Arguments
Recent Comments
Prev 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 Next
Comments 90051 to 90100:
-
Ken Lambert at 23:16 PM on 4 April 2011Arctic Ice March 2011
Tom Curtis #81 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). The leap is then made to 43% with a loss of the 'ice cap' - presumably the summer sea ice disappears entirely. So how then is the leap made to one month earlier snow melts down to 50 degrees north and 0.63W/sq.m? And all this from an area of the Earth's surface of less than 4.4%?? 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. Last time I looked there were hardly any Argo buoys above 60 degrees north, so what monitoring of ocean temperatures are we relying on to measure the solar energy absorbed in the Artic ocean? -
Ken Lambert at 22:55 PM on 4 April 2011Arctic Ice March 2011
muoncounter #80 The BP Arctic ice melt due to soot argument and mine are not incompatible. Tell us what is the average albedo of ocean surface at an average Arctic angle of incidence of 23.4 degrees, and what is the albedo of sooty snow and ice at similar angles of incidence? It seems that Sphaerica made the claim that I was talking gibberish and he (she) was sure that the Arctic ice melt was due to insolation higher than the tropics with a sun incidence angle of 66 degrees at the North Pole. I simply pointed pointed that this was wrong in fact. Sphaerica has not responded to claim that my schoolbook planetary geometry is wrong - nor has anyone else. Johnd makes salient points about heat flows affecting Arctic melt. -
JMurphy at 22:31 PM on 4 April 2011Soot and global warming
Some perspective on the LIA : However, the timing of maximum glacial advances in these regions differs considerably, suggesting that they may represent largely independent regional climate changes, not a globally-synchronous increased glaciation (see Bradley, 1999). Thus current evidence does not support globally synchronous periods of anomalous cold or warmth over this timeframe, and the conventional terms of "Little Ice Age" and "Medieval Warm Period" appear to have limited utility in describing trends in hemispheric or global mean temperature changes in past centuries. Mann et al. (1998) and Jones et al. (1998) support the idea that the 15th to 19th centuries were the coldest of the millennium over the Northern Hemisphere overall. However, viewed hemispherically, the "Little Ice Age" can only be considered as a modest cooling of the Northern Hemisphere during this period of less than 1°C relative to late 20th century levels (Bradley and Jones, 1993; Jones et al., 1998; Mann et al., 1998; 1999; Crowley and Lowery, 2000). Was there a "Little Ice Age" and a "Medieval Warm Period"? -
chris1204 at 22:07 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
PS: I just bought the book. -
chris1204 at 21:52 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Marcus @ 13: "Once more, HR, you seem to be full of denialist clap-trap. Try to do better next time please." Might I suggest, "More light, less heat" or "lighten up" [puns intended]. Meanwhile, heartfelt congratulations John on what has clearly been a labour of love. -
WSteven at 21:46 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
'Grats on your book, John. Now I'll have to see if my wife will let me buy a copy. ;) -
CBDunkerson at 21:25 PM on 4 April 2011Soot and global warming
thingadonta, you'll notice that we are not currently >in< the 1950s... or even 20 years thereafter. Any impact of that solar forcing or feedbacks set off by it are long gone. Atmospheric carbon dioxide was level at 270 +/- 10 ppm for thousands of years until ~1800. Then it started increasing. Thus, the optimal time to compare current temperatures against would be ~1800. That said, all three of the major temperature anomaly records start in 1850 or 1880... because we don't have significant thermometer readings before then. No "agenda" involved. Just using all the data we have available. Thus, the available anomaly records are technically not "pre-industrial"... they pick up after the first 10 - 15 ppm of CO2 increase. However, this is close enough that people are usually referring to the warming shown in those records when they say 'pre-industrial'. In essence, the current ~0.75 C total warming anomaly generally cited leaves out the small amount of warming from 1800 - 1880 caused by industrial greenhouse gas emissions. In any case, the accusation of "ideological" selection bias is pure nonsense... 1880 was long after the Little Ice Age and obviously 'chosen' based on the fact that it is the data we have. -
funglestrumpet at 21:15 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
