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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 80401 to 80450:

  1. It's the sun
    The IPCC did run 14 'anthro+nat' models and only 5 'nat' models that possibly were independent from the other (the last is not to prove, because the description is not longer available). This cannot be the correct method because Stott had a dependence between the models. If the anthropogenic forcings sum in a negative net forcing (what is necessary for a global cooling caused by the overwhealming of GHGs by aerosols, what commonly is called 'global dimming', occured mid century), then it is obvious that the natural forcings must show higher temperatures as far as they had no change in intensity (as to the time until '63, natural forcings had always caused a warming). If you use independent models (at least 9 of the 'anthro+nat' were it definitely) there cannot be a correct result. Otherwise we would not speak about a 'primarily anthropogenic' driven cooling. That was what made it curious to me. Possible additional influences could be, as told before, for example number and intensities of flares. Each major flare destroyes an huge amount of high-stratospheric Ozone what reduces the absorption of high frequency radiation there. This, of course, has only a small short term influence, but the long term effect that results in the lagrer absorption by oceans is currently not researched, but this is currently the only explanation for the sharp rise of the OHC in 2003. In this year we've seen the most and most intense flares, culminated in the biggest flare ever measured (X28..X40, not quite sure, because the direct measurements are only possible until X17.2).
  2. Antarcticice at 15:10 PM on 5 July 2011
    Glickstein and WUWT's Confusion about Reasoned Skepticism
    Ira Glickstein, seems to be like many of the experts on watts (including watts himself) not really an expert. Glickstein is an engineer (it even for once states what he is at the bottom of his comment) There are over 500 of the ill-informed backslapping him for his comments, it's all a bit sad really. Point B.6 shows the dishonesty of these comments Co2 lag is pretty easily explained by the planet taking that period of time to warm to level were Co2 starts to be added then further warming follows, a point Glickstein fails to even mention. P.S. WUWT seem to be crowing about a new paper they claim proves no warming between 1998 & 2008 the choice of the start and stop years is for pretty obvious reasons as it turns out the authors are statisticians not climate scientists, but WUWT are claiming this paper is going to appear in PNAS, I find it hard to imagine they would fall for such a cheap trick. http://wattsupwiththat.com/2011/07/04/a-peer-reviewed-admission-that-global-surface-temperatures-did-not-rise-dr-david-whitehouse-on-the-pnas-paper-kaufmann-et-al-2011/
    Response:

    [DB] Note that Whitehouse is a recidivist dissembler and has been eviscerated by Tamino on multiple occasions on multiple points.

  3. michael sweet at 14:22 PM on 5 July 2011
    German Energy Priorities
    Quokka, It seems to me that at 16 you have underestimated the cleanup costs of Fukishima. Since the 4 (6?) power plants that have been destroyed at Fukishima had a replacement value of at least $10,000,000,000 each (a reactor proposed near me is currently estimated at $18B), that alone is $40B. How much is evacuating the surrounding area, for years, worth? The farming must be worth a lot in such a large area, not to mention the fishing and tourism. If you want to count the costs against the entire nuclear industry you should cost Chernobyl and 3 mile island also. The reactors would be worth at least $20B. What is your estimate of the value of the land around Chernobyl for decades? What are the cleanup costs so far at Chernobyl (financed by other governments)? It starts to look like real money. It is very difficult to find investors in the US who are willing to take the risk. Most of the proposed plants require government financing. As Dana points out, nuclear is better than coal. It is hard to compare nuclear costs when it is so difficult to find out what they are.
  4. 2010 - 2011: Earth's most extreme weather since 1816?
