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K T at 17:01 PM on 18 March 2011Sea level rise: coming to a place near you
Sh*t, the whole of Singapore's going to be swamped. And THAT's where I live. -
L.J. Ryan at 16:52 PM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
scaddenp @633 360kJ is at minimum expended by the batteries. Surely you would accumulate more then 360kJ within the box. After all, the claim is reflected light (B from Tom Curtis's diagram) is twice the input. Why the discrepancy? So lets step it back, if your box was fully enclosed such all surfaces are reflective save two small aperture. One aperture to receive light the second to radiate light. Close the output while receiving 1W at the input. The energy accumulated within the box after 100 hrs is what, 360kj? If the first aperture is then closed does the box now contain 360kj of light? -
Rob Painting at 15:27 PM on 18 March 2011Examining the impacts of ocean acidification
Alan Marshall - We need to determine what this corresponds to in terms of a decrease in ocean surface pH. If we are to attempt to stop pH from falling below 8.0, I suspect a 2 C warming is too high IIRC this may be addressed on the FAQ section at EPOCA. Remember we are talking about 2°C of atmospheric warming, not the ocean. The decline in CO2 solubility from ocean warming this century is negligible. The effect on ocean stratification, on the other hand, could be dramatic. -
Tom Curtis at 15:24 PM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
RW1 @630, as it is difficult to carry on two discussions at once on the same thread, do you mind holding of on the discussion of the relevance of the light box until we have settled that it does not violate any law of thermodynamics? And to that end, do you agree that the light box does not violate any law of thermodynamics? -
TimTheToolMan at 15:21 PM on 18 March 2011What would a CO2-free atmosphere look like?
I see. Now Tom gets to dictate what I've "indicated" with a rubbish interpretation on what varying sensitivity means and I have no say in the matter. Real class SkS.Moderator Response: [DB] Your reply to Tom was deleted both due to the lack of substance and the devolution of the comment into childish behavior. When you start to personalize things you cross the line. Feel free to repost a reply to Tom, along with a substantive argument based on the peer-reviewed science. Show everyone why you are right. Merely disagreeing, and being disagreeable while doing it, adds no value to this dialogue. There are other venues for that type of behavior. -
2nd law of thermodynamics contradicts greenhouse theory
Keep in mind, everyone, that the gain of the box is 0.5, less than one, and hence a run-away feedback is not possible. Please see Does positive feedback necessarily mean runaway warming for details. Tom Curtis, I like your example. I did much the same thing on this thread earlier, except adding a value (which could be a column) of emissivity (0.612 for Earth, as measured), where your "C" was (1.0 - emissivity) * B, and "D" was emissivity * B. If you do that with 240 as input, the results are quite interesting, as per Trenberth 2009. -
alan_marshall at 15:11 PM on 18 March 2011Examining the impacts of ocean acidification
Ken Lambert @ 16 As far as I know, the transport of absorbed CO2 to the deep oceans is included in the models. The fact that surface pH is decreasing indicates that CO2 is absorbed from the atmosphere faster than it can be transported to the deep oceans. The model developed by the US National Centre for Atmospheric Research (Fig 1.) projects an end-of-century surface pH of 7.8, but it presumes a business-as-usual emissions trajectory. On the other hand, if the world urgently makes serious efforts to constrain emissions, the outlook is not quite so bleak. The UK Department of Energy and Climate Change (DECC), in drafting the UK Climate Change Act of 2008, commissioned a consortium of experts led by the Hadley Centre to model the trajectory for ocean surface pH under their ambitious “2016 4% Low” scenario. If annual global emissions were to peak in 2016 (developed countries sooner, developing countries later), and then decline in line with the Global Commons Institute’s Contraction and Convergence formula, the atmospheric concentration of CO2, as a result of cumulative emissions, would peak around 2050. DECC projects that under this scenario that by 2050, "the biological pump and deep ocean transport of carbon" will remove CO2 from the upper layers of the ocean as fast as the upper layers absorb CO2 from the atmosphere, resulting in pH levelling off at 8.0. I agree with their reasoning. Once atmospheric CO2 peaks, ocean surface pH can be expected to stabilise, even though the ocean average pH will continue to increase until the atmosphere and ocean are in equilibrium. I am pessimistic about the chances of securing an international agreement that would see global annual emissions peak in 2016. Nevertheless, I am a supporter of the Contraction and Convergence solution, and believe we need to start focussing politicians on setting a target to limit ocean acidification. Copenhagen secured an agreement on a target of limiting global warming to 2 C. We need to determine what this corresponds to in terms of a decrease in ocean surface pH. If we are to attempt to stop pH from falling below 8.0, I suspect a 2 C warming is too high. This is something for readers may like to investigate. -
scaddenp at 15:04 PM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
