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Comments 24151 to 24200:

24151. hank at 06:59 AM on 27 May 2016
       In-depth: Experts assess the feasibility of ‘negative emissions’
       

       Someone should lay out a comprehensive set of scenarios — for example if we laid off stripmining the ocean, let the top predators reestablish, and got the predictable recovery of the rest of the trophic cascade — that would maintain and improve a carbon sink that's currently just starting toward being destroyed.

       
       Yeah. those lovely maps of seamounts never known until the satellite era are a guidebook for the illegal trawling that destroys them. 

        

       Yeah, we used to have top trophic predators abounding.  Whales, cod, tuna, sharks.   Burp.  They were good, weren't they?  While they lasted.

        

       They'd recover, if we got our grubby hands off the oceans.

        

       So which countries navies are going to sign up to help with Sea Shepherd?

       .... crickets ....

       
       Then there's topsoil, and grasslands, and the herd grazers that used to maintain them.  Anyone?

        

       Or failing that there's the screwfly solution.

24152. Ger at 01:31 AM on 27 May 2016
       In-depth: Experts assess the feasibility of ‘negative emissions’
       

       Ranyl @#1:

       Decrease in efficiency: suprissingly little, around a 3%. Gasification of biomass delivers a higher volume stream of lower BTU gas, increasing the efficiency of turbines. Cooling of the syngas gas stream delivers extra steam, to an amount of 5% extra steam and capturing CO2 at the exit of the gas cleaning with a watershift installation (CO+H2O -> CO2 + H2) is easier than from flue-gas. Biomass has less Sulphur, much less, so cleaning of Sulphur isn't as expensive as in an coal gasification plant.

       How much land... Hardly anything extra, preferably a biomass which can grow on depleted land, waste land. Types like Arundo Donax, Cogon or other cover grasses to prevent eroding the land and in the vicinity of the power plant (as back-up fuel if import of MSW or bio-fuels is disrupted). If not needed, let your back-up grow an develop to a nice woodland like area. 'Simple' cover grasses can be harvested at least once a year.

       Supringsly little power down.. No need if one increase efficiency by re-using heat for industrial purposes (e.g. torrefact MSW), nearby food mills or bio-fuel production (ethanol distilation) and replace the old fossil coal burners of 34% eff. with something with an average eff. of 55%.  

24153. Ger at 01:01 AM on 27 May 2016
       In-depth: Experts assess the feasibility of ‘negative emissions’
       

       To add to #4 Tom Curtis: 

       Torrefaction (slow pyrolysis) and bio-oil production (fast pyrolysis) are production ready. Input for both processes can be all types of (preferably less than 20% wet, self sustainable process) biomass delivering a bio-coal which can be applied as replacement for coal with far less CO2/kWh than fossil coal. Applied as fuel in an integrated Gasification Combined Cycle plant less than half the CO2 as with coal. Also, as produced from agri-residues, delivers a fuel for locals, a smokeless fuel, far better than firewood. Better as in less CO2/kWh and no smoke.

       If plans are going as expected in the SE-Asia region, there will be an annual production of 300,000 tpa starting in Q1 2017, growing to a 1,000,000 tpa in 2019 with an calculate CO2 storage of 22.4% of the production.

       Countries in the ASEAN area have capabilities of exporting a 50,000,000 tons of this biocoal from several sources capturing a 11.7 million tons of CO2. Just a tiny bit, but if that can prevent the burning of forest to make way for food production, quite an extra bit can be saved from being emitted. 

       If the same torrefation is applied on MSW (less efficient) with a bit of imported bio-coal for producing stocks of fuel instead of rotting heaps (so far still allowed) in landfills, more is to be gained.

24154. Tom Curtis at 00:09 AM on 27 May 2016
       In-depth: Experts assess the feasibility of ‘negative emissions’
       

       SirCharles @2, at one point (3:00 forward) the video you show asserts that "no such [CO2 sequestration] technology exists" with regard to biomass, biochar and (presumably) other technologies such as carbon capture and storage.  This assertion is the basis of "survivable IPCC projections" are "science fiction".  It is also egregiously false.  One would have to suspect, deliberately so.  Biochar technologies, for instance, have been extensivly explored, and the base technology (charcoal) has existed on Earth for over a thousand years.  Biochar technologies may not yet been proven to be commercial or scalable to the extent required, but that is because they are in early development.  The same could also be asserted with equal truth of solar power, or wind power.  Like biochar, these are technologies still being developed and which look to be both commercial without subsidies and massively scalable within a decade or so.  Again, the same can be said of biochar.  The video does not, however, assert that the biochar technology is not yet proven, or commercial.  It asserts that it does not exist, thereby showing the video to be propoganda, not commentary.

       This is even more the case with the assertion that "no such technology as" biomass, ie, the growing of plants, actually exits.

       Equally troubling is the description of only RCP 4.5 and 2.6 as "survivable".  No RCP pathway represents an existential threat to humanity, although RCP 6 and RCP 8.5 will result in a massive economic challenge and a very large number of deaths through disease and natural disasters.  Describing only the lowest two pathways as "survivable" represents a gross alarmism which is as intellectually respectable as the denialism that asserts that RCP 8 is essentially without risk.

24155. denisaf at 22:46 PM on 26 May 2016
       In-depth: Experts assess the feasibility of ‘negative emissions’
       

       It is quite clear that even the best of the practical measures to capture emissions will do no more that slow the rate of increase in concentration level in the atmoshere and absorption in the oceans. Whilst these measures should be employed, focus should also be on measures to adapt to the impact of the irreversible rapid climate disruption and ocean acidification and warming. The measures being implemented in the Netherlands, London and New York to cope with sea level rise and storm surges are sound examples of adaption measures.

24156. SirCharles at 22:16 PM on 26 May 2016
       In-depth: Experts assess the feasibility of ‘negative emissions’
       

       The IPCC's 'Representative Concentration Pathways' are based on fantasy technology that must draw massive volumes of CO2 out of the atmosphere late this century, writes Nick Breeze - an unjustified hope that conceals a very bleak future for Earth, and humanity.

