Recent Comments

Prev  1745  1746  1747  1748  1749  1750  1751  1752  1753  1754  1755  1756  1757  1758  1759  1760  Next

Comments 87601 to 87650:

87601. muoncounter at 00:58 AM on 25 April 2011
       A Flanner in the Works for Snow and Ice
       RW1 #108: "to see if it was enough to melt the ice." Why not start on the observation side, rather than with an 'if'? Observed: Arctic ice melting (see any of the many threads here at SkS, along with copious literature). Observed: Warming (graph posted above); if that's not good enough, Comiso 2003 is a good read. Average temperature trends are generally positive at 0.33 +/-0.16C /decade over sea ice, 0.50 +/-0.22C / decade over Eurasia, and 1.06 +/-0.22C / decade over North America. The trend is slightly negative and insignificant at -0.09 +/- 0.25C/decade in Greenland with the negatives mainly at high elevations. Conclusion: There must be enough of a radiative forcing imbalance in the Arctic so that both ice extent is decreasing (and melt season getting longer) and temperatures are warming at rates much greater than the global average. Perhaps you can calculate whether all of this can occur with 0 net forcing. That would evaluate 'natural cycles.' But I'm reminded of a talk by Ken Wilson, a Nobel laureate in Physics, several years ago: He stated the memorable line: 'I don't mind reinventing the wheel, I just don't like reinventing the flat tire.'
87602. Tom Curtis at 00:52 AM on 25 April 2011
       CO2 effect is saturated
       novandilcosid @100, in 97 I identified several factors on the RHS of the equation that result in changes in value on the LHS, specifically, in changes to the back radiation. I also identified factors which cause relative changes to the value of the terms on the RHS of the equation. As your argument requires that the LHS determine the value the values on the LHS, but not in turn have their values determined by factors on the RHS, your argument fails because the value of back radiation has been shown to be partially dependent on RHS factors. Further, your argument also depends on the two non-evaporative values on the RHS being constant, and this has also been shown to be false. You chose to ignore that facts I have raised, and simply re-assert your position. Fine - that it your right, but it also make debate with you pointless and uninteresting. I will merely note that keeping your discussion factual seems a low priority to you. Curiously, not only are you uninterested in trying to grapple with the facts I presented, you then go on to refute your own case. First, you indicate that rate of evaporation per degree C is not known, but according to you that value follows by straightforward reasoning from the energy balance equation. Further, you indicate that both constant RHS with a 2.5% increase in evaporation per degree C and a decreasing RHS with a 5% increase in evaporation per degree C are reasonable suppositions. However, both suggest decreases in the value of the non evaporative terms on the RHS, and the second suggests a much larger decrease. These are terms you require to be constant which changing temperature for your argument to succeed, but now you entertain the notion that they are anything but.
87603. Ken Lambert at 00:34 AM on 25 April 2011
       A Flanner in the Works for Snow and Ice
       Tom Curtis Where did you get these numbers? 1979-1983: -7.40E+020 Joules 1984-1988: -4.18E+020 Joules 1989-1993: 8.24E+020 Joules 1994-1998: 1.41E+021 Joules 1999-2003: 2.06E+021 Joules 2004-2008: 6.97E+021 Joules
87604. Tom Curtis at 00:19 AM on 25 April 2011
       A Convention for Persons Displaced by Climate Change
       Harry Seaward @59, the number of environmental refugees has been extensively referenced in previous posts. The population data comes from wikipedia and other sources for the 1% per annum global growth. Regional growth is determined from this chart: 1.02^10 = 1.219, and 1.025^10 = 1.28 , or a 21.9% and 28% growth over 10 years respectively. That compares with the 26.1% growth over 10 years in Africa, or 26.8% for Nigeria. I determined population growth from 1995 by taking 1.03^(Year-1995). That should safely overestimate growth rates, and hence underestimate the growth in environmentally displaced people that cannot be accounted for by population growth.
87605. RW1 at 23:46 PM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       muoncounter (RE: 106), "Why only two years?" I would like to know how much the Arctic has warmed from 1979 to 2010. From that, see if it was enough to melt the ice.
       Moderator Response: [DB] Did you read the article that is the subject of this post?
87606. poptart at 23:24 PM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       I'm pretty sure that if we just choose to ignore the actual evidence, the problem will go away!
87607. muoncounter at 22:53 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       A series of FDs began on March 18. Maybe that's what is causing the Texas wildfires! Correlation, no? Why are the CR -> clouds folks not screaming about aircraft contrails? Stordal et al 2005: found indications that cirrus cloud amount increases have accompanied an increase in air traffic in the 16 year period 1984–1999 ... Our mean estimate of the radiative forcing (0.03 Wm⁻²) is close to the number given in the IPCC (1999) (upper limit in their assessment is 0.04 Wm⁻²) Wait ... these high, thin clouds are a positive forcing, slowing the escape of radiant energy to space. Airplane flight is definitely not a 'natural cycle.' Doesn't that spell anthropogenic global warming? Is that why we don't hear about contrails, but we do hear about the ephemera that is the supposed cosmic ray-climate change connection?
