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Comments 24051 to 24100:

24051. Glenn Tamblyn at 15:40 PM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike

       Lets consider a piston and cylinder with some air inside it. The air and the piston/cylinder are at a constant temperature.

       Now I push the piston in, reducing the volume to half. If I do it quickly enough so there is no time for heat transfer between the air and the cylinder/piston then the process is essentially adiabatic.

       So what should happen. No heat transfer, no mass transfer, so nRT is constant. So V is halved and P is doubled, and T doen't change surely.

       But that isn't what happens. The work needed to compress the piston has to be added in. So the total internal energy of the air increases, T increases so nRT goes up. V is halved, and P increases by more than double! And we now notice that T has increased.

       This often confuses people. They see the temperature increase and assume that the act of being more compressed is why T is higher.

       It isn't.

       T goes up because energy has been added due to the work needed to compress the piston.

       There is a reverse case. If we allow the volume to double, P would be cut in half. Now if this expansion had to do work, then internal energy would be expended to do it, P would drop by more than half, and temperature would fall.

       However, it is possible to contrive a situation where we can achieve this volume increase essentially without any work being done.

       The setup looks like this.
       
       A chamber is divided in two by a sliding door. On one side there is air at pressure P and temperature T. On the other side there is a vacuum. Everything is in thermal equilibrium, air and chambers.

       Then we very rapidly slide the door away and allow the air to expand into the other chamber. No work needed to be done on the air to allow it to expand.

       What happens?

       Volume doubles, n is unchanged, P is cut in half, and T remains unchanged!

       This is called Joule Expansion and was first demonstrated by James Prescott Joule in 1845 although others had known about it before hand.

       There is actually a cooling of the gas that occurs but this is due to a secondary process, not related to the simple picture of PV = nRT we are discussing here. This secondary process is discussed at the end of the Joule Expansion article and also a related one on the Joule-Thompson Effect which is essentially about throttling processes.

       Again the cooling seen in a real gas due to the JT Effect isn't intuitive so people can be misled and think that the act of being less compressed is the cause of the cooling. It isn't.

24052. Glenn Tamblyn at 15:35 PM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis
       
       "Heat stays the same but T goes up".
       
       This statement is a nonsense. If heat in the gas (actually it is more accurate to talk about the 'internal energy' of the gas) doesn't change, temperature cannot change. Because temperature is the direct measurement of some of that internal energy.

       The following article on Wiki has a good discussion of the Thermodynamic (or Kinetic) definition of Temperature.
       
       The eqution relating the internal energy of a gas, actually the kinetic energy of translation of the molecules in the gas, is as follows:

       E = 3/2 k_BT_k

       where:

       E is the mean kinetic energy of a molecule in the gas, in Joules

       k_B = 1.3806504(24)×10−23 J/K is the Boltzmann constant

       T_k is the kinetic temperature in kelvins (K)

       Temperature is directly proportional to the internal energy of the molecules.
       
       Temperature is the measurement of their internal energy.
       
       So saying heat doesn't change but temperature does is nonsensical. Temperature is the measurement of 'heat'.
       
       So if the amount of heat doesn't change, temperature cannot change, by definition.
       If the amount of heat does change, temperature must change, by definition.

       Next, this comment.
       
       "The equation states that product of pressure and volume is a constant for a given mass of confined gas as long as the temperature is constant.

       So, as long as T is constant and the gas is confined (V is constant), then, yeah.

       For the rest of us, PV = nRT"
       
       Mike if the temperature is constant (T is unchanged), then the internal energy hasn't changed. If the mass is constant (n is unchanged) then nRT is constant. So PV is constant, whether confined or not.
       
       What can happen when gas parcels are unconfined is that internal energy might change - T changes. Or mass might change - n changes. Without one of those changes PV is still constant.
       
       But when we are talking about bulk parcels of air in the atmosphere, there is very little mixing and it occurs relatively slowly. So any change in n is minimal. And similarly, without mixing into a parcel, convection cannot transfer much heat quickly into a parcel. Coinduction is a very very weak heat transfer mechanism in gases. And in the Troposphere where the air is 'optically thick', radiation is a poor energy transferer. So the assumption of Adiabatic processes is actually quite good. Heat transfer into a parcel is minimal.
       
       So vertically moving parcels of air essentially can't change n, essentially can't change internal energy through heat transfer since things are adiabatic. So nRT is constant so PV is constant.

       However, as they move to different altitudes they need to equalise pressure with the surrounding air. And this happens fairly quickly.
       
       So P must change to equilibrate with the surroundings. OK, thats fine, V changes to match so that PV remains constant. But there is a problem. And your first item in your list highlights this:
       
       "1. Parcel moves down and compresses".
       
       The parcel can't compress itself! It has to be compressed by something outside it.

       And that something is the surrounding air. Pressure equalisation means that the surrounding air compresses the parcel. PV would remain constant because everything is Adiabatic (see here for a definition of an Adiabatic Process) except that it is not an Isenthalpic Process.
       
       There is energy transfer into the parcel!
       
       This is not as a Heat Transfer - that satisfies the Adiabatic condition - but is an energy transfer into the parcel as work done on it. (See the definition of Work here)

       The surrounding air has to perform mechanical work on the parcel to compress it. And this adds energy to the parcel. This then means the internal energy of the parcel has increased. T has increased! So PV can increase.
       
       This is why descending air masses warm up. They are compressed by the surrounding air and this adds energy to them, increasing their temperature.
       
