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Comments 24451 to 24500:

24451. Eclectic at 22:18 PM on 12 May 2016
       There's no correlation between CO2 and temperature
       

       Ken @49, your question is answered in the thread "CO2 is not the only driver of climate".

       Quickest to go to the comments column there, and see Bozzza's (@20) laconic quote: "aerosols" ~ which is the short story . . . that could be expanded slightly to: "increasing industrialization produced reflective aerosols which counterbalanced the rising CO2, until the ever-higher CO2 levels overpowered the aerosol effect by around 1970 [combined with some clean-up of aerosol emissions].

       You will note Tom Curtis's (@21) longer explanation of additional factors which contributed to a "flat" 1940-1970 record.

24452. ConcernedCitizen at 21:06 PM on 12 May 2016
       CO2 effect is saturated
       

       Tom Curtis@414

       Not wanting to create a long thread, and to keep it trelevant to the theory postulasted here,  I focused on heat transfer space, not from the surface and not internally, so it wasnt a refutation of the GH effect at all.

        " but you neglect that the lack of greenhouse gases also reduces the introduction of energy into the atmosphere by absorption of thermal radiation from the surface, with the absorbed IR radiation from the surface being much greater than the emitted radiation from the upper atmosphere"

        At the top of the atmosphere, where the additional CO2 mollecules are now radiating  at higher altitude, you have said that less than 1% of energy is direct radiation from the surface which contradicts this statement.

        "if we add more greenhouse gases the air needs to be thinner before heat radiation is able to escape to space"

       Why?  If it isnt direct radiation from the surface (in  which case the energy is maintained regardless of what altitude its radiated at, and is very rare (free path lenght and all that)) then its a kinetic-radiative change of energy. 

       So, if a colision happens with CO2 at 6km and is radiated to space  the photon's energy  represents the temperature at 6km.

       Add more CO2 and now more of the collisions happen at 6.1km with the  photon's energy representing the temperature at that altitude.

       This doesnt mean there is more heat in the system.

       Better to say that adding more CO2 turns kinetic energy at 6.1 km into photons which have an even chance of being emitted towards the surface.  ie, more GH gas = more back radiaiton.

       Taking the Feldmanpaper data from the paper above, and using 370 and 390 ppm for CO2 at 2000 and 2010 MODTRAN gives a 0.3 wm^-2 forcing change, which isnt far off fro the Feldman value, so I am not doubting CO2 as a GH gas or CO2 non-saturation just that the mechanism proposed here isnt feasible.

       Add CO2 and now we have

       Look, I am not saying CO2  is saturated, but  the mechanism proposed here doesnt hold water when you pull it apart, and you certainly havent explained it,  all you have done is  explain the GH effect.

       Moderator Response:

       [RH] Removed excess blank space.  Concerned Citizen, the process has been explained to you in a very detailed and accurate manner. You're skating on this ice at the moment.

       Please note that posting comments here at SkS is a privilege, not a right.  This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

       Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

       Link to the commenting policy is just above the comment window.

       [PS] The detailed process with the  maths is in the Ramanathan and Coakley paper pointed to earlier. Do you dispute that paper?

24453. mancan18 at 19:50 PM on 12 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       Congratulations SkS, well deserved.

       As for the greatest threat from AGW, it is quite likely to be, using Donald Rumsfeld terminology, an unknown unknown. Climate Scientists know what they know i.e. known knowns. They are also aware of the known unknowns but are not yet sure as to their likely impact. However, considering that the world is directly on a climate path that existed long before humans first evolved, then the global ecosystem that will exist long after fossil reserves have been burnt, if they are not left in the ground, is an unknown unknown. It may well be that the resulting global ecosystem may not be favourable to humans. Of course humans now have a limited ability to control their own evolution and create their own climate and ecosystems. Whether that will be enough to avert the more adverse impacts of AGW is also an unknown unknown.

       Incidently, one of the best temperature graphics I have seen in recent times that shows the rise in global temperature since 1850, has been produced by Ed Hawkins, an academic from the University of Reading. It is worth a look. It might also be worthwhile for someone to create a similar graphic showing the rise in CO2, and run them side by side, even though the denialists will use the argument that correlation does not imply causality.