87608. dhogaza at 22:36 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       RHJames: "If I simply stand outside and feel the difference between full sun, and cloud, and just feel the difference in energy reaching Earth's surface, I can't help thinking this is what it's all about." This explains why sunny Bismark North Dakota is so much warmer in winter than cloudy Portland Oregon ...
87609. SNRatio at 20:34 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       Fig 1: Is the estimated cloud cover variance, given CR intensity, constant?
87610. Michael.M at 20:31 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       Correlation is not Causation! How often have we heard this tiresome meme in discussions of CO2 and Greenhouse-Effect, despite of strong theoretical and experimental based physics "how" the GHE works? And now the pseudo-sceptics dismiss all of their "scepticism" and we have to dicuss a slightly correlation that "somehow" affects cloud cover! It shows a typical pseudo-sceptic tactics: Take a point with known uncertainties, claim something nearly (but not completely) unsubstantiated, and blow it out of proportion to explain why anything but CO2 is causing Global Warming.
87611. Paul D at 20:13 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       RHJames: "If I simply stand outside and feel the difference between full sun, and cloud, and just feel the difference in energy reaching Earth's surface, I can't help thinking this is what it's all about." Well if you want to appeal to the (somewhat unscientific) mind of the common person on the street, then simple thoughts like that will appeal to many. Which suggests you aren't interested in education, rather you are appealing to a persons ignorance. In order to gain credibility skeptics need to express some consistency, that means not claiming that the climate system is to chaotic and complex on one hand, whilst at the same time suggesting simplistic answers will reveal the truth.
87612. SNRatio at 19:05 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       I think we may have yet another illustration of the difference between weather and climate here. While there seems to be some evidence indicating cosmic ray influence on cloud formation and, eventually, rainfall, the net long term effect on climate may still be negligible. In any case, it is small contributions, and if they mostly cancel out, as will very often be the case, the net effect will be close to zero. Clouds will often typically tend to have these kinds of net-zero-effects: As Ari J mentions, increasing albedo, and shielding outgoing radiation, for example. They may, however, not cancel out, and then the net effect may become much larger. Svensmark and other proponents have, however, not been able to demonstrate such effects, and at the same time guard against competing explanations. To me, omitting or skewing the discussion of competing models (arch s, #3) is rather telling. If we, for good measure, multiply the Erlykin estimate of temperature increase by 10, we get about as much warming as has occurred in one year recently. "Yep, it might account for one of 50 years of warming. What about the other 49?"
87613. novandilcosid at 18:31 PM on 24 April 2011
       CO2 effect is saturated
       In the headline post (advanced version) the author assumes a "final layer" which is a black body at 220DegK. I have three objections to this: 1. The "Final Layer" is nothing of the sort. Photons are emitted at all levels. Absorption ensures that most never make it out to space through the fog of overlying gas. The average emission height is determined by absorption. In general this level will be different for every frequency. 2. The atmospheric gases are not black bodies - nothing like black bodies. Unlike solids or liquids they do not emit a continuous spectrum, but preferred frequencies (lines), the envelopes of which both in detail abnd as a conglomerate are far from a black body. See http://spectralcalc.com/spectral_browser/db_intensity.php. A black body curve is not appropriate and the "blackbody temperature" cannot be used to estimate the average height of emission. 3. It is implied that the amount of energy absorbed is the difference between two blackbody curves. This is an erroneous view. Energy absorbed into the atmosphere is ALWAYS manifested as kinetic energy (atmospheric heat) at the point of absorption. That energy flows upward by convection and radiation, still manifested as kinetic energy. It is then radiated to Space by the GHGs, primarily Water Vapour, with a little from CO2 (15-18W/m^2) and Ozone. These GHG molecules are energised by collision with other air molecules (around 50 times per nanosecond) and if the energies are right and the star signs are right (ie around one chance in one hundred thousand) a photon is emitted at a preferred frequency. If that photon avoids absorption by other GHG molecules, it escapes to space and that energy is lost from the planet.
87614. adelady at 18:10 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       rhj - you must live somewhere very unlike my experience. We find here that if the day is chilly, clouds moving in can make it noticeably warmer/ milder. This goes double for after dark. (And it's often the sign of rain on the way.)
87615. Ari Jokimäki at 17:48 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       Then on the other hand, in northern winter clouds warm the weather considerably. Also, clouds warm everywhere during night-time. This is because clouds also have greenhouse effect in addition to their ability to reflect sunlight. Due to greenhouse effect, high clouds cause more warming by absorbing thermal radiation than cooling by reflecting sunlight. Clouds don't just cool. Also, more clouds doesn't necessarily mean more cooling.
87616. novandilcosid at 17:43 PM on 24 April 2011
       CO2 effect is saturated
       Tom Curtis @#97 disputes that the heat transport from the surface into the atmosphere is almost a constant whatever the surface temperature. He cites: Increased wind due to increased temperature. Changed Lapse Rate. Change in surface emissivity. Change in conductivity of the air due to higher moisture content. These may all be true [I actually dispute Lapse Rate changes: the lapse rate is controlled by the total energy into the atmosphere - net radiation, condensation of water, conduction, which I claim is virtually constant. So the Lapse Rate is a constant and Lapse Rate feedback may be a furphy.] but the LHS of the equation is always the sunlight absorbed by the Surface. Unless the albedo or solar constant change, sunlight absorbed by the Surface is invariant. On the RHS we have: Surface Energy absorbed into the atmosphere (NET radiation, condensed water vapour, conduction) plus Surface Energy radiated direct to space through the window. This latter term is nearly a constant, particularly if CO2 is nearly saturated (which it seems to be. It might change by a few percent if CO2 doubles - I look forward to calculated values for a doubling of CO2). If CO2 doubles we know that the LHS decreases by approximately 1W/m^2 (increased absorption of sunlight by CO2 in the upper atmosphere). This will approximately balance any decrease in Surface radiation through the window, so the Surface Energy absorbed by the atmosphere will remain the same.