       And the reverse applies to ascending air masses. Pressure equalisation means they have to do work on the surrounding air to expand and match pressures. Sp energy needs to be expended by the parcel to do that work. Since the process is Adiabatic, the only energy source available to supply the energy for this work is the parcels internal energy. So the parcels internal energy drops - it cools.

24053. pjcarson2015 at 15:24 PM on 19 June 2016
       Climate scientists have warned us of coral bleaching for years. It's here
       

       [Firstly to John Abraham; I should have said this earlier - I wish you well with your adoption.]

       To Moderator Rob P.

       The title of this article is “Climate scientists have warned us of coral bleaching for years. It’s here”

       My #4, to which you seem to object, simply states

       1. That it has been observed since at least 1965. (By Ron & Valerie Taylor of whom you should be well aware as you say you scuba.

       2. I observe where such previous and current coral bleaching has occurred.

       In other words, you don’t seem to notice I agree with you that bleaching occurs. I also agree that it will happen in future – but that it has also been observed to occur further back in time than suggested by the article.

       Is it necessary for “dude” “spam” and “cockamanie”?

       Moderator Response:

       [Rob P] - Heat-related coral bleaching on the GBR, IIRC, goes back at least as far as the 1920's (anecdotally at least). But those were small localized events, and nothing like the large-scale bleaching events occurring today which can be many thousands of square kilometers in extent.

       We cannot yet be certain, but it is unlikely that mass coral bleaching has, until very recently, occurred for thousands of years. The last major event believed to about 4000 years ago in the eastern Pacific due to, the authors claim, a more extreme ENSO cycle - see Toth et al (2012). And the last Interglacial, the Eemian, saw a global retreat of coral reefs away from the equator too (Kiessling et al [2012]).

       So past and present 'observations' in the peer-reviewed scientific literature paint a consistent picture: when summer sea surface temperatures become too hot, coral bleach and often die. With a warming ocean we expect the frequency and intensity of bleaching to increase - as we are witnessing. In the not-too-distant future the tropical oceans will become too warm and coral reefs will be destroyed - as has happened in the past many times when things got too hot for them.

       Of course this doesn't have to be, but humans, collectively, have shown no intention of curbing industrial carbon emissions and so the demise of coral reefs seems inevitable.

24054. Trevor_S at 14:25 PM on 19 June 2016
       Timeline: How BECCS became climate change’s ‘saviour’ technology
       

       I think it was either Kevin Anderson or Jason Box who pointed out we'd need arabale land one to two times the size of India to make this work.  Not sure where we will find that, then clear it all... Seems like it's nothing more than justification to put off until tomorrow (making the problem worse by chewing into the ever decreasing emisisons budget) what we need to do today.  Lower emissions... significantly.

24055. Mike Hillis at 13:05 PM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       @149

       PV = nRT is given here:

       https://en.wikipedia.org/wiki/Ideal_gas_law

24056. Mike Hillis at 12:48 PM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       @ 149

       From your link to Wikipedia:

       "P V = k where P is the pressure of the gas, V is the volume of the gas, and k is a constant.

       The equation states that product of pressure and volume is a constant for a given mass of confined gas as long as the temperature is constant."

       So, as long as T is constant and the gas is confined (V is constant), then, yeah.

       For the rest of us, PV = nRT

       Moderator Response:

       [RH] Edited out post @150 rather than delete (per request) in order to preserve the numbered comment reference used in this thread.

24057. Mike Hillis at 12:45 PM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       @ 149

       From your link to Wikipedia:

       
       "P V = k where P is the pressure of the gas, V is the volume of the gas, and k is a constant.

       The equation states that product of pressure and volume is a constant for a given mass of confined gas as long as the temperature is constant.

       So, as long as T is constant and the gas is confined (V is constant), then, yeah.

       
       For the rest of us, PV = nRT

        

       Moderator Response:

       [RH] Corrected comment @151.

24058. pjcarson2015 at 11:18 AM on 19 June 2016
       Climate scientists have warned us of coral bleaching for years. It's here
       

       To repeat,

       You replied as Moderator. Which facts and observations in my post are an issue?

       Moderator Response:

       [Rob P] This blog is based upon the findings of the peer-reviewed scientific literature and data gathered by reputable scientific organizations. Whilst it provides rebuttals to many of the common climate myths, we don't debunk every single myth some dude on the internet just came up with. If you don't accept the findings of decades of scientifc research, that's up to you, however it's not encumbent on SkS to debunk every cockamamie idea that comes along. Nor do we provide a service for spam to sites to promote the absurd. So no more links unless they are to legitimate sources (see the Comments Policy).
       
       Casual readers, however, might be interested to see the anomalous sea surface temperatures on the Northern GBR in 2016 that caused so much coral mortality. Note the extraordinary anomalous bleaching stress (thick black line) in the bottom left-hand side of the image, as compared to the three previous (non-bleaching) years.

24059. michael sweet at 09:57 AM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hills,

       Any  chemistry text will say that Boyles law is PV=Constant (Wikipedia) or page 297 Corwin Introductory Chemistry (textbook for the local Community College). Your claim that PV can somehow increase on their own without the addition of energy from an outside source is simply false. You must provide a scientific reference (blog science is not good enough) to support your absurd claim that PV can increase on their own.  Since PV = constant, the only way to change the temperature is to add energy.  Read Glen's comment for the correct explaination of how the work done by the atmosphere changes the heat content of the parcel.  (Heat and work are both forms of energy so work done = heat increase).