       => Survivable IPCC projections are based on science fiction - the reality is much worse

24157. MA Rodger at 19:28 PM on 26 May 2016
       2016 SkS Weekly News Roundup #21
       

       ubrew12 @5,

       I think it worth adding a couple of points or so.

       Firstly, the NOAA/ESRL Annual Greenhouse Gas Index is looking at the atmospheric content not emissions. So the trends in their numbers will be affected by natural pertubations. I think this results in an exaggerated rise, an additional acceleration, over the last couple of decades since 1990 or 2000.

       Secondly, if we do accept that acceleration in the AGGI numbers continues, it woud suggest the 2xCO2(e) level arrives in 20 years. But note, as well as being exaggerated by natural events, that underlying acceleration also assumes we continue to grow FF use as we did since 1990 or 2000. I don't see that happening.

       Thirdly, I agree that CO2 is the true devil because a significant proportion of it it will be with us for millenia. (It's likely destination will surely be our decendents using their technology to remove it rather than allow it to, for instance, send Greenland into melt-down.) Yet, I feel there is the potential for tackling SO2 emissions without tackling the positive forcings. Turning off coal-use or more effective/widespread scrubbing could easily see SO2 emissions massively reduced. Indeed the current trends are down. Sadly this is not so for the big GHGs.

24158. ubrew12 at 11:45 AM on 26 May 2016
       2016 SkS Weekly News Roundup #21
       

       Tom Curtis@4: That sounds reasonable.  The reason to exclude nonCO2-GHG's in an 'equilibrium climate sensitivity' calculation is their relative impermanence once 'action is taken'.  But that liability turns into an asset for sun-shading aerosol pollutants, since it is now their shading capability that is impermanent, not IR blocking.  So we should follow CO2 alone for an idea of future IR blocking-induced heating, but understand that once aerosols rain out an additional heating will incur.

24159. ranyl at 09:02 AM on 26 May 2016
       In-depth: Experts assess the feasibility of ‘negative emissions’
       

       Ta,

       Some questions came to mind.

       Do the scenarios with BECCS take in account the increased amount of biomass needed due to the drop in efficiency of power stations with carbon capture?

       How much land will be needed to grow enough biomass for BECCS to sequester a 10ppm atmopheric drop, which is equivalent to ~20ppm in real terms for as CO2 drops the sinks re-release the carbon they sequestered as CO2 levels rose?

       If 350ppm was the goal, then considering CO2e at ~480ppm, then that means ~260ppm of CO2 equivalence will have to be sequestered by 2100 to reach that goal.

       With that amount of carbon involved, ~100years of current emissions, and considering all the additional emissions to come from forest fires, melting permafrosts and biodiversity losses, adding in the need for additional land use for more food (due to population rise and increasing diet ambundance), is there enough land for BECCS (if actually carbon negative when all things considered, especially if you change land use) to make a real impact?

       Surprising how little massively powering down is mentioned, for even if BECCS is carbon negative to a degree is it as carbon negative as leaving the forest standing?

       Mind you massively powering is not popular in general terms even if it would make things like ecosystem regeneration easier to acheive.

       Wonder if BECCS could be intergrated into an ecosystem regenerating carbon sequestering system of land use like multiple species coppiced natural woodlands with paths and rides?

24160. scaddenp at 07:31 AM on 26 May 2016
       CO2 is not the only driver of climate
       

       Actually I am starting to think billev is just trolling. He has so absolutely refused to look at the OHC record despite it being a better measure of global warming that surface temperature. Now why would that be? Tom has pointed out his outrageous claim that Kraktoa comparison is invalid. (If 400ppm of CO2 is "too insignificant to affect climate", then how come 3.9ppm of something else can?). He keeps going on about thickness of steel as if this was somehow relevant. (We can calculate whether given thickness of steel could stop a bullet just as we can calculate effect of 3w/m2 of extra radiation). If he is just here to have amuse himself at our expense, then I suggest "Do Not Feed The Troll."

       The obvious alternative is that he has a cognitive bias against AGW from either ideology or group identity that prevents him comprehending any contrary fact, which also means we are wasting our time in trying to educate.

24161. DSL at 07:16 AM on 26 May 2016
       CO2 is not the only driver of climate
       

       billev: "What then caused the, "on schedule" beginning of another pause shortly after 2000?"

       What pause?  It's already been pointed out to you that most (90%+) of the accumulating energy is being stored in the oceans, and much less (3-5%). is being stored in the atmosphere.  Why would you base your arguments about warming on such a small sample of the climate system?  This is akin to reviewing a restaurant after having had a bite of appetizer and a drink of tap water.  Ocean warming shows no "pause."
       
       Further, you do realize that the greenhouse effect has been directly observed, yes?  Surface-based instruments have measured down-welling longwave radiation from the atmosphere for a while now.  So you can make baseless claims about the greenhouse effect not being real, but you're simply wasting time.

24162. Tom Curtis at 05:11 AM on 26 May 2016
       CO2 is not the only driver of climate
       

       billev @39:

       "First, the Krakatoa example is not a good one. There is no comparison between the effect of the current level of CO2 and the effect caused by the gas and ash disgorged by the eruption of Krakatoa."

       Argument by assertion is likewise an example of irrationality masquerading as rationality.  It is also an example of 'sloganeering', as defined and prohibited in the comments policy.

       As the argument stands, you have supported your argument from incredulity by an analogy (bullet and steel sheet) but merely assert that the analogy applies with respect to CO2 increases, but does not apply to the much smaller (as measured by parts per million by mass) injection of SO2 into the atmosphere by Krakatoa.

       Perhaps you should support your claim by some basic facts, such as:

       A)  The preindustrial CO2 level raised the Global Mean Surface Temperature (GMST) by approximately 33 C (12.8%) relative to what it would have been in the absence of CO2.

