Recent Comments
Prev 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 Next
Comments 117651 to 117700:
-
Marcel Bökstedt at 18:53 PM on 10 June 2010Request for mainstream articles on climate
What about articles in other languages than English?Response: You're not the first to ask about this. I could add another field to the submission form allowing you to select language. Upside, broaden the database. Downside, complicate the submission form which is already bloating a little and also complicate the directory. The deciding factor would be whether enough people think there's a need for a multi-lingual database of global warming links so I'm open to comments on this. -
Doug Bostrom at 18:41 PM on 10 June 2010Collective Intelligence and climate change
Thank you for calling attention to my analogy, batsvensson. Indeed, as with all analogies it is an imperfect mapping of one subject on another. I'm glad you found it thought-provoking. -
batsvensson at 17:11 PM on 10 June 2010Collective Intelligence and climate change
@doug_bostrom at 10:36 AM on 26 May, 2010 There is of course a trivial fallacy in this analogy which, deliberate or not, doug_bostrom carefully ignore to make his point to ridicule any with an opinion that diverts from his own. That's the way demonetizing of any unwanted opinions works. -
Doug Bostrom at 17:09 PM on 10 June 2010Irregular Climate: a new climate podcast
BP, scaddenp, I can go even more off-topic. There's not enough helium, turns out. Or that is to say, the pricing of helium was messed up to the point that we can afford to fill toy balloons with helium but many important science experiments depending on helium are now being jeopardized by the high price of the second most simple element. A complicated story leading to an even more off-topic discussion of politics and scarce resources. Maybe better not go there. -
Berényi Péter at 16:41 PM on 10 June 2010Irregular Climate: a new climate podcast
#96 scaddenp at 09:42 AM on 10 June, 2010 This is textbook stuff Yes, this is a problem with textbooks. The root mystery, not explained in those books is twofold.- How biological debris is transformed to kerogen in the first place? (chemical pathways instead of handwaving please)
- How does it get into carbonaceous chondrites?
-
OPatrick at 15:22 PM on 10 June 2010Request for mainstream articles on climate
Are you interested in 'opinion' pieces or just those articles that make at least some pretence at delving into the science? I feel there's some benefit from just building up a picture of where the balance of opinion in the media lies (hmmm, 'the media lies' - there's a phrase that trips off the finger tips), but perhaps this is not the place to do it?Response: Both. Opinion pieces may not be grounded in science but published in mainstream media reach a broad audience and have wide influence. Good to keep track of these. -
weliqwk at 14:54 PM on 10 June 2010Abraham reply to Monckton
Marketing rule #1 is that perception is reality, regardless of facts! Monckton is apparently quite skilled in the art. -
scaddenp at 09:57 AM on 10 June 2010Irregular Climate: a new climate podcast
Just a reference with experimental method described etc. Thermal cracking of kerogen in open and closed systems: determination of kinetic parameters and stoichiometric coefficients for oil and gas generation -
scaddenp at 09:42 AM on 10 June 2010Irregular Climate: a new climate podcast
"Hydrocarbons other than methane just do not form spontaneously from biological debris under moderate pressure and conditions close to thermodynamic equilibrium prevalent in the crust." Huh? this is news to hydrocarbon chemists! We are extremely interested in the reaction rates for conversion of source rock material to hydrocarbons.(It feeds into basin models for guessing when and how much oil/gas is produced). To do this, experiments put the rock under pressure/temperature and we measure the production rates of product. We also use a variety biomarker/isotope markers to match oil to possible source rocks. None of this makes any sense against your statement. It appears you are linked to either bogus information or extremely old information. This is textbook stuff and the analyses are more or less routine. -
Berényi Péter at 09:37 AM on 10 June 2010Has the greenhouse effect been falsified?