       The thread at WUWT where Goddard claimed that CO2 would fall as snow at the south pole was deleted after even Watts realized that it made him look stupid to have such junk on his site.  Goddard was then banned from WUWT for being so unscientific.  (Imagine what it takes to get banned from WUWT for being unscientific!!)

       It is clear that this thread is a waste of time and others have been doing a good job countering your blog "science".  I will no longer comment.

24060. Digby Scorgie at 09:56 AM on 19 June 2016
       Timeline: How BECCS became climate change’s ‘saviour’ technology
       

       Chriskoz @2

       Andy Skuce concludes as follows:

       "At best, CCS and BECCS would be able to provide a stopgap to a more sustainable future."

24061. Mike Hillis at 09:21 AM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Michael sweet @144

       Keep in mind that Steve Goddard thinks CO2 can fall as snow at the south pole and be sequestered there forever.

       That is an error. This is what Steve Goddard actually says:

       https://stevengoddard.wordpress.com/2012/06/12/antarctic-temperature-drops-below-the-freezing-point-of-co2/#comments

24062. Mike Hillis at 09:01 AM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       @ 145

       Are you saying that adiabatic processes can’t change the total heat content in the atmosphere of Venus (or any other planet) and that the high temperature near the surface is only caused by a redistribution of heat?

       Yup. Only the sun can change the total heat content of the atmosphere.

24063. Mike Hillis at 08:51 AM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       @144

       Heat and temperature are directly proportional in a given parcel of air.

       Yes, as long as you don't change the pressure or volume, which can change the T without changing heat content. High school chemistry teachers should know this.

       pV = nRT says if you increase PV, the T goes up even though you have not added heat. The work done to change the parcel's elevation and raise or lower the PV is uneven solar heating of the atmosphere.

       I will not state my argument again because repeating oneself is against comments policy.

24064. RedBaron at 08:33 AM on 19 June 2016
       Human CO2 is a tiny % of CO2 emissions
       

       William, 

        Most likely the soil causing it. That's good news and bad news. The good news is that it is reversable. The bad news is that we are fairly unlikely to do so. As although it really is easily reversable, there is a huge institutional resistance to even trying, and actually the trends are to accelorate it rather than mitigate it.

24065. RedBaron at 08:17 AM on 19 June 2016
       Timeline: How BECCS became climate change’s ‘saviour’ technology
       

       Getting closer, not quite there yet. Next step is forget putting CO2 in geological formations. The carbon needs to be in the soils. But it is doable.

       Technical Brief: The Liquid Carbon Pathway

        

       Now the Liquid pathway alone gets you between 5-20 Gt CO2/ha/year. (the 32 Gt CO2 mentioned in the source is a bit of an outlier. Yes people are getting those results and even better in some cases, but 5-20 is more common) That alone if used on enough agricultural land would sequester long term in the soil between 62% to 250% world wide yearly fossil fuel emissions. But since biochar is carbon too, and in a stable form, there is even more. Since making biochar can produce energy too...... This would be the next step...if things like solar and nuclear couldn't keep up.

24066. HK at 08:07 AM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis @143:
       "Adiabatic changes in temperature don't add or lose total heat...."

       Are you saying that adiabatic processes can’t change the total heat content in the atmosphere of Venus (or any other planet) and that the high temperature near the surface is only caused by a redistribution of heat?

       (A short yes or no is sufficient)

24067. michael sweet at 07:31 AM on 19 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hills,

       Your arguments started out interesting but have gone way down.  I suggest you review basic chemistry and physics before you post again.  You need to stop reading from the blog source you are getting your information from.  Keep in mind that Steve Goddard thinks CO2 can fall as snow at the south pole and be sequestered there forever.  If you want to convince readers here you have to get the High School Chemistry (which I teach) correct.

       Heat and temperature are directly proportional in a given parcel of air.  If the temperature increases as the parcel as it sinks, the heat increases. The heat has to come from somewhere.  It cannot come from the parcel itself as that would violate the first law of thermodynamics.  Glenn's explaination that the energy comes from the work the surroundings does (or that a rising parcel does on the surroundings) is the correct one.    Read his post again if you are unclear about where the heat comes from.

       Venus is the classic example of a runaway greenhouse effect.  Arguing that Venus is not a greenhouse planet will not get you any converts at a scientific site.  

       Can you find a scientific reference (paper or textbook) that caims Venus is not a greenhouse (I note that you have not referred to any scientific papers in your arguments, only blog science)?  If you cannot perhaps you should consider that it is because Venus really is a greenhouse and your blog science is incorrect.

       Your claim that heat can be transferred from the cold upper atmosphere to the warmer lower atmosphere is also a violation of the laws of thermodynamics.

       I will try not to comment again since dogpiling is against the comments policy.

24068. Ger at 01:32 AM on 19 June 2016
       Timeline: How BECCS became climate change’s ‘saviour’ technology
       

       chriskoz @2: most CO2 plants do take in is from rotting materials in the ground/on the ground. Most agricultural residues represent for the larger part the fast amount needed: for England alone there is a 14 million tons a year, relative easy, to obtain mass representing a 140 million GJ in primairy energy. And most agricultural is still for food (arable lands for food are still available). 

       Hungry world is struggeling not that they don't have arable lands but that modern high productive crops do need far more water and fertilizers per ha for which the farmers lack investments. Furthermore they lack the means to create the risk mitigation measurements for a planet heating up, especially in regions where it is already hot and with less water. 

       Greenhouses in hot & dry areas near sea's can turn a dessert in a food production area. Any CO2 can be used to enhance growth of plants in hydrocultures. You don't need much more, except for a ship load of investments. 