2 Meikol. Ok, so you agree that Climate Change is a fact. Why then are you and all those like you so intent on thwarting action to counter it? You might be in some doubt as to the origin of an asteroid headed for the earth, but would you really thwart action until we could be absolutely certain of its origin? No, of course not. But there again, there would no vested interests in having an asteroid hit the earth. The same cannot be said of Climate Change. Get your calculator out and try entering '2' then hit '+' and then another '2'. The answer will probably surprise you. As for the book, I hope it is the success it deserves to be. -
Marcus at 21:04 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
"A warmer Earth in any case will lead to less differences in climate, which means that there will be less, not more changes (once things have changed for better or for worse)." Lets *assume* for 5 seconds you're correct-though you're probably not. What impact do you think a lack of variability in climate is going to have on our crops? Once again I see the Denialist crowd speak without actually thinking. -
Marcus at 21:02 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
"Do you contemplate the existence of a warmist industry" So, tell us HR, who is *really* going to benefit from this supposed "Warmist" industry? After all, we *know* what the fossil fuel industry has to lose if climate change mitigation takes place, but I don't see a lot of scientists getting rich from predicting climate change. Once more, HR, you seem to be full of denialist clap-trap. Try to do better next time please. -
les at 20:38 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Congratulations to the Authors. One small recommendation: Given what 10 Bern noted, along with the discount, may I suggest you include a months worth of some general purpose SSRIs? This would enable inhabitance of the deniosphere to read the book, increasing your potential readership by at least 1%. -
Anne-Marie Blackburn at 20:35 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Congratulations John! Now the question is, when will you be touring the UK so I can get you to sign the book? Cornwall is beautiful :) -
Bern at 20:15 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
I can't believe the "It's not us" and "It's not bad" memes both appeared in the first 10 comments! Back on topic - congrats on the book, that's a real achievement. Shame it's 40% more expensive here in Oz than the US price (but I've seen some books where the difference was over 150%, so 40% isn't too bad. :-) -
thingadonta at 20:09 PM on 4 April 2011Soot and global warming
Sorry, that should read "20 year time lag from solar effects", and also "cloud cover changes which are both immediate and delayed", and "it was colder than the average over the last 10,000 years during the immediate pre-industrial period". (So don't chose it as a baseline!) I'll try to spell check next time. -
thingadonta at 20:03 PM on 4 April 2011Soot and global warming
"Since solar forcing is actually negative compared to the baseline that means the warming from greenhouse forcing is actually >greater< than the total warming observed thus far." No, solar activity gradually increased from around 1800-1950, meaning the solar forcing would continue until at least then. On top of this, you get at least a 20 year time lag from soal effects, which has been shown by various research papers. There are also could cover changes which are immedaite and sloightly delayed. Aside from this, the reason I mentioned 1700 rsther than 1800 as pre-industrial T is because of the very reason I outlined, 'baseline' should not be chosen irrespective of the relative natural climate at the time, which just happened to be very cold-Littel Ice Age (LIA). The LIA bottomed earlier than 1800. Also, if oen takes into account natural factors, baseline should be ~1950, because it was naturally colder than average over the last 10 years during pre industrial period. You dont chose as a baseline something well below a running mean unless one has an agenda, the very fact that the European Climate Union (or whatever they call themselves) chose this date is largely ideological, it has nothing to do with optimal temperatures, effects of industrualisation, or a running mean upon which to use as a baseline against human activities. -
les at 19:37 PM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