#71 Riccardo at 16:55 PM on 9 June, 2010 Far from the central frequency it may be approximated by a lorentzian Right. That's what I figured based on my rather old and dusty QM. Just one never knows for sure with these jumpy-bumpy molecules. -
Berényi Péter at 09:18 AM on 10 June 2010Irregular Climate: a new climate podcast
#90 doug_bostrom at 03:58 AM on 10 June, 2010 plants! Yes, something like that. The difference is that plants were not optimized for energy efficiency but to produce more plants like themselves. We can hack into the system, but there are limits. The same problem plagues biotechnology in general. The engineering principles behind the system simply do not allow for easy designability. Basically they are best for food production because of our design, not theirs. However, they can serve as a proof-of-concept example to the feasibility of molecular engines to be built with the ultimate precision, where each atom has its prescribed place in the structure and is held there by strong covalent bonds resistant to thermal damage. Enzymes are examples of machines like that along with DNA, microtubules and a plethora of other structures. There's Plenty of Room at the Bottom An Invitation to Enter a New Field of Physics by Richard P. Feynman, December 29th 1959 #91 doug_bostrom at 04:07 AM on 10 June, 2010 fossil fuels are inadvertently the end product of a process roughly analogous to what he describes I am not sure about that. At least the theory behind the biogenic origin of crude oil seems to be bogus. Hydrocarbons other than methane just do not form spontaneously from biological debris under moderate pressure and conditions close to thermodynamic equilibrium prevalent in the crust. The pressure and temperature needed is more like those at a depth of 150 km, the same as preconditions for diamond formation. Also, there are tiny diamondoid structures in crude oil as there are diamonds with microscopic oil inclusions. On the other hand, it is enough to subject a mixture of limestone, water and iron(II) oxide (FeO) to those pressures and temperatures to get oil (demonstrated in lab). The oil seeping to the crust may well be primordial. Hydrocarbons, next to water, are among the most abundant chemicals in the universe. However, theory of Earth formation has to be rewritten slightly to accommodate to a reductive interior of the globe. I am getting off-topic, sorry. -
scaddenp at 08:46 AM on 10 June 2010Irregular Climate: a new climate podcast
Yes, averaged over year. Biofuel is also after conversion to diesel. Still photosynthesis is 2% energy conversion versus solar thermal of around 20% -
Doug Bostrom at 08:08 AM on 10 June 2010Irregular Climate: a new climate podcast
scaddenp, I'm guessing that power density for "solar" is total net considered w/average actual available insolation, taking into account climate, diurnal cycle etc.? -
scaddenp at 07:32 AM on 10 June 2010Irregular Climate: a new climate podcast
Not to mention that plant conversion of solar energy to something we can use is rather inefficient compared direct means (about 2%). So power density for plants is around 0.5-1 W/m2 cf 10W/m2 for solar. (Sustainable energy without the hot air -
Doug Bostrom at 07:29 AM on 10 June 2010Collective Intelligence and climate change
"ClimateGate" Fail. The nut of the article Phillipe cited: But a closer look at these polls and a new survey by my Political Psychology Research Group show just the opposite: huge majorities of Americans still believe the earth has been gradually warming as the result of human activity and want the government to institute regulations to stop it. In our survey, which was financed by a grant to Stanford from the National Science Foundation, 1,000 randomly selected American adults were interviewed by phone between June 1 and Monday. When respondents were asked if they thought that the earth’s temperature probably had been heating up over the last 100 years, 74 percent answered affirmatively. And 75 percent of respondents said that human behavior was substantially responsible for any warming that has occurred. For many issues, any such consensus about the existence of a problem quickly falls apart when the conversation turns to carrying out specific solutions that will be costly. But not so here. Fully 86 percent of our respondents said they wanted the federal government to limit the amount of air pollution that businesses emit, and 76 percent favored government limiting business’s emissions of greenhouse gases in particular. Not a majority of 55 or 60 percent — but 76 percent. Large majorities opposed taxes on electricity (78 percent) and gasoline (72 percent) to reduce consumption. But 84 percent favored the federal government offering tax breaks to encourage utilities to make more electricity from water, wind and solar power. And huge majorities favored government requiring, or offering tax breaks to encourage, each of the following: manufacturing cars that use less gasoline (81 percent); manufacturing appliances that use less electricity (80 percent); and building homes and office buildings that require less energy to heat and cool (80 percent). Thus, there is plenty of agreement about what people do and do not want government to do. Our poll also indicated that some of the principal arguments against remedial efforts