24069. chriskoz at 00:45 AM on 19 June 2016
       Timeline: How BECCS became climate change’s ‘saviour’ technology
       

       Digby@1,

       We made a little bit of progress with our ideas about CO2 capture. I think CCS (old term) and BECCS are diferent concepts. CCS, also refered to as "clean coal", was an excuse by mining moguls to promote burming more FF, becaue we can, in theory, burn it "clean" i.e. do not emit CO2 into atmosphere. The idea is best debunked and ridiculed by aSkS post Sequestering carbon nature's way: in coal beds, esp. its graphic.

       Now, BECCS is something totally different: shows that it's possible to net remove CO2 from atmosphere - employing fast growing biomas - burn the biomass and store captured CO2. And the beauty of the concept is: you obtain energy from the process, unlike in "clean coal" where you assume to input energy into the process, presumably coming from the coal itself, reducing its thermal efficiency, so making it even more "dirty" than it was in the first place. However, I'm still skeptical how realistic is the deployment of  BECCS on the scale needed. The amount of biomass cycling must be enormous, because the its energy density is smaller than that of quality coal (we sgopped burning wood to charcoal in favour of mining coal in 19th century precisely for that reason), and if there is enough land to grow said biomass, then an efficient way to gather it and bring to BECCS facilities and enough power is left to compress and store CO2 underground. That requires big infrastructure. Just raising such infrastructure requires lots of money and energy. How many years does it need to operate to break even on CO2 emissions?

       The existing PV technology, although it's not negative emmsions, offsets its production emissions after ca. 1 year of its life. I'm not so sure about BECCS. In practice, BECCS may turn out to be utopia, because simply there is no enough land to start with B, while hungry world is struggling to turn every arable land for food production. Needless to say cobtinue with ECCS...

24070. Mike Hillis at 23:49 PM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Adiabatic changes in temperature don't add or lose total heat, because when the volume goes down the T goes up so total heat in parcel remains the same. Just the temperature changes. The amount of heat in the parcel of air remains the same, all that changes in the temperature and volume according to

       PV = nRT

       So if PV goes up, T goes up, but when the temperature goes up the total heat contained stays the same because the volume goes down. That's how it works. Heat stays the same and volume goes down, the temperature goes up. Follow with me closely:

       1. Parcel moves down and compresses

       2. Heat stays the same but T goes up

       3. Parcel equilibiates T with lower elevation surrounding air by adding heat to it

       4. Parcel moves up and expands

       5. Heat in parcel stays the same but T goes down

       6. Surrounding air adds heat to parcel to equilibriate T

       All heat added to parcel from surrounding air is at higher elevation, all heat lost from parcel is at lower, so heat is moved from high elevation towards low until it reaches the surface.

       This is for ALL vertical motion of air, whether is be large air masses, small parcels, or brownian motion, and at any and all elevations.

       And since horizontal motion of air is many times faster than vertical, the air parcels are quickly moving around the planet, which is why the poles on Venus are the same temperature as the equator, and the night side is at warm as the daylit side.

       Glenn @ 142 says

       this energy has to come from somewhere. And the only energy source available is the internal energy of the rising air parcel

       No, the source of energy is the Sun

       Moderator Response:

       [RH] Please avoid using all caps, per comments policy. 

24071. Glenn Tamblyn at 18:05 PM on 18 June 2016
       Human CO2 is a tiny % of CO2 emissions
       

       william
       
       I would think its most likely an effect of El Nino. Even if carbon sinks start to shut down, they wont be that precipitous.

24072. Tom Curtis at 17:15 PM on 18 June 2016
       Climate scientists have warned us of coral bleaching for years. It's here
       

       pjcarson2015 @4:

       "Incidentally, in my previous post I referred to chapters in my site, “Planet Earth Climate Topics” at ..."

       Yes.  As always you spammed an add for your site which contains, as usual, a great paucity of facts, a significant number of inventions, and a curious refusal to correct errors.  On this topic it contains no information in addition to the text of your post @3 and therefore is not an independent source of evidence, or indeed a source of evidence at all.

       As to your post @3, yes coral recovers from bleaching.  Recovery, however, takes time.  If there are repeated impacts during that time, recovery will be slow, or not occur at all.  As can be seen below, events causing damage to reefs have accellerated in recent times, and for the Great Barrier Reef, that has lead to a long term decline in coral cover (second figure):

       

       (Source)

       

       (Source)

       As you can see, that decline has been precipitous for the southern most (and most disturbed) portion of the reef.

       What is worse, as can be seen from calcification studies, that decline comes at the tail of a reversal of a century long increase in reef health in the mid 20th century (figure d):

       

       Granted that bleaching events currently account for only 10% of reef damage.  However, the GMST during the last bleaching event was less than the 2 C limitation on global warming aimed at by international agreements.  If global warming is restricted that limit (currently very unlikely on present policies), that means we will be getting multiple equivalent bleaching events every decade within fifty years.  That is far to rapid a pace to recover from, so that bleaching events alone would be sufficient to destroy most of the Great Barrier Reef.

24073. Digby Scorgie at 15:14 PM on 18 June 2016
       Timeline: How BECCS became climate change’s ‘saviour’ technology
       

       Professor Kevin Anderson has some scathing things to say about BECCS.  I'm also reminded of the article by Andy Skuce on 13 January 2016: "The quest for CCS".  At best it is just a stopgap measure.