    Norman @233: Trapp et al, 2009:
    "We investigate the transient response of severe thunderstorm forcing to the time-varying greenhouse gas concentrations associated with the A1B emissions scenario. Using a five-member ensemble of global climate model experiments, we find a positive trend in such forcing within the United States, over the period 1950 – 2099. The rate of increase varies by geographic region, depending on (i) lowlevel water vapor availability and transport, and (ii) the frequency of synoptic-scale cyclones during the warm season. Our results indicate that deceleration of the greenhouse gas emissions trajectory would likely result in slower increases in severe thunderstorm forcing. Citation: Trapp, R. J., N. S. Diffenbaugh, and A. Gluhovsky (2009), Transient response of severe thunderstorm forcing to elevated greenhouse gas concentrations,"
    From Trapp et al, 2007:
    "Fig. 1. Difference (A2 − RF) in mean CAPE, vertical wind shear over the surface to 6 km layer (S06), mean surface specific humidity (qs ), and severe thunderstorm environment days (NDSEV) for March–April–May (MAM) (a–d) and June–July–August (JJA) (e–h), respectively. The RF integration period is 1962–1989, and the A2 integration period is 2072–2099.">/blockquote>
  5. Monthly Climate Summary: May 2011
    I'm with Eric on this. I dont think monthly weather summaries say much about climate at all. We dont know how ENSO will be affected by warming - the jury is well and truly still out.
  6. Monthly Climate Summary: May 2011
    Eric, Does overall warming effect the ENSO? and if so, how?
  7. German Energy Priorities
    @20 dana1981 If you want to look at comparable Western European economies, then try this. It is still not obvious to me that Germany is THE pacesetter. The standout of course is France because of nuclear power. From the Google data, both France and Germany have reduced their emissions about 20% from 1991 to 2007. The UK by about 15%. By 1990, France had already essentially completed their build of nuclear.
  8. German Energy Priorities
    quokka - most of the countries in your graph with larger emissions cuts than Germany are Eastern European, and probably had a lot more to do with economic struggles after the collapse of the USSR than actual efforts to reduce emissions. In recent years, emissions have started to rise for many of those countries. As I noted in the post, Germany is at around half the per capita emissions of USA, Canada, and Australia, and has reduced emissions >20% since 1990 due to concrete efforts to make that happen, not just economic struggles. I think it's fair to call them a pace setter.
  9. The chief troupier: the follies of Mr Monckton
    Thank you to all posters who replied to my comment, your answers were very informative, Did anyone check "The fair farming group"? A reply to their screed on the ether by someone knowledgeable could be handy. The members are farmers, but you would have to say that has been their hobby, one is a stockbroker, one a banker etc. . That is really beside the point, but they do have the ear of numerous pollies and ex pollies. Their wacko petition to parliament perhaps should be countered.
  10. 2010 - 2011: Earth's most extreme weather since 1816?
    I would say that you are making the hypothesis that there is unforced cycles in the weather pattern and these alone are enough to explain weather. An alternative hypothesis which doesnt require unexplained cycles is to use existing physics and postulate that these are result of global warming. Now I would also agree that while weather patterns are consistent with global warming hypothesis, the predictions about extreme weather are not sufficiently robust (model cell size is too large) nor is the observation period long enough to make strong statements on variations compared to natural variability. However, as a guide to how insurance companies and governments with a lot at stake, I would act in precautionary way rather than depend on the hope of that this is a cycle which has no physical basis yet.
  11. A Detailed Look at Renewable Baseload Energy
    Mark Harrigan @134, the issue of "spin up time" is significantly overstated. In framing the issue, anti-renewable campaigners assume the auxiliary power stations must be independent gas or biofuel plants. One alternative is to design them as solar-thermal plaints with auxiliary gas heating. As the plant is already in continuous operation, the plant will neither need to spin up from scratch nor consume fuel in idle times.
  12. 2010 - 2011: Earth's most extreme weather since 1816?
    scaddenp My series of posts are an attempt to determine the validity of this question by Jeff Master "Has human-caused climate change destabilized the climate, bringing these extreme, unprecedented weather events?" I am investigating if these are extreme, unprecendented weather events by looking at long time series of weather related phenomena in various regions of the globe. Would a destabalized climate look much different than past climates? When I look at long term climate patterns I see these cycles (longer than 30 years). Maybe my vision is poor. But I still have not seen variations that seem to be "outside the envelope". They may beome a reality, that is a different question with its own set of complications. The question here are 2010-2011 weather extremes an example of climate disruption caused by global warming.
  13. 2010 - 2011: Earth's most extreme weather since 1816?