have been failing to take hold. Only 18 percent of respondents said they thought that policies to reduce global warming would increase unemployment and only 20 percent said they thought such initiatives would hurt the nation’s economy. Furthermore, just 14 percent said the United States should not take action to combat global warming unless other major industrial countries like China and India do so as well. So the takeaway is that we see the usual incoherence about wanting to fix the problem but not personally wanting to pay for so doing, yet encouragingly most people seem to comprehend the fundamentals. Here's another recent survey: A U.S. national survey released Tuesday finds that public concern about global warming is increasing, with public belief that it is occurring rising to 61 per cent, up from 57 per cent since January. And 50 per cent of Americans believe the phenomenon is caused by people — an increase of three points. Fifty-three per cent of respondents now worry about the impact global warming will have (an increase of three points) and 63 per cent believe it will affect them personally (an increase of five points). Researchers believe that with a pickup in the economy and renewed consumer confidence, Americans' thoughts are returning to environmental issues. "The BP oil disaster is also reminding the public of the dark side of dependence on fossil fuels, which may be increasing support for clean energy policies," said Anthony Leisorowitz, director of the Yale Project on Climate Change Communication, in a release. The survey was conducted by researchers at Yale and George Mason Universities. The survey also found that 77 per cent of respondents support the regulation of carbon dioxide as a pollutant; 87 per cent want more funding for research into renewable energy sources and 83 per cent support tax rebates for consumers who purchase fuel-efficient vehicles and solar panels. The survey was conducted using an online panel of 1,024 American adults aged 18 and older between May 14 and June 1, 2010. The margin of error is plus or minus three percentage points. Global warming concerns rising in U.S. -
Philippe Chantreau at 07:16 AM on 10 June 2010Collective Intelligence and climate change
Not exactly on topic but close, there is an interesting discussion of opinion surveys in the NY Times: http://www.nytimes.com/2010/06/09/opinion/09krosnick.html?pagewanted=1 -
Riccardo at 06:00 AM on 10 June 2010On temperature and CO2 in the past
Marcel Bökstedt, i'm not denying the existence of the carbon cycle. But whatever it is, in the end only the concentration in the atmosphere is relevant to the forcing. If I can measure it, that's it, the full and actual carbon cycle is there. Only if we do not have access to it or if we want to make projections, we need to consider the full carbon cycle as you say. -
Marcel Bökstedt at 05:29 AM on 10 June 2010On temperature and CO2 in the past
Riccardo> Yes, I agree with your analysis. Only the CO2 in the atmosphere should contribute to warming. But it is not true that the other CO2 is irrelevant to climate sensibility, because it will interact with the rest of the system. If we warm the planet and the sea, some of the dissolved CO2 will go into the atmosphere. What is happening today is that we are producing CO2, which is initially added to the atmosphere. This will initially add to the amount of CO2 in the atmosphere, but as we know, some of it will go into the sea and do bad things there. But the CO2 will not stop moving. We are talking about long term effects here, not short time climate sensitivity, so we will have to wait and see what happens to our added CO2. Some of it will go into the deep sea beacause of slow overturning. Some of it will go back to the atmosphere as the sea warms. The CO2 we initially produced will probably eventually contribute an increase in the CO2 in the atmosphere, and probably also an increase in the CO2 in the sea etc. But as you say, only the amount that goes into the atmosphere will contribute to warming. The eventual warming produced by the amount of CO2 we added, will only depend on the amount of CO2 which ends up in the atmosphere. On the other hand, it does not seem so easy to compute how big this proportion is. And if we don't know this, we can't say how big the long time climate sensitivity is for burning a certain amount of coal. -
Riccardo at 05:03 AM on 10 June 2010On temperature and CO2 in the past
Marcel Bökstedt, not sure i understand what you mean by "add a certain quantity CO2 to the system". As far as climate sensitivity and climate are concerned what matters is how much is in the atmosphere contributing to the forcing. The latter is measured directly from the ice cores, whatever happens to the other CO2 reservoirs is irrelevant for the determination of climate sensitivity. -
Marcel Bökstedt at 04:34 AM on 10 June 2010On temperature and CO2 in the past