1J/s for 100 hours, thats 360kJ accumulated. Of course your torch also absorbs energy so guess that is going melt at some point. RW1 - this lightbox example is simple demo of how not to make inappropriate inference about energy from energy flux through different surfaces. Do you agree with light box as TC has set it up? -
L.J. Ryan at 14:35 PM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
e @631 Let's assume the flashlight radiates with a 1W bulb for 100 hrs. How much energy is contained within the box at the end of a 100 hrs? How long to accumulate a gigawatt? -
Bern at 14:01 PM on 18 March 2011Sea level rise: coming to a place near you
Thanks for the article, Daniel. I hadn't seen that particular site before when searching for sea level rise mapping. For folks in Australia, I highly recommend the OzCoasts mapping found here. It's based on much higher-resolution elevation data than the Uni of Arizona mapping, so gives a more accurate picture for the selected areas of Australia that have been mapped. Having said that, they only look at up to 1.1m of sea level rise, as their "high level" SLR. Their interface kinda sucks, too, for people used to Google Maps style pan & zoom interfaces! I think the mapping at this site is not bad, also. It lets you look at SLR up to +60m (the *real* worst-case scenario, though it'd most likely be centuries away) -
2nd law of thermodynamics contradicts greenhouse theory
LJ@629>However, energy can NOT accumulate within the box, This is not correct. Don't forget that the flashlight is continuously outputting radiative energy (converted from energy stored in batteries). If the energy cannot escape, then yes of course the radiative energy accumulates in the box. Otherwise you would violate conservation of energy, because if the flashlight is outputting energy and it does not escape and it does not accumulate, then it must have been destroyed. It would of course stop accumulating after the flashlight runs out of battery or shuts off. Fortunately in the earth system analogy our "flashlight" will not run out of juice for a very long time. -
RW1 at 13:44 PM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis (RE: 615), "By simplifying the situation, ie, by getting rid of any concerns about convection and light absorbed by the atmosphere etc, we should be able to raise any issues you have with the consistency of the GHE with the laws of thermodynamics without getting hung up on trivia. Do you agree?" No, I don't agree that it is trivia. Understanding the energy flows relative to the radiative balance is absolutely fundamental to the entire GHE and ultimately surface temperatures (i.e. how much surface emitted radiation is coming back from the atmosphere and how much is passing through). All I'm saying is latent heat and thermals are just redistributing energy around the thermal mass of the system - mostly from the tropics to the higher latitudes. The bulk of this energy condenses to form clouds, weather systems and returns as precipitation. Any amount of it that ends up radiated out to space is equally offset at the surface by a lesser amount returning, which cools the surface. All the energy flows are constant, thus this effect is already accounted for in the 396 W/m^2 emitted at the surface. -
L.J. Ryan at 13:33 PM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis @626 "Do you have any problems with that?" As I said A=C, so with that we agree. However, energy can NOT accumulate within the box, B can not equal 2A, no way can't happen. Your scenario is a light/energy doubler. If you change your filter to reflect 75% what happens? Take it further, enclose a flashlight within a completely and perfectly reflective box, at what point is there infinite energy therein? -
Rob Painting at 13:11 PM on 18 March 2011Maize harvest to shrink under Global Warming
John D This study merely benchmarks the average response of the average variety averaged out over the entire period studied, it tells us nothing about how plant productivity is advancing, or not Indeed, for these trials, but given that these programs have been going on for many decades, and the 30°C mark has been identified as a limiting factor. It doesn't bode well for the future. -
Rob Painting at 13:03 PM on 18 March 2011Maize harvest to shrink under Global Warming
John D @32 - What happens in a laboratory enclosure is often quite distant from what occurs in the field. John D @ 35 - But if you want to be pedantic, then a trial plot, or a paddock used for a full blown trial meets the criteria of a laboratory being a place where scientific research and experiments are conducted. Seems you can't decide exactly what you mean. -
Tom Curtis at 12:57 PM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
C Truth @627, the ideal gas law is included in atmospheric physics in calculating the lapse rate, as shown in this university lecture, and as explained by me very briefly in 563 above. It is also included in analysis of convection, but as convection in the atmosphere is what establishes (on average) the lapse rate, that is saying the same thing. It follows that any explanation of the green house effect that incorporates the environmental lapse rate already incorporates the gas law. As previously discussed in this thread, the standard theory of the greenhouse effect incorporates the lapse rate as an essential element of the theory. So, yes, understanding the gas law can provide insights into the greenhouse effect, and those insights were discovered decades ago, and are the basis of the modern understanding of the greenhouse effect. -
Tom Curtis at 12:43 PM on 18 March 2011What would a CO2-free atmosphere look like?
