put' it ahead of hydro and geothermal which have severe geographical limitations. With modern technology designs the risk are frankly extremely low BUT - the hazard is enormous -and if something does go wrong humans have not demonstrated an ability to manage it. This compounded with the human fallibility issue I mentioned earlier is a very big negative. The only way I can see forward for nuclear is if it is highly regulated AND the industry steps up to the plate and imposes on itself a rigorous accountability, management discipline and transparency to better manage itself. I'm not sanguine about that happening but I see it as the only way forward for Nuclear if we want to reduce CO2 emissions by as much as the science says we need - because (as I will post elsewhere) renewables are simply not (YET) up to the task - or at least it is not proven that they are - again part of the debate that is needed The cold truth is that the world is full of lesser evil choices. We need the debate to mature to that fact and have a sensible informed discussion about the nuclear option and renewable options- not one based on fear or poor logic or data or wishful thinking.
80352. BBD at 02:17 AM on 6 July 2011
       German Energy Priorities
       dana1981 #31 It's also vital to consider what is coming. Electrification of personal transport (with overnight charging the norm) and increased use of day/night AC in cities will drive baseload demand upwards significantly. High-renewables scenarios invariably require much reduced demand in order to 'work'. It's another reason to be extremely sceptical of such claims.
80353. Tom Curtis at 02:16 AM on 6 July 2011
       German Energy Priorities
       quokka @33, what is the discount rate? Also, I consider the idea of discounting future costs for calculation of levelized costs dubious. Assuming we are looking at a long term energy solution, then eventually power plants will exist in all phases of their cycle in about even numbers. Therefore the ongoing cost of the industry will include all features including decommissioning at current values, and that is the cost we are interested in. In this our perspective is different from that of an investor (for whom discounting is appropriate).
80354. JoeRG at 02:15 AM on 6 July 2011
       It's the sun
       ... in (a) as obtained from 58 simulations produced by 14 models with both anthropogenic and natural forcings. ... The simulated global mean temperature anomalies in (b) are from 19 simulations produced by five models with natural forcings only. Well, this is taken from the caption of the figure (and I do not expect that all of the models were made by the autors). So what would you expect from one who's reading this, unable to find any description (because of dead links, just a hint that leads to Stott) and finally realizing that the graphs did match neither the original model nor the physical behaviours that are to expect? Should he say "hurray, it's from the IPCC, it's fine"? Of course, very amazing. I suggest you check the various reports for links to the original works. I would, if you can give me the list of the used models. I can't get it from the IPCC page. Regrettably there is no 'Appendix 9C' -for whatever reasons- where the underlying papers/reports would have been listed. Besides, you argued -using this figure- that the models are 'excellent'. I showed -using the same figure as well- that they are not, at least if modified by the IPCC, because of mismatches to reality and, as shown by pointing out the difference to Stott, wrong adaptations. (Of course, it's a completely different topic.) Back to topic. You are right, the flares are quite a hypothesis. But, perhaps you can give another possible explanation (eventually a paper) for the needed ~3W/m² of positive radiative imbalance. With the value of Trenberth 2006/2009 (0.8..0.9W/m²) it would need about 5 years to get the observed OHC-rise (by 6*10^22J) that obviously occured within a single year - given that the measurements are correct.
80355. BBD at 02:10 AM on 6 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom Curtis #138

       So, do you know of any reliable source that budgets nuclear operational CO2 emissions including the entire fuel and waste cycle?

       See EU figures from Energy Sources, Production Costs and Performance of Technologies for Power Generation, Heating and Transport accompanying the Second Strategic Energy Review 2008. See Table 2.1, which shows lifecycle emissions as follows: [kg CO2(eq)/MWh] Natural gas OCGT: 640 Natural gas CCGT: 420 Oil CCo-fT:585 Coal PCC: 820 Coal CFBC: 960 Coal IGCC: 855 Nuclear: 15 Wind on-shore: 11 Wind off-shore: 14 Solar PV: 45 Solar CSP: 135 Not really game-changing numbers when it comes to evaluating nuclear against wind (especially offshore) are they? And SPV and CSP do not emerge as quite so green as many suppose. You say:

       Please note that these costs to health and in CO2 emissions pale in comparison to equivalent figures from coal. There is no basis from these considerations to get rid of nuclear power in favour of any fossil fuel, or to not introduce nuclear power as a substitute for fossil fuels.

       Then why are you devoting so much time to discussing them? You go on:

       But the selective statistics used for comparison data make a proper comparison between nuclear and renewable options difficult, and significantly overstate the advantage of nuclear, if any.

       The limitations of renewables are examined in some detail upthread. It's the engineering argument that gets ignored every time: Nuclear power is superior to renewables because is it a proven, scalable, mature baseload generation technology that can - and will, given the chance - significantly displace coal from the global energy mix. Renewables are fundamentally unsuited to baseload, extremely expensive, extremely low density, untried at large scales and fraught with uncertainties we have neither the budget (opportunity cost) nor the time (AGW) to explore. Finally, there is no excuse whatsoever for this:

       That already exceeds the 0.04 figure. Perhaps the nuclear industry does not count cancer deaths from radiation exposure in their figures. No doubt they will also assure us that smoking does not cause lung cancer.