87617. rhjames at 17:39 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       delady "rhj, and when you're outside on a clear, frosty morning do you notice the difference when cloud cover moves in? I notice that it gets a bit less nippy at those times." Certainly - I can ski in a T shirt in full sun, but when the clouds come over, it's back on with the parka. That's a huge change in energy reaching me.
87618. novandilcosid at 16:35 PM on 24 April 2011
       CO2 effect is saturated
       Tom Curtis responded in #97 to my statement that surface energy into the atmosphere is essentially constant. "Specifically, you insist that an increase in temperature will result in an increase evaporation" Too right! We recall that the statement is only true when the energy flows are integrated over the entire surface over an entire year, then averaged. A second stipulation is that the system is in equilibrium - there are no net inflows or outflows. This is essentially what Kiehl & Trenberth say in their 1997 diagram, and is also implied by any statement that "the average temperature of the planet will increase by X degrees." While the statement will not be true at specific locations, it is true for the planet as a whole (remembering that 70% is water). [Off topic: The amount of increase in evaporation per DegC is disputed (see for example Schneider, Gorman and Levine, 2009, http://arxiv.org/abs/0908.4410 ). It is also unknown if relative humidity changes. The modellers assume constant RH (no better estimate), Clausius-Clapeyron water vapour increase (6.5%/DegC) and around 2.5%/DegC for evaporation. Actual measurements suggest that RH has decreased with increasing temperature, and that the rate of evaporation increase is 5%/DegC. Essentially the water properties of the atmosphere are unsettled science. Many climate scientists disagree with the assumptions in the models.]
87619. novandilcosid at 16:14 PM on 24 April 2011
       CO2 effect is saturated
       Tom Curtis @ #94 wrote: " But those same figures above clearly show that there is a substantial reduction in radiation to leaving the troposphere outside those that range, but between 500 and 850 cm^-1. " The most active region is the band between 625 and 725. (See http://spectralcalc.com/spectral_browser/db_intensity.php) The lines here are around two orders of magnitude greater intensity than the lines in the rest of the band. 1. The question relevant to saturation is how much additional surface energy is absorbed outside the saturated 625-725 band, ie by how much does the window close, in W/m^2? I have always assumed that this is small - not more than 0.5W/m^2 for a doubling of CO2. 2. At the top of the atmosphere, what is the emission strength from CO2 in these weak parts of the band? The 625-725 region is emitting about 15-18W/m^2 (see plots of outgoing radiation measured in space eg http://acmg.seas.harvard.edu/people/faculty/djj/book/bookhwk7-1.gif http://www.mathstat.dal.ca/~folkins/Cloud-LWspectrum.jpg . http://climateaudit.org/2008/01/08/sir-john-houghton-on-the-enhanced-greenhouse-effect/ ). The much weaker lines outside this region won't be emitting much. So I guess I'd like to see some calculation of both these effects in the weak band to see if it is relevant. If the powers are small then this part of the band can be ignored, even though the majority of the emissions from them are plainly from below the Tropopause.
87620. novandilcosid at 15:52 PM on 24 April 2011
       CO2 effect is saturated
       Tom Curtis @#94 wrote: "the range 630 to 710 cm^-1 come from the stratosphere. (I am not agreeing, I am just not disputing.) Certainly it comes from high enough that, as shown in 82 and 86 above, that increasing CO2 concentrations make no difference to the amount of radiation escaping from the troposphere at those wave numbers, which is all that is relevant to this discussion. But those same figures above clearly show that there is a substantial reduction in radiation to leaving the troposphere outside those that range, but between 500 and 850 cm^-1. 1. I dispute that there is no change in energy radiated from the troposphere. I think the figures in #82,86 are NOT sufficient to estimate what happens: they are disclosing the opacity of the atmosphere as seen from the ground. This is not helpful when trying to determine what the effects are in the region which is already 100% opaque. It seems obvious that for the level in the atmosphere at which 20% of the photons make it through the CO2 fog to outer space, a doubling of the thickness of the fog will move the 20% emission layer higher. 2. The $64 question is where are the photons coming from in the very active 625-700 region with CO2 at 380ppm? My calculations suggest only 10% are coming from below the Tropopause, the remainder from above. If that is the case, then for this band a doubling of CO2 will mean emissions from higher in the stratosphere. The net effect in this band will therefore be an INCREASE in power radiated to space.