TTT @79: First, Lindzen did not just arrive at the figure by a different calculation. He got it wrong. Even if we suppose he was determining the value by using the law value for climate sensitivity (0.5 degrees per doubling) that he accepts, despite the fact that it is contrary to all the evidence, then he still significantly understates the relevant cooling. Second, the idea that climate sensitivity is inconstant in a range between 1 and 4.5 K per doubling is just nonsense. The net greenhouse effect on Earth including feedbacks is at least 33 degrees C. If climate sensitivity varied in the range you indicate, then that net greenhouse effect should vary in the range from 11 degrees C to 49.5 degrees C. In other words, the mean global surface temperature should vary from -8 degrees C to 30.5 degrees C without any changes in forcing. Given the observed range of natural variation in the Holocene, even if we assumed (contary to fact) that they were unforced, the range of variation of climate sensitivity would be limited to plus or minus 0.05 degrees C. Of course, climate sensitivity probably does vary depending on the lay out of the continents, and as a function of MGT. But that is hardly heartening to deniers, because studies of such variation show we are currently in a trough of low sensitivity, and that increasing temperatures will probably result in increasing sensitivities. -
Chris Colose at 12:43 PM on 18 March 2011What would a CO2-free atmosphere look like?
TTTM, I have no idea why you are still arguing this. First off, a “no-feedback” sensitivity is useful in that it provides a baseline from which to compare the impact of internal feedbacks on the system (in fact, defining this reference system is a central aspect of feedback analysis). What this ‘reference system’ is depends largely on the application of interest. When we traditionally talk about positive and negative feedbacks, they are ‘positive’ or ‘negative’ relative to a blackbody reference system that restores radiative equilibrium via the Planck function when something like CO2 or solar is perturbed (largely because this is well understood). For someone interested in soil moisture and vegetation changes in global warming, it might be more useful to let other variables freely change, define this as the reference system, and define the feedback as just those processes of interest. If you change the reference system, you also change the feedback. This is an important point and not just semantical. But Lindzen was asked a straightforward question: would Earth be hotter or colder with no CO2? To his credit, he managed to get the sign right! But he threw in his own quantitative estimate, and the answer he sold implied both a reference system and a feedback. When you’re talking to policy makers, they are interested in the real world, and the real world is a reference system plus feedbacks. He was not asked “how would the temperature change if everything in the world stayed the same and we removed CO2,” in which case he would have still been wrong, just less so. If he wanted to give a no-feedback answer, than he should have made that caveat in the testimony, in which case I would still have made this post for educational and thought-experiment purposes anyway. But you are simply arguing that Lindzen is allowed to make up whatever number he wants, whether it be 2.5 C or 250 C colder. That’s not how science works, sorry. -
Eric (skeptic) at 12:32 PM on 18 March 2011Sea level rise: coming to a place near you
ok thanks, I will read through the other threads. Minor note on browsing (please delete this comment): the images of the impacts are stored at 900-1000 pixels wide and downloaded in that resolution then scaled by my browser to 500 pixels. The download was a bit slow on my connection so if they could be stored around 500 pixels wide that would reduce download time by about 4xModerator Response:[DB] Sorry for that, Eric. I had to compromise with what to show or not show for the exact same reason. When I created the original files, I used cartographic license to decide the optimal scales to visually depict each area affected by SLR. Too small a resolution would have compromised many a picture.
Anyone can use the linked mapping program to look at any location in the world themselves (for those feeling left out because I didn't choose their city). It's actually pretty simple to use.
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TimTheToolMan at 12:24 PM on 18 March 2011What would a CO2-free atmosphere look like?
"defending such an incorrect answer is indeed "complete hogwash"." Somewhere along the line, I am suddenly defending Lindzen's answer. This is typical of AGW arguments. If they cant argue their point successfully then they turn it into a point they CAN argue against successfully. MY point about AGWers criticising Lindzen is that their criticism is largely of Lindzen answering without feedbacks and this criticism is invalid. THE answer (whether Lindzen's or anyone else's) of CO2 warming in the atmosphere irrespective of feedbacks is a perfectly valid answer in its context. -
johnd at 12:19 PM on 18 March 2011Maize harvest to shrink under Global Warming
Rob Painting at 11:09 AM, if you are unable to differentiate how the development of new varieties of plants involves trials that range from those in laboratory enclosures, through trial plots to full blown field trials, then you need to research more. But if you want to be pedantic, then a trial plot, or a paddock used for a full blown trial meets the criteria of a laboratory being a place where scientific research and experiments are conducted. This study provided results that are the averages of about 20,000 separate trials conducted over the period 1999-2007. The yields provided from individual trials ranged from about zero to 15mg/Ha under the Optimal conditions, and from about zero to about 8mg/Ha under Drought conditions. That is a considerably wide range. I would suggest that any projections about how maize, or any plant variety, may perform in the future should be based on those varieties that out perform the average. This study merely benchmarks the average response of the average variety averaged out over the entire period studied, it tells us nothing about how plant productivity is advancing, or not. If it had divided the period in half, we might have been able to see how plant technology is advancing through later development of new varieties, but it doesn't, so the study offers nothing to indicate whether optimism or pessimism is the most appropriate response. The whole premise of the study is based on the status-quo remaining so. If anyone wants to remain up to date as to how any plants are likely to respond to changing conditions, then they should focus on the varieties that progress through trials to commercial release and analyse what data is available from the commercial breeders. Then perhaps one has a yardstick that is more relevant, and more up to date than some academic study based on averages. -
What would a CO2-free atmosphere look like?