947 - Glenn. Nice article link. As an aside, and of only the slightest relevance to this blog post, I note his statement "The planetary warming resulting from the greenhouse effect is consistent with the second law of thermodynamics because a planet is not a close system"... as noted above and to which 934 Ryan should have assumed I was alluding. Now, I suggest that as, as noted by the Economist, this is the 150th anniversary of some relevant and great physics (the unification of Electric and Magnetic fields) - we pay respect to this great moment by giving up on this assault on the nodal discipline of physics by attempting to prove/disprove another of it's great achievements (the laws of thermodynamics) through bean-counting and pseudo-modelling. -
Glenn Tamblyn at 19:19 PM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
Fred "If we make the simplifying assumption of an effective emission level in the atmosphere, this fixes the outgoing radiative temperature (at 255K as it happens). Anything which increased that temperature would increase outgoing radiation, and the atmosphere would cool down. Anything which reduced that temperature would have the opposite effect." You are missing several factors here Fred. As GH Gas levels increase, then the altitude at which emitted photons have a clear path out to Space increases. With altitude Temperature decreases so the emission temperature decreases so less radiated because the altitude of radiation increases. To use a simple analogy, its like a Cloud Bank. At the bottom of the 'cloud' a photon can 'see' the ground so can reach it. At the top of the 'cloud' a photon can 'see' Space and can reach it. One of the two effects of increased GHGas levels is to increase the upper altitude of the 'cloud'. So when a photon can reach Space it will be emitted from air that is colder. There is an excellent article on the radiative physics of the GH Effect by Prof Ray PierreHumbert in Physics Today here http://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf Have a look at his figure 3a, modelled and measured spctrum of radiation leaving the Earth. At around wavenumber 670, right in the highest absorption region for CO2, the amount of energy reaching space spikes up. Right in the middle of the highest absorption part of the CO2 band the emission temperature spikes back up! Why? Because the altitude at which the path to Space at that wavenumber is clear because of the high levels of absorption is SO high that it is above the altitude where lapse rate causes a temp drop with altitude and is high enough that atmospheric temps are climbing in the upper stratosphere. The models of radiative transfer are so accurate that they capture this altitude dependent temperature behaviour superbly. That graph is a thing of transcendent beauty. -
Glenn Tamblyn at 19:03 PM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
Wow. Comment 945 and counting! Not to intrude too much on everyones fun, but a few questions for Fred: "From the source, surface, to the sink, atmosphere, most of the energy transfer is via conduction, convection and evaporation." Source please! Radiation transfer from an object at temerature x is determined only by its temperature, not other parallel heat transfer mechanisms. "and the simplistic “back-radiation” theories of AGW are wrong. ". Oops. Small problem here Fred. Back Radiation has been observed for decades and has been increasing in the radiation frequencies of the GH gases. Damn pesky thing observations aren't they. A beautiful theory derailed by a mere observation. "That is why we must use the net transfer of energy to the atmosphere, e 873, from the surface, and not the back transfer (the negative term in Stefan Bolzmann) to calculate any possible GHG effects" Wrong Fred. Yes the net of the two flows will be what determines (is) the actual energy flux. However this is made up of several different phenomena that occur because of different mechanisms. Radiation flux from the surface is driven solely by surface temperature. Absorption by the atmosphere depends of the absorption properties the GH gases alone. Back Radiation depends on the temperature of the lower atmosphere at an altitude where the path back to the surface is not 'optically thick'. Several phenomena coming together to create the GH Effect, rather than the GH Effect being caused by the net of the heat flux. -
CBDunkerson at 19:00 PM on 4 April 2011Soot and global warming
