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Comments 19651 to 19700:

19651. Jfaw70 at 02:35 AM on 7 May 2017
       Sea level rise due to floating ice?
       

       Can anyone tell me how much is trapped in sea ice and there released when sea ice melts? There must be billions of tons of trapped air in floating sea ice I would assume, but I'm no expert. I don't have to be an expert to know what happens to the water level in my bath tub when I push a cup into in upside down.

       Moderator Response:

       [JH] How much what? Please clarify.

19652. saileshrao at 02:17 AM on 7 May 2017
       Evidence Squared #10: Debunking William Happer's carbon cycle myth
       

       Unfortunately, John Cook and Peter Jacobs are also oversimplifying in the first video. Just because the metabolic carbon cycle is closed doesn't mean that it is balanced. Indeed, 20 million acres of land get desertified and 30 million acres of land get deforested each year, which shows that the metabolic carbon cycle isn't balanced. The planet's ecosystems are far from being in equilibrium.
       
       In his PNAS paper from 2008, Barnosky estimates that the biomass of all wild megafauna was steady at around 200 Million tons (MT) between 10K-100K years ago. Since then, the human-livestock population has overwhelmed the planet's ecosystems.
       
       Currently, the human biomass alone is 500 MT and we metabolize 0.93 GT of dry matter biomass (IPCC AR5 WG3 Chapter 11). Our livestock biomass is well over 1000 MT, but they metabolize 4.69 GT, FIVE times as much as all humans put together, because they are an unnatural mix of mostly young animals, who get slaughtered before they reach puberty.

19653. BaerbelW at 01:19 AM on 7 May 2017
       There is no consensus
       

       qwertie @749 & 750

       I disagree that we have to follow the framing of those who still deny the consensus and to then basically censor ourselves by no longer mentioning particular studies.

       As for the details from "Consensus on consensus", they are already just a click away and - at a guess - it wouldn't matter at all if that information were also included right within the rebuttal. They'd still ignore and/or twist it to their liking.

19654. Eclectic at 21:47 PM on 6 May 2017
       Humans are greening the planet, but the implications are complicated
       

       LinkeLau, like you I would not care to quantify the degree of benefit coming from "increased greening".  However, not many years ago there was a study by agricultural scientists, indicating that another 1 degree rise in AGW would cause a roughly 5% drop in wheat/maize/rice production (per Hectare), and 2 degree rise would cause a 10% reduction.  If so, then this reduction in food for humans would override any benefit from increased leafy food for livestock.

       Alas, I have not managed to re-discover the reference for the study, but IIRC it involved 3 research centres, one of which was in Sri Lanka and one in USA or Europe, and one in Australia I think.

       In trying to quantify things, we must remember that the increased greening of the land would not apply to the 73% percent of the globe which is ocean ( and including Antarctica ).  And probably not apply to a further 3% which is already commited to conventional crops.

       I speculate that there would be no extra sequestration of carbon by seaweeds, since they are already suffering from a surfeit of "available carbon" courtesy of ocean acidification.

       Rainforest would be in the region of 2% [and falling] of global area, and that amount is small and unlikely to be permitted to increase.  So an increased "cloudiness" would likely not occur, to have any effect on cooling through more reflectiveness.

19655. LinkeLau at 19:15 PM on 6 May 2017
       Humans are greening the planet, but the implications are complicated
       

       Dear Tom@4

       Thank you for your extensive answer and elaborations.

       1) In general I think it is a very hopefull message that additional plant growth could eventually drawn down all anthropogenic CO2 emissions, but I also understand that 'the price is high' for many plant and animal types. On the other hand - and maybe it is a form of my ignorance - I somehow trust that nature will find a new balance which will be positive for some plant and animal types and negative for others. Is it too bold to state that more vegetation in the long term means more biomass and also a wider variety of species? If we take a look at the dense rainforrest we are all happy about the variety of species that live there. Why couldn't that happen in large parts of lets say Australia, the Soviet Union, Canada or the US? With current agro technology development (agro towers, led light spectra, meat production based on stem cells, etc.) most of these lands will probably become obsolete for food production in the near future (30-100 years). So, reforrestry could at least sequester a lot of the access CO2 we pumped in that air. Lets 'built' forrests on agro ground that is no longer needed. It is already done in the Netherlands where obsolete grounds are 'given back' to nature.