87621. Ari Jokimäki at 14:59 PM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       muoncounter: "It's not clear what you're saying here: are these cloud cover decreases due to lower CR flux? Svensmark et al 2009 make this quixotic remark:" I might have simplified the situation bit too much there. Erlykin et al. say: "The well-known Forbush Decreases in CR intensity (denoted‘FD’ and typically 3% for 2 or 3 days) caused by changes in the solar wind - and attendant CR modulation - following solar ‘eruptions’, should, if the CC, CR correlation is causal, give rise to CC reductions. Indeed, even if not causal but if both CR and CC changes are due to a third variable (solar irradiance, for example) then a correlation should result. Svensmark et al. (2009) have claimed such a correlation for CR FD and the liquid cloud fraction (LCF), but this has been disputed (by us, Laken et al.,2009 and by Calogovic et al.,2010)." muoncounter: "Who did this analysis? Again, which way are the changes?" Laken et al. (2010). muoncounter: "Do they claim any significance to this decrease?" They refer to Bazilevskaya et al. (2008) and to be more precise, they say that the decrease has been "less than 0.6 %". muoncounter: "Isn't this the best take-away? The contribution of CR to ‘climate change’ is quite negligible." Erlykin et al. conclude: "The increase in temperature predicted is 0.002°C, a value quite negligible in comparison with the Global Warming in this period (~ 0.5°C) and the conclusion is that cosmic rays have a negligible effect on climate."
87622. muoncounter at 14:30 PM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       RW1 #105: "data from 1979 and 2010." Why only two years? -- from here
87623. RW1 at 14:06 PM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       I need data from 1979 and 2010. How much has the Artic warmed?
87624. Aardvark at 13:52 PM on 24 April 2011
       Has sea level rise accelerated since 1880?
       I posted this originally to Tamino's blog, but it didn't show up for some reason. So I am reposting it here The reason Houston and Dean are using a quadratic fit is that they are trying to ascertain the long term average rate of acceleration. They note that Douglas (1992) has determined that it is necessary to analyze upwards of 50-60 years of continuous data in order to determine a significant trend, because decadal scale oscillations in the acceleration are common in the observed record. By significant I do not mean “statistically” significant: rather, I mean significant with respect to the determination of the type of long term trend that the climate models forecast in response to the increase in atmospheric greenhouse gases. If we had thousands of years of data, this could be done by first decomposing the data with a Fourier series analysis, and then analyzing the low frequency signals for statistics on acceleration. But we don’t have enough data to do that, so the next best thing is to fit the data to a quadratic curve, which by definition yields the “average” acceleration rate of the entire sample space. Houston and Dean are explicit with respect to their reasons for starting the analysis at 1930. Quoting from the paper: “A review paper on sea-level acceleration by Woodworth et al. (2009) notes that the analysis by Church and White (2006) shows a positive acceleration, or ‘‘inflexion’’ point, around 1920–30. They do not use the mathematical definition of an inflexion point as the point where the curvature (second derivative) changes, but instead define it as a change in sea level trend. They say that the inflexion point around 1920–30 is the main contributor to acceleration from 1870 to 2004. Woodworth et al. (2009) concluded there was consensus among the authors that acceleration occurred from around 1870 to the end of the 20th century; however, with the major acceleration occurring prior to 1930, the sea-level rise (Figure 1) appears approximately linear from 1930 to 2004. Church and White (2006) did not separately analyze this specific period.” So, Houston and Dean analyze from 1930 forward to determine if the acceleration is a persistent (long term) trend or not. If the acceleration is a response to atmospheric greenhouse gas emissions, the trend should in theory be persistent and observable in the record since 1930. Tamino's method of analysis consists of averaging over shorter and shorter time scales as one moves along the time axis. This effectively weights higher frequency signals more and more as one approaches the present time. This method ensures that such a plot will look more “active” on the right hand side of the plot.(i.e. the left hand side of such a plot will always have less high frequency events than the right hand side) Since the most recent data indicate a short term increase in acceleration , this ensures that Tamino's plot will appear to show this acceleration as if it were a novel event, which is misleading. Houston and Dean acknowledge that there is a recent trend showing increased acceleration, especially evident in the satellite altimetry data. They discuss this observation at length. They conclude that this type of higher frequency event is not unique in the observational record, and that although it may represent a long-term change in the rate of acceleration, it is not possible to determine this with the limited amount of data available (again, 50-60 years of data is needed) They speculate that it is more likely just another decadal oscillation ,for several reasons they give in the paper, but they do not form any definite conclusions on this point. The Houston and Dean analysis is appropriate for use in determining the long term trend of acceleration in the 20th century (at least since 1930) . Whether this is important information or not depends on the results of the hindcasting verification runs of the climate models . If the climate models hindcast a significant positive 20th century long-term acceleration, and if, as Houston and Dean demonstrate, such an acceleration is not present in the observational record, it gives good reason to be concerned that the process descriptions that govern the models are in error. I don’t know enough about the climate models to know what their hindcasts indicate, so I can’t asses the relative significance of these results with respect to climate modeling.
87625. Harry Seaward at 13:26 PM on 24 April 2011
       A Convention for Persons Displaced by Climate Change
       Tom @ 57 Where are you getting your data from? Please reference.
87626. RW1 at 13:24 PM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       Out of curiosity, how do we know the ice loss is due to an increase in temperature in the Artic?