80356. BBD at 02:04 AM on 6 July 2011
       German Energy Priorities
       dana1981 #31

       I think it's worth noting that baseload power is generally inefficient power, because much is wasted during off-peak hours.

       First, can you show from actual national-scale grid load curves where you get this? Second, you are miscasting the way baseload is provided to a correctly balanced grid. The day/night variation is managed by intermediate and peaking plant. The vast majority of baseload is consumed 24/7/365. So baseload is both efficiently generated by plants running at optimum capacity 24/7 and efficiently consumed. The rest of what you say, presumably based on the report, is not (how shall I put this?) widely accepted.
80357. Tom Curtis at 02:02 AM on 6 July 2011
       German Energy Priorities
       michael sweet @28, the 4000 thyroid cases where for Chernobyl, not Fukushima. It is unlikely that the health impacts of Fukushima will be anywhere near as large due to the prompt evacuations and cautious approach in dealing with the situation. Even the economic impact will be small compared to that of the tsunami, or compared to the overall production of power by nuclear power plants. Even assuming the economic cost runs to 1 trillion dollars, the cost per kWh based on Quokka's estimate of cumulative power production runs to only 1.5 cents per kWh. I share your concern about the pollyanderish attitudes of nuclear proponents, the patently inaccurate statistics sometimes presented, and the distorted claims they make about renewables. Never-the-less, I think we should keep things in perspective, and in perspective nuclear power including Fukushima is safer for the Japanese than car travel, and probably also than train travel as well.
80358. quokka at 01:58 AM on 6 July 2011
       German Energy Priorities
       #26 JMurphy You ask what else is wrong with the shopping list of Table 1. Try this sort of stuff:

       A shortage of key components and skilled labor could result in increased costs for nuclear power plants and /or slow any transition to a nuclear renaissance

       Which may be paraphrased as "if bad things happen, then it would be bad" but quantifies nothing. You could say the same thing about any expansion of any heavy industry. Undoubtedly it takes development of the supply chain, contractors need to adapt to the special requirements, training and education takes time and so on. Nobody doubts this. We do know however that the problems are surmountable because we have an existence proof in the case of France which did manage to overcome such problems. This is not to claim it is necessarily easy or inevitable. But nothing is easy or inevitable when it comes to clean energy. or this:

       Decommissioning costs can sometimes be greater costs than the costs of building a plant in the first place