24454. Tom Curtis at 18:10 PM on 12 May 2016
       CO2 is not the only driver of climate
       

       Ken Kimura @19, if you sum all forcings (ie, not just that from CO2) using the values estimated by Meinhausen et al (2011), the trend in the forcings from 1940 to 1970 is 0.0003 +/- 0.0007 W/m^2 per annum.  That is, it is essentially zero, and may well have been negative.  On top of that, there was a substantial El Nino early in the sequence and a La Nina following the volcanic eruption in 1965 which together with the very low trend in forcings may have tipped the temperature record negative.

       Having said that, if you look at this model of the ENSO adjusted temperature responce to forcings, you will see to large temperature spikes around 1939 and 1945 that are not accounted for by the model and which also contribute to the negative slope.  It is difficult to know that to attribute those spikes to.  They may be due to unusually large forcing by Black Carbon during World War 2.  They may also be due to an artifact in the temperature record due to the sudden, very large reductions in temperature coverage along with the simultaneious large changes in methods of measuring Sea Surface Temperature brought about by WW2.

       What they are not due to is the Pacific Multidecadal Oscillation (which is captured by the ENSO signal) or the Atlantic Multidecadal Oscillation (which does not have a suitable pattern to explain the phenomenon).  Nor are they due to a fundamental misunderstanding of the forcings, or the relative effects of natural and anthropogenic forcings.  The model I linked to allows you to weight the various forcings, making natural forcings much stronger in effect than anthropogenic forcings if you desire.  Any such attempt, however, greatly increases the number of temperature discrepancies.  That fact shows conclusively that theories that attempt to explain the twentieth century temperature record without anthropogenic factors being the dominant factor post 1940 (and a significant factor prior to 1940) are doomed to failure. 

24455. bozzza at 17:27 PM on 12 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       You are saying desertification could get a guernsey for biggest threat?

24456. bozzza at 17:25 PM on 12 May 2016
       Arctic Ice Volume is diminishing even more rapidly than Area
       

       Figure 2 only has a downward trend of less than ten years.

       How does the trend look now in 2016?

24457. Tom Curtis at 17:19 PM on 12 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       bozza @6, I don't think anybody knows what the biggest threat is, and certainly I do not.  We know there are several very large threats but exactly which is largest depends on time scale and how much we push global warming; but in addition to that the error margins on how bad the threats are are such that a clear worst effect cannot be picked on a global basis.  Even if we push global warming to the extreme, in which case the seasonal rendering of tropical regions of the Earth uninhabitable to humans due to heat stress may be pipped by the effect of deoxydisation of the oceans (the probable cause of the worst mass extinction todate).  The later also has a less clear cut off so that it may occur at lower temperatures.  These are likely the worst possible impacts from purely anthropogenic global warming.  Ocean acidification and changes in the hydrological cycle (which involves both more intensive flooding, droughts and storms) are likely the worst impacts at more moderate levels by my inexpert estimate.

24458. bozzza at 17:16 PM on 12 May 2016
       CO2 is not the only driver of climate
       

       ..aerosols !

24459. brendan1 at 16:06 PM on 12 May 2016
       Coal made its best case against climate change, and lost
       

       Thanks for the article and the graphics, I enjoyed the description of the law suit as well.  We have been discussing the direct impacts of coal burning in my climate change course, which makes this article very relevant for me.  Not only that, but we have also discussed the idea of social costs (by looking at K. William Kapp's writings on the subject), and I enjoyed the fact that you touched on that.  It seems like if the true social costs inflicted by fossil fuel burning were made to be answered for by the companies who do it, no one would want to use this method for energy because of the massive costs.  In a perfect world, the giant subsidies could go toward sustainable forms of energy instead.  I don't know if this can ever happen in the United States in time.  

24460. bozzza at 15:48 PM on 12 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       Thus, Tom, this begs the question of what Climate Change has as it's biggest threat if not sea level rise?

       I presume desertification...

24461. Ken Kimura at 15:01 PM on 12 May 2016
       CO2 is not the only driver of climate
       

       If the unremitting rise of CO2 from industriail activities is the dominant factor, why did the global temperature decrease from 1940 to 1970?

24462. Ken Kimura at 14:43 PM on 12 May 2016
       There's no correlation between CO2 and temperature
       

       I had read the article and still I did not understand why the global temperature did not increase
       from 1940 to 1970. Could you tell me what is the main cause of it?

       Moderator Response:

       [PS] From the article, "If CO2 causes warming, why isn't global temperature rising over this period? To answer this, one needs to recognise that CO2 is not the only driver of climate. There are a number of factors which affect the net energy flow into our climate. Stratospheric aerosols (eg - from volcanic eruptions) reflect sunlight back into space, causing cooling. When solar activity increases, the amount of energy flowing into our climate increases. Figure 5 shows a composite of the various radiative forcings that affect climate."