Riccardo> I can't see that Hansen et. al. discuss this problem in section 2, if they do maybe you can give a more precise refrence? They do consider the "Vostok ice core" and plot forcing and GHG forcing against time. They claim that this determines long term sensibility of about 6 degrees for doubling of atmospheric CO2. But what they don't say anything about is the following: Suppose that you add a certain quantity CO2 to the system. How much of this will eventually stay in the atmosphere and contribute to the warming, and how much will eventually stay in the ocean? One point is that "eventually" is a long time, so any quick answers are suspect. And Hansen does not discuss this point in that particular paper as far as I can see. My place does not have an electronic subscription to get Masson Delmotte. Maybe you could just tell if it approaches this question? -
Doug Bostrom at 04:07 AM on 10 June 2010Irregular Climate: a new climate podcast
Thinking further about BP's concept, fossil fuels are inadvertently the end product of a process roughly analogous to what he describes, only the process was not engineered for the purpose of energy capture and storage, the concentration of chemically stored energy was pure happenstance and of course moving the energy from chemical form into a stream of free electrons is highly inefficient. The other issue is that by oxidizing fossil fuels at the rate we are we're de-sequestering a lot of carbon stuffed away over the course of eons and releasing it on a prodigious scale. So we have an example of how plants can accidentally do what we want, capture and store solar energy. Presumably we can do better if we attack the problem directly. -
Riccardo at 04:01 AM on 10 June 2010On temperature and CO2 in the past
Marcel Bökstedt, no doubt the problem is complicated and be sure no one will ever make any claim on the global climate sensitivity just from CO2 and T from an ice core. I didn't, indeed. But having said this, you can still have good informations on climate sensitivity as crudely shown before. For an undoubtely better and more detailed explanation I'd suggest a carefull read of both section 2 in Hansen et al. 2008 and section 4 in Masson-Delmotte et al. 2010 quoted in the post. -
Doug Bostrom at 03:58 AM on 10 June 2010Irregular Climate: a new climate podcast
BP, plants! Of course they're not as durable as pavement but in so many ways they resemble what you describe. Self-replication, photoelectric effect, mitochondria, etc. Plants with postive and negative terminals... :-) -
Berényi Péter at 03:49 AM on 10 June 2010Irregular Climate: a new climate podcast
#88 gallopingcamel at 16:09 PM on 9 June, 2010 At this moment the economics favour coal or fission but that could change. Of course it can. And will. No one doubts solar is the ultimate solution. After all we have this huge fusion reactor nearby with a pretty steady 3.84×1026 W output. We don't even have an idea how to turn it off. On top of that almost the entire biosphere is run on solar energy for billions of years. Therefore it works. The only thing we need is a closely packed matrix of micron sized solar panels manufacturing some non-flammable and non-toxic but energy-rich chemical (like sugar) and storing it locally, interlaced with tiny networked fuel cells capable to turn it into electricity on demand. And one more thing. This surface should not cost more than roof tile and has to be as durable as pavement. It can be done, if machinery is constructed with (macro)molecular precision using self replicating desktop factories. Collateral benefit is that the obvious raw material for such technology is carbon, derived from airborne carbon dioxide saving transport costs. A rapid, perhaps catastrophic decline of CO2 due to over-exploitation is to be avoided by maintaining fossil fuel burning as long as possible. If it's not enough, lime can be used to replenish resources. However, we should still work out how to sequester the resulting huge amount of lime milk, otherwise ocean alkalinification may struck hard. -
Ari Jokimäki at 03:46 AM on 10 June 2010Request for mainstream articles on climate
The date should be the publishing date of the article you're submitting. The system currently checks if the link you are submitting already exists in the database. I'm not sure if there are any other checks for the article already existing in the database. -
Doug Bostrom at 03:31 AM on 10 June 2010Request for mainstream articles on climate
There is a remarkably comprehensive weekly list of climate-related articles presented and maintained at the site A Few Things Ill Considered, GW News. The list covers the popular press, specialist popular science media as well as academic literature. As well, the Knight Science Journalism Tracker is pretty good, includes technical critique of the technical quality of articles themselves, often identifying for instance when a piece is sourced purely from a press release or includes more in-depth effort. The tracker can be found here. -
Neven at 03:27 AM on 10 June 2010On the Question of Diminishing Arctic Ice Extent
I posted this over at Websites to monitor the Arctic Sea Ice, but I repost it here so more potentially interested people might read it: If it's OK I'd like to point out that I have tentatively started a blog that is dedicated to assembling news and data concerning the Arctic sea ice, as I kind of miss one central place where everyone who is interested can discuss what's going on. The blog is HERE and I'd appreciate it if people would come over and spread their knowledge, 'cause I'm lacking in that department. :-) -
Marcel Bökstedt at 03:27 AM on 10 June 2010On temperature and CO2 in the past