       B)  CO2 levels have risen by 43% since the the preindustrial.

       C)  Therefore it is obvious because very thin sheets of steel will not stop a bullet that the increase in CO2 could not have had any effect on GMST.

       I can then introduce you to the idea of a non-sequitur.

       More seriously, as this example argument demonstrates, you rigourously refuse to quanitify your argument because any such quantification (if not ridiculous based on known facts) will show your argument to be an absurdity.  Instead you rely on arguments from incredulity, from assertion, and from unjustified analogies.  Specifically to your analogy, you have not shown that the preindustrial CO2 concentration has no effect, so that it is analogous to a steel thickness which has no effect.

24163. Tom Curtis at 04:52 AM on 26 May 2016
       2016 SkS Weekly News Roundup #21
       

       ubrew12 @1&3, if you wish to determine the effect of human activities on climate, you should include all effects including the cooling effects of aerosols and albedo changes for LUC.  Doing so shows a total current anthropogenic forcing of about 2.1 W/m^2, not the 3.1 obtained by looking at WMGHG alone as you are doing.  What is more, as is apparent on this graph, the forcing is rising steadily, not accelerating:

        

       You may think that is unreasonable in that the aerosol effects will wash out of the atmosphere fairly rapidly in the event that we cease anthropogenic emissions (which is correct), but equally, if we cease anthropogenic emissions non-CO2 well mixed GHG will rapidly decompose, and CO2 will be fairly rapidly be taken up by the ocean until ocean/atmosphere equilibrium is reached.  The upshot is that the long term climate effects are best determined by considering CO2 alone, and allowing for the effects of the CO2 cycle.  For the short term effects, however, there is no substitute for looking at all forcings, including the negative anthropogenic forcings. 

24164. billev at 04:19 AM on 26 May 2016
       CO2 is not the only driver of climate
       

       I will try to address the several statements directed to me.  First, the Krakatoa example is not a good one.  There is no comparison between the effect of the current level of CO2 and the effect caused by the gas and ash disgorged by the eruption of Krakatoa.  The graph showing the relationship between various forcings and the temperature record causes me to wonder why these forcings would follow such a reasonably precise 30 year pattern.  I would not think a continually increasing presence of CO2 would follow such a timed pattern. If opposed forcings caused the pauses in warming then, again, why such a patterned occurence?  One earlier post informed me that the warming pause in the 1950's and 1960's was caused by the presence of aerosols  What then caused the, "on schedule"  beginning of another pause shortly after 2000?  As far as the argument that small amounts can be effective I say that that is not always the case.  A one inch thick sheet of steel can stop a small arms bullet but a 1/2500th of an inch thick  sheet of steel cannot.  If a person cannot detect a rather precise pattern of warming and pause in warming in the Global temperature record starting in 1880 I can only say that to me the pattern is obvious.  Whether it will continue in the ensuing years who can say.  But I do believe that more attention should be paid to that distinct possibility. It would seem to offer a better prediction of future temperatures than most of the computer models have done. 

       Moderator Response:

       [RH] Note that your comment here has a complete lack of supporting evidence or citations of any research in support of your position. We expect a little bit more from commenters on SkS than most other websites. You're more than welcome to argue your position but you're currently skating along a thin line of sloganeering. If you wish to retain your commenting privileges you're going to have to up your game a few notches.

       Alternatively, if you're here to try to learn something new about these issues, please acknowledge that you don't understand the science and other commenters who are knowledgeable will be more than happy to supply you with information, along with the requisite citations to review. 

24165. ubrew12 at 01:50 AM on 26 May 2016
       2016 SkS Weekly News Roundup #21
       

       Thanks for responding.  However, at around 1850,  CO2 and CO2+nonCO2-GHG's are at the same Pre-Industrial value: 280ppm.  Which value applies today?  CO2 or CO2+nonCO2-GHG's?  I'm sure the Infrared Radiation doesn't discriminate: the latter applies to climate sensitivity calculations.  Hence, 560ppm within 10-20 years.  Here's the relevant graph from the article: 

24166. barry1487 at 20:40 PM on 25 May 2016
       Climate denial arguments fail a blind test
       

       Australia has a small population so any measures to reduce greenhouse gas emissions will have insignificant impact

       Same goes for many countries. Collectively, a bigger impact. If every country dropped out of mitigating CO2 emissions on the same argument... so see it as a collective issue, not nationally self-serving. Atmospheric CO2 is borderless.

       It would be better if the focus was on issues to cope wth the consequences of climate change

       Why not focus on both? Reducing emissions means less to deal with later on.

24167. bozzza at 19:47 PM on 25 May 2016
       2016 SkS Weekly News Roundup #21
       

       No, those numbers only apply to carbon emissions !

24168. denisaf at 17:19 PM on 25 May 2016
       Climate denial arguments fail a blind test
       

       Denial of the occurrence of irreversible rapid climate change and ocean acidification and warming just shows lack of understanding of physical principles and the available evidence. Denialists, of course, often have vested interests that inhibits their seeking to gain understanding. For example, here in Australia, we have politicians who are denialists, presumedly because they believe that it will get them votes.

       Another issue is what measures should be implemented to cope with the situation as best as physically possible. Australia has a small population so any measures to reduce greenhouse gas emissions will have insignificant impact, despite policies to encourage solar and wind systems. It would be better if the focus was on issues to cope wth the consequences of climate change, such as sea level rise.

24169. Bob Loblaw at 11:34 AM on 25 May 2016
       CO2 is not the only driver of climate
       

       billev:

       Your first sentence falls into the myth "CO2 is just a trace gas". (Follow the link to see why that is wrong. Same link that scaddenp posted.)

       There seems to be quite a bit that you just "can't believe". It's not a strong argument. (It's not an argument at all, as Tom points out in his last paragraph.) If all you can do is keep saying you can't believe stuff or don't see proof, then you'll soon get moderated out for repetition.