TimTheToolMan - The amount of warming CO2 creates is a very important question. It's unfortunate that Lindzen's answer makes absolutely no sense given known physics, data, and constraints - and given the observations and the physics, defending such an incorrect answer is indeed "complete hogwash". -
TimTheToolMan at 11:53 AM on 18 March 2011What would a CO2-free atmosphere look like?
"That said, defending Lindzen's answer as just as valuable "as any other answer" is complete hogwash." I see. And so the amount of warming CO2 creates in the atmosphere is not useful to know even though its essential to understand that before moving on to understanding the feedbacks? Its ALL hand waving Dan and Chris. -
Eric (skeptic) at 11:43 AM on 18 March 2011Sea level rise: coming to a place near you
Blowing up the sea level projection:
it looks like there should be close to 5 cm/decade, but we are only measuring 3 cm/decade.Moderator Response: (DB) This thread is about visualizing the impacts of sea level rise; debating actual SLR vs projections is discussed on other threads and is off-topic here. Thanks! -
Chris Colose at 11:40 AM on 18 March 2011What would a CO2-free atmosphere look like?
The reason I created this post was not just to address Lindzen, but to create some thinking about broader issues in planetary climate. In a PRACTICAL sense, these questions might not be important right now on Earth, but they are important for example to astrophysicists exploring the limits of habitability. This is important as many new planets continue to be discovered (e.g. Gliese 581 g), since the extrasolar planet database is now at ~500 new worlds, a few of which could potentially support liquid water depending largely on their atmospheres. These questions are also important for considering some of the big questions in Earth's past, such as getting into and out of a snowball, how to offset a faint young sun, etc. While having zero CO2 sustained in the atmosphere might be very hard to do, it is a type of extreme case with much of the same physics operating as other extreme cases, like a 30% fainter sun. In the snowball deglaciation problem, we consider the opposite spectrum in which a substantial fraction of the atmsophere is CO2. This is also important for considering the evolution of Mars or Venus. While climate science on the blogs does not generally talk about these things, and there's not a heavy denial thinktank attacking them (because how Venus evolved doesn't effect fossil fuel industries or the fear of governmental control), there's still many scientists out there who do think about them. That said, defending Lindzen's answer as just as valuable "as any other answer" is complete hogwash. It doesn't matter if you double CO2, make an atmosphere of 90 bars of CO2, or think about a 50 ppm only atmosphere. The point is to understand the underlying physics, to get our understanding as close to reality as possible, and this does not involve making things up. It's perfectly fine to consider exotic cases in modeling, but you want to be self-consistent in obeying physical constraints (e.g., you can't remove some 10 C of the greenhouse effect and hope to keep the water vapor and ice the same). Even with compeltely neutral feedbacks, Lindzen is still off by a factor of 2-3. It is also legitimate to criticize the efforts being done so far constructively, but saying that it's all fantasy just because we are dealing with something you may not be familiar with, might be "too far out" from modern Earth, or whatever other lopsided rationale you build up displays great ignorance into the field of planetary climate. -
Daniel Bailey at 11:32 AM on 18 March 2011What would a CO2-free atmosphere look like?
Hypothetically, one could say that without hands to wave, hypothetical "skeptics" would be incapable of communication. Hypothetically. One could also posit that without CO2, communication might well be impossible. Without a seance, anyway. This conversation only hypothetically happened anyway. Electrons being virtual. The Yooper -
Albatross at 11:21 AM on 18 March 2011What would a CO2-free atmosphere look like?