24074. Glenn Tamblyn at 12:52 PM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis at @135

       "as I already said, as the air moves down it adds heat to the air it decends to. As it ascends, it takes heat from the air it ascends to. In BOTH directions, it transfers heat from higher to lower"
       
       Actually Mike, you have this back-to-front. As air moves down heat is added to it from the surrouning air. And as air rises heat is removed from it by the surrounding air. You are leaving important aspects of the problem out - potential energy changes and work.
       
       A parcel of air that is rising in the atmosphere is being lifted by some force, air pressure, buoyancy, whatever. So work is being done on it. However, because it is rising, the air parcel is also gaining potential energy. When we work out the math, the work done on the parcel exactly matchs the potential energy gain. So conservation of energy says no net change in the energy of the parcel. At the scale of air movements in the atmosphere there is little mixing between parcels, so no scope for significant heat transfer between them And in a dense atmosphere radiative transfer is very poor. So the movement of the air parcel is essentially adiabatic - no net heat flow in or out.
       
       So the parcel would rise to a higher altitude essentially unchanged same volume, same pressure, same temperature. However, pressure can't stay the same. At higher altitude air pressure is lower, and air pressure must equalise. So the parcel has to expand to equalise pressure with the surrounding air. But in order to expand the parcel has to push the other parcels around it aside to make room for its expansion. It has to do work on them. So there is an energy transfer from the rising parcel to the surrounding air as work. But conservation of energy says this energy has to come from somewhere. And the only energy source available is the internal energy of the rising air parcel. In order to supply the energy needed to push other air parcels aside, the rising parcel loses internal energy. Its temperature drops as it transfers energy to its surroundings.
       
       For descending air parcel it is the reverse. as it descends, pressure equalisation means that the surrounding air compresses the parcel, doing work on it, adding to its total energy which since the situation is adiabatic can only manifest as an increase in the temperature of the parcel.
       
       Rising air heats its surroundings and is thus cooled by them, falling air is heated by its surroundings and cools them.

24075. pjcarson2015 at 11:14 AM on 18 June 2016
       Climate scientists have warned us of coral bleaching for years. It's here
       

       You replied as Moderator. Which facts and observations in my post are an issue?

       [Incidentally, in my previous post I referred to chapters in my site, “Planet Earth Climate Topics” at pjcarson2015.wordpress.com]

24076. HK at 08:13 AM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis @136:
       My point is that Venera’s measurements clearly show that the IR radiation escaping from Venus can’t come from near its surface, but from much colder and therefore much less radiating layers in its upper atmosphere.
       If the high temperature was caused by any physical process that adds heat rather than slows down the heat loss to space (as the GHE does), the spectrum of the outgoing IR from Venus would look completely different. Using the wavenumber scale (as done in the graph), the peak radiation would be more than 20 times higher (thus the need to enlarge the y-axis!), and shifted to about 1440 cm^-1.

       BTW, the 15 µm band (667 cm^-1) is important for the Venusian greenhouse effect exactly because almost all the heat loss to space happens from the very cold, upper layers of the atmosphere and not from near the surface.

24077. william5331 at 07:40 AM on 18 June 2016
       Development banks threaten to unleash an infrastructure tsunami on the environment
       

       To understand what is happening you can read the updated version of Confessions of An Economic Hit Man by John Perkins and The creature from Jekyll Island by Edward Griffin.  The Secret History of the United States by Stone is also very revealing.  In a sentence, The world Bank has little to do with the world except  that it is a mechanism for America to exploit the world and increase its hegemony over it.  Huge loans are made to countries that can't possibly repay them and when they default, America gets her pound (more like a ton) of flesh.  Countries are forced to privatize their services which American corporations snap up.  Favorable votes in the UN are also sometimes the currency of repayment.  Right at the base of it is that banks hate when countries, businesses and individuals finance their advancement from their own profits.  They want to give loans because that is how they make their money.  They will put pressure on wherever they can to achieve this aim.  Griffins book, in a very readable and clear fashion, shows what a scam the Federal Reserve (and other reserve banks) are.

24078. scaddenp at 07:39 AM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis, just to be clear here - do you believe that if you put venus atmosphere into an ordinary GCM using only known physics, then the temperature and isothermal structure of surface is not reproduced?

       ie it is "unexplained" by known physics?

24079. Tom Curtis at 07:29 AM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis @135, you also said:

       "Tidal forces and the friction it gererates will eventually stop the rotation of Venus, but until then, the motion, all motion, within its atmosphere, will continue to generate heat katabatically."

       What you should have said is that, "until then, the motion, all motion, within its atmosphere, will continue to generate and remove heat in equal proportions katabatically" unless you take the delussory view that all atmospheric motion on Venus is downward.

       What this mechanism does, and the only thing it does, is to generate the lapse rate in the troposphere.  That is, it establishes a linear relationship between the temperature difference and distance along the vertical axis within the troposphere.  It cannot, by itself, determine the exact value of the temperature at any point in the troposphere.

24080. william5331 at 07:22 AM on 18 June 2016
       Human CO2 is a tiny % of CO2 emissions
       

       According to some reports, we didn't emit more Carbon dioxide in 2015 than in 2014.  Perhaps our output has leveled off or may even decrease as more and more energy saving, renewable generation and a flat economy take hold.  I find this frightening.  If you look at the Mana Loa Carbon dioxide site for April, Carbon dioxide went up 4.16ppm despite this lack of increased carbon output.  All things being equal one would have expected, possibly, a 2.5ppm increase.  Apparently all things are not equal.  Is this some effect of the strong El Nino we experienced or have one or more carbon sinks started to shut down. If this continues to the end of 2016 and into 2017, we just may be in a spot of bother.  All things being equal, we would expect the line to revert to the long term increase and should see some quite small increases on into 2017. 