       [And I'll bow out, for now, to avoid the policy against dog-piling.]

24170. Jim Eager at 08:50 AM on 25 May 2016
       Climate denial arguments fail a blind test
       

       "Remove the political context and just deal with numbers."

       Snort! Good one there Barry.

       Never mind that AGW dinial is all about politics, not numbers.

24171. Tom Curtis at 07:39 AM on 25 May 2016
       CO2 is not the only driver of climate
       

       billev @35, the dry mass of the atmosphere is 5.352 x 10^18 kg.  In 1883, Krakatoa errupted, ejecting 2 x10^10kg, or 3.7 parts per 1000 million of sulfur into the atmosphere.  That became the dominant change of effect on climate for the subesequent few years, reducing global mean surface summer temperature by 1.2 C in the following year.  The effects of the erruption are described by wikipedia, saying:

       "Global climate
       In the year following the eruption, average Northern Hemisphere summer temperatures fell by as much as 1.2 °C (2.2 °F).[10] Weather patterns continued to be chaotic for years, and temperatures did not return to normal until 1888. The record rainfall that hit Southern California during the “water year” from July 1883 to June 1884 – Los Angeles received 38.18 inches (969.8 mm) and San Diego 25.97 inches (659.6 mm) – has been attributed to the Krakatoa eruption. There was no El Niño during that period as is normal when heavy rain occurs in Southern California, but many scientists doubt that there is a causal relationship.

       The eruption injected an unusually large amount of sulfur dioxide (SO2) gas high into the stratosphere, which was subsequently transported by high-level winds all over the planet. This led to a global increase in sulfuric acid (H2SO4) concentration in high-level cirrus clouds. The resulting increase in cloud reflectivity (or albedo) would reflect more incoming light from the sun than usual, and cool the entire planet until the suspended sulfur fell to the ground as acid precipitation.

       Global optical effects
       The eruption darkened the sky worldwide for years afterwards, and produced spectacular sunsets throughout the world for many months. British artist William Ashcroft made thousands of colour sketches of the red sunsets halfway around the world from Krakatoa in the years after the eruption. The ash caused "such vivid red sunsets that fire engines were called out in New York, Poughkeepsie, and New Haven to quench the apparent conflagration." This eruption also produced a Bishop's Ring around the sun by day, and a volcanic purple light at twilight.

       In 2004, an astronomer proposed the idea that the blood-red sky shown in Edvard Munch's famous 1893 painting The Scream is also an accurate depiction of the sky over Norway after the eruption.

       Weather watchers of the time tracked and mapped the effects on the sky. They labeled the phenomenon the "equatorial smoke stream". This was the first identification of what is known today as the jet stream.

       For several years following the eruption, it was reported that the moon appeared to be blue and sometimes green. This was because some of the ash clouds were filled with particles about 1 µm wide—the right size to strongly scatter red light, while allowing other colors to pass. White moonbeams shining through the clouds emerged blue, and sometimes green. People also saw lavender suns and, for the first time, recorded noctilucent clouds."

       By your reasoning that the amount of CO2 in the atmosphere is too small to have a significant effect, it follows that Krakatoa could have had not effect on the climate as well, and the reports above are pure nonsense.

       The Sun shines steadilly, producing from 1360 W/m^2 to 1361.6 W/m^2 at the Earth's mean orbital distance over the entire historical sunspot record.  That variation of 0.06% of insolation, or 600 parts per million, is considered to be the major driver changes in the Earth's climate by some people.  By your reasoning with regard to CO2, however, it can have no effect.  That is particularly the case given that the current increase in CO2 concentration relative to the preindustrial changes the Earth's energy balance (all else being equal) by 1.9 W/m^2 or (once albedo is accounted for) by 69.6% more than the difference between the Maunder Minimum and the grand solar maximum of the 1950s.

       In essence, if your argument was valid against CO2, there are no changes in the Sun's radiation or atmospheric factors that could make any difference to the Earth's climate.

       Of course, your argument against CO2 amounts to an argument from incredulity.  It is not an example of reasoning, but of irrationality masquerading as reason.  The Dilbert quote in the above link is apposite. 

        

24172. scaddenp at 07:15 AM on 25 May 2016
       CO2 is not the only driver of climate
       

       You claim that small concentrations of CO2 affecting temperature is illogical, but try here to  check your grasp of what is logical.

       Now try this for logical.

       Statement A: "pauses in that warming that does not appear to be compatible with CO2 being the the principal cause of the warming."

       Statement B: "temperatures are obviously subject to the effects of other factors."

       See the problem? What is more, both myself and Glenn have demostrated to you that when you take into the "other effects", the temperatures are accounted for. Did you somehow fail to read our posts, or do you just have trouble comprehending things that conflict what you want to believe? I would note, that our demostrations were not simply "hand-wavy" points but quantitive based on physics and measurement.

       "The various alternating periods of pause and warming have occurred on what appears to be a consistant schedule."

       Not that I can see at all. How about you put up some evidence to back what you believe instead of just making wild assertions and ignoring responses? Did you base your conclusions on facts you have studied or what you would prefer to believe?

       Current climate theory (asserting that earth's climate is changed by the net forcings, natural and manmade) is able to account for present and past climate change, qualitatively and quantitively, using only known physics. By contrast you seem to believe that instead climate is changed by some unmeasurable, undetectable natural cause which is nonetheless accumulating heat in our oceans at rate of 4 hiroshima bombs/sec. Now that to me defines illogical.

       Ignoring responses that people make to you and simply repeating wild assertions without evidence is sloganeering and not permitted on this site.

24173. billev at 04:37 AM on 25 May 2016
       CO2 is not the only driver of climate
       

       To state that CO2 at one cubic foot per every 2500 cubic feet of atmosphere is the leading driver of climate seems illogical to me.  Since 1880 there is a strong indication of a definite pattern of warming and pauses in that warming that does not appear to be compatible with CO2 being the the principal cause of the warming.  The various alternating periods of pause and warming have occurred on what appears to be a consistant schedule.  This makes it difficult to believe a constantly increasing entity such as CO2 or random climate effecting incidents are influencing this pattern of temperature change.