    Like gravity, the physics of climate is well understood but like hyperion, all that understanding will not make some things predictable. "If the model is incapable of making valid tested predictions why would you consider it scientific" Well first and foremost, climate models make numerous testable predictions. Some predictions are more robust than others (the level to which the physics is captured by the computer model as well as influence of chaos) and some with greater certainty than others. The strawman is to demand a prediction from the model that it cannot deliver and ignore the predictions that it can make. Note how well Broecker's prediction for temperature in 2010 made in 1975 was. I will also grant that the actual accuracy was considerably better than the model was actually capable of delivering. I would reject current climate theory if the robust predictions of the models do not match predictions within the uncertainties of the model but I see no evidence for that.
  14. A Detailed Look at Renewable Baseload Energy
    Mark Harrigan @135, as stated previously, my major problem with the nuclear industry is that they simply do not honestly report the costs of the nuclear industry in summary statistics. They are not alone in this, with anti-nuclear lobbyists being, if anything, even more dishonest. The consequence is that for non-experts no clear indication of the risk can be found, and in terms of comparisons with renewable energy sources, the risks and costs of nuclear power are significantly understated. I will give you two examples of this. First, you assure us that "The technology is CO2 free in operation", but it is not. In operation, the generation of nuclear power requires the mining, and refining of uranium, the manufacture of fuel rods (or alternatives in newer designs), the transport of ore, refined uranium, and rods to the appropriate location, and then the transport and removal of the spent fuel and other waste. None of these are emission free operations. And for none of these are their equivalent CO2 emissions from renewables. I am willing to accept that the overall emissions from these processes are small relative to power production, that they are much smaller than the equivalent costs for coal (and to a lesser extent natural gas and oil), and that in principle they can be eliminated by moving to an emissions free economy. But they exist. Consequently they should be included in any estimate of operational CO2 emissions from nuclear power. So, do you know of any reliable source that budgets nuclear operational CO2 emissions including the entire fuel and waste cycle? I have even greater trouble with the mortality figures. Deaths for solar and wind power are essentially limited to those caused by accidents during instillation and (for wind power) maintenance. Further, large scale construction projects have a lower death rate per hour worked than small scale construction projects. But 11 times smaller than for PV? And that is assuming that no deaths from operational accidents, nuclear accidents, or in the mining, processing and waste management cycles. Using Quokka's estimate, the 0.04 deaths per Terrawatt represents 2800 deaths. Using BBD's preferred source, there where 28 deaths among emergency workers at Chernobyl, and 15 from Thyroid Cancer up to 2002; but an expected 4000 Chernobyl related cancer deaths are expected in the effected population. (See also http://www.iaea.org/Publications/Booklets/Chernobyl/chernobyl.pdf) 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. Mining is a major cause of mortality in the uranium fuel cycle. In the US across all mines, on average there is one death per annum per 520 full time workers. Given that there are well over a hundred uranium mines world wide, that probably translates into deaths in the hundreds each year just from mining operations alone. Indeed, mining uranium has unusual hazards, both from the radioactivity of the ore itself, and from the release of radon gas. One study shows an excess of 24 deaths (actual deaths: 34, expected: 10.2) from lung cancer in a cohort of 757 Navajo uranium miners. Based on these figures, total deaths from the nuclear power industry, excluding accidents such as Chernobyl and Fukushima is likely to be much higher than the 0.04 per Terrawatt indicated. Again, if you have reliable information including whole of fuel cycle figures, I would be very interested. One small point that goes unnoticed in these mortality figures is that large nuclear industry accidents have a very large health cost relative to mortalities. For example, only 15 people died of thyroid cancer to 2002, but around four thousand people got thyroid cancer who otherwise would not have. You can probably see my concerns from these examples. I also have concerns about reported costs of generation. Do they include the costs from large scale accidents as well. 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. 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.
  15. 2010 - 2011: Earth's most extreme weather since 1816?
    scaddenp @ 240 and 241 Not sure I understand your line of reasoning. The definition of science is given above. Gravity has a linking mechanism, all matter attracts and it does so by the working equation F=G(M1*M2)/r^2. Certain systems of gravity cannot be predicted. They are outside the realm of science. Even accumulating more information on the system will not make it more predictable. Example of chaotic gravity. After 10 years with Hyperion you may not be able to build a model to predict its motion but gravity is still scientific. If you have the measurements of its mass, Saturn's mass, its distance from Saturn, you can come up with a precise measure of the gravitational force acting on this moon. 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?