       Response:

       [DB] See for yourself:

       

       [Source]

87627. Harry Seaward at 13:23 PM on 24 April 2011
       A Convention for Persons Displaced by Climate Change
       Muon @ 56 I wasn't referencing soley a drought. I was referencing the 3 events (heavy rain - plant growth, cold winter - plant die-off, drought - drying conditions) that led to the fires. It is worth investigating if any or all of the three are related to AGW, but no one should yet make claims that they are. And, certainly these wildfires can't be construed to represent evidence of AGW.
87628. Bob Lacatena at 13:05 PM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       101, Ken,

       Even Alec Cowan is now chiming in with an apologia for all the errors I have identified in the arguments of Sphaerica, Tom and even Adelady.

       Wow. Did you really misread Alec's post that badly? Really? Or do you just think that everyone else's reading comprehension skills are that poor? I feel like I just dropped out of a twister into Oz.
87629. Bob Lacatena at 13:03 PM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       101, Ken, First, you didn't find a mistake in my calculations. You thought you found a mistake, and you were in error (see post 96 by Tom and post 98 by me, both correcting your misunderstanding of what an "annual average" means, and why it would be particularly inappropriate to use in our situation). Second, Tom didn't find a mistake in my calculations, he pointed out your mistake, and added that if I had used your suggested average annual value then I would also need to remove the compensation that I'd already built into my calculation (i.e. dividing by four, to account for only one season of melt, which is a more correct method of working with the problem). Tom pointed out your error, and how I would have needed to adjust my calculation had I made the same mistake you did. As far as your angle of incidence claims, anyone here can go back and read the thread. I already corrected you several times on that. You are focused on the exact spot of the north pole, when the area of interest is that entire area from about 50˚N and up. So far, the major errors are yours, first in thinking you've found errors in other people's work, and then compounding that by failing to understand where you've gone wrong (even when we clearly point it out to you), and then further compounding that by misrepresenting what we have written.
87630. Ken Lambert at 12:05 PM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       Gentlemen and Adelady After finding an error (by a factor of three) in the first line of Spherica's latest effort I did not follow the rest through. Tom obviously did follow it and found an error the other way which offset the first. How would anyone reading this be expected to take Sphaerica seriously after a string of errors which included an angle of incidence at the north pole of 66 degrees when in fact it is 23 degrees at the summer peak. Even Alec Cowan is now chiming in with an apologia for all the errors I have identified in the arguments of Sphaerica, Tom and even Adelady. Anyone care to find an error in any of my numbers?? If not then please declare my arguments correct and the others wrong.
87631. David Horton at 10:51 AM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       Mmmm, two possible explanations for global warming one with poor to no correlation and no theoretical underpinning, the other with clearly understood physics and extremely good correlation. How to choose, how to choose, what a dilemma.
87632. adelady at 10:19 AM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       rhj, and when you're outside on a clear, frosty morning do you notice the difference when cloud cover moves in? I notice that it gets a bit less nippy at those times.
87633. arch stanton at 10:16 AM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       I bought Svensmark’s book because I like to expose myself to both sides of an argument and I wanted to get the “best” of the pro-GCR side. When I pointed out to other readers (on Amazon) how biased the book’s review of scientific literature was I was truly amazed at how quickly I was “voted down” (I never even got into Calder’s (the real author) dubious history of scientific reporting). I admit that it is an interesting hypothesis, but only folks highly selectively biased by personal belief could possibly believe that galactic cosmic rays have a climate effect greater than that of the change we have seen in atmospheric CO2 levels. Little in the scientific literature supported it then and even less does now.
87634. Tom Curtis at 09:54 AM on 24 April 2011
       A Convention for Persons Displaced by Climate Change
       Some attempt to quantify the number of Climate Change displaced (or migrating) people, ie, those displaced or migrating for environmental reasons that would not have been displaced or migrated were it not for climate change. The simplest and crudest way to make such an estimate is to eliminate population growth from the equation. World population is growing at just over 1% per year, with growth in even the fastest growing regions barely exceeding 2% a year. We can optimistically estimate population growth in environmentally degrading regions as being at 3% per annum, or 55.8% over 15 years, 142.7% over 30 years, and 408.2% over 55 years. With 25 million environmentally displaced in 1995, that would lead to an expectation of 39 million environmentally displaced by 2010; of 61 million environmentally displaced by 225; and of 127 million environmentally displaced by 2050. This compares to Myers predictions of 50, 100 and 200 million environmentally displaced for each of those years. That means he is predicting 28% more environmentally displaced in 2010 than can be accounted for by population growth alone, with 64% more in 2025, and 57% more in 2050. From the figures provided in posts above the 2010 prediction seems reasonably accurate, with the number or environmentally displaced people (including environmental migrants) being somewhere between 30 million and 80 million. That means that it is highly probable that a significant number of people have already been displaced by climate change. It is very probable that that number will grow in the future.