Thingadonta: "Why is the benchmark for T 'pre-industrial levels'..." We should determine the total change in temperatures caused by industrial carbon dioxide emissions from some point other than when those emissions started? Which, by the way, was around 1800... not 1700. On the whole, 'earlier temperature changes were caused by the Sun' bit... temperature forcings from solar fluctuations are obviously temporary. When the solar output changes the forcing 'goes away'. Thus, if solar forcing were currently equal to the 1800 level then none of the current cumulative temperature change would be due to the Sun. Since solar forcing is actually negative compared to the baseline that means the warming from greenhouse forcing is actually >greater< than the total warming observed thus far.Moderator Response: [Dikran Marsupial] I suspect the 1700 startpoint is because of land use changes, which are as much industrial as agricultural (particularly iron smelting - for which coke was also used in the 18th century). -
Chris S at 18:51 PM on 4 April 2011Soot and global warming
Does anyone know why West Europe is not included in the figure? I think I've tracked down 'Bond et al. 2000' (poor referencing there) to "A technology-based global inventory of black and organic carbon emissions from combustion. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 109" but that does not break down the geographic units in the same way as the figure does (e.g. Europe is taken as a whole and North Americas is not split into the US & Canada as in the figure). -
lord_sidcup at 18:10 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Many congratulations John. Sounds like a very interesting read. -
RSVP at 17:56 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
A warmer Earth in any case will lead to less differences in climate, which means that there will be less, not more changes (once things have changed for better or for worse). -
shoyemore at 17:01 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Well done, John, and thanks for the discount offer! -
Philippe Chantreau at 16:13 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Congrats John, I'm sure you had no shortage of material to write about... -
thingadonta at 16:12 PM on 4 April 2011Soot and global warming
"....necessary to keep global temperatures from rising more than 2°C above preindustrial levels in the next 50 years" Why is the benchmark for T 'pre-industrial levels', when this time period (ie around 1700) was the amongst the coldest in the last 10,000 years?, ie the Little Ice Age? Shouldn't a T baseline be when c02 effects on T apparently became stronger?, such as from about 1950? Using 'pre industrial T' as a baseline might appeal to ideological conveniences (if one is anti-industry, anti-caplitalist, anti-fossil fuels, pro-socialist control, pro-alternative energy etc etc), but it is generally scientifitcally accepted that most of the warming from ~1700-1950 was caused by the sun, not by human industrial activities. Moreover, the T at 'pre industrial levels' could be argued to be not the most optimal for human and ecological health, (there is no real 'optimum' in any case); in terms of human health, optimum T is certainly a little warmer than Little Ice Age conditions, so neither such a temperature, nor climate period, should be used as a baseline for social objectives. -
OPatrick at 15:22 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Denial is a fact. What is causing it is a bit of a greay area, but maybe if I read some books on it I might have a better idea.... -
L.J. Ryan at 15:07 PM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
KR You said : However, you make the (false) assumption that this power level is a boundary condition on the surface. and T = [ P / ( ε * σ ) ]^0.25 K [ 240/(0.612 * 5.6704*10^-8 ]^0.25 - 273.15 = 15.2C from where does the P (240W/m^2) LW originate....the surface? This very flux is the sole source of LW...without the 240 W/m^2 of SW input the there will be no LW. So save changes to albedo or solar radiation, this IS a boundary condition for radiative energy. Said otherwise, because P input to the surface must equal P output at equilibrium...you can not get more LW flux out then SW flux in. Re-radiating Pout can not increase Pin. Delta T must be a function a non-radiative input. To claim effective LW emissivity of 0.612 is measured, is specious. How do measure “effective emissivity”? Emissivity with the qualifier effective, only aids in obfuscation. “Don't bother looking a the real mechanics of GHG physics, it can all be explained by effective emissivity" -
HumanityRules at 15:01 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Danno beat me to it! "This is most obvious in the denial industry ......" Do you contemplate the existence of a warmist industry????? Congrats as well. -
David Horton at 14:59 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Congratulations John. -
miekol at 14:45 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