24081. Mike Hillis at 07:20 AM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       And just to be clear on Tom Curtis @ 133:

       "Given that, the idea that after 4.6 billion years there continues to be a net settling of the atmosphere that is needed to generate excess heat is absurd."

       We are not talking about generating heat. We are talking about transferring heat, in this case, transferring it from every layer of the atmosphere to the surface. The heat comes from the sun, absorbed by the atmosphere so that only 10% of the light that falls on Venus ever reaches the surface. The bulk of the heat is transferred to the surface by the gravity heat pump mechanism I described.

24082. Mike Hillis at 06:11 AM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       2 and 3 and 4.5 I meant

24083. Mike Hillis at 06:10 AM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       HK @ 134 Venus is much hotter than Earth and radiates at shorter wavelengths, so we can pay more attention to the 2 and 3 4.5 micron bands and less to the 15 mike band. Take another look at the graph.

24084. Mike Hillis at 06:07 AM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Tom @ 133 as I already said, as the air moves down it adds heat to the air it decends to. As it ascends, it takes heat from the air it ascends to. In BOTH directions, it transfers heat from higher to lower. Read again what I said.

24085. RedBaron at 03:27 AM on 18 June 2016
       Study: Most fossil fuels unburnable without carbon capture
       

       There is somewhere between 35 and 40 Gt CO2 emissions yearly worldwide. To draw down CO2, (decrease the stocks in the atmosphere) we must adjust the flows into and out of the atmosphere until we achieve a net negative flux.

       There are approximately 5 Giga Hectares of land in the world currently being used to produce food for human populations. (only ~1%+/- is in permaculture or other ecofriendly management) Agriculture has been proven to be capable of being an emissions source or a sequestration sink depending on the methods used. Currently right now agriculture is an emissions source. (99% being managed by either industrial or traditional subsistence methods)

       Working backwards, for agriculture to offset emissions and achieve a net negative flux for atmospheric CO2 worldwide each hectare of agricultural land producing food would need to sequester long term into the soil over approximately 8t CO2/year. 8t CO2/ha/year X 5 Gha = 40Gt CO2/year

       Can we do that? According to Dr. Christine Jones we certainly can.

       Liquid carbon pathway unrecognised

       The case studies mentioned by Dr. Christine Jones above show a range in results between 5 & 20 tonnes CO2e/ha/year increases in soil carbon by using permaculture pasture cropping methods. (direct seeding grain crops into perennial pasture and cell or pulse rotational grazing integrated together)

       Why pasture cropping is such a big deal

       In no way is this example alone or even out of the ordinary. There are multiple case studies on people getting similar results with other carbon farming practises.

       So quite likely if done on enough land we could offset between 62% and 250% of all emissions worldwide. That is VERY conservative BTW, because it doesn't even include the oceans or the forests which already are removing about 1/2 of the ~35 to 40 Gt CO2 emissions yearly worldwide.

       Makes me wonder why CCS technology is even being discussed? We know soil degradation is a very serious problem. 

       Only 60 Years of Farming Left If Soil Degradation Continues

       We also know renerating degraded soils includes restoring Soil Organic Carbon (SOC)

       Soil regeneration

       So no, CCS technologies is a fail from the start whether it works or not. We actually need that carbon... But we need it in the soils worldwide, not some CCS technology. It's a very bad idea and pulling resources away from where it needs to be...implementing the infrastructure required to change agricultural models of production to regenerative systems.

24086. HK at 00:02 AM on 18 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis:
       Did you check out KR’s link in @123? Look at figure 3c on page 4 (lower left). The red curve shows measurements by the Soviet Venera 15 probe of outgoing IR radiation from Venus.

       Do you have any idea of what that curve would look like if the extreme temperature on Venus was caused by gravitational compression – or any other heat source – rather than IR absorption in the atmosphere?

       Hint: You would have to expand the y-axis a lot!

24087. Tom Curtis at 22:34 PM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis @132, don't be a fool.  Downward motion of air heats the air, but upward motion of air cools it.  If the same amount moves up as down, there is no net heat generated, and hence no possibility that this mechanism will raise temperatures above what they would have been from solar input alone.  As it happens, convective equilibrium is achieved within hours in the troposphere.  Given that, the idea that after 4.6 billion years there continues to be a net settling of the atmosphere that is needed to generate excess heat is absurd.

24088. Mike Hillis at 21:51 PM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Tom Curtis 131

       The atmospheres of rocky planets, including Earth and Venus are very thin, and have reached quasi-equilibrium a long time ago. Ergo, no net conversion of potential energy to kinetic energy, and no overall warming of the atmosphere by gravitation. End of story. Your explanation is a non-starter, and shows all the accumen demonstrated by various inventors of perpetual motion machines (which it would allow, if valid).

       Quasi equilibrium is not equilibrium. Small motion, even brownian motion, is enough. All small parcels of gas, even single molecules, generate heat on the way in and release it on the way out. Gas moves in, compresses, heats up, releases heat to the neighboring gas at lower elevation, moves back up, cools, absorbs heat from neaghboring gas at higher elevation, moves back down, etc. If you don't understand how vertical movement of gas generates heat and transfers it in a downward direction, then you probably don't understand why Death Valley is so hot, or why the San Gabriel and Santa Ana winds heat up as the elevation decrease, even at night. These are called katabatic winds https://en.wikipedia.org/wiki/Katabatic_wind and happen all over Antarctica. In the extreme, as on Venus and Jupiter, they explain everything. Taken to the extreme extreme, near the core of Jupiter, the temperature is 20,000 K. and the Kelvin Helmholtz theory isn't even necessary (that theory requires permanent compression....not needed).