       Possibly, but not for plants that are built today and almost certainly not for the existing fleet of water cooled, water moderated reactors. And that is what counts - not the cost of decommissioning cold war era dual purpose facilities. The IEA estimates decommissioning at something like 15%-20% of the original capital cost. It has surprisingly little effect on the Levelized Cost of Electricity because it is discounted well into the future. See my link above for IEA estimates.
80359. Philippe Chantreau at 01:51 AM on 6 July 2011
       Glaciers are growing
       NikFromNYC, you need to look at the story closer. As I recall, the 2035 claim was discussed on this site. The search engine works well. It turned out to be another molehill made into a mountain through the usual disingenuous methods. Tom addressed the Antarctic cooling canard. Overall, your post adds little that is of value for one seeking good information. Your claim that the Himalayan temperature increase is due to land use changes is not only unsubstantiated but unplausible considering how much is actually there to use and how long it has been used in one way or another. It's not like forests are being cut down on the icy slopes. As for what is useable, it is scarce and has been used by the locals for a very long time. Ramanathan has shown that, at the altitudes where the brown cloud aerosols are found, they exert a strong positive radiativce forcing. This forcing is a much better candidate for the temperature increase than your land use hypothesis. The glaciers get a double whammy from the black carbon deposited on their surface and the atmsopheric BC heating them up.
80360. MichaelT at 01:43 AM on 6 July 2011
       German Energy Priorities
       There is an interesting report by the German Advisory Council on Global Change, an advisory council to the German government. An English version can be found here: A Social Contract for Sustainability It shows in detail the path to a carbon-free economy. It is quite a good read. I think it has not yet been mentioned here that the German plan also includes CO2-emission reduction by an overall reduction of energy consumption and an increasing energy efficiency. So phasing out all the nuclear plants does not mean that you will have to substitute their absolute share in today's energy production. So even replacing old coal and nuclear power plants with new coal and gas p/p may not have as negative an impact as some may think.
80361. Riccardo at 01:40 AM on 6 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       In support to what Dikran wrote on the predictability of the double pendulum, a nice animated gif: it shows two solutions differing by 0.001 degrees in the initial conditions of the second mass.
80362. Tom Curtis at 01:33 AM on 6 July 2011
       Glaciers are growing
       NikFromNYC @16, I am unsure what point there is to your post other than to sow confusion. The topic of the main article above is the ongoing retreat of glaciers world wide, something you do not dispute. You do attribute the retreat of Himalayan glaciers to black carbon (soot) from the Indian industrialisation, and indeed that is probably a factor; but it is hard to dispute that they would continue melting in a warming world, even in the absence of black carbon. More importantly, the ongoing retreat of Andean, African, North American and New Zealand glaciers shows the primary cause of retreat is a global factor, specifically the rise in temperatures through the 20th century. You throw out a couple of of topic canards. First you suggest that Antarctica is cooling. In fact it is warming: The map on the left is from O'Donnell et al, a team closely associated with Climate Audit, and one of the very few pieces of actual science produced by people associated with Climate Audit. It is not without its problems, including a number of methodological choices that introduce a cooling bias to their study, but even so it shows a clearly warming Antarctica with some cooling regions. You also mention the IPCC's error with regard the Himalayan glaciers. The incorrect prediction of glacial melts was made by the IPCC Working Group 2, which looks at the impacts of global warming, not the science of global warming. It therefore is no reason to call into question the very high standard of the IPCC Working group 1 reports. What is more, it is just one error from among tens of thousands of factual claims across 3000 pages of the IPCC report. An error rate of less than 1 in 10,000 is no reason to doubt the general reliability of the IPCC. In contrast, many of the more highly touted denier documents struggle to keep their error rate down to 1 per sentence. Having said that, may I suggest you take comment about that error to the appropriate topic (which I suggest you read).
80363. dana1981 at 01:31 AM on 6 July 2011
       German Energy Priorities
       I think it's worth noting that baseload power is generally inefficient power, because much is wasted during off-peak hours. In one of the German reports linked in this post, they discuss that once there is a certain level of renewable penetration, it will actually become cost ineffective to build new baseload power plants. Essentially the combination of intermittent renewables plus peak generators (i.e. gas turbines) is more cost effective and efficient than a bunch of baseload sources.
80364. quokka at 01:25 AM on 6 July 2011
       German Energy Priorities
       @michael sweet You make completely unsubstantiated assertions about "20-30 years of underestimates of problems and overestimates of reliability" and declare you no longer "trust" nuclear proponents. This kind of dialog is simply not good enough. It is perhaps even more important to examine all of the evidence in matters of energy than in matters of climate science because only through understanding the realities of energy is there any hope of having any chance of even containing the climate problem. In well managed nuclear fleets there is an undeniable trend to greater reliability over the decades as operational experience and knowledge has been achieved. In the US fleet, capacity factor has been at around 90+% for the last decade. This is an excellent result. You could hardly ask for better, although from memory I think Sth Korea does do a little better. See here and open the PowerPoint presentation. I presented a scenario to examine the proposition that the Fukushima accident is "proof" that nuclear power is too expensive and put some numbers on it. This meme echos around the blogosphere just like climate denialism. I was not making any attempt at an accurate estimate of costs which in any case are not well known at this time. But what I did show, I believe, is that the meme has little basis. This is what we should all do when confronted with such claims. First ask the question - do they make any sense? Are the numbers anywhere near the ball park? If you want to put some numbers together, the go ahead, but do not ask me to do it for you.
80365. BBD at 01:14 AM on 6 July 2011
       German Energy Priorities
       Tom Curtis #24

       It does, I think, call into question the claimed superiority of nuclear power to renewable power claimed by "nuke boosters". Nuclear power is superior to renewables because is it a proven, scalable, mature baseload generation technology that can - and will, given the chance - significantly displace coal from the global energy mix. Renewables are fundamentally unsuited to baseload, extremely expensive, extremely low density, untried at large scales and fraught with uncertainties we have neither the budget (opportunity cost) nor the time (AGW) to explore. I seem to recall that we've been through this in detail already.