Climate change is a fact. What is causing it is a bit of a grey area. -
danno at 13:58 PM on 4 April 2011Upcoming book: Climate Change Denial by Haydn Washington and John Cook
"Obviously you've created this site just so you can make money from selling books!!! CONSPIRACY!!!!" Congrats on the book John, I hope it's a success. -
scaddenp at 12:37 PM on 4 April 2011Muller Misinformation #1: confusing Mike's trick with hide the decline
TTTM has quite some faith in CA I see. I wonder if he has read this and checked the CA version against the originals. -
michael sweet at 12:35 PM on 4 April 2011It's cooling
Eric, We can agree that Harp seals appearing in small numbers in the Northern USA are not an indication of global cooling. -
pbjamm at 12:13 PM on 4 April 2011Muller Misinformation #1: confusing Mike's trick with hide the decline
TTTM@118 I recommend a website called Skeptical Science. it contains all the information you need to educate yourself on the subject of climate change. As for you accusation of censorship, complete nonsense. People here are allowed to present any evidence they like so long as it is on topic and not an accusation of fraud. Pick any thread you like as evidence of this. I recommend Meet the Denominator and The greenhouse effect and the 2nd law of thermodynamics to see just how accommodating the Moderation Policy is if followed. If you continually run afoul of it then the problem lies with you. -
Tom Curtis at 12:04 PM on 4 April 2011Arctic Ice March 2011
Ken Lambert @73, based on the third chart in Daniel Bailey's post @43, the average summer sea ice has retreated just over 2 degrees of latitude over the last 30 years. At the latitude of the limit of summer sea ice, that represents an additional 0.01 percent of the Earth's surface in which sunlight is falling on ocean rather than ice. Allowing for the exposure time of only about three months, and arctic summer insolation of around 500 w/m^2, and a change of albedo from 0.9 to 0.1, reasonable ball park figures, that represents a globally averaged forcing of 0.01 w/m^2 or just 1.25% of the equivalent change in greenhouse forcing over the same period. Complete loss of the ice cap would expose about 15 times as much ocean to direct sunlight, resulting in about 0.15 w/m^2 globally averaged, or about 8% of the change in CO2 forcing since the start of the industrial era. Obviously, globally averaged these effects are trivial. They do, however, represent a significant increase in regional forcing in the arctic. The regional increase from the melt since 1978 represents a 2.8% increase of forcings within the Arctic Circle; while the loss of the Ice Cap would represent a 43% increase in regional forcing. The small area within the arctic circle to which you allude means the small globally averaged effect of arctic ice melt has a correspondingly large regional effect, and is shown to be a significant factor in arctic amplification. What you are neglecting in terms of global effect is the consequence of early snow melts over northern latitude lands. A rough calculation shows that a one month earlier snow melt down to about 50 degrees latitude will result in a forcing comparable to the change in green house forcing over the last 30 years. These are just ball park figures. A more detailed analysis was made by Flanner et al who estimate that combined ice and snow effects result in a forcing of around 0.63 w/m^2 over the last 30 years, or nearly 80% of the greenhouse gas forcing over the same period. This discussion, if important, should probably continue on the thread discussing that paper. -
mspelto at 11:41 AM on 4 April 2011Soot and global warming
cbrock the point you miss is that unlike all other alpine glaciers where summer snowfall is modest and dust and particles accumulate on the surface and enhance melt, summer monsoon dominated glaciers have there main accumulation in the summer with nearly daily snowfall burying the soot so it cannot accumulate at the surface. It is not that complicated, but nor can we extrapolate the same process from all glaciers. If we go further north into Tibet monsoon accumulation is not nearly as important and soot can have a role. -
Bern at 10:33 AM on 4 April 2011The Climate Show Episode 10: David Suzuki and the sun