Tom Curtis @77, You said it better than I could. TTT, seems to be missing the entire point of this exercise. And TTT, does not understand that it is not about what I or you "like" or not, it is a question of what the physics state/dictate. The physics state that Lindzen is wrong, but I understand that being a "skeptic" means that one has to concede nothing and rarely, if ever, admit fault. Here we have yet another example of that, this time courtesy of TTT. -
TimTheToolMan at 11:20 AM on 18 March 2011What would a CO2-free atmosphere look like?
@Tom "So perhaps your "fantasy figure" is better than Albatross's "fantasy figure" for you, but only if it is your intent to deceive." I'm not the one who feels strongly about a certain "answer" to the question. I doubt sensitivity is constant and therefore whether its 1K, 3K or 4.5K per doubling right now isn't as important as some say it is. I do feel strongly about criticisms leveled at people because they quote an answer calculated in a different way. -
Rob Painting at 11:09 AM on 18 March 2011Maize harvest to shrink under Global Warming
John D -What happens in a laboratory enclosure So now an African field is a laboratory?. Please get serious. The point of my last comment (which you clearly do not understand) is that these trials are simply a continuation of earlier ones, where hardier breeds have been identified. The study analysis is therefore of the hardiest known breeds at the time. I expected you would actually understand what selective breeding is, before commenting here. My mistake. -
Paul D at 11:02 AM on 18 March 2011Sea level rise: coming to a place near you
piloot. OK add 5m to sea levels then add the storm which would add another 5m. The point being is that you have to think in terms of mean or average increases, then add your highest yearly tides, storms etc. The result is that flooding occurs more frequently. -
TimTheToolMan at 10:54 AM on 18 March 2011What would a CO2-free atmosphere look like?
"Instead of ROFL, you might want to try and engage in some actual science. And to be quite honest, your post @75 makes no sense whatsoever. " I'll spell it out for you then. You say you cant ignore feedbacks because they DO exist and hence ignoring them would not make sense when deriving an "answer" but along precisely the same lines of reasoning you cant ignore CO2 either because CO2 DOES exist. But of course you can ignore any effect you want and both answers are perfectly valid within the context of the assumptions made on their calculation. Just because you dont like it, doesn't make it wrong. The ROFL part is because you're insisting the answer with feedbacks is more valid than the answer without when in fact neither answer is valid in any practically useful sense. -
Tom Curtis at 10:47 AM on 18 March 2011What would a CO2-free atmosphere look like?
TTT @73 and 74, the issue of the Earth's probable temperature with very low, or no CO2 is a critical issue with regard to climate sensitivity. If it is a fact that with no CO2, water vapour levels would fall sufficiently that the mean global temperature was -19 degrees C, or less, then the notion that climate sensitivity is 0.5 degrees per doubling of CO2, or even 1.5 degrees per doubling, are absurd. That might be a merely academic point. Where it not for one fact, there would be no way to independently test the consequences of very low CO2. But, as it happens, during at least two periods in the past the Earth had very low CO2. Consequently model experiments on very low CO2 can be tested against geological data from those events. What is becoming evident is that low climate sensitivities are inconsistent with the Earth entering a snow ball (or slush ball) state. And they are even more inconsistent with the Earth leaving such a state, in that without a strong greenhouse effect, the strong negative forcing of global ice cover cannot be overcome. This leaves aside the rhetorical issue, ie, the reason Lindzen concocted his figure. Lindzen asserts a low value for the temperature change with no CO2 to create in his audience a false impression that climate sensitivity is low. Giving a more accurate figure would have been counterproductive to his rhetoric. So perhaps your "fantasy figure" is better than Albatross's "fantasy figure" for you, but only if it is your intent to deceive. -
Charlie A at 10:44 AM on 18 March 2011Maximum and minimum monthly records in global temperature databases
I was trying to discuss statements made in your article and in your comments. Such as the statement in your article that "This analysis undermines, yet again, many of the simplistic contrarian models e.g. that natural variability is driving warming," Please explain how your analysis relates to attribution of the detected warming. You refer back to your comment #46. "In other words, we must look to processes that warm or cool the globe to explain the excursions in Figures 2 and 3. The conventional wisdom is that (human induced) CO2 warming did not set in on a large scale until the 1970s, whereas warming earlier in the century was due to other (natural) variations. There is nothing explicit in the chart to upset that view." I agree with your observations about conventional wisdom, but was hoping for something in your analysis that actually supported that conventional wisdom rather than merely being consistent with it; or an analysis that merely failed to explicitly disprove the conventional wisdom. -
Albatross at 10:35 AM on 18 March 2011What would a CO2-free atmosphere look like?