       Moderator Response:

       [RH] Note that, your lack of understanding the science does not mean that the science is illogical. 

       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.

24174. Glenn Tamblyn at 16:38 PM on 24 May 2016
       CO2 is not the only driver of climate
       

       billev
       
       You seem to be assuming that the clearest correlation between rising CO2 and some climate signal will be against the surface air temperature record.  Thermodynamically, this isn't reasonable, your apparent underlying premise is wrong.
       
       The logic is as follows:

       • CO2 is the largest single driver of climate in our current state, but it is not the only one.
       • The Net of all drivers will determine the total radiative imbalance for the planet.
       • A positive imbalance will produce an accumulation of heat in the various components of the system.
       • Because of it's much higher thermal mass the oceans will represent the largest single location where heat accumulates. If the net of all forcings is positive, this is where we would expect to see the clearest, least noisy signal and the best correlation.
       • Much smaller thermal masses such as the atmosphere represent a much noisier signal and are not expected to show as clear a response.

       Near monotonic increase in the heat content of the oceans is the strongest, clearest expected signal based on the thermodynamics. Unfortunately air temperatures are the dataset of most interest to us since that is where we live. But they aren't the primary evidence of the underlying process, ocean heat is.

       If you look at the graph in comment 2 above, although it doesn't show the most recent years, it gives a good indication of what was happening in the first half of the 20th century.

       • GH Gases hadn't yet marched away as a clear forcing.
       • After the eruption of Santa Maria in 1904, volcanic activity was low until the eruption of Mt Agung in 1964.
       • Although it isn't clear from the graph, solar activity was likely a little higher.
       • Land use impacts were still small.

       In the late 20th century:

       • There was higher volcanic activity.
       • GH gases, particulary but not only CO2 had a much larger impact.
       • Solar output has been declining slightly.
       • Land use changes took off.

       And very importantly, prior to 1957 we dont have any meaningful data on ocean heat content. So we can't usefully investigate the extent that atmospheric warming may have been driven by heat transfers out of the oceans. So we need to be careful to not draw more conclusions than can be justified from the more limited evidence from the early 20th century. There is some evidence tentatively suggesting that the early 20th century warming was particularly in the Arctic, possibly suggesting a change in ocean currents in the North Atlantic.
       
       The data for climate change is a jigsaw puzzle, with clearer pictures in more recent decades and less certainty earlier on. But when the first analyses of past ocean heat content changes appeared around the turn of the century they were rightly labelled 'the smoking gun'.
       
       Atmospheric temperatures are incredibly important to us since they reflect what is happening where we live. But thermodynamically the changes in the ocean are the biggest piece of evidence.

24175. scaddenp at 11:55 AM on 24 May 2016
       CO2 is not the only driver of climate
       

       Billev, what is done is to measure all the of known forcings acting on the climate and recalculate onto a common basis (as if change in radiative input at the top of atmosphere). See the graph in comment 2 or 23. (In fact read the responses to Kimura).  What theory would predict, is that climate would follow the net forcing. ie sum up all the positive and negative forcings.  This is discussed in some detail on this post.

       These are the measurements behind the attribution. You have already agreed that energy is not magically created and that climate change must have some cause.

       The relevant figure is:
       

       This is for surface temperature record. It is more striking for Ocean Heat Content which so far you have avoided, despite it being a considerably less noisy record than surface temperature. (The noise is surface temperature is ocean/atmosphere heat exchange.)

       Note also that you can run models with only natural forcings, only anthoprogenic forcings, or both. The results are these (IPCC TAR).

       

       Note that anthropogenic works better than just natural, but both is closest.

       
       Now it is good to be skeptical and demanding a high level of certainity in drawing conclusions, but I notice that you seem to be only applying that to the question of whether CO2 causes this. You stated here
       that you " I would tend to think it is an alteration in the Earth's relationship with the Sun". Where was the evidence that gave you that suggestion and did you look for the proof? The orbital forcings are extremely slow, but have been negative (would cause cooling) for millenia.

       The anthropogenic hypothesis passes the test of conforming to all we know about the physics of climate. The predictions made by the science (if not the strawman versions erected by pseudo-skeptics) fit extremely well with actual observations. I do not believe you can make that claim for any other potential cause of climate change.

24176. Bob Loblaw at 11:46 AM on 24 May 2016
       CO2 is not the only driver of climate
       

       billev: "I made no reference to the fact that those temperatures are obviously subject to the effects of other factors."

       Yet such a conclusion is the logial consequence of your statement that you expect "that temperature rise should be continuous like the steady, and accelerating, rise of CO2 in the atmosphere". You can't evade the logical consequences of your position by saying "I didn't say that". If you agree that your original statement is in conflict with your actual position, then please say so.

       As for measurements showing how temperatures since 1910 can be attributed to various factors, please look at the graphs in comments 2 (author's response) and 23, and read the text that describes them. In fact, read the entire chain of comments.

24177. barry1487 at 09:17 AM on 24 May 2016
       Climate denial arguments fail a blind test
       

       Remove the political context and just deal with numbers. Good one.

24178. ubrew12 at 02:34 AM on 24 May 2016
       2016 SkS Weekly News Roundup #21
       

       The article 'Far from turning a corner, Global CO2 emissions still accelerating' contains a graph showing current CO2 at 400ppm and 'CO2+nonCO2 GHGs' at 500ppm.  This second line may hit 560ppm (a doubling from pre-Industrial 280ppm) within the decade.  Am I correct in assuming we are, within the decade, essentially 'locked in' to the equilibrium climate sensitivity of 1.5C to 4.5C?  If so, this seems a critical argument to start making.