       2. I don't have any expertise in this field and also based on logic reasonining it is hard to find an answer, but given the very cloudy atmospere in the rainforest I would guess that a lot of temperature will be trapped near surface, but as a compensation extra clouds reflect incoming solar. What the net effect will be? I can only guess. If I take a look at the maps that NASA produced it seems that the rainforrest could also have been a dessert without the forrest (assumption: the forrest keeps the forrest although solar irradiance is very high in some of those areas)

       3. Probably without these resistance to aridity the world would have been as it is now. Maybe this is one of the reasons (a miricle?) why the earth did not experience a runaway greenhouse effect before: plants adapt to a large extend if temperature as well as CO2 in combination increase to a high level by creating their own biotope? The cloudiness that follows (see reainforrest) helps re-radiating solar irradiance and that could start a new cooling phase?

19656. Tom Curtis at 10:31 AM on 6 May 2017
       Humans are greening the planet, but the implications are complicated
       

       LinkeLau @3:

       1)  All coal and peat used to be plants as some time.  It follows that, at least in principle, all anthropogenic CO2 emissions could be drawn down by additional plant growth.  It is not clear, however, that that could be done without forests colonizing much, or all of current agricultural land, plus land opened up by global warming (ie, former areas of perma frost, or areas formerly lying under ice caps).

       Having said that, if you look at the last time the Earth approximated to those conditions, ie, the Carboniferous 300 million years ago, you had a situation where trees were able to colonize much of the land surface because of the complete absense of vertebrate grazers.  The energy stored as sugars by photosynthesis approximately balance the energy given up by respiration by the plants and their predators.  To a first approximation, a joule of energy stored as sugars can support either 10 tonnes of plant biomass, or a tonne of animal biomass.  That is significant  because the Earth currently supports what is probably the greatest level of animal biomass it has ever supported - which greatly limits how much carbon sequestration due CO2 fertilization is possible.  It is also significant because any growth in plant biomass for CO2 fertilization will drive a corresponding increase in plant grazers which will also significantly limit the possibilities of sequestration.

       2)  Two complex for me to say.  Given that stomata will shrink, that will to some extent compensate for the increased leaf area.  Once you also through increased predation into the mix the change in evapotranpiration is, I suspect, not predictable.

       3)  The increased resistance to aridity is the one clear benefit from the CO2 fertilization effect.  The effect of increased vegetation is to reduce temperature fluctuations (primarily because of the heat capacity of their retained water mass) but to warm the planet because plants have a lower albedo than do most soils (particularly arid soils) or sand.

       I agree that CO2 fertilization is likely a positive effect, but it is not straightforwardly so.  Remember that increased plant growth will also apply to weeds.  Further, increased leafy mass will increase the populations of insects that predate on plants, making it more difficult to protect crops. 

19657. DPiepgrass at 10:02 AM on 6 May 2017
       There is no consensus
       

       Oh, and specifically it's no longer useful to cite Doran 2009 which asked if "human activity is a significant contributing factor in changing mean global temperatures". Denialists will interpret "significant" as "anything above zero" and claim to be "in" the 97%. Instead be sure to quote one of the other 97% surveys that uses the word "most" or "mostly".

19658. DPiepgrass at 09:54 AM on 6 May 2017
       There is no consensus
       

       This page needs to be updated because denialists are using a new strategy: rather than deny the consensus itself, they deny what the consensus view is. One guy that I debated at length repeatedly ignored the words "most" and "mostly" present in many of the survey questions, instead summarizing the survey questions as asking whether warming is affected by humans "at all" so that scientists' views would not be in conflict with his (he and the 3 followers 'liking' all his posts ignored me as I repeatedly pointed out the ridiculousness of claiming "most" = "any at all".)

       Also, this page should give the EXACT wording of each survey question and the percentage of publishing climate scientists in agreement. According to the "consensus on consensus" paper, for instance, I noticed that 88% of members of the AMS surveyed whose area of expertise was climate science, agreed in 2014 that half or more of the warming was caused by human activities, including 78% who agreed that “the cause of global warming over the past 150 years was mostly human”. “An additional 6% answered ‘I do not believe we know enough to determine the degree of human causation.’” (Stenhouse 2014)

       Notice the window on this question: 150 years. Now, it’s clear the numbers on this very web site that humans caused substantially less than half of global warming in the early 20th century and before. Why, then, do 88% of American climate scientists still agree, despite this, that the roughly 1°C of global warming over the last 150 years was half-or-more human-caused? The obvious answer: although the human contribution was below half before 1940, it was far more than half in the last 50–65 years. So on average, in aggregate, humans are responsible for 50% or more, and much more than that if we limit the window to 50–65 years.