       Figure 5 shows all the factors other than CO2 affecting climate of the period and Fig 6 sums all them, positive and negative,  to show little net forcing till 1970. Please take some time to study actually study and understand the figures.

24463. Ken Kimura at 13:02 PM on 12 May 2016
       There's no correlation between CO2 and temperature
       

       The global temperature did not increase from 1940 to 1970.
       How do you explain this?

       Moderator Response:

       [PS] Read the article. (Net forcings, see figures 5 and 6 on the intermediate version of the article). Warning: Asking questions without any interest in the answers is simply sloganeering and forbidden by the comments policy.

24464. Ken Kimura at 10:06 AM on 12 May 2016
       Ivar Giaever - Nobel Winning Physicist and Climate Pseudoscientist
       

       From 1940 to 1970, the world industrialized nations produced far larger amount of CO2 than before due to the rapid economic growth.
       However, the global temperature did not increase during the period(Figure 1).
       How do you explain this?

       Moderator Response:

       [PS] This is offtopic here. Please see co2 temperature correlation. Climate responds to net forcings not just CO2. See the graph of net forcings versus temperature at bottom of article and make any comment on that topic, not here.

24465. Tom Curtis at 09:55 AM on 12 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       John A. Broussard @4, the total land lost to date is to small to even show on the scale of a global map.  Even a six meter sea level rise (not expected for several centuries) appears more as a highlighting of the coast rather than a significant land loss:

       

       This does not mean sea level rise is insignificant.  People living on river deltas (Bangladesh, much of the Egyptian population) or what are in effect extended sand bars (Florida) along with will lose almost all their territory from such a sea level rise.  Further, 40% of the world's population lives in coastal areas and will experience some negative impact from sea level rise, either through increased storm damage and flood risk (due to slower drainage of rivers due to the elevated sea level); or through the necessity to move cities or major infrastructure several kilometers inland (or build massive sea walls to obviate that necessity, with the risk of a Katrina like catastrophe as a result).

       Consequently, while the idea of an updated index of sea level rise impacts is a good one; using a global map to provide that index is unsuitable.  On the other hand, in some areas local maps might be very useful.

24466. Tom Curtis at 09:44 AM on 12 May 2016
       CO2 effect is saturated
       

       ConcernedCitizen @413:

       "The quesiton isnt whether the GH effect exists, it is wether CO2 is saturated as GH gas."

       You say that, but immediately mount an argument that, if valid, would mean there is no greenhouse effect, not that it was saturated.

       "The suggesiton is this: A CO2 mollucule at 6 km radiates a photon upwards. This photon was either radiated out from the surface and stayed as a photon at 15 microns all the way up, and finally, this CO2 molecule was the last one in the chain, and the photon made it out to space."

       In fact, both of these are true for very small parts (<1% at a guess) of the energy radiated to space by CO2 from the middle to upper troposphere.  For most energy, it will have been radiated from the surface (68%), or transferred by latent heat or conduction (18%), or absorbed in the atmosphere from solar radiation (14%).  From there, most energy transfers will have been by collisions with other molecules, with transfer to molecules travelling downwards as likely as those to molecules travelling upwards, and with lateral motion of molecules receiving energy as great as either upwards or downwards motion.  Most upwards motion will be from emissions from molecules, but (firstly), radiation will be as likely to take energy downwards as up, equally likely to take it laterally as either; and the molecules radiating the energy are more likely to be H2O molecules in the lower troposphere than CO2 molecules (and hence have a different, but lower energy content per photon than that eventually radiated to space by CO2).  Of course, some of the radiation will have been by radiated by other greenhouse gases (CH4, NO2, O3, etc) which typically have a higher energy content per photon than that radiated by CO2.  Of course, energy radiated by a greenhouse gas other than CO2 will have to be absorbed by that same greenhouse gas (except for a small amount radiated by H2O) and then transferred to CO2 by collisions (probably mediated by collisions with N2 and O2).  Even energy transferred by radition from CO2 and absorbed by CO2 will have different energies to that finally radiated to space because of doppler energy shifts, and pressure broadening (and a couple of other effects).