24179. billev at 02:06 AM on 24 May 2016
       CO2 is not the only driver of climate
       

       When I say contiuous warming I am referring to those parts of the NOAA graphs of Global mean temperature from around 1910 until the early 1940's and from about 1974 until around 2002.  I made no reference to the fact that those temperatures are obviously subject to the effects of other factors.  There is currently a World wide debate over whether or not to move from the use of fossil fuels in order to reduce the production of carbon dioxide because it is causing global warming.  What measurements have been made to show how much of the amount of temperature rise since around 1910 can be directly attributed to the rise in carbon dioxide levels?    

       Moderator Response:

       [TD] Click the Intermediate tab in this post.

24180. MA Rodger at 21:55 PM on 23 May 2016
       It's cooling
       

       Concerning Vietnam's mid-winter snows @298, I did think to have a quick look into GHCN data to check out the most recent winter temperatures. Cao Bang was the station I hit upon, in the hills north of Hanoi at 800ft altitude. The NOAA data (spoilt a bit by an evident data entry error for Jan 2016) shows January 2016 was colder than recent years for its Mean Min Temp (colder than 2011 but not as cold as 1963). The data does show Januarys have been getting colder over the last few years (still not as cold as the 1960s) but the winters have also been getting shorter with Novembers & Marchs getting warmer.

       The NOAA data also gives Lowest Min Temp for each month, so we can see at 800ft we come very close to the snow line in January with lowest temperatures dropping below 40ºF in half the Januarys (dropping to 32.7ºF in 2014, & below freezing in 1995). Mid-winter snowfall higher up in the mountains of Vietnam thus should be quite normal.

24181. denisaf at 15:14 PM on 23 May 2016
       Lord Krebs: scientists must challenge poor media reporting on climate change
       

       This is a typically misleading anthropocentric discussion. The stark reality is that irreversible rapid climate disruption and ocean acidification, pollution and warming is under way largely due to the operations of industrialized civilization. The most that society can possibly do is to make decisions to slow this physical process slightly by reducing the use of fossile fuels as rapidly as is practical while adopting measures to cope wth such unintended consquences as sea level rise.

24182. pattimer at 07:05 AM on 23 May 2016
       Ocean Oxygen – another climate shoe dropping
       

       A really thought provoking article here and thanks for that Howard. Not only is exceesive nutients caused naturally by a warming world with more precipitation but due to the Haber process we are at the same time considerably adding to this excess. 

24183. Bob Loblaw at 06:45 AM on 23 May 2016
       The things people ask about the scientific consensus on climate change
       

       In addition to Glenn Tamblyn's comment (mentioned in the moderator's response above), I have also responded to billev's latest comment over here.

24184. Bob Loblaw at 06:41 AM on 23 May 2016
       CO2 is not the only driver of climate
       

       Argggh. On editing, after a failed attempt to post, I missed the links to biilev's original comment. It is here. The thread is on this post.

24185. Bob Loblaw at 06:38 AM on 23 May 2016
       CO2 is not the only driver of climate
       

       Glenn's post immediately above this one is in response to several comments by billev over on this thread. In billev's last comment, he said:

       If the CO2 caused energy imbalance is the reason for the Earth's temperature rise then that temperature rise should be continuous like the steady, and accelerating, rise of CO2 in the atmosphere.

       I am wondering, billev, just exactly what you would accept as convincing evidence that CO2 is having an effect. From the statment quoted above, it would appear that you want to see no variation from a continuous rise in temperature. That is a suprising expectation, because for it to be true, then rising CO2 would have to have two effects:

       1. It would have to have an effect that causes an increase in global surface temperature.
       2. It would have to have an effect that prevents any other known causal factors from also affecting temperatures over the period in question. That would mean:
       • reductions/increases is solar radiation could no longer cause reductions/increases in temperatures
       • increases in volcanic activity and resulting aerosols could no longer cause surface cooling
       • El Nino/La Nina cycles could no longer cause variations in global surface temperatures
       • changes in global albedo resulting in increased or decreased global absorption of solar radiation could no longer cause variations in temperature
       • changes in orbital parameters affected received solar radiation could no longer have an effect on climate
       • ...and any other factors - either known or unknown - that used to affect global temperatures could no longer have any effect.

       That would make CO2 one heck of a dominating factor, and it is so unreasonable that I think that such a belief falls into the category of "Impossible Expectations" in the five characteristics of science denial:

       

       ...but that may not be what you intended to mean, billev, when you made the statement I quoted above. If not, please feel free to expain further just what you expect in the way of evidence - what would convince you?

24186. BBHY at 21:51 PM on 22 May 2016
       Lord Krebs: scientists must challenge poor media reporting on climate change
       

       I was reading a related article over at ThinkProgress, "media-downplays-climate-science".

       Looking at the comments to that article, I have to wonder if those people are using Skeptical Science in the opposite way that it was intended. They have pushed just about every counter argument from the list over here, and just disregarded that they have all been thoroughly debunked.. I see "The consensus is false", "There were ice ages in the past", "It's a liberal hoax", "It's a trace gas", etc. They have them all.

       I would like the think that regardless of the persistent deniers/skeptics and poor media coverage, most of the populace has moved beyond the reach of these many falsehoods, but then there is still the congressional majority party that is not on our side.

24187. Glenn Tamblyn at 15:06 PM on 22 May 2016
       CO2 is not the only driver of climate
       

       billev
       
       Following on from the previous post here.

       This topic is about the other driving factors behind climate so worth reading first. 
       
       Firstly, a smaller point, the rise in the earths heat content may not be monotonic because there is a seasonal cycle. The earth absorbs more sunlight during the southern hemisphere summer when the darker (all that ocean) southern hemisphere is pointed more towards the sun This seasonal cycle may be large enough to overwhwlm the warming from CO2 etc for a year or so, thus on a seasonal scale the rise may not be monotonic. However the rise in total heat content should be roughly monotonic on timescales of multiple years.