87635. muoncounter at 09:41 AM on 24 April 2011
       A Convention for Persons Displaced by Climate Change
       HarryS #53: Clarifying: At #51, you suggested that three 'weather events' explain the severity of the current drought. I'm not so sure it's that easy. Point 1: Here's the rainfall total for Alex: That wasn't enough over Texas to do as you suggest. Point 3: The current drought began in October, not in the spring as your model stated. Recent drought history for the southern US shows significant areas of D4 'exceptional' in 2000, 2006-2007, 2009 and now 2010. Sure, there's no smoking gun to show that the latest exceptional drought is directly due to AGW; it is, however, yet another set of extreme events that fit right into the pattern. Seems like 'exceptional' isn't so unusual any more. Perhaps they need a D5 category - I suggest 'Biblical.' I suppose it could all be coincidence. But that's not much of a scientific argument.
87636. Tom Curtis at 09:32 AM on 24 April 2011
       A Convention for Persons Displaced by Climate Change
       Adelady @49, I disagree on two counts. There are a very large number of displaced people in Somalia, but most of those have been displaced for some time due to conflict in Somalia so are not environmentally displaced. Also, in the case of drought it is very rare that all water stocks are exhausted, and aid agencies often supplement water supplies to a substantial extent. It is therefore very unlikely that all, or even most of the effected people will abandon their homes and lands. You will notice the source I linked quoted 52,000 as of 30 March. The number displaced has probably grown since then, but not 3000% percent.
87637. Tom Curtis at 09:26 AM on 24 April 2011
       A Convention for Persons Displaced by Climate Change
       michael sweet @50, as I've probably made clear, I don't like the "refugees" terminology because, no matter how well defined and understood in academia, in normal use it is likely and has been misunderstood to indicate a much narrower group of people than Myers intended. This leads to people making unwarranted assertions about the impact of AGW, ie, that there will be 50 million people displaced by Global Warming by 2010 in good faith, whereas the actual prediction and figures support there being over 50 million displaced or migrated due to environmental degradation in 2010, including that caused by specific development projects. Nor do I consider the numbers I have quoted as in any way rigorous. Even the reports they come from do not consider them rigorous. What they are is indicative, and proof that those who just dismiss the idea of 50 million environmentally displaced people have made only laughable attempts to quantify the issue. So, I am quite happy for you to quote the figures I and Albatross turned up, you should always do so with the appropriate caveates. On a side note, a common meme is that Myers methodology was just to add up the populations of the effected areas. As the "effected areas" include China, India, Egypt, Bangladesh, and Pakistan (amongst many others), the population of the effected areas is over 2 billion people. Obviously the slander against Myers is simply ridiculous.
87638. muoncounter at 09:20 AM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       A few questions: "Forbush decreases (few percent decrease in cosmic ray flux that lasts few days) have been claimed to cause cloud cover changes." It's not clear what you're saying here: are these cloud cover decreases due to lower CR flux? Svensmark et al 2009 make this quixotic remark: We find that low clouds contain less liquid water following Forbush decreases, and for the most influential events the liquid water in the oceanic atmosphere can diminish by as much as 7% "In a recent analysis, it was found out that in mid-latitudes rapid changes in cloud cover are associated with changes in cosmic ray flux and in surface temperature." Who did this analysis? Again, which way are the changes? "the cosmic ray flux has decreased about 0.6% in last 50 years." Do they claim any significance to this decrease? Isn't this the best take-away? The contribution of CR to ‘climate change’ is quite negligible.
87639. rhjames at 09:10 AM on 24 April 2011
       Cosmic ray contribution to global warming negligible
       I suspect cloud formation has a major influence over our climate. Even the IPCC admitted that cloud formation is poorly understood. Cosmic rays may not be the main driver, but a deeper understanding of the mechanisms involved would surely be a significant step forward. If I simply stand outside and feel the difference between full sun, and cloud, and just feel the difference in energy reaching Earth's surface, I can't help thinking this is what it's all about.
87640. Harry Seaward at 09:02 AM on 24 April 2011
       A Convention for Persons Displaced by Climate Change
       Muon @ 52 I'm not sure of your point. It takes a while of little or no rain (basically below average) for a region to enter a drought state. Please clarify.
87641. Bob Lacatena at 08:33 AM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       93, Alec Cowan,

       I know that you are making a personal effort to help those people to understand...

       Actually, no, not really. I mean, if a light bulb happens to go off over their head, fine, but no, that's not the point. I know the odds are one in a billion (and what I mostly want to do with someone like RW1 is to at least get him to stop posting his own gibberish and confusing others). I post comments mostly for the lurkers, for the thousands of people who only read and don't post comments. Some of those are as close-minded as the person posting (Ken, RW1), and out of reach. Some have made up their minds, but aren't as close-minded as it seems, and when the light goes on for them, even if it only plants the seed of doubt in their own position, something has been accomplished. Others are more on the fence, or even trusting of the science, but can begin to doubt the science if the trickery and distractions aren't laid bare for them. I well remember the days when I myself was mislead by "skeptic" arguments, and it took a lot of work and hours (by me) to realize that they were all smoke and mirrors. So I see nothing wrong with being up front, providing calculations, admitting to errors when I make them, and letting a conversation drag on for way, way longer than it should (a la RW1), because the point is not to "win the argument." The point is, instead, to demonstrate fallacious arguments, unsubstantiated claims, and an obstinate unwillingness to think and reason, although not to the person posting, but rather to others who are reading both sides of the debate. People with arbitrary or incoherent positions don't have to "admit defeat" to be exposed.