       The net consequence of this is that:

       1)  Of the energy finally radiated to space by a single CO2 molecule, not all will have come by the same  pathway except in very rare cases;

       2)  The energy finally radiated by CO2 to space will typical have followed a very convoluted pathway through the atmosphere, spending almost as much time travelling downwards as upwards, and twice as much time travelling laterally as either downwards or upwards (with different parts of the energy travelling different paths as per (1));

       and (most importantly)

       3)  Because the lower layers of the atmosphere are warmer, and hence radiate more energy, and downward radiation is as probable as upward radiation at all levels of the atmosphere, the majority of energy entering the atmosphere (59%) will follow a convoluted path that returns it to the Earth's surface.

       The upshot is that the convoluted pathway of energy from the surface introduced by the presence of greenhouse gases in the atmosphere serves as a filter limiting the escape of energy to space.  There is a bias in that filter caused by the lower temperatures at higher altitudes which means that less than 50% of the energy escapes to space.

       Unfortunately for your theory, none of this fits your simplistic analysis.  In your analysis, either all radiation is upward only, in which case all energy emitted from the surface escapes to space without impediment.  And indeed, if all radiation was upwards only, there could be no greenhouse effect - but such a situation is unphysical.

       Alternatively, on your second scenario, energy is transfered upwards by collisions and IR radiation from the upper troposphere reduces the thermal energy relative to the case with no greenhouse gases: but you neglect that the lack of greenhouse gases also reduces the introduction of energy into the atmosphere by absorption of thermal radiation from the surface, with the absorbed IR radiation from the surface being much greater than the emitted radiation from the upper atmosphere.  So, while the IR radiation to space cools the atmosphere, the IR absorption from the surface warms it at a much faster rate.

       
       In both scenarios, you ignore essential features of the system in order to draw obtuse conclusions.

       Moderator Response:

       [PS] Thanks Tom. ConcernedCitizen, note that the effects of increased CO2 has been directly measured (see "Observational determination of surface radiative forcing by CO₂ from 2000 to 2010") so it real despite your difficulties in understanding why.

24467. mitch at 01:50 AM on 12 May 2016
       Coal made its best case against climate change, and lost
       

       Thanks for giving the background on the Minnesota lawsuit. I have been wondering why the case was in court.  My expectation is that if other GHG lawsuits get to court they will have a similar outcome.  The 'fossil fuel' scientists are too few and too old.

24468. John A. Broussard at 00:46 AM on 12 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       It's time for a world map, posted on this site, showing the daily, monthly, yearly loss of land to the rising seas (e.g. recent disappearance of several islands in the Solomons)

       An up-to-date depiction of lost land and threatened losses would be very effective in demonstrating the actual and approaching effects of global warming.

24469. dana1981 at 00:29 AM on 12 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       Thanks!

24470. ConcernedCitizen at 22:59 PM on 11 May 2016
       CO2 effect is saturated
       

       M A Roger @411

       Tom Curtis @412

       The quesiton isnt whether the GH effect exists, it is wether CO2 is saturated as GH gas.

       The suggesiton is this:  A CO2  mollucule at 6 km radiates a photon upwards. This photon was either radiated out from the surface and stayed as a photon at 15 microns all the way up, and finally, this CO2  molecule was the last one in the chain, and the photon made it out to space.

       Or the CO2 mollecule was impacted by an O2, or N2 molecule and thus kinetic to radiative change happened, with the energy of the photon representing the energy at that altitude, ie, temperature.

       The proposal here is that an additional CO2 mollucule at 6.1 km causes cooling.  HOw so? Lets look at the wto cases.   Either the photon was passed up from the surface, and this is the last CO2 mollecule in the chain, in which case it is pased out to space with exactly the same energy as before.  Ie, no loss of energy, no warming.

       Or, if the photon came from kinetic energy and was radiated out to space, then yes, the energy of the photon would be less, because it represents the temperature at 6.1 km,  but if the CO2 mollecule werent there then this radiation wouldnt happen at all and the kinetic energy would have just stayed in the system. 

       So I dont see how the suggesiotn that 'A CO2 mollecule radiates from higer and colder' means additional energy in the system and hence warming.

24471. Rob Honeycutt at 21:57 PM on 11 May 2016
       Comparing models to the satellite datasets
       

       Christy actually is comparing TMT with a similar comparison of the atmosphere from CIMP5 model. So, it's now what he's comparing that's misleading, it's how he's doing it.

24472. shoyemore at 17:55 PM on 11 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       Congratulations! 

       Totally merited.