I'm with Bérenyi Péter on this one. I think that he is asking a hard question, one that worries me too. I also believe that what he writes is related to my too complicated and too vague comment earlier in this thread. The problem as I see it is that in a technical, mathematical sense there seem to be too many unknowns in the equations to say something definite about climate sensitivity by paleographic studies. Maybe I'm just missing a point. The problem enters when you interprete figure 1, but it seems to me that it also enters into other attempts to estimate sensibility using historical investigations of climate. There are two variables that should determine the system: The temperature forcing T' (from the sun) and the total amount of carbon in the atmosphere and in seawater C'. I assume that C' did not vary in the time frame we are considering. If it did, this would only make things more complicated. On the other hand, T' has definitely changed (Milankovich etc). So we do have a lot of data on the variation of temperature T at the dome and the carbon concentration in atmosphere C as long as C' is constant. There are four variables T,T',C,C', and it seems that figure 1 can only give one approximate relation. But for two of the quantities to determine the two others, we need two independent relations between the four quantities. We don't have any historical record of what happens when the total amount C' goes up - in the time frame we are considering it never happend before, but this is what we are doing today. What we want to do is to compute the derivative dT/dC' which would tell us how much the temperature (at least at the dome) goes up if we add some more CO2 to the system. To get an estimate for the sensibility, we need an independent constraint on the variables involved. This cannot come from the historical data, but maybe we can derive it in another way. It could for instance come from an analysis of how the temperature T at the dome is related to the temperature of the sea at different levels. This could possibly determine how much of the CO2 goes into the atmosphere, and how much goes into the sea. But now the physics is getting too complicated for me. -
CBDunkerson at 02:38 AM on 10 June 2010Request for mainstream articles on climate
Another question to guide our efforts - should we be carefully checking to make sure nobody else has submitted the same article? Wire service (Reuters, AP, UPI, et cetera) pieces often get printed in hundreds of different papers with slightly different titles. Likewise, as hengistmcstone notes above, some people put articles in by the date they were published and others by the date on which they are adding them. Thus, it often isn't easy to determine whether an article is already listed or not. Are duplicates ok or a major hassle? Also, I can never find the link to the page listing all the recently submitted articles. I always end up having to search for the post that originally announced it and going from there. Making it more prominent (than wherever it is currently) might help to drive submissions. As might a 'new submission' link on that page itself.Response: The submission form won't let you submit an article twice. What I do when submitting an article is I first just enter the URL then hit submit. If the URL has already been listed, it'll tell you. If not, it gives you the form validation error "you haven't entered the title, bias,etc" and I finish filling out the form. It's a bit clunky - what I'd like to do is program some JavaScript that checks for submitted URLs while you're filling out the form but haven't had time to do that yet.
I will make the link to recent articles more prominent and good idea to add a link to the submission form. Good feedback, thanks! -
hengistmcstone at 02:26 AM on 10 June 2010Request for mainstream articles on climate
Hi, Ive gotta say this is a really good website, About submitting stuff to the Skeptical Science database. You ask for a date. That is the date of the original article not the date submitted to the database right? It might also be helpful if you remind us that it is using american notation (I think) i.e YYYY/MM/DD. I figured that out but you know the old saying about the british and the americans - separated by a common language:-) Sometimes it's not easy to define the bias. Ive submitted three that I think are skeptical of AGW but you might disagree with that assessment. I would suggest a fourth category of bias - "mixed" - as there is a lot of stuff that pretends to be fair but is really undermining AGW rather than directly attacking it. Particularly Tom Fielden of the BBC! Ive added you to my blogroll on my own blog Salutations and well done Skeptical ScienceResponse: The date should be the date of the original article, not the date of submission. Good point re the YYYY/MM/DD - I'll add some clarifying text. I guess if an article is hard to categorize, label it neutral. -
Ned at 01:27 AM on 10 June 2010On temperature and CO2 in the past
And again, when I wrote "I don't know why you think [...] that we can only draw conclusions about climate sensitivity when CO2 is a feedback rather than a forcing" I actually meant exactly the opposite. Argh. This is karmic justice for my referring to BP's comment as "a mess". Next time I write a comment here I will read it at least three times before clicking Submit. In the mean time, apologies to everyone reading this thread. -