TTT, Instead of ROFL, you might want to try and engage in some actual science. And to be quite honest, your post @75 makes no sense whatsoever. -
Larry E at 10:28 AM on 18 March 2011Examining the impacts of ocean acidification
Thanks for giving this important issue some exposure. I would like to add that data for pH or carbonate saturation that are global averages tell one story, but some areas are far more susceptible to these acidification effects than others. Here are some interesting references: McNeil BI, Matear RJ (2008). Southern Ocean acidification: A tipping point at 450-ppm atmospheric CO2. Proceedings of the National Academy of Sciences (105:48; p.18860). http://www.pnas.org/cgi/content/abstract/105/48/18860 Bernie D, Lowe J, Tyrrell T, Legge O (2010). Influence of mitigation policy on ocean acidification. Geophys. Res. Lett. (37:15; p.L15704). http://dx.doi.org/10.1029/2010GL043181 DO - 10.1029/2010GL043181 McNeil & Matear (2008) show in what a short term timeframe significant ecological impacts can be anticipated in high latitude waters, with Southern Ocean "wintertime aragonite undersaturation ... projected to occur by the year 2030 and no later than 2038. Some prominent calcifying plankton, in particular the Pteropod species Limacina helicina, have important veliger larval development during winter and will have to experience detrimental carbonate conditions much earlier than previously thought, with possible deleterious flow-on impacts for the wider Southern Ocean marine ecosystem." And later, "Our results show wintertime aragonite undersaturation to potentially begin once atmospheric CO2 concentration reaches 450 ppm, which is the year 2030 using the IPCC IS92a scenario (Figs. 3 and 4). It must be emphasized, however, that the timeframe for atmospheric CO2 to reach 450 ppm could be earlier or later depending on the trajectory of future CO2 emissions. ... Early aragonite undersaturation is of particular concern for the zooplankton species comprising Pteropods, which form aragonite shells. Southern Ocean Pteropods comprise up to one-quarter of total zooplankton biomass in the Ross Sea (13), Weddell Sea (14), and East Antarctica (15), can sometimes displace krill as the dominant zooplankton (16), and dominate carbonate export fluxes south of the Antarctic Polar Front (17), and even organic carbon export (18)." Troubling to me is not only the ecosystem implication, but also that the Southern Ocean is a major carbon sink, and shell-building zooplankton is an important part of that. Bernie et al. (2010) deals with averaged global effects, comparing onset and severity of acdification problems to climate models and climate change mitigation scenarios. It notes that the Arctic will undergo changes faster than the paper predicts, that effects in coastal areas and at depth around the world are highly variable and not examined. The paper estimates that if with "aggressive mitigation" CO2 emissions peak in 2016 and decline at 5% per year to a low long-term value, the global average pH decline could be limited to 8.02, "roughly a doubling of current acidfication." However, without mitigation by 2100 the level would be 7.67 to 7.81. The Bernie et al. paper notes limitations of similar previous studies and that this is the first to study "acidification under a range of emissions scenarios and analyze what aspects ... have most impact on future acidification. The key feature of this study is the explicit relation of future pH to aspects of global climate change mitigation policy." -
Tom Curtis at 10:17 AM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
L.J.Ryan, I forgot in my post 615 to mention the equalities only apply in the equilibrium condition. To explore the non-equilibrium condition, let us assume time steps equal to the average time it takes light to cross the depth of the box once. We use the average time because the photons may be at different angles, and hence have different path lengths. Let us also assume that 100 photons enter the box in each time step. We set the initial time step,0, to the time photons first start entering the box, but before they strike the back wall of the box. In that case, the number of photons in each of A, B, C, and D for progressive time steps are: Following Phil's suggestion, I have modeled this on a spreadsheet, using the following formulars: Column B2 and subsequent: 100, column C2: 0, Column C3 and subsequent is the sum of columns B and D for the preceding row. Column's D and E2: 0; and for columns D and E3 and subsequent, 0.5 times the value of column C in the preceding row. The first twelve steps show as follows: STEP A B C D 0 100 0 0 0 1 100 100 0 0 2 100 100 50 50 3 100 150 50 50 4 100 150 75 75 5 100 175 75 75 6 100 175 87.5 87.5 7 100 187.5 87.5 87.5 8 100 187.5 93.75 93.75 9 100 193.75 93.75 93.75 10 100 193.75 96.875 96.875 11 100 196.875 96.875 96.875 12 100 196.875 98.4375 98.4375 Clearly there is a problem for the spreadsheet that it allows fractional photons. What would happen in the real case is that occasionally 99 photons would leave the box, and occasionally 101, but typically 100 would leave the box. Furthermore, the mean value of photons leaving the box once the equilibrium state is reached would be 100. So, ignoring the quirk of fractional values, it is plain the system quickly approaches the state described in my 615. Do you have any problems with that? -
Albatross at 10:15 AM on 18 March 2011Maize harvest to shrink under Global Warming
Rob @31, I agree with your position on this. This is, IMHO, an interesting example of a "skeptics" who is in denial. Johnd is continuing to make unsubstantiated assertions. These findings are no doubt inconvenient to him--I know he'll deny that, but that much is clear from his posts and efforts to obfuscate. What he fails to realise is that hand waiving and talking through his hat does not further his case. If someone elects to dismiss the findings of a paper published in Nature (or any reputable journal for that matter), it is incumbent on them to bring substantial evidence and science to the table in order to be taken seriously. From the start of this thread he has been making comments clearly without having bothered to read the paper, and he was called on that. Being a true "skeptic" does not mean that one has to contort in order to dismiss the findings of papers which do not support your position. "Skeptics" are permitted to agree with some of the literature on AGW without compromising their position-- in fact, doing so from time-to-time would work towards improving their credibility. To stay on topic, these findings are also consistent with those of Samson et al. (2011), who found that Africa is going to be one of the countries which is most negatively affected by AGW. We are doing them no favours if we decide to bury our heads in the sand and ignore these troubling findings. We have all been warned of the possible perils ahead. -
TimTheToolMan at 09:54 AM on 18 March 2011What would a CO2-free atmosphere look like?