24473. Finnjävel at 15:57 PM on 11 May 2016
       Comparing models to the satellite datasets
       

       Good article.

       Though there is one point that needs more effort; comparing model based surface trend with satellite TMT channel trend. Of course the mid troposphere trend is lower than surface trend and TLT trend. 

       

       

       Satellite data nicely proves the greenhouse warming.

       Important question is are the model runs direct surface temperature runs, or somehow tweaked to 10km. My guess is that it is just surface data.

       So Christy is comparing apples and oranges.

24474. Tom Curtis at 07:54 AM on 11 May 2016
       Skeptical Science wins 2016 NCSE Friend of the Planet award
       

       Congratulations to Skeptical Science, and individually to Dana and the two Johns (Abraham and Cook).  A very well deserved award.

24475. scaddenp at 07:15 AM on 11 May 2016
       CO2 was higher in the past
       

       MA Rodgers. Whoops! I did indeed miss the CO2(e). Good point. On that basis, we would indeed be heading for Miocene-type climate (eventually).

       Bozza - based on past climate with assumed similar net forcings. It takes a very long time for icecaps for melt and change in albedo would be very slow till nearly gone.

24476. Rob Honeycutt at 04:57 AM on 11 May 2016
       Scientists are figuring out the keys to convincing people about global warming
       

       MA Rogers...  And, of course, at that point contrarians will flip completely the other way and say, "Oh yeah? That just means the GHE is saturated." ;-)

24477. MA Rodger at 23:02 PM on 10 May 2016
       Scientists are figuring out the keys to convincing people about global warming
       

       Tackling the 400ppm CO2 is so small a quantity, I feel there is another argument that may have traction in the minds of doubters. In normal circumstances it would be true to say "0.04% is so tiny!" but is it really when we talk the atmosphere? That is not a normal circumstance as we are talking tiny tiny molecules and a troposphere 12km thick. (Hopefully I haven't suffered decimal point drift in this below.)

       CO2 molecules are today above 400ppm by volume or 607ppm by weight within the atmosphere. As the atmosphere weighs 5.15 million billion tonnes, that means (with an atomic weight of 44), there are 42,800 trillion trillion trillion CO2 molecules up there.

       Now, consider the physical size of each CO2 molecule, imagine each molecule presents an area towards the Earth's surface equal to just the size of one of its carbon atoms which are ~70 picometres in diameter (imagine the molecules all stood on their ends with the other two atoms hidden behind the first carbon atom). Given this, and with the globe having an area of 510 million sq km, a photon if considered to be a point object leaving planet Earth by the shortest route (straight up) through an average bit of atmosphere; that photon would have to pass unabsorbed through over 320,000 CO2 molecules to escape into space unhindered.

       That suggests the atmosphere contains rather a lot of CO2, not rather a little.

24478. billhurley at 22:57 PM on 10 May 2016
       White House: Climate Change Poses Urgent Health Risk
       

       I have heard to that hurricane intensity will increase but the number of hurricanes themselves will not. However, this confuses me. Aren't stronger tropical storms going to result too? Doesn't this mean they become hurricanes and thus increase the number of these storms?

24479. MA Rodger at 22:47 PM on 10 May 2016
       CO2 was higher in the past
       

       Ravenken @64.

       I feel scaddenp @65/66 is a little quick converting your measure ppm CO2(e) into ppm CO2.

       The use of CO2(e) as a measure of climate forcing also has to take on board the anthroprogenic negative forcings which are less well defined but which will (indeed, can only) reduce the CO2(e) figure.

       The net forcing equivalent to that during time past when CO2=500ppm is a good start point for considering when the globe would lose the southern ice cap. The northern one is more suseptable to increases in temperature. The IPCC suggest in this SLR graphic that a temperature rise above pre-industrial of ≈1.5ºC would see Greenland melt down. (Mind, the ≈ is a worry.) And as the summit drops to warmer altitudes, it would become a tipping point and irreversable outside a renewed ice age. So if Antarctica is 500ppm, Greenland would be 400ppm.

       Of course these are very slow multi-millenia processes. The forcing from methane etc and also the negative forcings are short-lived compared with CO2. And even CO2 will drop over such long time periods. But then melting the very last snow flake on the planet (or just in the NH) is not some target we should be taking as something to avoid. We will be in deep deep do-do far far earlier than the arrival of an ice-free hemisphere or two.

24480. bozzza at 17:55 PM on 10 May 2016
       CO2 was higher in the past
       

       @ 54,

        What happens to the sensitivity predictions if we include the slow feedback of melting ice sheets?