80366. KR at 00:47 AM on 6 July 2011
       It's the sun
       JoeRG - "The IPCC did run 14 'anthro+nat' models and only 5 'nat' models... " That would be quite amazing, considering that the IPCC collected data and science from many contributors, but did not run any research itself. I suggest you check the various reports for links to the original works. You appear to feel that 'solar flares' have a much larger effect - but unless you can point to some data, perhaps a paper or two, that supports your hypothesis, preferably with some suggestion as to mechanism, it's just an unsupported opinion, not science.
80367. KR at 00:41 AM on 6 July 2011
       Uncertainty in Global Warming Science
       Ken Lambert - "Please expand on the 'cooling' we have seen over the last 'few hundred' years and the reasons for same." I believe you are being disingenuous here, Ken. I would point out the Little Ice Age - volcanic and solar forcings identified as major factors, as in Free and Robock 1999, and the mid-20th century cooling - primarily due to aerosol effects outweighing other factors from the 40's to the early 70's. Not a single 'cooling', but rather multiple ups and downs over the last few hundred years. There is no ongoing baseline TSI imbalance that we have not accounted for - we have data covering both climate warming and cooling, meaning imbalances both postive and negative, and there is no leftover such as the one you have (repeatedly) postulated.
80368. NikFromNYC at 00:35 AM on 6 July 2011
       Glaciers are growing
       Glaciers hold only 1% of the planet’s ice. Antarctica and Greenland hold the rest, with the greatest amount in glaciers being in the Himalayas. I don't know how Cogley weighed his data. That the vast majority of glacial volume is in the Himalayas and that soot is causing more melting there than warming (http://esciencenews.com/articles/2011/03/03/soot.packs.a.punch.tibetan.plateaus.climate) provides additional pause. A map is here: So, a chart of a sampling of ice loss from glaciers world wide says very little about what to expect from what really matters: temperature or sea level rise. That we are in a temperature peak that I believe to be mostly natural makes loss of loss from tiny glaciers that lack thermal inertia in extremely cold locations in isolated climate zones does not impress me as much as the idea that world sea ice is starting to melt in an actually meaningful manner. That the IPCC claimed the Himalayas would melt by 2035 means that unless those who allowed such a claim to pass through their peer review process need to go or I have little trust in current claims of impending doom. Addendum: The 5x5 temperature grids around the Himalayas actually do show a hockey stick shapes, adding a whopping 2 degrees since 1990!: http://appinsys.com/globalwarming/climap.aspx?area=china http://appinsys.com/globalwarming/climapgr.aspx?statid=N5:25-30N:85-80E http://appinsys.com/globalwarming/climapgr.aspx?statid=N5:25-30N:90-85E So no wonder glacial melt is surging. Local heating over the Himalayas. This has been suggested to be due to local land use changes as a sudden 2 degree jump certainly isn't due to a local spike in CO2. Can I find this warming in a map? Nope! Evidently it must be a very local effect then if it doesn't show up as a very large super red region above India: http://i45.tinypic.com/n6szgh.jpg But boy oh boy look at the extreme *cooling* in Antarctica where 90% of world ice is contained!
       Response:

       [DB] Nice Gish Gallop.  This thread is on 'Are glaciers growing or retreating?'; please stay on-topic to ensure your comments do not get deleted.

       For the casual reader, appinsys is well-known to be a site of active disinformation on matters related to climate and climate change.  The other graphics that Nik provides to further his narrative are of unknown provenance and should be regarded as questionable.

       A reliance on primary sources is best.

80369. michael sweet at 00:27 AM on 6 July 2011
       German Energy Priorities
       Quokka says "Most of their value is depeciated away already. In themselves they are not a huge loss." These reactors had value even if the owner has written it all off. You are arguing tax law to underestimate the loss from the accident. The loss should reflect the replacement value (or perhaps what they could have sold for before the accident), not the tax value. It is clear that it is difficult to estimate the value of a nuclear accident. My very strong impression is that nuclear supporters consistently underestimate their problems. This makes it difficult for me to understand what the costs really are. After 20-30 years of consistent underestimates of problems and overestimates of reliability, I no longer trust nuclear proponents. I think this is a general problem that the nuclear industry has. Have they figured out where they are going to put all their waste yet? You have still not estimated the value of the loss of 1,000's of square km that have had to be evacuated (for years if not decades), the loss of value of homes near other nuclear plants, since no-one wants to be exposed to such a problem themselves, and the value of the 4,000 non-fatal throid cancers (and other cancers) documented previously in this thread. It appears to me that you are greatly underestimating the economic effect of this disaster. Saying I can double or triple them does not make me feel better. This is why I no longer trust nuclear proponents estimates. It appears to me that the Germans also are tired of incorrect estimates of reliability and cost. That is why they are leaving nuclear.
80370. Eric (skeptic) at 00:07 AM on 6 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Thanks for the reply Tom. It still seems like a big leap from average to local. How do we know that an increase in convection on average will yield locally severe convection? An alternative outcome is wider areas of diffuse convection rather than narrower areas of concentrated convection. The average convection can still rise without a rise in strong convection and locally severe weather.
80371. John Brookes at 00:07 AM on 6 July 2011
       German Energy Priorities
       The current ITER project for fusion power could solve most problems by mid century. Its certainly one option which should have money put into it, along with the renewables.
80372. CBDunkerson at 23:45 PM on 5 July 2011
       A Detailed Look at Renewable Baseload Energy
       According the the EIA's latest Monthly Energy Review the United States now generates 11.73% of its energy from renewable sources vs 11.10% from nuclear power. Until now, nuclear had exceeded renewable generation since the 1960s. Also see this news article on the report. To me it seems likely that this trend of renewable energy production growing faster than nuclear, and surpassing it in total power generation, will continue for at least the next twenty years. Quite simply there is too much public opposition to nuclear. Famous nuclear accidents like Three Mile Island (1979), Chernobyl (1986), and Fukushima (2011) keep the dangers of radiation exposure fresh in people's minds. Probably the best thing the nuclear energy industry could do for their cause would be to shut down every nuclear power plant with a design similar to those which have failed in the past. Indeed, they should have done so twenty years ago. Let the newer designs prove their safety record, without it being wrecked in the public consciousness by problems at older plants, and in another twenty years or so people might be ready to accept nuclear on a large scale. If they instead continue to operate poorly designed reactors decades past their originally intended 'end of life' more nuclear accidents, and thus continued public opposition, are guaranteed.
80373. Eric the Red at 23:43 PM on 5 July 2011
       Monthly Climate Summary: May 2011
       Stevo, The leaning is that warming will lead to more frequent and stronger El Ninos, with fewer and diminished La Ninas. But as scaddenp stated, the jury is still out.
80374. The Skeptical Chymist at 23:02 PM on 5 July 2011
       Database of peer-reviewed papers: classification problematics
       Ari The 2010 paper "Expert credibility in climate change" is duplicated in the database. Also, once a paper has been added to the database, is it possible for anyone with the firefox add-on to add that paper to extra myths/arguments? The add-on looks like it should work for this but I find you can't send the report
80375. Tom Curtis at 22:47 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Eric (skeptic) @256, as I stated in 232,