Ned at 01:19 AM on 10 June 2010On temperature and CO2 in the past
Sorry, when I wrote "The relationship between CO2 and temperature is not that T influences ..." there is obviously a "just" missing there. It should be The relationship between CO2 and temperature is not just that T influences pCO2 via solubility in seawater; it's also CO2 influences T via radiation. Both of these were true at the last glacial maximum and both are true today! -
Ned at 01:18 AM on 10 June 2010On temperature and CO2 in the past
BP writes: This is the only tiny part of the half million years long dataset, that actually tells us something about climate sensitivity to CO2 variations. Because this is the only time when there is a well documented change in carbon dioxide independent of ocean outgassing. Sorry, but this comment of yours is a real mess. First, there's never a change in atmospheric CO2 independent of the ocean/atmosphere CO2 exchange. Right now we're adding CO2 to the atmosphere, and about half of it is ending up in the oceans. At the end of a glacial stade, when temperature begins to rise rapidly, the CO2 that moves from the ocean to the atmosphere amplifies the warming. The relationship between CO2 and temperature is not that T influences pCO2 via solubility in seawater; it's also CO2 influences T via radiation. Both of these were true at the last glacial maximum and both are true today! The magnitude of that feedback does in fact tell us something about climate sensitivity -- a low sensitivity implies a low feedback. See, e.g., Annan and Hargreaves 2006. I don't know why you think that we can't draw any conclusions about climate sensitivity from paleoclimate data ... or that we can only draw conclusions about climate sensitivity when CO2 is a feedback rather than a forcing. -
Neven at 00:43 AM on 10 June 2010Websites to monitor the Arctic Sea Ice
If it's OK I'd like to point out that I have tentatively started a blog that is dedicated to assembling news and data concerning the Arctic sea ice, as I kind of miss one central place where everyone who is interested can discuss what's going on. The blog is HERE and I'd appreciate it if people would come over and spread their knowledge, 'cause I'm lacking in that department. :-) -
Riccardo at 00:27 AM on 10 June 2010On temperature and CO2 in the past
Berényi Péter, it looks like you're just trying to engage a controversy not about the science but just for the pleasure to say something. The sentence you quote from the post is not referred to CO2 concentration but to forcing. Please try to do science, otherwise is just a waste of time. -
Berényi Péter at 00:10 AM on 10 June 2010On temperature and CO2 in the past
#35 Riccardo at 04:41 AM on 7 June, 2010 That's all it's said. Nope. It says "The slope of the curve is related to the local climate sensitivity and then a non-constant climate sensitivity between glacial and interglacial periods may be inferred. In particular, during the warm periods the climate sensitivity is higher than average. In other words, the temperature increase produced by a forcing is higher when the system is in its warm phases." But the slope of the curve is not related to climate sensitivity, local or otherwise. It is determined by CO2 solubility in seawater as a function of water temperature and by the relation between ocean and East Antarctic plateau temperatures. Climate sensitivity comes nowhere into the equation. You also claim in the article "They clearly show that we are already far outside the range of natural variability during the last half a million years and heading forward." Now, that's true. Except it is neither "we", nor temperature, but carbon dioxide partial pressure in the atmosphere. This is the only tiny part of the half million years long dataset, that actually tells us something about climate sensitivity to CO2 variations. Because this is the only time when there is a well documented change in carbon dioxide independent of ocean outgassing. And the story it tells is rather interesting. During the fifty years between 1958 and 2007 atmospheric CO2 has increased from 314.82 ppmv to 380.42 ppmv above Antarctica. If the linear CO2-temperature relation derived from Dome C ice core is mindlessly applied to this 65.6 ppmv increase, it would imply a corresponding temperature jump of 8.12 K in fifty years, which is observed not to occur. On the other hand with the quadratic fit it is plainly impossible, because with that formula carbon dioxide concentration could never even increase beyond 293 ppmv. Therefore in this respect we are on unknown ground for sure. However, as it happens, we also have an almost complete temperature record for the Vostok site since 1958. No surface temperature trend is measured in fifty years (0.0159 ± 0.0177 K/yr). The null hypothesis, that local climate sensitivity to CO2 is zero there, cannot be rejected. -
Ned at 00:05 AM on 10 June 2010On the Question of Diminishing Arctic Ice Extent
muoncounter writes: Logistic models don't have to go to zero. Ah, yes, you're right of course. I'm not sure why I assumed you were extrapolating March sea ice to 0. Sorry! Comment in haste, repent at leisure is my motto. -
mike roddy at 00:01 AM on 10 June 2010Monckton Chronicles Part III – Acid Reflux?