24481. bozzza at 17:52 PM on 10 May 2016
       CO2 was higher in the past
       

       ooh, also how does comment 66 alter things?

24482. bozzza at 17:50 PM on 10 May 2016
       CO2 was higher in the past
       

       @ 65

       I'm interested in this comment:

       500ppm for sufficiently long period of time (1000s of years) is postulated to be enough for it to be more or less ice free at poles, (though Antarctica would likely retain some ice as much higher in altitude than north pole).

       How did you come across that idea may i ask?

24483. bozzza at 17:48 PM on 10 May 2016
       Consensus on consensus
       

       To further your basic point, Glenn:

       Edward DeBono wrote a book called mechanism of mind saying that the mistakes of the system were what made it work. (It's an old book so it might be wrong...!!??!)

24484. scaddenp at 11:53 AM on 10 May 2016
       CO2 was higher in the past
       

       Should have checked before commenting. There is evidence of Milankovich cycles operating in Pliocene and moderating the size of the West Antarctica ice sheet. See here. The milankovich forcing seems to have been operating since at least Oligocene (see here) but in the without low CO2, they did not precipatate ice ages. At 500ppm, our climate would likely be similar to the warmer Miocene.

24485. scaddenp at 11:41 AM on 10 May 2016
       CO2 was higher in the past
       

       Current CO2 is 400ppm, not 490ppm. 500ppm for sufficiently long period of time (1000s of years) is postulated to be enough for it to be more or less ice free at poles, (though Antarctica would likely retain some ice as much higher in altitude than north pole). Note that in Pleistocene we have ice age cycle driven by Milankovich cycles. In Pliocene, there was no such ice age cycle although the Milankovich cycle was almost certainly present (driven by earth orbital mechanics) and CO2 was around 400ppm and solar input roughly the same.

24486. Ravenken at 10:12 AM on 10 May 2016
       CO2 was higher in the past
       

       "Periods of low CO2 coincide with periods of geographically widespread ice ... This leads to the concept of the CO2-ice threshold - the CO2 level required to initiate a glaciation."

       Sorry for my ignorance, CO2-ice threshold... my understanding is we are around 490 CO2 equivalent right now... Is the converse of deglaciation the same 'number'? Am I also correct that the current 'number' is 500?

24487. Rob Honeycutt at 05:23 AM on 10 May 2016
       Climate Bet for Charity, 2016 Update
       

       Gotcha. Now I get what you're saying.

24488. pattimer at 03:01 AM on 10 May 2016
       Climate Bet for Charity, 2016 Update
       I am sure you are on a safe bet though :-)
24489. pattimer at 03:00 AM on 10 May 2016
       Climate Bet for Charity, 2016 Update
       What I mean by that comment is that you would end up with 0.209 after 120 months if the average continued as it has done for the these past years. ( I am not implying that this is what you expect) but it would end up at 0.109 if the remaining years had an anomaly of 0 ( and I am not implying that this is what Kiwi expects)
24490. Rob Honeycutt at 01:13 AM on 10 May 2016
       Climate Bet for Charity, 2016 Update
       

       Yes. That's effectively what I've said, that KT's methods are going to end up with the same result in the end. Although, I'm not clear on what you mean when you say, "Your running average is effectively assuming that the remaining months will continue with the same average anomaly and Kiwi's is assuming that the remaining months will have an anomaly of zero."

       That's not registering for me somehow. 

24491. pattimer at 00:46 AM on 10 May 2016
       Climate Bet for Charity, 2016 Update
       Rob. It seems to me that both these methods will come to the same when the 120 months are up.....Or am i missing something?Your running average is effectively assuming that the remaining months will continue with the same average anomaly and Kiwi's is assuming that the remaining months will have an anomaly of zero. It is no surprise then when an average of 0.209 over 5 years and 3 months will return a running average of 0.109 if remaining months are assumed zero. When the time is up these assumptions have no bearing on your final answer.
24492. Christian Moe at 22:37 PM on 8 May 2016
       Handy resources when facing a firehose of falsehoods
       

       I don't think the factsheet's claim “The IPCC is 20 times more likely to underestimate rather than exaggerate climate impacts” bears scrutiny.