87642. Chris Colose at 07:11 AM on 24 April 2011
       Wakening the Kraken
       It's worth keeping in mind that the relative efficiency of methane as a greenhouse gas depends very much on its concentration. At modern concentrations, CH4 is molecule-for-molecule a better greenhouse gas than CO2 (say, if you increase methane from 2 to 3 ppm and CO2 from 390 to 391 ppm). This relative efficiency is very easy to work out using the Myhre et al 1998 table of radiative forcing (Table 3). For example, when comparing an increase of 1 to 2 ppm of methane vs. 389 to 390 ppm increase of CO2, the methane generates 30x more radiative forcing. But if you compare that methane change to a CO2 increase of 149 to 150 ppm, it is only 11x stronger. Methane too, can only be thought of as a powerful greenhouse gas because it is nearly in a logarithmic limit and you are starting from a low baseline concentration. If you were to compare the effects of two nitrogen/oxygen only (IR-transparent) atmospheres, but one with 100 ppm of CO2, and one with 100 ppm of methane, the CO2 atmosphere would generate more reduction in the outgoing radiation. This is because CO2 absorbs at wavelengths more well placed near the peak of the Planck function for a body at Earth-like temperatures. Thus, if that 100 ppm methane atmosphere was all oxidized into CO2 (and it stayed in the air), you would generate warming. The implication is that methane is not intrinsically a better greenhouse gas at all, it only looks more important in the current atmosphere when you compare a molecule-for-molecule increase between CH4 and CO2. This is important to keep in mind when looking at prospective greenhouses with relatively high abundances of methane.
87643. Alec Cowan at 06:59 AM on 24 April 2011
       A Flanner in the Works for Snow and Ice
       @Sphaerica #93 You are doing it the same style as with RW1 in other posts. Don't provide your own calculation. I know that you are making a personal effort to help those people to understand, but they simply don't want to understand and the final result is negative. They present their own calculations and considerations, they tend to be more tight when they are criticizing one obvious mistake in the rival's, they tend to be sloppy when they have to introduce "their evidence" to contrast the post or the so-called "climate science". I mean they need all those numbers to pluck everything opposing their intended conclusions. The technique that Ken Lambert has used here is much more coarse and by following the path he proposes you are helping him to disguise his technique which includes criticism developed in the fringes of a reality-check calculation on part of one of the chosen rivals, taking what can be played down and/or declare a personal achievement(A), declaring the results out of scope or negligible (B) and distorting the line of argumentation just to jump to their chosen playfield using a variety of sub-techniques such as, but not limited to, telling that the rivals don't know what their talking about(C), affirming the they have the *real* (*=little cherubims) epistemological path to a proper answer -the twist starts there- (D) to finally -by using verbal lidocaine or the technique rod fishers use to wear out a fish- throwing a subdued admonition that point to dismiss methods and morals of the rival and start his own song starting with "I" (E) (Examples here) Sphaerica, this technique is not counteracted by an endless exchange of comments where one part continue to do bonafide calculations and reasonings and the other just try to constantly sneak their technique. You may think that you are doing well, and that can be true, but look what you are talking about and you will find that you where brought to a terrain chosen by them. The fact is that we'll probably have a couple of troubling months in front of us, as Washington & Cooke's book will be soon released and the publicity, be it little or be it huge, will drive here a lot of infuriated "skeptics" that will subscribe in dozens and attack in pack, so the episodes involving some Paul these days will be ten-folded. Those people will be counting on the toes and fros that I'm criticizing and you might be providing a culture medium if you and others spread to thin and continue to use reality checks as front row science and disregard counteracting the technique they use. Not only it is a huge waste of effort but it also promotes the idea of a sloppy climate science, exactly what the (so-called) "skeptics" pretend. From here: "I am glad your calculation agrees with mine that the effect of arctic ice melt is trivial (2.8% increase in arctic forcings since 1978)". A "What about the effects on the other 95.6% of the Earth's surface, like the 70% occupied by the oceans where we still can't find the absorbed heat". B From here: "What is your point in calculating the incoming and ignoring the outgoing?" C "Surely the whole discussion of AGW is about the *net* warming effects. One might as well suggest that we only look at possible changes incoming flux on *any* part of the Earth, while ignoring the changes in outgoing flux". D ("outgoing flux" and "cellar door", don't they sound charming?) From here: "Tom, wilfully leaving out relevant information of which you are aware simply is a distortion of the case to suit a particular bias". E
87644. Alexandre at 06:51 AM on 24 April 2011
       Wakening the Kraken
       Sphaerica #17 My understanding of the issue seems right, then. It's only those Modtran figures that don't match. Maybe I'm failing to interpret its results properly. Ron #18 No, it's not the unit. Archer's Modtran uses ppm as well... Anyway, thanks for the responses.