       Please no talk about perpetual motion machines. The solar system has been in motion for only 4.6 by, and that's a long time but not perpetual. Tidal forces and the friction it gererates will eventually stop the rotation of Venus, but until then, the motion, all motion, within its atmosphere, will continue to generate heat katabatically.

24089. Tom Curtis at 17:47 PM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Returning to Mike Hillis @ 121:

       1)

       "The greenhouse effect doesn't explain why the dark and sunlit sides of Venus are the same temperature, and why the poles are as hot as the equator."

       Actually, it has been predicted since Svante Arrhenius in 1896 that increasing the greenhouse effect will warm the poles more than the equator, in winter more than in summer, and it has also been shown that the greenhouse effect warms nights more than days.  Carried to extremes, these features easilly explain why Venutian nights should be as warm as days, and polar regions as warm as tropical regions in the lower troposphere.  In contrast, no presentation of the theory you appeal to purports to show the same thing.

       2) 

       "This does"

       The blog post for which you provide a link appeals to a paper showing temperature hotspots at high altitudes to prove that the adiabatic lapse rate applies throughout the entire atmosphere.  That is, it appeals to a paper that falsifies its claim as proof of that claim.  It further claims the existence of the adiabatic lapse rate (where it exists) is proof of their preferred theory (of which more in a later post) even though it is a well known feature, and an important feature of the standard greenhouse theory since Manabe and Wetherald (1967), and a well known feature of all atmospheres in regions dominated by convection long before that.

       3)

       "Venus is not like earth, in that its atmosphere directly absorbs sunlight on the way in, via the H2SO4 clouds."

       In fact measured solar flux on the Venutian surface is between 35 and 40 W/m^2 at the surface (see figure 6).  On the other hand, global mean net solar flux (accounting for differences in latitude, season and the day night cycle) in only about 8 W/m^2.  Both of these are substantially smaller than is the case on Earth, due to the thick cloud, but they are more than sufficient to generate an adiabatic lapse rate in the Venutian troposphere (as is proven by its existence).  If all solar heating was dissipated in the clouds, as you claim, the surface would be cooler than the clouds, just as the tropopause is cooler than the stratosphere due to the heating of ozone in the stratosphere by UV radiation on Earth.  That is, if you were right about this point, the very precondition for validity of your preferred (in not understood) theory would be false.

       4)

       "The reason the temperature everywhere on Venus is the same is, gravity is the same all around Venus."

       The only way gravity 'generates' energy, and hence raises temperatures, is the conversion of gravitational potential energy to kinetic energy by masses falling towards the surface.  For an atmosphere in equilibrium, there is no net infall of material, and hence no net energy conversion from potential to kinetic forms.  The atmospheres of rocky planets, including Earth and Venus are very thin, and have reached quasi-equilibrium a long time ago.  Ergo, no net conversion of potential energy to kinetic energy, and no overall warming of the atmosphere by gravitation.  End of story.  Your explanation is a non-starter, and shows all the accumen demonstrated by various inventors of perpetual motion machines (which it would allow, if valid).

24090. Glenn Tamblyn at 15:54 PM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Also Mike.
       
       The forcing effect of CO2, at so much per doubling, isn't the same ratio all the way up to those very high concentrations. Additional wavelengths come into play at those higher concentrations, a process called Continuum Absorption comes into play, and the Lapse Rate of the atmosphere of Venus is more like 10.4 Deg C per km vs 6.5 here on Earth. Also there is SO2 present on venus that isn't present here on Earth. And since there is cloud covering the entire planet, not just part of it even though SO2 clouds aren'e as effective as emitters as water clouds, this still produces a bigger GH effect from clouds than here on Earth. Since the Bond Albedo of Venus is around 0.9 - 90% reflection, much from those clouds, the GH effect impact of those clouds would also be substantial.
       
       You can't extrapolate simply from the current climate on Earth, you actually need to run the radiation modelling programs with venus's atmosphere to get the correct result.
       
       From the post above "In the dense Venusian CO2 atmosphere, pressure broadening from collisions and the presence of a large number of absorption features unimportant on modern Earth can come into play (figure 1b), which means quick and dirty attempts by Goddard to extrapolate the logarithmic dependence between CO2 and radiative forcing make little sense."
       
       A better way of thinking about it, is to use the radiation calculations to determine what the effective radiating height for the atmosphere is, the average altitude that radiation to space originates from. For the Earth that is around 5 km up, for Venus it is over 50 km up. The average temperature at that altitude will be at around the effective radiating temperature the planet needs to be at to be in energy balance. For the earth that is -18C. For Venus it is more like -80 - -90 C. So a lapse rate of 6.5, over a 5km altitude makes the surface of the Earth around 32.5C warmer than the effective emission level so around 14-15C.
       
       For Venus, a lapse rate of 10.2 approximately and an effective emission height of over 50 km gives a surface temperature something of the order of 510-550 C warmer that the effective emission level, so the surface temperature should be something like 420-470C.
       
       

24091. Tom Dayton at 14:42 PM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Mike Hillis, Skeptical Science is not intended to be an encyclopedia. You need to exert A little independent effort before posting your off topic diatribes.