Scott Mandia, thanks for the 800 pound gorilla link. I've been wondering where to find a comprehensive and readable summary like that. Maybe you can answer this question: Is biological degradation caused by overfishing and oil volcanoes having a substantial impact on the ability of the ocean to sequester CO2? Are there equations available? The Gulf is an especially rich ecosystem, so I would assume that the CO2 impact would be significant. -
Ned at 00:00 AM on 10 June 2010Climate's changed before
Upon further investigation, the "recycling" here is kind of fascinating. Johnston's document relies heavily on a 2007 paper by Lindzen in E&E (yes, another E&E paper ... Johnston is looking worse and worse). That E&E paper was recycled by Lindzen in a 2009 blog post. That blog post by Lindzen, in turn ... is the very same "skeptic argument" quoted by John Cook and then debunked at the top of this thread! In other words, we've come full circle ... -
JMurphy at 22:55 PM on 9 June 2010Climate's changed before
Ned wrote : Thus, it's perhaps not surprising that I'm very unimpressed by the link Roger provides to a document written by a law professor at the University of Pennsylvania. You're not the only one. Not only does the author of that piece start off by thanking McKitrick, Lindzen and Pielke Jnr for their assistance, but the use of terms like "group of activist scientists" and "faith in the climate establishment" give a good flavour of the author's pre-conceived views. Also, the first foot-noted link goes to the American Enterprise Institute for Public Policy Research, which has an article using academic papers which have been countered (e.g. Lindzen & Choi, 2009; Mclean, de Freitas & Carter, 2009); attempts to discredit the peer-review process; accepts the views of the Wegman Report with regard to 'tribalism' in climate science, and uses examples from the leaked CRU emails. Only the committed so-called skeptic would advance that paper as 'evidence' for anything other than his/her personal preference. -
muoncounter at 22:41 PM on 9 June 2010On the Question of Diminishing Arctic Ice Extent
Ned #80, Negative?? Why worry, this is skeptical science, after all. "I don't think that any single simplistic empirical model will ultimately provide a good representation of the time evolution of sea ice, because I think we're likely to go through a series of different regime shifts over time" Agreed; I'm more interested in shapes of curves and rates of change than prediction. And one can learn a lot by observing (and trying to explain) where, when and why a dataset systematically departs from a simple curve. For an example, what will happen to the ice melt regime when the summer melt season consistently opens a "Northwest Passage" for more months of the year? I can't imagine that wouldn't drastically alter polar oceanic circulation, with huge consequences. "eventually the March curve would approach 0, and that just doesn't seem physically realistic" Logistic models don't have to go to zero. There is a more general version of the curve with both nonzero upper and lower asymptotes. For example, shown below (link in case it doesn't show) is such a curve applied to 50 years of atmospheric CO2 data. The curve goes flat on the left to match the general shape of ice core CO2 (Law Dome in particular), which shows a more or less constant level of 280-300 ppm for several hundred years back.More good news, the upper limit for this graph is only 450 ppm (but that's to be seen, no?)