       "1) Increased temperature implies increased specific humidity; 2) Increased specific humidity implies more water condenses as a result of cooling due to updrafts or frontal systems; 3) More water condensing implies more latent heat released; 4) More latent heat released implies a stronger updraft generated which: 4a) Results in greater cooling, with more water released; and 4b) Results in more air being drawn into the updraft, carrying more water with it."

       I was focussed on the prediction regarding precipitation, but to make it more general I should probably add: 4c) A stronger updraft results in stronger local winds; and 4d) A stronger updraft carries precipitated water to a greater altitude, giving it a chance to freeze and fall as hail. Also of relevance is: 5) The greater the rate of condensation, the larger the drops of condensate, which increases the risk of large hail. All of these follow straightforwardly from the increased specific humidity with increased temperature. The effects are also observationally verified by the global pattern of thunderstorms, with (contrary to Norman @252), the strongest and most frequent thunderstorms forming in the tropics. This can be seen on this plot of the average number of lightning strikes per year for the years 1995-2003 from NASA: Lightning is a good proxy for the intensity of thunderstorms, including wind strength. From my experience living in equatorial Africa (the southern end of that orange blotch) and in tropical and sub-tropical Queensland, it is also a good proxy for hail frequency, intensity and size (all much larger in Africa than in Queensland), but there may be an increased frequency of large hail in more temperate regions. As Norman correctly points out, humidity alone is not enough for a thunderstorm; but heat and humidity are both definite factors in the strength of thunderstorms. If you increase both, ceterus paribus you will increase the frequency and intensity of thunderstorms. As it happens, increased warming is also expected to increase Convective Available Potential Energy, another key factor (see maps in my 246. Consequently, every element of "severe" thunderstorms, with the possible exception of tornadoes, is expected to increase globally with a warming climate, though not in all regions. That is, we can expect more damaging winds, more large hail, more flash floods, and more lightning strikes. And tornado frequency is also predicted to increase, though I can't lay out the logic of it the way I can for thunderstorms in general.
80376. Camburn at 22:21 PM on 5 July 2011
       Google It - Clean Energy is Good for the Economy
       skywatcher: I have posted the link on this site concerning Devils Lake and the upper mid-west of the USA. There is most deffinetely a wet and dry cycle.
80377. Rob Painting at 21:56 PM on 5 July 2011
       OA not OK part 2: Thermodynamic duo
       The peanut-tossing analogy is a doozy!
80378. Dan Olner at 21:31 PM on 5 July 2011
       OA not OK part 2: Thermodynamic duo
       This stuff is mind-blowingly confusing, thanks for making it sound so clear! I've always been completely flummoxed trying to understand how chemical energy and mechanical / kinetic energy can go back and forth and still keep within thermodynamic limits.
80379. Dikran Marsupial at 21:05 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Norman wrote: "It would seem the mathematical model of the double pendulum is scientific since the equations can offer testable explanations about the nature of the pendulum and offer predictibility about the overall behavior of pendulum. That is if you would use the equations and run a long term simulation, the simulation would trace out the same area as an actual pendulum if this were videotaped." This is not correct. The mathematical model would only be able to trace the behaviour of the real pendulum if you could measure the initial conditions with infinite precision. If you could do that, the sofwtare model would also trace out the trajectory of the pendulum exactlty. Your comment suggests that you fundamentally do not understand the nature of chaotic systems. They can be completely deterministic, but that doesn't mean they are predictable, because their behaviour is extremely sensitive to initial conditions. "A software model of the pendulum would be worthless as a science as it would not give any useful prediction of the pendulum's nature. It gives exactly the same predictions as the mathematical model; they are equivalent. The only difference is that the software model can solve the equations from the mathematical model (which do not have explicit mathematical solutions). "The science of meterology does not try to make predictions about the weather beyond a few days because they know such activity is nonscientific and useless. The prediction means nothing. Are you saying that we can't predict climate because we can't predict weather more than a few days in advance? "One could not predict anyone actual thunderstorm in the region months in advance, but a good climate model should be able to predict is a region will have more our less moisture over a given period of time. If it can't do this and make a valid prediction, the model would not be good for much and a new one should be developed. If you make the region large enough (i.e. a scale corresponding to the grid size of the GCM), then GCMs already do provide usefully accurate projections of that nature. Modellers would not claim to be able to predict rainfall at e.g. a catchment scale, as they average over grid-boxes that are far larger than a typical catchment and so can't capture such small-scale dynamics. For sub-regional or catchment level hydrology they generally use the method of statistical downscaling.
       Moderator Response:

       [DB] Presented without my usual fanfare:

       

80380. Eric (skeptic) at 20:32 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       So far the best definition of "extreme" above is that it must result in safety warnings. A run-of-the-mill thunderstorm does not meet that criteria although a severe thunderstorm does. What has been lacking so far is a connection from warming and more moisture in general to specific localized severe events. Specifically the logic so far has been: 1. Global average temperature rises along with global average surface moisture 2. (this step is missing) 3. Locally severe weather results.
80381. scaddenp at 20:03 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       " but a good climate model should be able to predict is a region will have more our less moisture over a given period of time. " Well yes they do (example above) and validate so long a "region" is large. Its also harder to do regions than global, but that does not mean that global models are not useful and should be replaced. At the back of idea on science is that if we understood the world sufficiently well, then we must be able to predict the outcome of an experiment. However, both chaos theory and quantum theory throw that idea out. Prediction can be limited without any loss of understanding the processes. You can predict that a system will behave chaotically within a certain proscribed phase space and that is a valid, testable prediction.
80382. les at 19:42 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Despite 249 " perhaps we could reserve this thread for talking about the weather (stay on topic)" Because I think understanding what it means to "predict" is on topic: 248 "A software model of the pendulum would be worthless as a science as it would not give any useful prediction of the pendulum's nature." The problem, IMHO, Norman and many people have is that they do not actually look at the nature of the problem. The words used assume (lets say) that the system under study is what I'd loosely refer to as "Newtonian"; by which I mean a system for which, given the equations, one can predict to any degree of precision you wish, at any time in the future, the phase state of the system - in constant time. Newtons equations dynamics are like that. But not all good, scientific, physical system are. In a Quantum system, the phase state is calculable, in constant time but not to any required precision. You only get probability distributions. To scientifically (and QED is one of the best scientific theories we have!) predict a quantum system is to determine correctly probability distributions... that is their nature. Gas laws are are macroscopically like Newtonian mechanics - you get volume/pressure/temporarily - but expressed as statistical mechanics, more like QM... you get probability distributions... again, that is the nature of gasses. Chaotic systems can not be calculate in flat time - since you have to calculate each iteration - and precision is problematic as different precisions is, effectively, changes in initial conditions. Chaotic system, however, behave well in terms of attractors, self-similarity metrics etc. that, again, is their nature. In each case there's an appropriate, predictable, statistically well found state description which is scientifically meaningful. It is a common error to try to apply the term 'predictable' as understood in the Newtonian sense able to systems to which it does not apply. And why is this, IMHO again, appropriate to this thread? Because extreme events in this context are not tails of normal/Gaussian distributions where you can pick some sigma and say "there! beyond that value". They are more like Pareto/Zipf distributions and other statistics apply... same difference as between Newton and Chaos.
80383. skywatcher at 19:26 PM on 5 July 2011
       The Planetary Greenhouse Engine Revisited
       Michele, I'm seeing a very bizarre interpretation of the physics of the atmosphere, at odds will all previous observation of it. Your second paragraph in #54 is wrong in every sense. If extra CO2 emitted energy trapped by the rest of the atmosphere (a weird concept), one of its implications would be that glacial periods, with low CO2, would be very hot! Large ice sheets tend to suggest that they weren't... I seriously think you need to rethink your ideas about radiation physics, as there is an awful lot of experimental evidence and working modern technology that suggests your physics is wrong.
80384. Norman at 19:24 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Tom Curtis @ 249 Not quite Tom, I am not making any claim about the predicability of any given climate model and extreme weather events. I do agree this is not the thread for climate models. There already is one on this topic. I was just answering Dikran's questions. My point was that if a model was not capable of making predictions it would not be scientific. If a model can make valid predictions it is a useful science tool.
80385. Norman at 19:11 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Tom Curtis @ 246 There are very few tornadoes in the tropics. Lots of thunderstorms just not severe type. The tropics have some of the warmest moist air on the planet. You need more than warm moist air to form severe thunderstorms. You also need the wind shear. I also have a question about CAPE. A thunderstorm brings heat to the midlattitudes of the atmosphere. Wouldn't that tend to increase the stability of the air and suppress severe thunderstorm activity?
80386. skywatcher at 19:11 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Norman, you seem so close to the right answer, yet you desperately try not to see it sometimes. "the mathematical model of the double pendulum is scientific since the equations can offer testable explanations about the nature of the pendulum and offer predictibility about the overall behavior of pendulum." As I'm sure Dikran intended, replace 'double pendulum' and 'pendulum' in your statement with 'climate' and you're all the way there. In what way would the 'software' model of the pendulum be different from the 'mathematical' model, if it contains exactly the same physics? And like the climate model, you can then learn an awful lot about the overall behaviour of the pendulum by running the software model for an extended period of time / many times. For example, you could learn exactly where you can stand and not be hit by the aforementioned pendulum! In fact, you could learn what the boundaries are that the pendulum won't cross. You could learn the places the pendulum is most likely to be, and the points in space it crosses most or least often; or the average velocity and acceleration of differnt parts of the pendulum. In a climate model, although the individual trajectory of the climate is not exactly predictable, we can say very well that it will fall within certain bounds. Those bounds (for temperature) head upwards as a consequence of the trajectory of CO2 forcing, in just the same way as the bounds for temperature in Brisbane will head upwards as we head towards summer. Somewhere within those bounds will be the actual temperature, which is clearly more likely to be higher in 10 years than lower in 10 years. In 50 years the chances of it being higher at BAU rise to beng almost certain. Knowing the trajectory of the bounds of temperature, along with the most likely multi-year average temperature, the likely rates of change and the states of different parts of the system, is very important indeed, just like knowing where it is safe to stand next to your pendulum, or knowing details about the movement patterns of your pendulum. Best not to confuse meteorology with climate science too - the former (in this analogy) tries to predict the exact position of the pendulum at some point in the future, the latter predicts its average trajectory and the boundaries outside which it will not travel.
80387. chris at 19:09 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Norman at 18:33 PM on 5 July, 2011