  16. Google It - Clean Energy is Good for the Economy
    The pluses and minuses of high dams here get a lot of debate. Plus - new fisheries (introduced species - salmon), recreational lakes, flood control, MAYBE irrigation potential, and of course power. Minus - earthquake hazard, loss of habitat and/or farming potential, unsolved problem with native fisheries (which is more complex problem than just dams in case of the very valuable whitebait), competition with downstream irrigators for water, loss of whitewater recreation/tourism. In my opinion, you prioritize sites, sacrifice some rivers with a lot of dams, leave others free. An unavoidably complex process of evaluating conflicting values.
  17. German Energy Priorities
    #18 Agnostic, Do you have any recent data to back that up. According to these 2005 figures, Germany was performing somewhere in the middle of the pack with respect to both Kyoto commitments and in absolute per capita emissions reductions.
  18. Eric (skeptic) at 11:56 AM on 5 July 2011
    Google It - Clean Energy is Good for the Economy
    The costs depend on the dam. Some dams would create value by steadying the water level and creating a better fishery. Most of the land on the flood plain around me is used for grazing or sometimes pasture or most often it is just mowed for aesthetic or recreational reasons. Some is wooded and that would be lost (harvested). A run-of-the-river hydro in my case would capture a tiny fraction of a dam (perhaps 10X less head and hundreds or thousands of times less flow). Also a run-of-the-river installation below my house would have to be completely submersible to withstand 30 foot floods. Incidentally I can anchor a floating generator with no approval whatsoever since it is "removable". Anything else would be a regulatory nightmare.
  19. Google It - Clean Energy is Good for the Economy
    adelady: I was indicating dams on the river. They would serve a two fold purpose. Flood mitigation as well as a source to generate power. The externalized costs of a damn must be balanced against the cost of flooding. In the case of the upper Missouri Basin, we know that we are in a wet cycle and it previous cycles are an indication, flooding will be common for the next 60+ years. An example of the area flooded just this year...you could build a sizeable dam and the flood control provided could allow dam external to be flat for 50 years. There were millions of acres flooded this year alone. In the USA this would be easy to fund. Just take 100Billion out of defense, (which is severaly bloated) use 50 billion to reduce the deficit and use the other 50 billion to build dams.
  20. Trouble Brewing in the North
    DB: Can we just start calling you Dr. Who?
  21. German Energy Priorities
    Germany is unquestionably the pace setter when it comes to reducing CO2 emissions in terms of what it has already achieved and what it proposes. Its 2020 target can be achieved though probably not without supplementation such as import of electricity from France and Denmark or improvement in the storage and distribution of energy over the present decade. Both are possible. The latter is more important, particularly ability to store electricity and efficiently release it in response to periodic increased demand.
  22. Google It - Clean Energy is Good for the Economy
    Good point adelady. I was not externalising costs and I agree that should be on same basis as carbon. This is a debate that goes on quite a bit here as we look for more hydro power. Except in a maybe 8 more sites, wind and geothermal are cheaper (ignore externalised costs) than hydro and in those 8 sites, there are significant external costs to building a dam. Just remember that not only is run-of-river more expensive per GJ, but there is considerably less total GJ available in practical terms.
  23. Google It - Clean Energy is Good for the Economy
    "... usually more expensive per GJ than high dam." Externalised costs? If we insist on accounting for externalised costs for carbon, we should do the same for renewables. Surely one of the great advantages of wind and solar (esp PV) is that it allows multiple uses of the power producing area. And dams not only disallow other uses, they destroy other valuable things. Like forests and farmland and communities. Or does the accounting include all of these things - I don't know.
  24. Great Barrier Reef Part 1: Current Conditions and Human Impacts
    Rob thanks for your comments about fisheries in NZ! It is funny, but your point about the crazy definition of "overfished" used by fisheries managers comes up all the time (at least in my world). It is maddening that a population reduced to a third or more of its very recent size will often NOT be considered overfishing by fisheries biologist and managers. We ran a post and a forum about this issue recently on SeaMonster here and honestly, the variety of definitions of what "overfishing" is underlies a lot of the dispute about the state of the world's fisheries, although the topic rarely comes up (in part because when you burrow in, it gets very complex). Yeah, I have a soft spot for plants! It causes be lots of trouble in a field where plants are considered vermin to be exterminated (ie, "slime" in high-priest of marine environmentalism JBC Jackson's vernacular) I feel like a coyote or wolf biologists in the 19th century. I still have hope minds can be changed...