Yeah, rofl Albatross with your insistance that your fantasy figure is better then my fantasy figure. " The biosphere is a fully coupled and interactive system, you cannot ignore feedbacks." The biosphere is full of carbon and hence carbon dioxide. -
Phil at 09:48 AM on 18 March 2011Sea level rise: coming to a place near you
rhjames @5 I'm guessing that Scandanavia, like Scotland, is experiencing rebound after the last Glaciation. The potentially bad news for piloot is that the extent of Glaciation in the UK means that the lower half is sinking due to the same effect. The same could be true of the Netherlands, since it lies at a similar latitude. -
rhjames at 09:39 AM on 18 March 2011Sea level rise: coming to a place near you
piloot - I tried to check sea level change in your area. If the Scandanavian countries nearby are any indication, you have little to worry about. Sea levels have dropped about 250mm over the past 130 years. It looks like there are other bigger influences than climate change out there.Moderator Response:[DB] Rates of isostatic rebound experienced thus far will be dwarfed by the rates of SLR to get to the 1 meter SLR expected by 2100 (1,000mm over 90 years). Unless Hansen is right about the nonlinearity of ice sheet loss to come, in which case that rate jumps to 5,000mm over 90 years.
The current mapping tool does not reflect impacts from isostatic rebound; some future iteration will (it is being looked at).
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johnd at 09:37 AM on 18 March 2011Maize harvest to shrink under Global Warming
Rob Painting at 09:24 AM, the purpose of the field trials is to identify how each variety performs under field conditions. They have no way of knowing this unless they conduct the trials. What happens in a laboratory enclosure is often quite distant from what occurs in the field. Of all the people that have posted on this thread, surely it was incumbent upon yourself to bring such understanding to the discussion. -
piloot at 09:29 AM on 18 March 2011Sea level rise: coming to a place near you
The situation for the Netherlands doesn't seem fair or realistic in this comparison. Half of the country is already below sea level and man-made that way, surrounded by dikes and (wind)mills, completed with an enormous irrigation network to constantly pump the water out and to protect it against storms from the North Sea or floodings from meltwater out of the Rhine. If the map would have a setting for nil change, it would still show half the country flooded (like the less than 1 meter change now), which just isn't the case (I'm typing this from 4 meter below sea level as we speak and I'm still dry). A storm (usually combined with moon setting) in 2006 caused an almost 5 meter sea level rise above the average level in Holland, but the dikes still held (in contrast to 1953 which killed 1863 people, causing a huge delta plan with new dikes and barriers to prevent that form ever happening). The whole system is constantly maintained, monitored, fortified and updated, in contrast to poor countries with low lying areas. I'm not saying sea level rise won't be a problem, but for Holland the consequences won't be like portrayed in the map. -
scaddenp at 09:25 AM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
Tom, I really like this. Same idea as Science of Doom example but much simpler. -
Rob Painting at 09:24 AM on 18 March 2011Maize harvest to shrink under Global Warming
John D - Whilst we don't know how many different varieties were trialled or how each performed. The idea that the trials would incorporate any old rubbish maize is nonsense. Simple invention on your part. And quite frankly odd, why would an organization carrying out such trials, use varieties that were ill-suited to the prevailing conditions?. The CYMMT was set up in the 1970's, they've been breeding for maize drought tolerance ever since. Selective breeding is an ongoing process. I expect the private seed companies to have agricultural expertise too. Charlie A - planting and harvesting times are not optional. These are determined by local conditions. -
rhjames at 09:19 AM on 18 March 2011Sea level rise: coming to a place near you
This is all very interesting, but I have a problem with justifying the comment "currently we're on track to reach 1m." As I live in Sydney, and Sydney is mentioned, I checked the Fort Denison data, which shows no sea level rise over the past few years, and about 8mm over the past 25 years. 1998 was the hottest year over the past 160 years, and this year so far has seen a temperature drop. Now, I may well accept that sea levels will rise, but I can't say we're "on track" to reach 1m increase by 2090. We need to see some temperature increase, and/or sea level increase. -
johnd at 08:59 AM on 18 March 2011Maize harvest to shrink under Global Warming