I know I've made the point previously, but the graphs showing warm nights / warm days, and winter/summer warming, suffer greatly from the use of a modern reference period. If you zero both graphs back at the beginning of the plotted period, you get a much better feel for what the difference between the trends really is. As they stand now, a casual observer might think "what's all the fuss about, they're fairly close together in recent years". Other than that - I saw all the graphics on the hot-topic website in the show notes, except that first screen cap from the video - it tells one of the most important parts of the story, might be a good idea to get Glenn to add it there, if he hasn't already. Another good rebuttal, though, and a good show in general - sad about the loss of the video, it really does make it more enjoyable to follow along. The interview with David Suzuki was good, though! -
Trueofvoice at 10:30 AM on 4 April 2011Muller Misinformation #1: confusing Mike's trick with hide the decline
"Mike’s Nature Trick was originally diagnosed by CA reader UC . . ." If "UC" has discovered compelling evidence of scientific fraud, I'm sure he or she has published the results in a peer-reviewed journal. Perhaps Tim would provide a link. -
muoncounter at 10:07 AM on 4 April 2011Arctic Ice March 2011
Albatross#79: "The obfuscation and dissembling continues" We're actually in the midst of an obfuscation cross-fire. On this thread, friend KL declares that solar input to the Arctic is limited by geometry; based on this irrefutable argument, the sun can't be a significant factor in either warming the Arctic Ocean or melting ice. Over on the soot thread, friend BP declares that soot, with its known capacity for absorbing energy, is responsible for melting Arctic ice. Which is it? Does the denier left-hand know what the denier right-hand is thinking? Or will this apparent conflict cause the deniersphere to implode? -
Albatross at 09:25 AM on 4 April 2011Arctic Ice March 2011
Johnd, The obfuscation and dissembling continues. As for you opining "The comment made by someone else earlier regarding considering the Arctic as an airconditioning system, this analogy can only be applied by acknowledging the fact that an airconditioner works by first removing hot air." Please show some respect, that "someone else" was in fact Dr. Meier from the NSIDC--someone who in all likelihood knows more about the Arctic and the earth's climate system than you or Mr. Lambert could ever hope or dream to know. You of course have now elected to try and dissemble that statement in an attempt to fabricate more faux debate and to detract from the inconvenient loss of Arctic sea ice. If you want to talk clouds then take that to another thread (I have suggested the Flanner thread @ 77)--but ignoring or belittling the important role of lowering of albedo in the Arctic arising from the reduction in the snow and sea ice cover associated with AGW is not helping your cause or credibility. This thread, again, is essentially about the upcoming Arctic se ice melt season. Do you have anything specific to say about that? Is the sea ice minimum this year going to be greater or smaller than 2010? Please substantiate your answer with evidence as logicman has done. -
Tom Curtis at 09:04 AM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
Fred Staples @939, first let me surprise everyone and congratulate you on being almost entirely correct. I notice that you indicate that: 1) The effective temperature of the outgoing radiation is 255 K; 2) That the effective altitude of radiation to space is about 5 km. From these it follows that 3) The (average) temperature of the atmosphere at about 5 km is about 255 K. You also note that: 4) The lapse rate (in the troposphere) is entirely determined by the local gravitational accelerationg, g, and the specific heat of the atmosphere; and that 5) The lapse rate is approximately 6 degrees per km (6.5 is more accurate). Therefore: 6) The average surface temperature is (5 * 6.5) + 255 = 288 K. That is the greenhouse effect in a nutshell. To see this, consider an example in which the atmosphere absorbs (and radiates) no IR radiation. In that case the effective altitude of radiation to space would be 0 km, and hence the surface temperature would be (0 * 6.5) + 255 = 255 K. It is not the lapse rate, therefore, which is responsible for the elevated surface temperatures, for it is (near) constant in both scenarios. Rather it is the presence of IR absorbing and radiating gases in the atmosphere. We can consider the case where the concentration of GHG in the atmosphere decreases. This will lower the effective altitude of radiation to space, and consequently lower the surface temperature (but not the effective temperature of radiation to space). Conversely, if we increase the concentration of GHG, that will raise the effective altitude of radiation to space, the surface temperature will rise, all else being equal. Hence, from principles you have just espoused, the green house effect follows by simple logic. Back radiation does come into the picture. Without the return of some energy from the atmosphere to the surface, thus reducing the net transfer of energy from surface to atmosphere, an increase of the Earth's surface temperature would be impossible. But that transfer (in keeping with the 2nd law of thermodynamics) can never exceed the energy transfer from the surface to the atmosphere (except locally and temporarily). If it rises to a level which would warm the surface by more than the amount indicated by the lapse rate and the effective altitude of radiation to space, the result is simply an increase of of convection and evapo/transpiration, thus nullifying the effect. -