       Smart climate deniers may ignore this reasoning and focus on numbers like 78%, saying 22% disagreed and that's not a consensus. (The one I spoke with will simply change the subject and dazzle you with his encyclopedic knowledge of contrarian claims, never admitting that he holds a minority opinion or disagrees with scientists.) Yet if the question had asked about the most recent 50-65 years instead of 150 years, the consensus might have been 97%.

       We can't stop denialists from twisting words around, but if the survey questions and methodology are not easily discoverable to the public then it is harder to counter their claims.

19659. LinkeLau at 08:57 AM on 6 May 2017
       Humans are greening the planet, but the implications are complicated
       

       I am a bit puzzled why the Greening trend is not discussed much more. It is a) factual and b) might have large effects on global warming. Some questions that arise are:

       - how much carbon could vegetation take out of the air? If terrestrial vegetation now has a total of about 600 gigaton of embodied carbon, can that grow to 800 gt, or maybe even double to 1.200 Gt? In that case a large part of human produced CO2 can be taken out of the air. Or is this a false assumption?

       - what happens with humidity and cloud development when forests become more dense? How does this effect cooling or heating?

       - as stomata have to be less open when co2 level increases plants become more h2o efficient. This would mean plants can more easily survive on dry and hot places. And how does this affect the temperature as formerly dry places (desserts) are reforrested again. It seems that dessers now cool off quicly and also have a sort of Albedo effect

       overall, this seems to be a very positive side-effect of raising co2 levels but it seems a bit ignored.

19660. chriskoz at 08:26 AM on 6 May 2017
       Evidence Squared #10: Debunking William Happer's carbon cycle myth
       

       Tom@1,

       I find more appalling Happer's Godwin argument video where, he starts the discussion by comparing Paris Argeement to be "like  Munich Agreement".

       So Happer jumped to the Reductio ad Hitlerum - an ultimate emotive fallacy right from the start, and totally unprovoked.  Reductio ad Hitlerum is a technique used at the end of emotional discussions by trolls or angry disputers who run out of rational arguments. So any rational discussion ended before it started because a rational person will not want to compare their argument to the worst attrocities in history because it's like descending into mud to restlle with pigs.

       It's absolutely shoking that a person with scientific credibility (PhD in atomic physics) and experience (e.g. in optics and spectroscopy) would descend into such primitive, emotive fallacy, a 100% contradiction of epistemic reasoning. Can such "scientist" be capable of evidence based reasoning? I think he is not.

       At this point I have to recall that some commenters herein, have expressed a hope, that the new president could make a positive impact on AGW mitigation despite his ignorance of the problem, if he surrounds himself with right advisors who help him with right decisions. A hope, that I very much doubted from the start, because people tend to surround themselves with the peers they like and represents similar level of intelligence and moral development. That rule applies especially to the case of T-man: pigs like to roam in mud with other pigs, they are very  unlike to e.g. go to the university to listen to the lectures they don't understand. By that exact measure, T-man found himself a "scientific" advisor he likesw to hang out with and who shares his emotive stupidity. I don't need to add that Happer among scientists is the same as T-man among world leaders: a total failure.

19661. nigelj at 06:57 AM on 6 May 2017
       New publication: Does it matter if the consensus on anthropogenic global warming is 97% or 99.99%?
       

       Andy Skuce @5, yes I totally understand you needed to defend your published paper. I also think the Cooke methodology is the right approach and powell is making too many assumptions. I would have been terribly tempted to take the powell approach myself, and it's good you have highlighted why it's wrong. 

       I also just cannot believe you would get a 99.5% (for example) consensus on climate change, as climate change just has so many vested interests and ideological dimensions that are largely absent from plate tectonics, where the modern "overall" consensus appears to be virtually 100% (there is dissent on various details). The only ideological dimension to geology is likely to be the creationsim dimension.

       Climate change has far more ideological dimensions. This all gives me confidence that 97% is a compelling number and that anyting in the range 90 - 97% is plausible.

       But I was thinking more from the publics point of view of whether they care if it's 97% or 90%. In crude terms I would think the public would regard anything above 90% as pretty compelling. The public would probably regard a 60 / 40% split as much less compelling, and so on down the scale.