  25. 2010 - 2011: Earth's most extreme weather since 1816?
    And by same token we can predict earth or mars location and attitude 10 years out to high degree of precision. That make gravity an inconsistent theory?
  26. Great Barrier Reef Part 1: Current Conditions and Human Impacts
    Dear jmsully, The AIMS Osborne paper, although strikingly similar to Sweatman et al in many regards, comes to a different conclusion about the historical state of the GBR. In their abstract, Osborne et al state: "While the limited data for the GBR prior to the 1980’s suggests that coral cover was higher than in our survey, we found no evidence of consistent, system-wide decline in coral cover since 1995" Thus, like many others (eg, Bruno and Selig 2007 PLoS One), they interpreted evidence of no trend during that time period as indicating no trend during that time period. Sweatman et al - along with Andrew Bolt, Bob Carter and others - in contrast used this evidence to support their argument that the GBR is pristine or near pristine, ie, it hasn't change much if at all (i.e. they argued that the state of the reef in 1995 is representative of the system baseline).
  27. 2010 - 2011: Earth's most extreme weather since 1816?
    Norman, all predictions are couched in terms of their inherent uncertainty. You could predict the location of say Saturn's moon Hyperion in 10 years time but you dont have a chance in hell of predicting it attitude. Does that make gravity unscientific?
  28. Trouble Brewing in the North
    "At the moment, this post says "Posted on 14 July 2011 ..." Ice fortress ... Bastille Day ... it all sorta fits, no?
    Response:

    [DB] Fixed pub date (and they said I'd never make it as a Timelord...).

  29. It's the sun
    Joe, I cant make sense of your sentence. ": while the global dimming the only natural caused temperature is higher than the total (anthro+nat)." Its certainly not obvious to me why you think IPCC misrepresents Stott. What do you mean by "global dimming"? "it is surely not the only parameter that may be of importance" Well when you have some other parameter that makes physical sense, let us know. Meanwhile I will continue to look at the well-established, measurable physics of GHGs. If you ignore them, you cant get planetary temperature right so why do think changing their forcing is so insignificant compared to same change in solar forcing?
  30. Google It - Clean Energy is Good for the Economy
    I am assuming Camburn is proposing a lake in national park. I suspect Camburn thinks all "alarmists" are greenies and so is trying a wind up. I dont know the US at all so happy to take his word for it, though from experience here, run-of-river generates less power and so usually more expensive per GJ than high dam.
  31. German Energy Priorities
    #13 peter prewett, Oldbury has old Magnox reactors which are known to be difficult and expensive to decommission. They are not representative of decommissioning issues or costs for water moderated, water cooled reactors such as PWRs, BWRs and CANDUs.
  32. German Energy Priorities
    I did a little back of the envelope calculation to test out the proposition that cost of the Fukushima accident is "proof" that nuclear power is too expensive. This is what I came up with: Over the whole history of nuclear power worldwide, total electricity generated: ~70,000,000 GWh (from eyeballing the chart here: http://www.world-nuclear.org/info/inf01.html ) Assuming that has displaced black coal at ~900 grams/kWh CO2 implies an emissions saving of ~63,000,000,000 tonnes CO2 For an assumed cleanup cost of $100,000,000,000 at Fukishima that is an additional CO2 abatement cost of ~$1.40 per tonne CO2 over the whole history of nuclear power.
  33. The Planetary Greenhouse Engine Revisited
    Re Michele - Also remember, in your analogy, liquid water is the enthalpy contained in the non-photons. Thus, the topography you speak of is not a landscape that directs water flow - it is the liquid water itself! And given that (except at sufficiently great heights) there is little conduction and no spontaneous convection in the part of the atmosphere being considered, in a radiative equilibrium the only flow of water from one place to another is by evaporation and condensation. But to get a better understanding, again, please try going right to the physics of radiation; this analogy could lead you astray.