87645. funglestrumpet at 06:48 AM on 24 April 2011
       Lindzen Illusion #1: We Should Have Seen More Warming
       Just a thought regarding bringing people into line who are thought to be deliberately making misleading statements. I can sympathise with the desire that academic freedom should not be made to suffer as a result of any control mechanism established to counter such behaviour, so how about the following? Establish an open email forum for making accusations of academic misdemeanours. (Only open to bona fide scientists specialising in the field i.e. established peers of the person who is the subject of the complaint). Whilst only an email rather than a formal letter, it should follow a strict code of practice, which the scientific community decide upon. This is then made available to view publicly on some dedicated web site. The ‘accused’ should then respond, explaining their position. There then follows a series of exchanges with supporting evidence until the matter is either resolved, or in need of arbitration. All correspondence is automatically open to view by anyone, so that they can see how the debate is going. I think the press might get some mileage out of this, thus raising the profile. There would be the need for checks and balances. For instance frivolous complaints should be subject to sanction (scientific community to decide on exactly what that should be). There would need to be an international administration (U.N.?) where records would be kept etc. And they should also be responsible for passing on emails from other interested parties (restricted to those operating in the field) so that all correspondence is of value to the debate i.e. a filtering process might be necessary. (This secondary correspondence should be kept private to the sender, recipient and arbitrators.) Serious thought would have to be given to the arbitration panel, perhaps even formed from the judiciary with the power to call on guidance from learned scientific personnel. Finally, the issue is resolved and if the case is found proven, some sanction (scientific community to decide – possible publication of findings on the public website set up for the purpose?) This is only my loose thoughts on the matter, please treat it as seed corn for discussion. To the moderator. There seems to be quite a lot of discussion on this topic. How about a separate thread with invitations to post from other scientific fields – it will impinge on them after all.
87646. muoncounter at 06:20 AM on 24 April 2011
       A Convention for Persons Displaced by Climate Change
       Harry S#51: "Texas then entered the spring of 2011 in a drought situation " Records show this most recent Texas drought started in October 2010. So its not quite so cut and dry, so to speak.
87647. Ron Crouch at 05:06 AM on 24 April 2011
       Wakening the Kraken
       Don't forget Alexandre that although methane concentrations in this article have been quoted as ppm you will more frequently see them referred to in ppb. Seeing that methane has risen from ~850 ppb in 1750 and now is at ~1800 ppb it's not likely that you'll see rises in concentrations of 1 ppm. So for the example you previously used in #11 a 1 ppb increase in methane would only be an increase of .471 W/m2 which when multiplied by 19.96 would equal your stated 9.4 W/m2 for a 1 ppm increase in CO2. That's fairly close to the 20 times the warming potential correct? Of course if it did rise by 1 ppm compared to 1 ppm CO2 then the warming potential would be 20,000 times that of CO2 (that would constitute a very very large input of methane to the atmosphere).
87648. Bob Lacatena at 04:41 AM on 24 April 2011
       Wakening the Kraken
       RE relative GHG "strength" of CH₄ and CO₂ I've looked into this before, and while I don't remember all of the particulars, you did already touch on the important factors, which are that residence time, absorption band, and other factors all come into play. Basically, the answer is that trying to come up with a single scalar value that represents "warming" potential for a substance is a fool's errand (well, not really a "fool's"... the task has value, but you have to understand the limitations of what you're trying to get). Certainly it matters what current levels are, and what they're changed to, in both gases you are comparing. Time frame matters. Current opacity at various wavelengths matter. So adding methane may be more powerful for the next ten years, for example, but not fifty years from now. Adding it to an already souped up CO₂ atmosphere is more powerful than adding more CO₂. Etc. In the end, I think a simple scalar rating like that is like trying to rate the fastest car in a race. Some cars accelerate better, some corner better, and some have a higher top speed. Some can stay in the race longer without a pit stop. You can't just say "car #23 is faster than #52" because it depends on the track, the conditions, and the length of the race.
87649. Bob Lacatena at 04:30 AM on 24 April 2011
       Wakening the Kraken
       5, James Wight,

       Wasn’t the Holocene Optimum caused by Milankovitch cycles?

       Yes. And no. Strong positive feedbacks (not methane in the current theory, I believe, but CO₂... although I'm not that well read on it) are a major and necessary factor to the Holocene Optimum. Milankovitch cycles started it but are not of and by themselves sufficient to begin or end a glacial period. CO₂ was necessary to complete the transition. To learn more search for "last glacial termination" on Google, and look for things like this paper: Denton et al (2010).
87650. Bob Lacatena at 04:19 AM on 24 April 2011
       Christy Crock #1: 1970s Cooling
       40, Alexandre, What I find even more frightening is that the human induced aerosols are helping us right now, by adding a strong negative forcing in concert with the positive forcing from CO₂. The day we cut back on fossil fuel use, CO₂ levels will still stay high for a century or more, both because of residence time, and because the ocean is becoming so saturated with it... any attempt by nature to reduce it in the atmosphere will simply result in nearly equal replacement from the ocean for quite some time. But aerosols will drop fairly quickly, and so that negative forcing will disappear, and temperatures will shoot up (or at worst continue to rise evenly but inexorably) even after fossil fuel use is reduced. We'll have to suffer through that further increase before the situation starts to stabilize. Not good. And yet Dr. Christy focused on misrepresenting this science from 35 years ago, rather than the complex and disquieting truth behind aerosols, both then and now.

Prev  1745  1746  1747  1748  1749  1750  1751  1752  1753  1754  1755  1756  1757  1758  1759  1760  Next