michael sweet at 06:08 AM, the most disappointing form of hand waving is that when the only knowledge that can be offered to a discussion is "it's been peer reviewed". That carries the implication that the peer review process is perfect, and that each peer reviewed paper encapsulates all the knowledge there is to know on the subject. If you carefully read back through this thread, you will find that most of the comments questioning the paper are not on the integrity of the study process, but rather whether the findings provide anything new or are even relevant to the real world. Even if you have little appreciation of how or why field trials such as those that provided the base data for the study are conducted, you surely must appreciate the fact that not all new varieties being trialled perform up to expectations. The difference between what this study did by including the results of all the varieties trialled, and what the plant breeders would have done, is that the plant breeders would have selected the results from those varieties that met or exceeded their expectations and having done so, worked to refine or further develop the desired traits before releasing them for commercial use. You can be fairly certain that when such new varieties are being released and promoted, that it will be the data for each specific variety that will be used to illustrate how each variety will perform under different conditions,and certainly not what this study projects. It is largely irrelevant to the real world and provides virtually nothing new to those whose purpose is to actually produce the food required. Given the rate at which new varieties are produced, the study is likely many steps back from where plant breeders would currently be, certainly well off the pace. The one point I do question about how the study was conducted is about why they used rainfall data other than what normally would be collected at the immediate trial site. It will be unknown if any bias is present unless rainfall had been measured at the trial site, in which case, that is the data that should have been used. If you can provide some insight as to whether my concerns are valid or not, then I would certainly be interested to listen. The use of rainfall data collected at other than the immediate trial sites has on occasion been sufficient reason for the findings of such trials to fail passing the peer review process here in Australia. -
Phil at 08:11 AM on 18 March 20112nd law of thermodynamics contradicts greenhouse theory
L.J.Ryan C will equal D. This scenario is very similar to the spreadsheet I posted here. You can model Tom's box using a 5 column spreadsheet thus; In row 1 type A, blank, B, C, D (to represent the quantities on Tom's diagram) In row 3 type 100, 0, =A3+B3, =C3*0.5, =C3*0.5 In row 4 type 100, =D3, =A4+B4, =C4*0.5, =C4*0.5 Copy row 4 into the next 30 lines of the table. You will find equilibrium reached after about 17 iterations and that Tom's calculations match in every detail. To check the conservation of energy you must let the accumulated energy in the box dissipate. To do this copy row 30 into 31 and set cell A31 to 0. Copy row 31 to the next 15 or so cells. If you sum column A and D (don't forget, column D represents Tom's arrow C) you will find they are equal. -
Kiwiiano at 08:04 AM on 18 March 2011Sea level rise: coming to a place near you
Oi! You've listed Christchurch in NZ as liable for flooding with a rise in sea level. Don't forget a good chunk of Auckland, Tauranga, Napier, Wellington, Nelson, Greymouth, Dunedin and Invercargill. About the only main center that will escape it will be Hamilton. And Lawrence.Moderator Response: [DB] Christchurch was chosen as it had recently been in the news due to the earthquake there. All coastal cities in NZ (as you note) and throughout the world will have to deal with sea level rise at some point. -
shoyemore at 08:00 AM on 18 March 2011Maximum and minimum monthly records in global temperature databases
Charlie A #49, You seem to want to discuss matters which you would be better to raise elsewhere, such as Early Century Warming Your points about this post are answered adequately in #46. If you re-read the post carefully, you will find it also deals with these matters, such as in the paragraph after Figure 1. -
funglestrumpet at 07:42 AM on 18 March 2011Sea level rise: coming to a place near you
Articles like this could be separated into a general information on Climate Change section that the general public would, if directed there, go to in preference to a lot of the other articles on this site, which are often esoteric in nature and beyond a lot of us, me included. This article would do wonders for public involvement in the issue if they were to become worried that the value of their property was going to suffer. Let's face it, property prices are going to tumble long before the waves are licking at the front door. To paraphrase the wise man quote abov: The Tides, They Are A Changin'.
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