Peter Hogarth at 09:02 AM on 4 April 2011Soot and global warming
Berényi Péter at 04:14 AM on 4 April, 2011 You need to read a fair slice of the recent peer reviewed literature to gain a better picture. Your proposed correlation of Arctic Ice reduction and soot from China does not correspond to the actual data from the Arctic. Overall amounts of Black Carbon has reduced in the Arctic in the past few decades. We discussed this here in 2010 where I gave several references from 2009 and 2010. Obviously more work has been done since and here are some further references from 2011. Matsui 2011 shows Russian Biomass Burning is still the most important source of Black Carbon in the snow in the North American Arctic, in agreement with previous studies, whilst Skeie 2011 shows using a model cross checked with an assembly of recent measurements, with emphasis on the Arctic, that Black Carbon reached a measured peak in the 1960s, falling off since, and interestingly (as mentioned before) also reached relatively high levels in the 1920s. -
johnd at 08:41 AM on 4 April 2011Arctic Ice March 2011
Ken Lambert at 00:38 AM, your quantifying of the various factors, area, insolation etc, have been effective counters to the emotional rhetoric that normally drives such debates. All the calculations you've done can be summed up by comparing the average situation as what is represented at the equinoxes, whereby the near polar regions have a nett energy deficit of about 200 w/m2, whilst the near equatorial regions have a nett energy surplus of about 200w/m2. The comment made by someone else earlier regarding considering the Arctic as an airconditioning system, this analogy can only be applied by acknowledging the fact that an airconditioner works by first removing hot air. In the planets "air conditioning" system this comes about by the flow of heat towards the equatorial regions. Because of the high cloud cover along the equator most heat is liberated from areas just north and south of the equator, where there are fewer clouds, and cloud cover is more variable. Thus irrespective of what angle the issue of Arctic ice is looked at, it is either clouds over the Arctic regions that control incoming solar radiation, or clouds along the near equatorial region that control the liberation of outgoing heat from the system that plays the major role. This is merely reflected by the polar regions, being controlled by a "knob" that is not in the polar regions. -
KR at 08:35 AM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
A tiny Excel exercise for L.J.Ryan and others: Create a new spreadsheet. Enter the values below: A1: 1.0 A2: A1-0.01 Copy A2, paste from A3 to A50. B1: =(240/(A1 * 5.6704*10^-8 ))^0.25- 273.15 Copy B1, paste from B2 to B50. Explanation: With 240 W/m^2 (fixed) radiated as power, and varying emissivities, what gray body temperature (in degrees C) is required to radiate that 240 W/m^2, using the Stefan-Boltzmann relationship? An emissivity of 1.0 represents a perfect black-body, 0.98 represents the Earth's surface with no GHE, and an emissivity of 0.61 is quite interesting. -
cbrock at 07:44 AM on 4 April 2011Soot and global warming
mspelto- I think the primary mechanism of depositing soot onto the Himalayan glaciers is snowfall, known as "wet deposition". This is in contrast to "dry deposition", which is particles impacting the surface and sticking. Wet deposition is a very efficient process, as ice crystals may form on soot particles, and falling snow can also capture soot on the way down. Thus the main "accumulation zones" are probably also where most of the soot is found. During a thaw cycle, the top layer of snow melts and the water runs down into the snowpack, leaving the soot behind. The accumulated result of many such cycles can be an increased concentration of soot at the top of the snowpack--it can get concentrated there. So I wouldn't expect the main effect of the soot to be limited to the terminus of the glacier. The important