       Then there is another assumption you are making that isn't correct. You are assuming that the temperature change, thus the heat accumulation, will all happen in the atmosphere and that thus the atmospheric temperature should rise nearly monotonically. However less than 2% of the aded heat is going into the atmosphere; most, around 93%, is going into the oceans.

       At the same time there are internal energy transfers that occur between the atmosphere and the oceans and since the oceans have hugely more thermal mass than the atmosphere a small flow from the oceans to the air, relative to the heat capacity of the oceans, can constitute a significant change in temperature for the atmosphere. As a result, atmospheric temperatures are a very 'noisy' signal; variations due to this internal variability can mask any underlying trend for significant periods, and the resulting temperature rise, of the air, won't be monotonic. The standard timescale defined by the World Meteorological Organisation to be used to detect climate changes in the atmosphere is 30 years. Running averages over 30 years or so should show roughly monotonic change. Anything on significantly shorter timescales would be more fortuitous, depending on the vagaries of internal variability.
       
       There is another approach. Since most of the extra heat is going into the oceans, we would expect the heat increase there to be roughly monotonic. And it is.
       
       This is the heat increase of the top 2000 meters of the ocean, which is a bit over half its volume. Apart from a seasonal signal you can see it is quite monotonic. A few dips associated with volcanic eruptions in 1982 and 1992, and a dip around the time of the big El Nino in 1998. Also some variation during the 60's but instrument coverage back then wasn't very good and there was likely some significant aerosol cooling before the various Clean Air Acts started clearing up air pollution. But since then, broadly, it is very monotonic. And in fact, the rate of heating is increasing, which is what we would expect with CO2 levels rising.
       
       
       
       

24188. Alun at 10:57 AM on 22 May 2016
       Lord Krebs: scientists must challenge poor media reporting on climate change
       

       400ppm is seen by many as being so small as to be irrelevant. I find I can get most people to pay attention to the fact that low concentrations can be important by pointing out that if we had HCN at 400ppm, there would be no life on earth. The issue isn't the concentration, but what happens at this concentration.

24189. Tom Curtis at 07:15 AM on 22 May 2016
       It's cooling
       

       John Hartz @301, the article was written on May 17th, and therefore was grotesquely exagerrating when it says, "Sydney is almost FIVE DEGREES ABOVE AVERAGE for a whole month".  That may yet be the case, although that is unlikely.

       Moderator Response:

       [DB] A note to all participants:  'sam' has recused himself from further participation here, finding the burden of complying with this venue's Comments Policy too onerous.

24190. Tom Curtis at 07:11 AM on 22 May 2016
       The things people ask about the scientific consensus on climate change
       

       joeygoze @13, I have yet to see a scientific paper reference Newton's laws of dynamics, or of optics, or the laws of thermodynamics (except, for the later, for those written in the very early 20th century or earlier).  Even such recently developed theories as plate tectonics are not referenced in papers discussing issues centrally related to it (eg, orogeny).  In similar manner, it would be astonishing to find a modern climate science paper referencing that CO2 is a major driver of climate, or that changes in CO2 concentration have a direct impact on global mean surface temperatures unless the paper was from an entirely different field (where assumption of such basic knowledge cannot be made), or where the reference is not for the fact of influence, but for a specific estimate of the value of the impact.

       The reason for such lack of referencing is that these are examples of 'text book knowledge', ie, facts that are so well established in the field that it can be reasonably supposed that anybody in the field (or for Newton's laws of dynamics and optics, any scientist) will know them, and have an approximate idea of their origin.  They are also facts which are simply accepted as a matter of course - about which there is a consensus.

       In general, specific referencing indicates that the fact in question is either controversial within the field, or specialist knowledge which is probably only known to a very few members of a sub-discipline.  In the example of orogeny, things which are probably well known to specialists in Chinese orogony, but not to experts in orogony in general, let alone all geologists are referenced.  Consensus, as measured by a lack of need to reference, trails the real consensus among experts because textbooks trail current knowledge - but it is real, and is relied on in science, for if scientists had to reference everything they would never get anything done.

24191. Wol at 06:04 AM on 22 May 2016
       Lord Krebs: scientists must challenge poor media reporting on climate change
       

       When all's said and done, and the professional deniers and the conspiracy theorists are taken out of the equation, the fact remains that the public at large is hopelessly ignorant of anything to do with science. The bookshop shelf space devoted to faith healing, crystal therapy, homeopathy etc is usually multiples of that on scientific subjects - even when the former is not on the science shelves.

       So many people look at a half degree of warming and take a similar attitude to it as those who argue that 400ppm is such a small amount it can't possibly have any effect. I can't see how any amount of education can get around this mindset.

24192. Kiwiiano at 05:48 AM on 22 May 2016
       Lord Krebs: scientists must challenge poor media reporting on climate change
       

       Researchtony: "This is where the contradiction lays. If CO2 increases do we life better and longer as the dinosaurs lived, happy and lush environments, or do we all die from extreme heat etc."

       Obvious...across equatorial regions we die of extreme heat as they are in India currently with 50ºC days and while it may be lusher in middle & high latitudes we just have to wait out the many 1000's of years of very erratic weather for soils to reestablish and the biosphere to adapt. 

       Good luck with that....

24193. Tom Dayton at 04:44 AM on 22 May 2016
       The things people ask about the scientific consensus on climate change
       

       joeygoze, reference to and acceptance of previous scientific publications is "consensus."

24194. joeygoze9259 at 01:23 AM on 22 May 2016
       The things people ask about the scientific consensus on climate change
       

       Back on topic, there is a clear issue about if a consensus has any place in scientific process?  The question was asked, "wouldn’t every experiment have to reestablish every single piece of knowledge from first principles before moving on to something new?"  Point being the justification to rely on a consensu.

       Although it is true scientific papers do NOT reestablish every piece of knowledge, when writing and publishing journal articles, we certainly do reference prior work to support the arguments and experimentation going forward.  It is improper to begin a scientific journal article as "everyone believes X" and therefore, we move on to the next hypothesis, experimentation and conclusion.  The "everyone believes" is not science.