       Don’t get me wrong: I’m sure it’s qualitatively true that the IPCC is more likely to be over-conservative, as suggested e.g. in Brysse et al. (2013) (“erring on the side of least drama”), supported by examples e.g. in Rahmstorf et al. (2007), and practically guaranteed by the IPCC process. :-)

       But “20 times” smacks of spurious quantification; at least I'm not aware of a study actually evaluating a representative sample of IPCC statements to reach such a conclusion. Apparently the source is Freudenburg and Muselli (2010), herafter FM10, discussed in the basic rebuttal to “IPCC is alarmist”. They do have a “20 times” finding, but it’s not an evaluation of IPCC findings, and doesn’t support the stated conclusion. FM10 purposely avoided drawing on the IPCC. What they did was to scan newspaper stories about new science, not evaluate the science. The most you can say, based on FM10, is that even newspapers overemphasizing scientific disagreement over climate change were much more likely to report new science as saying climate change was ’worse than expected’ than the opposite. But this may tell us more about journalistic norms for ’newsworthiness’ than about tendencies in the science, let alone the IPCC.

       To the extent FM10 think otherwise (they’re not very clear), the analysis is flawed. For one thing, it falls prey to ’single-study syndrome’, since each newspaper story would likely report one new dramatic study, whereas the IPCC considers all the evidence. For another, if journalists think a good story involves ’conflict’, ’balance’ and ’danger’, these journalistic norms could well lead them to represent the science as both contested and worse than expected at the same time. Neither representation should be taken as representing the true state of the science.

       However, FM10’s premise is that the newspapers’ ’worse-than-expected’ framings do reflect the tendency of the science, and even reflect it conservatively, because the papers (including WaPo and NYT) have been shown to be biased against the consensus, and so would be expected to report that the consensus view is alarmist. But when their own findings overwhelmingly contradict this assumption, does that actually confirm that the science just turned too massively gloomy for the newspapers to ignore despite their assumed bias, or does it simply mean the assumption was wrong? Anyway, their authority for this bias is Boykoff and Boykoff’s “Balance as bias” (2004), which mainly shows that the newspapers in question framed the causes of climate change (anthropogenic or natural) as still in dispute, and doesn’t really go into whether they framed the magnitude or impacts as exaggerated.

24493. Christian Moe at 21:49 PM on 8 May 2016
       Handy resources when facing a firehose of falsehoods
       

       OK, here are some suggestions on the Fact-Myth-Fallacy sheet. I'll start out constructive. :-)

       The ocean acidification myth just argues by assertion OA "isn’t serious", which hardly merits rebuttal, but the fallacy addresses the specific myth/misunderstanding that the oceans cannot be acidifying because they’ll never become acid. I suggest that this specific claim should feature as the myth text too, otherwise this part doesn’t make sense.

       There are two "models are unreliable" myths; one of these is juxtaposed with the fact that "models are based on fundamental physical principles", which is true for GCMs (though not for, say, statistical models), but doesn’t actually address reliability. I’d suggest formulating the myth here along the lines that "models aren’t reality, scientific evidence comes only from observing nature". Anoher possibility would be to merge the two myths into one.

       The fact about the West Antarctic ice sheet is juxtaposed with a myth and a fallacy about Antarctic sea ice. The fallacy text fails to dispel the ice sheet/sea ice confusion exploited by deniers. It offers an accurate but weak retort that the sea-ice claim is oversimplified. Instead, it ought to call out the sea-ice argument as a red herring irrelevant to the discussion of ice-sheet mass loss and sea-level rise.

       The replies to the "CO2 lagging temperature" myth are fine, but it would be good to have space to add that the present CO2 rise is entirely due to our emissions, since deniers exploit the confusion between the ice-age relationship and the modern CO2 rise to claim the latter comes from the ocean.

       "Climate change is having negative impacts on all parts of society." Does this unqualified statement hold, already, everywhere? It’s good to fight cherry-picking, but it’s also fallacious to conclude from a poor cherry harvest that every individual cherry is doing badly. One alternative would be to follow AR5: "In recent decades, changes in climate have caused impacts on natural and human systems on all continents and across the oceans" (WG2 SPM). (Both statements obscure the climate justice aspect that impacts will disproportionately harm the poor.)

       "Risks from extreme weather are increasing… some forms … more confidently linked to global warming than others." Should that be "some risks" or something? Some forms of extreme weather (cold extremes) are decreasing, as expected.

       I have one further objection, but it'll take a little space so I'll put it in another comment.

        

24494. BBHY at 19:15 PM on 8 May 2016
       CO2 is just a trace gas
       

       Coincidently, clouds are about 0.04% water. I've noticed quite a difference between sunny and cloudy days.