       "One could not predict anyone actual thunderstorm in the region months in advance, but a good climate model should be able to predict is a region will have more our less moisture over a given period of time."

       Fair enough. And by your criterion climate models have done exactly that, predicting pretty well that global warming will result in enhancement of precipitation extremes and in defining the location of those regions of the Earth that have lesser and greater rainfall, respectively, as the world has warmed. See for example: [*] X. Zhang et al. (2007) Detection of human influence on twentieth-century precipitation trends Nature 448, 461-465 abstract [**] RP Allen et al. (2008) Atmospheric warming and the amplification of precipitation extremes Science 321, 1481-1484 abstract
80388. JMurphy at 19:03 PM on 5 July 2011
       German Energy Priorities
       quokka wrote : "If you look at the Sovacool piece and in particular Table 1 - Disadvantages of Nuclear Power, it reads more like a hand waving anti-nuclear polemic than anything else." What about the rest of the article ? As for your EROEI piece, I have no problems with what is written, nor the conclusion : All of this goes to show that for the UK to get over the looming energy gap there is little better in energy terms than to go for the on-shore wind, a suite of offshore renewables, and much as I hate to say it, probably a wedge of nuclear too. Clean coal is a dead end. Let's just hope that we can move away from whatever limited percentage of nuclear has to be used, however, sooner rather than later.
80389. Tom Curtis at 18:55 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Norman @248, as I understand it, you are currently arguing that predictions based on climate science that extreme weather will not increase are not science because they are not predictable despite the fact that we are now almost 250 posts in on a thread showing very clear that predictions of increased extreme weather have been made, and that those predictions are being confirmed by measurable results. Given that context, the claim you are making is simply not plausible. What is more, the epistemology of science on which it is based is naive and demonstrably false. If you find a more appropriate thread, I can discuss that with you. In the meantime, perhaps we could reserve this thread for talking about the weather (stay on topic).
80390. skywatcher at 18:49 PM on 5 July 2011
       Google It - Clean Energy is Good for the Economy
       #46: "... we know that we are in a wet cycle ..." Any peer-reviewed evidence for that? I would equally say that the risk of large floods has increased due to a warmer atmosphere (as predicted), and so the risk will last as long as the atmosphere is warmer, ie much more than 60 years. Frankly in this whole thread you've posted opinions without any supporting evidence, leaning heavily on your own 'experience' to dismiss the benefits of a carbon tax for encouraging a switch to cleaner energy sources. So I'll dismiss your claims with my 'experience'... if a product is cheaper than a competitor's as a result of one being carbon-taxed and the other not, I'll buy that product and the competitor will eventually go out of business. Meanwhile the manufacturer using clean energy will grow at the expense of the dirty manufacturer. Cleaner energy use preference will increase significantly, regardless of overall energy efficiency, for which there is always a uniform motivation. This will also bring clean energy costs down, benefitting everyone, quite apart from the natural process of lowering costs that happens as a technology reaches maturity. Definitely seems a positive process to me, both economically and environmentally.
80391. alan_marshall at 18:37 PM on 5 July 2011
       OA not OK part 2: Thermodynamic duo
       Thanks Doug, I liked the memorable illustration of the peanuts.
80392. Norman at 18:33 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Dikran Marsupial, You ask some really good questions that are thought provoking. It would seem the mathematical model of the double pendulum is scientific since the equations can offer testable explanations about the nature of the pendulum and offer predictibility about the overall behavior of pendulum. That is if you would use the equations and run a long term simulation, the simulation would trace out the same area as an actual pendulum if this were videotaped. A software model of the pendulum would be worthless as a science as it would not give any useful prediction of the pendulum's nature. The science of meterology does not try to make predictions about the weather beyond a few days because they know such activity is nonscientific and useless. The prediction means nothing. It is a very good question and I don't know if I answered it to your liking. However, in the world of climate models, climate is an aggregate of weather patterns for a region. One could not predict anyone actual thunderstorm in the region months in advance, but a good climate model should be able to predict is a region will have more our less moisture over a given period of time. If it can't do this and make a valid prediction, the model would not be good for much and a new one should be developed.
80393. Dikran Marsupial at 17:20 PM on 5 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Norman wrote: "If a climate model is to be considered scientific then it must pass the test of predictability. If the model is incapable of making valid tested predictions why would you consider it scientific?" As I pointed out earlier, you can write down the physics of a double pendulum on a side of A4 paper. You can use that description to make a computational model of a double pendulum (often set as a student project - it isn't difficult). Can that sofware model make useful predictions of the trajectory of a double pendulum? No. Does that mean a mathematical model of a double pendulum is non-scientific. I look forward to a direct answer to this question.
80394. quokka at 17:04 PM on 5 July 2011
       German Energy Priorities
       More on the consequences of the Fukushima accident: TEPCO recently reported that 124 of it's workers have received a radiation dose of over 100 mSv. Working Conditions Improve at Fukushima Assuming an increased risk of a fatal cancer of 5% per Sv, that's an expected increase in the number of fatal cancers among plant workers of just one. By comparison in the aftermath of Chernobyl, 300,000 'liquidators' received an average dose of nearly 150 mSv. The UNSCEAR Chairman has said that he doesn't expect to find health effects either in the general population or plant workers based on current evidence. It will take a couple of years for UNSCEAR to compile it's study. U.N. body to probe Fukushima radiation impact
80395. Tom Curtis at 16:53 PM on 5 July 2011
       German Energy Priorities
       quokka @23:

       "The four destroyed reactors at Fukushima Daiichi had a total capacity of 2719 MWe. We can add reactors 5 and 6 to the list that will never operate again giving a total capacity of 2719 + 1827 = 4546 GWe."

       I presume that is 4,546 MWe. That still yields a replacement cost of 7 to 22 billion for all reactors. I agree, however, that even a Fukushima style accident every thirty years or so does not mean that nuclear is better than coal or gas. It does, I think, call into question the claimed superiority of nuclear power to renewable power claimed by "nuke boosters".
80396. quokka at 16:30 PM on 5 July 2011
       German Energy Priorities
       #22 michael sweet The four destroyed reactors at Fukushima Daiichi had a total capacity of 2719 MWe. We can add reactors 5 and 6 to the list that will never operate again giving a total capacity of 2719 + 1827 = 4546 GWe. The most modern of all these reactors came on line in 1979. Most of their value is depeciated away already. In themselves they are not a huge loss. In any case $10 billion per new reactor is way off. Current builds run between about $1.6 billion per GWe (China CPR1000) to about $5 billion per GWe (Finland EPR-France)to $3.8 per GWe (UAE - Sth Korea). You can find IEA assessment of new nuclear build costs over a range of countries here: New Nuclear Power Costs For Japan, they report $3billion/GWe overnight costs. My Fukushima accident costs were just an assumption. If you double or triple them, it does not diminish the validity of what I was saying.
80397. Michele at 16:13 PM on 5 July 2011
       The Planetary Greenhouse Engine Revisited
       @ Patrick I never argued that the radiation flows because I am strongly convinced that it doesn’t occur. What flows is the wasted energy which is collected into the one/two cul-de-sac and then converted to radiation and so disposed of. I think that if you continue to argue about the total radiative balance we could leak the true causes leading to actual temperature profiles (GH effect). Of course the radiation/evaporation also takes place on the way but it seems to be very tiny as its contribute to the lapse rate seems to be negligible: if it had a real weight the lapse rate of troposphere, e.g., would be always hyper-adiabatic, whereas we well know it is, at large scale, adiabatic or at least hypo-adiabatic. Aside that, it is undeniable that the atmosphere, by means of the temperature gradients, behaves as a scavenger which sweeps and collects the waste energy toward the tropopause and the mesopause where the heat has only one way to escape to space: it has to be converted thermally to radiation. as the results of my simulation show, also if roughly. The temperature profiles are determined by the conduction/convection and, above all, by the conversion heat->radiation localized within the collection regions where the heat remains confined.
80398. Stevo at 16:05 PM on 5 July 2011
       Monthly Climate Summary: May 2011
       Thanks for that scaddenp, I had been able to find nothing about it.
80399. From Peru at 15:41 PM on 5 July 2011
       Trouble Brewing in the North
       Maybe we could call you The Incorruptible Moderator If only the collapse of a ice shelf could have the public impact of this:
80400. DLB at 15:25 PM on 5 July 2011
       Great Barrier Reef Part 1: Current Conditions and Human Impacts
       John Bruno @13, what do you mean by "they interpreted evidence of no trend during that time period as indicating no trend during that time period" ?

Prev  1600  1601  1602  1603  1604  1605  1606  1607  1608  1609  1610  1611  1612  1613  1614  1615  Next