thing about soot in snow is that it doesn't directly absorb a lot of sunlight and melt the whole snow surface. Instead, it changes the local snow grain in which it is embedded, causing the grain to partially melt and form a larger, rounder grain when it refreezes. These larger grains absorb more energy than the fluffy snow, and they also allow sunlight to penetrate more deeply into the snowpack. It is these feedbacks of snow grain morphology that cause the bulk of the warming impact of the soot. Complicated stuff, and not very well understood. Soot is only one of many causes of snow metamorphosis. BP- Concentrations of soot in the Arctic atmosphere have declined quite a bit since the breakup of the USSR, although they seem to have leveled off and may be slightly increasing now due to Chinese emissions. Most soot in the Arctic snow seems to come from forest and agricultural burning, anyway. It is a big stretch to attribute the dramatic Arctic sea-ice decline in recent years to Chinese soot emissions--it is probably a minor player given the big changes in air and ocean temperature that have occurred in the last 40 years. It's also interesting to see you pointing to one of Hansen's GISS models to support one of your points. I presume then that you accept the general findings from that group's other climate simulations? -
Stu at 07:40 AM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
Fred Is the atmosphere being actively compressed by gravity? Is it more dense here at the surface than it was yesterday? The answer, of course, is no. Therefore no work is being done. Indeed, we can experience this in everyday life. Pump up your bicyle tyres quickly to 60psi. You've done work on them and they've gotten hotter due to compression. Leave the bike alone for a bit and come back later. The tyres are now at the ambient temperature. How did that happen? They're still at 60psi (the force analagous to gravity here is the tension of the inner tube) but the fact that they're at significantly higher pressure than their surroundings doesn't make them hotter*. Gravity, like the tension of an inner tube, is no substitute for thermodynamics. *PS I had one 'sceptic' argue back that when you cycle around the tires get hot. Apparently not familiar with friction! -
muoncounter at 04:48 AM on 4 April 2011Soot and global warming
kdkd#17: "Grab a range of different data sets ... " Here's one. What a correlation! By BP's logic, "reduced summer ice cover in the Arctic is clearly caused by ... " atmospheric CO2.
Time series of annual arctic sea-ice extent and atmospheric concentrations of CO2 for 1900-2007. Sea-ice observations are from the Walsh and Chapman dataset 1900-78, merged with sea-ice concentration retrieved from satellite passive-microwave data (1979-2007) using the NORSEX algorithm, with ice extent updated to 2007. The CO2 scale is inverted.
-- from The Nansen Group, Responding to Climate Change 2010
-
Berényi Péter at 04:14 AM on 4 April 2011Soot and global warming
#17 kdkd at 21:36 PM on 3 April, 2011 I'm going to go out on a limb and conclude that there's a 95% chance or greater that your causal explanation is only a very very small part of the story. While on that limb, please read the peer reviewed literature, then come down safely. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110, D04204, 2005 doi:10.1029/2004JD005296 Distant origins of Arctic black carbon: A Goddard Institute for Space Studies ModelE experiment Dorothy Koch and James Hansen "The (former) Soviet Union (FSU) was implicated as a major source of Arctic haze in many studies. Novakov et al. [2003] found that black carbon emissions from the FSU in the late 1990s was less than 1/4 their peak levels of 1980. European emissions are also about 1/3 their levels in the 1970s. However China and India have doubled their BC emissions since the late 1970s. Thus BC emissions are more heavily weighted toward south Asia than they were in the 1970s and 1980s, when many of the Arctic haze studies took place." -
Philippe Chantreau at 04:04 AM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
Fred Staples, "Please don’t expect anything conclusive." Fear not. -
Philippe Chantreau at 03:54 AM on 4 April 20112nd law of thermodynamics contradicts greenhouse theory
LJR, your shouting is not impressive. As for this question " have confidence radiative forcing will work?" Answer is yes. Muoncounter above summarizes well some of your confusion. You should look again at Pr Jin-Yi Yu's lecture. This statement:"So if I have got it wrong so does he" does not follow from logic at all.
Prev 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 Next