24495. BBHY at 19:08 PM on 8 May 2016
       Handy resources when facing a firehose of falsehoods
       

       "...they had a bachelors in meteorology and math and a masters in physics"

       I usually respond to that sort of argument that the molecules of CO2 don't care about your college degrees. Your opinions about liberals, taxes, Al Gore, scientists and the government mean nothing to the molecules of CO2. They just go on merrily about their business, absorbing infrared heat energy, and they are quite good at it. 

       The more molecules of CO2 we put into the atmosphere, the more infrared heat energy gets absorbed and the more the Earth warms up. That's really what happens regardless of how you feel about it. 

24496. Glenn Tamblyn at 16:07 PM on 8 May 2016
       Consensus on consensus
       

       William.
       
       There is actually an evidence base for why consensus messaging is an important part of communication. It is evidence from psychology. Your argument has a basic assumption. That we are all rational, all of the time, and thus arguing the evidence about climate will work.
       
       When in reality, most of us most of the time are actually rather irrational. We use mental short-cuts, heuristics, quick gut-reactions, and all sorts of ways of forming a view of some sort with least effort. And we strongly filter what we hear based on our inner world-view, our value system, our fears and hopes. Difficult external knowledge can have a hard time sinking in when it conflicts with our prior ideas. And our minds are very good at doing all sorts of tricks and cognitive biases.
       
       So 'Just the facts Ma'am, just the facts' doesn't work so well when it is competing agaisnt our inner monologue.
       
       One important aspect of our biase-addled minds is that we follow the herd, want to fit in, want to be accepted by those around us. So we often tend to think what others think; it feels safer.
       
       This is the power of consensus messaging. It is saying to people, 'its alright, everyone else thinks this too'. So long as the scientific consensus is soundly based - which it is - there actually is no problem, and good reasons for using consensus messaging.

24497. chriskoz at 08:13 AM on 8 May 2016
       Consensus on consensus
       

       william@1,

       In case you've missed the point of this "consensus on consensus" study: it does not argue that consensus is the evidence of AGW (as your comment incorrectly implies). It does provide the statistical evidence that 97% consensus on AGW among climate scientists is not an outlier.

       You're correct that such study does not prove AGW. But you're incorrect that such study is useless. The study provides evidence to the wide public - i.e. those who rely of expert opinion because they are incapable or unwilling to spend time and effort to shape their own oipinion - that expert climate scientists publish solid & accurate knowledge. That every eveidence indicates climate expert opinions should be acknowledged as much (if not more than) the opinions of other science experts, like e.g. astronomers. Any "news" of conspiracy theories among climate scientists dissiminated dniers are pure. often evil falshood.

24498. BBHY at 03:58 AM on 8 May 2016
       Consensus on consensus
       

       Personally, I find the evidence very convincing, but there are lots of different kinds of people and not all of them are swayed by evidence. Numbers and physics just turns some people off. The consensus is a way to reach those people. We need to bring as many people as possible on board to solve this problem.

24499. Tom Curtis at 10:56 AM on 7 May 2016
       Scientists are figuring out the keys to convincing people about global warming
       

       Johnboy @13, indeed.  Afterall, it is a core denier argument that:

       1)  Increasing the CO2 concentration by 0.016% of the atmosphere is too small a change to have any conceivable effect; but that

       2) Decreasing the CO2 concentration of the atmosphere by 0.014% of the atmosphere would be completely devestating, preventing photosynthesis and thereby killing all multicellular life on Earth; 

       and that

       3)  Increasing the CO2 concentration by 0.016% of the atmosphere significantly increases plant growth and is necessary to feed a hungry world.

       Of course, it is necessary to being a 'rational' denier that you never mention point (1) in the same blog post as you mention points (2) and (3).  It is necessary that they be believed at different times so that there is no fear of contradiction /sarc

24500. Tom Curtis at 10:47 AM on 7 May 2016
       Scientists are figuring out the keys to convincing people about global warming
       

       nigelj @12:

       "One educational tool could be a decent graphic of temperatures over the last 2000 years, with CO2 concentrations overlaid over this, like a double hockey stick."

       It is not as directly educational as you might think.  The reason is that the heightened temperatures from 1000-1200 and the reduced temperatues from 1400-1750 were respectively due to reduced and increased volcanic activity, not to the small changes in CO2 concentration over those periods.

       

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