24092. Mike Hillis at 13:56 PM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       How many times would we have to double Earth's CO2 to be the same as Venus, which is 96% CO2 and is 93 times denser than Earth's? The answer is 18. Starting at 400 and doubling:

       800
       1600
       3200
       6400
       12800
       25600
       51200
       100k
       200k
       400k
       800k
       1.6m
       3.2m
       6.4m
       12.8m
       25m
       50m
       100m

       With a climate sensitivity of 2C per doubling, Earth would only be 2 x 18  or 32 C warmer than it is now, using the greenhouse effect of CO2

       Moderator Response:

       [RH] Try using central estimates for CS of 3°C.

24093. Mike Hillis at 13:38 PM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Lots of posturing, yet no explanation why the poles of Venus are as hot as the equator, why the night side is as hot as the day side, and why Jupiter, which has an atmosphere made of H2 and He which are not greenhouse gases, has a temperature of 260 F at a depth in the atmosphere where the P is 11 bars.

       Moderator Response:

       [RH] Need I remind you that you are currently skating on thin ice with regards to your commenting privileges. Posting links to blog posts instead of published research and then calling published research "posturing" does not help you. Stick to the published research, if there is any, to support your position, please.

24094. Glenn Tamblyn at 12:44 PM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       It always amazes me how many people get the Ideal Gas Law wrong with the 'Pressure causes Temperature' idea. But explaining it never helps, they just don't get it.

24095. pjcarson2015 at 10:39 AM on 17 June 2016
       Climate scientists have warned us of coral bleaching for years. It's here
       

       Currently there is anxiety about coral bleaching, affecting particularly the northern Great Barrier Reef. Valerie Taylor had a short informal interview in The Weekend Australian’s Magazine, May 14. You may recall she made many documentaries with her husband Ron about sharks. She’s now 80, and still dives. [Current researchers would/should have been aware of their well known documentaries.] She says of the GBR,

       “In 1965 we went from one end of the reef to the other, over six months, and we found bleaching then. In the ‘70s we went back and you’d never know it happened. The coral had recovered; nature had taken care of it. I’ve seen reefs in PNG that were as white as snow and I’ve just come back from there and they’re terrific.”

       She thus observes that bleaching is reversible. (Presumably spores from unaffected corals can flow in again to re-colonise affected areas once the cause has departed.)

       Coral bleaching and repair occur independently of atmospheric CO2 levels.

       As it is mainly the relatively untouched northern areas of the GBR affected, it is unlikely that run-off is the cause. The current bleaching decreases towards the south, flowing on the north-to-south counter-clockwise current from Vanuatu, and becoming depleted in the process. Upstream undersea volcanic activity around Vanuatu produces toxic H2S (Chapter 4a, Cyclone Pam), in time oxidising to sulphuric acid, which may also be a concern; Chapter 5 shows acidity produced by CO2 is not.

       Other coral bleaching areas around the globe, eg Seychelles, Caribbean, Maldives, etc are downstream from undersea volcanic areas.

       Moderator Response:

       [Rob P] Coral reefs are dying out at the rate of 1-2% per year, and it's very much 'settled science' that the mass coral bleaching and subsequent mortality that we are observing is as a result of sea surface temperatures rising above their normal summertime maximum. See Ove Hoegh-Guldberg's 1999 paper for a detailed rundown.
       
       This why NOAA's Coral Reef Watch program can reliably predict bleaching events some months in advance. The bleaching of the Great Barrier Reef, and elsewhere, was predicted 3-4 months before it happened, and their climate model-based projections anticipate extraordinary bleaching in the Coral Triangle later this year.

       

24096. Rolf Jander at 08:43 AM on 17 June 2016
       Development banks threaten to unleash an infrastructure tsunami on the environment
       

       "Good Bye Mother Nature"

       The Guess Who.

24097. MA Rodger at 08:27 AM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       KR @123.

       The Nikolov and Zeller poster is not entirely make believe. Their initial modelling of a planet with zero GH-effect is correct but is so silly with its assumptions I wasn't bothered to look further into their arguments. So I cannot speak for how bad the rest of it is.

       That initial model in 2.1A is for a planet with its day-side locked to always face the sun. The average temperature will thus be a little over half the black body temperature. And this should not be a great surprise; with its dark side permanently unheated, half the planet has a temperature effectively at absolute zero. Smith (2008) helpfully have done these sums & show the effects of rotation & thermal inertia.

24098. scaddenp at 07:32 AM on 17 June 2016
       Venus doesn't have a runaway greenhouse effect
       

       Gee, I am surprised this rubbish keeps coming up, when it was laughed at even in "skeptic" circles. You might like to read what Roy Spencer has to say on the subject as I suspect you would trust that source rather than "warmistas" here or say physics textbooks. This has come up here before and even our friend Camburn wouldnt buy it. If you think this is plausible, then I think he has a bridge he would like to sell you.

24099. william5331 at 06:10 AM on 17 June 2016
       New study finds evidence for a 'fast' dinosaur extinction
       

       Pretty convincing.  The Iridium data from his site would be pretty well the clincher.

24100. knaugle at 05:53 AM on 17 June 2016
       Development banks threaten to unleash an infrastructure tsunami on the environment
       

       Consider that there is some thought that Biscayne Bay area of Miami will be uninhabitable in 30 or 40 years because of rising sea levels and the rather porous substrate.  Yet right NOW there is a building boom.  Why?  I've read that it's because developers calculate that it takes 20 years for them to turn a profit and they will be long gone before it's a problem.

       
       So the question is.  Did I get this right?  Or am I making it up?

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