  34. Rob Painting at 08:15 AM on 5 July 2011
    Great Barrier Reef Part 1: Current Conditions and Human Impacts
    ETR - Bleaching is short-term, it occurs when surface waters rise 1-2°C above the normal summer maximum. See my post Coral: life's a bleach... and then you die In the Caribbean many of the reefs are not recovering, as bleaching and associated disease are killing them. Many areas, that were once coral reefs are now covered in seaweed and slime (macroalgae - John Bruno will tell me off for using the word 'slime'). See 'Doctor Doom" - Jeremy Jackson's talk Look at the state of the Caribbean sea surface temperatures now: If that trend continues through to September/October 2011 we will have another bleaching event in the Caribbean. Not a rosy future for coral sadly.
  35. Eric the Red at 08:03 AM on 5 July 2011
    Monthly Climate Summary: May 2011
    Stevo, Much of the pattern is also totally in line with a stron La Nina. Long term trends are much better indicators than short term anomalies.
  36. A Detailed Look at Renewable Baseload Energy
    Mark Harrigan Many good points at 134, culminating in:
    Can we advance the debate by seeking solutions to the problems of renewables?
    Yes, of course. But this is implicit in all future renewables scenarios, as we see with Diesendorf (2010). People have been thinking about the solutions for a long time. There is real potential here, but the upper bound appears to be ca 30% of the global energy mix by 2050. If not rather less. This is the problem with renewables. The potential is either misrepresented (high renewables scenarios), or optimistic (30%). Even assuming the latter, there is a very large elephant in the room.
  37. 2010 - 2011: Earth's most extreme weather since 1816?
    adelady @ 238 You have pointed out one of the needs for a study to considered scientific, predictablitity. They do know some chemicals in cigarette smoke are capable of damaging DNA (which could lead to cancer). So there is a tenuous link even if it can't be specifically detemined. If a climate model would predict events sometimes and not so well at other times then it would fail in the predictablity deparment and I would not consider it science based upon the accepted definition of this concept.
  38. German Energy Priorities
    (continuation) But there is the alternative of nuclear fusion. The easiest process is the Deuterium(H-2) + Tritium(H-3) fusion, that produces Helium-3 plus one neutron: H-1 + H-3 → He-3 + n This reaction still requires a relatively rare isotope, Tritium. It can be obtained from litium: n + Li-6 → H-3 + He-4 n + Li-7 → H-3 + He-4 + n Litium is still a non-renewable metal that must be mined. But there is the D-D reaction, that uses just deuterium: H-1 + H-2 → H-3 + H-1 or He-3 + n This uses the abundant deuterium, found in the abundant water on Earth. Water is considered renewable (actually isn’t, but there is so much of it that will behave as if it were a never-ending resource, just like the hydrogen burned to helium in sun in a similar nuclear fusion reaction)
  39. 2010 - 2011: Earth's most extreme weather since 1816?
    Norman "It would be a science if the models have known mechanisms for explaining why the preciptiation will increase ... and then if they had predictability." Come on. This is like saying that you can't rely on health experts telling you that when cigarette consumption increases in an area you can expect to see more cases of lung cancer as well as other cancers - because the mechanism for working out how smoke (of all kinds) initiates cancer is poorly understood. Nor can health experts predict with any confidence which particular smokers will contract cancer as against heart disease or stroke or emphysema. Epidemiologists can tell you the expected rate for these diseases given a certain rate of smoking. Doctors can identify which people have developed these diseases and they can treat them - but they can't tell in advance which person will, or will not, develop any smoking related illness. Does that mean it's not science?
  40. Trouble Brewing in the North
    At the moment, this post says "Posted on 14 July 2011 by MarkR". Does this mean we have the time machine Tom Toles suggested as the fix for global warming? :-)
  41. 2010 - 2011: Earth's most extreme weather since 1816?