       A properly written scientific article, using Global Warming as an example, would be like the following and part of the Abstract/Introduction section of a scientific journl article.

       "Current global warming theory dictates that CO2 has been a major driver of climate change throughout the 20th century (Ref, ref, ref, ref, ref).  A variety of studies demonstrate CO2 forcing has a direct impact to global mean temperatures (ref, ref, ref, ref, ref)....."

       There is no need to invoke a consensus, the prior body of scientific literature supports the new paper.  There is no need to reestablish all prior knowledge, you just properly reference it. 

24195. John Hartz at 01:04 AM on 22 May 2016
       It's cooling
       

       More inconvenient facts for Sam to digest...

       As the world warms, the weather is changing in ways far more dramatic than a little extra heat there, a little less rain there.

       Entire weather patterns are shifting, and we're already seeing the results in Australia this autumn.

       First up, some dramatic statistics to illustrate the unprecedented Australian temperature anomalies being experienced in Australia this month. Then we'll hear from an expert on why it's happening.

       • Sydney is a whopping 4.9 degrees above average for May. Sydney's average May daily maximum temperature is usually 19.5. The average is 24.3 degrees so far this month.
       • One more time for emphasis, Sydney is almost FIVE DEGREES ABOVE AVERAGE for a whole month. Wow.
       • In fact, the Sydney maximum has topped 20 every day in May so far. Tuesday hit 28. The COLDEST day of the month was 1.3 degrees ABOVE the average.
       • Hot streaks do not usually last this long. Not even close.
       • Melbourne temperatures are also way up this month. It's May 2016 average of 20.3 degrees (to date) is 3.6 degrees above the long term May daily average of 16.7.
       • It's a similar picture across Australia. Canberra is nearly four degrees above average so far this May, Hobart and Brisbane three degrees, Adelaide nearly two degrees, and Darwin and Perth both one degree.
       • The fact that it's much warmer than usual across Australia is very much in keeping with the long term Australian trend (depicted below), as well as global data showing that the world just had its hottest ever seven months — and its hottest April by a huge margin.

       Sydney And Melbourne Copping Record May Heat. The Reason Why Is Scary by Anthony Sharwood, Huffington Post Australia, May 17, 2016

24196. One Planet Only Forever at 00:41 AM on 22 May 2016
       What Sir David King gets wrong about carbon pricing
       

       sauerj,

       I am thrilled to learn that some of the GOP supporters of CFD did sign the pledge. I am hopeful that there are a significant number of "signers in appearance only", meaning they only signed it because of the threat of disinformation campaign marketing attacking them for not signing it.

       I am actually hoping that some of the GOP "signers of convenience of the Pledge" will start to argue for more rational considerate taxation of the richest to reduce taxation on the less fortunate and for the delivery of support to the less fortunate who need assistance to live a decent basic life while changing to using more responsible and unavoidably more expensive energy.

       More responsible and considerate ways of doing things are guaranteed to be more expensive and difficult than getting away with less responsible behaviour (and defineitely be less rewarding for the ones currently getting the most benefit from those understood to be unsustainable damaging activities). Getting the GOP (and Democrats) to openly admit that challenging fatal flaw of the marketplace of popularity and profitability is a key step to getting leadership that effectively advances global humanity to a lasting better future for all (rather than people in positions of power and influence trying to abuse disinformation marketing to create appearances while striving to get a better present for only a portion of humanity, or boldly promoting selfish greed and intolerance, to the detriment of the future of humanity).

24197. geoffrey brooks at 23:54 PM on 21 May 2016
       What Sir David King gets wrong about carbon pricing
       

       Carbon taxes have to be paid by the ultimate user. A simple way to collect these taxes (in the US) would be to add $1 a gallon carbon user tax to gasoline, nationwide.

       Natural gas's carbon tax should be assessed at 900BTU/cu ft, which is equivalent to 115,000BTU in a US gallon of gas...or 1 cent per cu ft. 

       Electricity is rated at 3400BTU/kw - so the % of energy generated by burning carbon would be taxed at 3 cents/KW. 

       I also think that there should be a 100% tax penalty for using electricity generated by burning dirty dangerous coal - so that proportion of a homeowner/electricity users bill would be assessed at 6 cents/KW.

       The public power companies provide charts telling us where the energy come's from (coal, natural gas, renewables). The public utilities should be paying an ADDITIONAL carbon tax (not passed on to the users) for every KW they generate from coal.

       Carbon taxes for a better world...

24198. Alun at 23:32 PM on 21 May 2016
       Lord Krebs: scientists must challenge poor media reporting on climate change
       

       Scientists do have to challenge the PR spin of the stock market behemoths. If they don't, the behemoths just get their boys appointed to run the research and then the quality scientists get sacked.

       Challenging media coverage on specialist sites is helpful for ensuring that interested parties know what to challenge, but it is of no use in educating the population and politicians. They don't read these sites. Expanding these services to deal with the mainstream media is what is needed and scientists doing it directly too.

24199. Joel_Huberman at 23:12 PM on 21 May 2016
       Lord Krebs: scientists must challenge poor media reporting on climate change
       

       Scientists already are providing feedback about media coverage of global warming issues. ClimateFeedback.Org hosts comments from multiple climate scientists about important media articles. This important group is currently trying to get crowd funding so that it can expand its media coverage.

24200. Eclectic at 22:21 PM on 21 May 2016
       It's cooling
       

       Thanks for that info, MA Rodger.

       Sam's ideas and claims are certainly a joke.

       As to Thailand, Sam links us to a blogger in Bangkok [ww.iamwannee.com] who goes on to say that April 2016 was "sweltering" [unquote] and seemed like "the hottest year ever" [unquote] .

       It seems clear that Sam doesn't check his sources, and doesn't apply any common sense.  And accepts any second-hand "denier" guff that comes his way.

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