-
Ned at 22:13 PM on 9 June 2010Climate's changed before
The legal system is not really a good model for the scientific method. Thus, it's perhaps not surprising that I'm very unimpressed by the link Roger provides to a document written by a law professor at the University of Pennsylvania. I picked one area with which I am somewhat familiar (sea level rise, discussed on pp. 65-68) and examined it. Unfortunately, it turns out to be exactly what one would expect from someone trained in the adversarial legal system rather than in the scientific method -- he is making a case rather than skeptically evaluating the evidence. (Roger, do you understand the actual meaning of the word "skepticism"?) It also seems to have been heavily influenced by a recent error-riddled paper on sea level rise by Madhav Khandekar in Energy & Environment, which might explain some of Johnston's problems. Bottom line, I would file Johnston's paper in the recycling bin. If there are any valid points in there, they're obscured by a lot of obvious garbage. There are much better resources out there for understanding climate change. -
Ned at 21:35 PM on 9 June 2010On the Question of Diminishing Arctic Ice Extent
muoncounter, thanks for the comment and especially the links. Bob Grumbine also uses a logistic model to analyze trends in Arctic sea ice. I am dubious about this. First of all, I don't think that any single simplistic empirical model will ultimately provide a good representation of the time evolution of sea ice, because I think we're likely to go through a series of different regime shifts over time in which different constraints become more or less important and thus different time periods would follow different models. (Sorry to be so vague; I'll try to take some time later to figure out how to express my thoughts on this better). As an indicator of this, take a look at the residuals of your Sept. model. There are a long series of points in the 1970s that have negative residuals, and a long series before 2007 (1996-2006?) with positive residuals. With regard to the March curve, we're still very much on the "shoulder" of the logistic curve, and even in the absence of any physical understanding that would seem to suggest that small errors in the model would lead to large errors in predictions further down the line (though in the figure you wisely don't attempt to extend the curve too far). But eventually the March curve would approach 0, and that just doesn't seem physically realistic -- even with a very large warming I don't see how we could produce an ice-free Arctic Ocean in winter, given the absence of insolation, unless there's an immense increase in the poleward heat flux. Anyway, sorry if this all sounds negative ... that's not my intent! -
JMurphy at 18:54 PM on 9 June 2010On the Question of Diminishing Arctic Ice Extent
Interesting article relevant to this discussion : Arctic Sea Ice at Lowest Point in Thousands of Years -
Doug Bostrom at 18:29 PM on 9 June 2010Climate's changed before
Roger, if a lawyer or judge does not understand what he's reading or hearing he can be lied to without being aware of it. Inability to discriminate truth from fiction implies that useful judgment is suspended. The conclusions of an ignorant jurist are unreliable even as they are necessarily unbiased. -
Berényi Péter at 18:00 PM on 9 June 2010Monckton Chronicles Part III – Acid Reflux?
A temperature - CO2 (partial) pressure - pH equilibrium phase diagram of ordinary seawater (as measured in the lab) would be welcome. Allowing for proper relaxation time, with plenty of undissolved calcium carbonate at hand of course. The same measured in natural marine environments ranging from tropic to polar would be even better. No hydrochloric acid contamination please. -
Riccardo at 16:55 PM on 9 June 2010Has the greenhouse effect been falsified?
Berényi Péter, the absorption line shape is governed by collisional and Dopler broadening. The former is a lorentzian, the latter a gaussian. The resulting line shape is called Voigt line shape. It's the convolution of the two and depends on both temperature and pressure. Far from the central frequency it may be approximated by a lorentzian. -
gallopingcamel at 16:09 PM on 9 June 2010Irregular Climate: a new climate podcast
doug & co, It is encouraging to find that we can agree on something. Let's hope we can build on this. Barry Brook tolerates me even though I sometimes question the importance of CO2 in relation to climate. As you point out (#87) the problem of disposing with the long lived higher Actinides is a serious issue. Borehole disposal needs to be considered but my hope is that emerging Generation IV nuclear technologies (e.g IFRs & MSRs) will convert most of these materials into fission products with relatively short half lives (<100 years) while producing respectable amounts of electric power. In fairness to Barry Brook's monomania, he strikes me as someone who would support "Fuel Cells" or "Photovoltaic" if there was a break through in cost/performance. At this moment the economics favour coal or fission but that could change. -
Climate's changed before
Roger, >Like any lawyer or judge, such a cross examiner ... takes an unbiased view of the evidence and what is presented. Cross examinations are biased by definition. They are an examination of your opponents witness, hence the "cross" part. That paper is just a summary of AGW skeptic talking points. If you are going to claim an unbiased view of the evidence, at least listen to what the other side has to say in rebuttal. In any case, science isn't determined by lawyers, it's determined by scientists publishing peer-reviewed research. Take a look around this site and the others linked for you to get a feel for what the science actually has to say. -
Rogerthesurf at 14:52 PM on 9 June 2010Climate's changed before
yocta, Its not supposed to be a scientific paper, its looking at the arguments and evidence to see if they stack up from a legal proof point of view. Like any lawyer or judge, such a cross examiner does not have to understand the technical side of things, but takes an unbiased view of the evidence and what is presented. Cheers Roger
Prev 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 Next