    Dikran Marsupial @ 236 I will attempt to answer: "Norman, take a GCM, which embodies our knowledge of climate physics. Apply CO2 radiative forcing, and observe an increase in rainfall frequency and intensity. Does it then become science?" Here is the Wikipedia definition of science which is similar to other definitions. Science Definition. "Science (from Latin: scientia meaning "knowledge") is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the world." The testable explanations would be the mechanisms I have been asking for. The mechanisms that drive extreme thunderstorms are well established and predicatable. Meteorologists can look at initial conditions and predict with high degree of confidence the severity of thunderstorms that will develop. Now for your question. It would be a science if the models have known mechanisms for explaining why the preciptiation will increase (such as, increased evaporation caused by a warming earth due to CO2 forcing) and then if they had predictablitly. If the model forcasts a given increase in frequency and intensity of rainfall over an area during a specified period of time, and the actual rainfall in the area comes close to the model's prediction over a given number of areas (one correct prediction would not be enough to qualify the model as science) then I would say the model is now a science. It has achieved the goal of predictability that is necessary for it to be considered a science. In the example you provided it goes back to what one considers extreme. In your example 40 mm a day is considered extreme. "Extreme rainfall is chosen as precipitation greater than 40 mm/day chosen on the basis of prior research indicating that rainfall at this intensity has the potential of causing soil erosion and flooding." I don't think any farmer in my area would consider a 1.57" rainfall in a day an extreme amount. I would doubt such a rain would lead to flooding unless the soil was highly saturated and it all fell in a really short time.
  42. German Energy Priorities
    peter prewett And the residence time of CO2 in the atmosphere is...? It boils down to the lesser of two evils, every time.
  43. The Planetary Greenhouse Engine Revisited
    Re Michele Well then. Where is it the physics inconsistency? Radiation doesn't behave just like water flowing under gravity, but borrowing your analogy anyway, what you've forgotten is that evaporation doesn't only occur in the valley, it occurs on the hill as well. In fact there is more evaporation, per unit area, on the hill than in the valley (the analogy gets tricky here as to why, but we could say it is because the wind is stronger on the hill. Actually it is by said evaporation that the water reaches the valley as well as space, and here the analogy falls apart almost completely. So please consider radiation physics.)
  44. Dikran Marsupial at 05:41 AM on 5 July 2011
    2010 - 2011: Earth's most extreme weather since 1816?
    Norman@235 In post 231, I asked you a specific question, that you ought to be capable of answering directly. Sadly all to often discussions of climate science with skeptics end up with the skeptic unwilling to state his position clearly and unambiguously. I have learned that that is usually the indicator that no further progress will be made and it is a waste of time to continue. That modelling extreme events involves uncertainties does not mean it isn't science.
  45. A Detailed Look at Renewable Baseload Energy
    Mark Harrigan Thanks for your thoughtful response. First, I obviously agree with you on the (to some) surprisingly 'safe' nature of nuclear (see #101 for another way of looking at this: sum total plant operating history over last 40 years = 11,255 years; 18 INES rated incidents over this period, only Three Mile Island, Chernobyl and Fukushima 1 rated above INES 4). But the risk/hazard question is real, although it pays to remember that Generation III plant is inherently far safer than Generation II. Also, those who fret most about terrorist threats to reactors and waste transport know least about reactor containment vessels and Type B transport package specs. The best way to keep operators on their toes is continuous, unscheduled, independent inspection with absolute power to require access and disclosure. Nothing less will do. And yes, I can see it being a big problem with the Russians and the Chinese and other contrarians, but that's a political fight worth having and frankly I'd be very happy with somewhat ill-tempered Chinese and Russian teams picking over US and EU plant really looking for something wrong. We would of course be doing the same for them. Even so, this is where it gets hard. If you ask around on this site about the risk/hazard analysis of AGW, you will get a variety of answers, mostly high/high or worse. That's the policy bullet to bite. What infuriates me is that only Hansen and Lovelock actually criticise the massed ranks of anti-nuclear activists among the climate concerned for getting in the way of a difficult but necessary decision to expand nuclear. Anti-nuclear sentiment is Janus-faced; its other aspect is ill-founded renewables advocacy. The policy 'missing link' is the frankly naive claim that western democracies will somehow turn to austerity and energy poverty and deindustrialise to make it all work. It's wishful thinking on a par with AGW scepticsim - and similarly dangerous. Mike Hulme was correct to classify AGW as a 'wicked problem'. This sort of thing is exactly what he was talking about.
  46. 2010 - 2011: Earth's most extreme weather since 1816?
    Dikran Marsupial @ 231 Here ia quote from a very long report on climate models. The report is very long and detailed so I have not had to time to read through all of it. It seems climate models are fairly good at reproducing some climate effects based upon the actual events and they do continue to improve and evolve as more knowledge is gained and added. "Modeling of extreme events poses special challenges since they are, by definition, rare. Although the intensity and frequency of extreme events are modulated by ocean and land surface state and by trends in the mean climate state, internal atmospheric variability plays a very large role, and the most extreme events arise from chance confluence of unlikely conditions. The very rarity of extreme events makes statistical evaluation of model performance less robust than for mean climate. For example, in evaluating a model’s ability to simulate heat waves as intense as that in 1995, only a few episodes in the entire 20th Century approach or exceed that intensity (Kunkel et al. 1996). For such rare events, estimates of the real risk are highly uncertain, varying from once every 30 years to once every 100 years or more. Thus, a model that simulates these occurrences at a frequency of once every 30 years may be performing adequately, but its performance cannot be distinguished from that of the model that simulates a frequency of once every 100 years." Quote from this report: Climate models report.
  47. Eric the Red at 04:29 AM on 5 July 2011
    Great Barrier Reef Part 1: Current Conditions and Human Impacts
    jmsully, I was about to link to that article when I read your post. The bleaching appeared to be a short-term occurrance, similar to that observed in the Caribbean and elseware.
  48. 2010 - 2011: Earth's most extreme weather since 1816?
    Tom Curtis @ 219 I did as you suggested. I sent a query to Munich Re about what criteria they use to determine a dissater in their charts. I will have to wait and see if they answer it.
  49. 2010 - 2011: Earth's most extreme weather since 1816?
    Tom Curtis @ 232 I was reading up on the formation of preciptitaion events and what determines their severity. The thunderstrom you describe is known as an air-mass thunderstorm. Generally they are the least severe and the rain will cool the updraft and destroy the cycle. Even these need the one common factor in thunderstorms. You need a layer of unstable air (one where if you move a parcel of ground air to a higher level it will end up being warmer than the surrounding air and so continue to rise). I looked at some weather links to determine what causes the most severe thunderstorms. Moisture in the air is the definate fuel for storms but there are many factors that go into determining the intensity of a thunderstorm. I do not know if the 4% increase in moisture content of the air will make much difference (will continue to research this). Here are some links. Atmopheric stability and storm formation. Factors that determine the intensity of a thunderstorm. Stability of the atmosphere is one of the major factors in determining the severity of a thunderstorm. The less stable the more likely an intense storm will develop. Also upper wind variation is really important or the storm will choke itself off. The upper wind moves the region of downdraft away from the updraft allowing the storm to continue and intensify. Other factors are how fast the overall storm is moving. A strong strom that moves rapidly will not be a likely to produce flooding as a similar strong storm that moves much slower over an area. Will global warming create more regions of unstable air? Will these regions of unstable air be more unstable because of global warming? Will wind shear become stronger as the earth warms? If these questions can be determined to be a yes then I would agree with the hypothesis that global warming will increase the number of severe storms, more rain, hail, wind and tornadoes all with the potential to increase damage to target areas. In the US the term used is severe weather. An extreme weather event would be one significantly worse than normal severe storm events.
  50. It's the sun
    Well, I didn't understand the figure. Of course, because the IPCC didn't adopt it the right way from the original (Stott et al (2006b)). In the original work it is as I told that it has to be: while the global dimming the only natural caused temperature is higher than the total (anthro+nat). So what did the IPCC do, or at least the authors that wrote the chapter?! (Possibly this may be the reason why the link to the corresponding appendix is now broken in the IPCC documents. Who knows...) Ok, I'm again off topic. Back to it. The first paper you've linked is a good chance to get enhanced knowledge about another part of Sun's influence. But, if you are aware of it, this is in addition to the solar components that were used so far (TSI and SSN) and it is surely not the only parameter that may be of importance. Perhaps it will come up to the IPCC documents in the future (I hope so). As to Hansen, I will have a closer look at it. But obviously he didn't know about the global dimming because in Fig.1 (base of the whole work) the net forcing is steadily rising (except the volcanoes) what definitely would have disabled a cooling that was observed. I'll come back to it (in the right topic, of course).

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