       I would suggest most of the public are smart enough to know there will be a few scientists paid by fossil fuel companies etc so that you are unlikely to ever get a 100% consensus, and that anything above 90% is plausible and compelling.

       However there are some people who clearly think in terms of anything less than 100% is not good enough, because thats how their minds work, but theres not much you can do about those people. 

       I dont know any specific research on how people perceive levels of consensus. However the issue is similar to probabilities and weighing the odds, and both economic science and psychology believe we make virtually 'all' decisions and judgements in life by "weighing the odds" in our minds. A google search would reveral material and research on this.

       So given how our minds work, if economics is right, I think our response to some level of consensus would most probably be proportionate to the level of consensus (no one number is likely to be a trigger, why would it be). To make sense of this I personally weigh the level of consensus against numerous other things, like the probability of whether renewable energy in large scale is feasable. My conclusion is that we have a climate change problem, and should do something

       Clearly different people will weigh the odds differently until a public view emerges on climate change. So all our understandings and actions are weighing the odds of multiple things, which is a stark sort of reality to grasp. On the other hand humanity has progressed a long way taking this approach, despite numerous problems along the way.

19662. michael sweet at 00:57 AM on 6 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       Bret Stephens most recent op-ed piece was rerun in my local paper.  Stephens claims that environmentalists incorrectly supported the corn ethanol biofuel business.  He cites a memo released by the Clinton Energy Department in support of his claim.  He claims that incorrect support shows that we have to proceed slowly on any changes we make to deal with AGW.

       I recall that environmentalists never supported corn ethanol.  Corn ethanol has always been supported by industrial farmers to use up excess corn they raise.  Perhaps someone here has better recall than I do.

19663. JARWillis at 00:09 AM on 6 May 2017
       New publication: Does it matter if the consensus on anthropogenic global warming is 97% or 99.99%?
       

       nigelj @4  I did once take on a denier somewhere on social media using this exact argument and he just became increasingly abusive. But you can't draw reliable conclusions from an uncontrolled trial of one subject (first with the news!) so it might be worth trying again.

       I suppose the crucial thing is to be polite and patient. Difficult though.

       While I'm here I must say I am a great admirer of the good people on this site.

19664. Andy Skuce at 16:38 PM on 5 May 2017
       New publication: Does it matter if the consensus on anthropogenic global warming is 97% or 99.99%?
       

       I agree that quibbling about the precise high consensus on AGW is rather pointless. However, Powell's paper had some harsh criticism of Cook et al 2013 and was not something that we felt we could ignore, especially as it was published in a peer-reviewed journal.

       We are convinced, as we explain in our paper, that the correct consensus estimate is around 97%. There really is a small percentage of scientists  (and published papers) that rejects or minimizes the dominant human cause of recent global warming. If you adopt a methodology, as Powell did, that only those papers (or scientists) that explicitly reject AGW, then you would miss several papers that implicitly reject AGW or minimize the human influence. These scientists should not be counted as endorsing the mainstream view that human emissions are the main cause of recent warming.

       My view is that it probably makes little difference for messaging purposes what percentage you use as long as its above 90%. But as far as I know, no experiments have been done to test this. 

19665. Andy Skuce at 16:17 PM on 5 May 2017
       Is the climate consensus 97%, 99.9%, or is plate tectonics a hoax?
       

       There were a couple of fairly recent articles cited in the paper that would count as rejection of plate tectonics:

       Ollier, C. D. (2006). A plate tectonics failure: the geological cycle and conservation of continents and oceans. Lavecchia, G. and G. Scalera (eds.), 427-436.

       Scalera, G. (2003). The expanding Earth: a sound idea for the new millennium. Why expanding Earth? A book in honour of OC Hilgenberg. INGV, Rome, 181-232.

       These are published in books and it's doubtful if they were rigorously peer reviewed. There are probably others. Incidentally, I believe Ollier also rejects the mainstream position on climate change.

       The last prominent western scientist to reject plate tectonics was the American petroleum geologist Art Meyerhoff.

       The Soviets were slow to embrace plate tectonics, mainly because of the influence of the influential old men who ran major research institutions. The Communist Party actually accepted the theory before many of the Soviet Union's scientists did. 

       My first ever geology course at Sheffield University in 1972 was taught by the department head, who was a plate tectonics denier.

       There's more on this in my blog article Consensus on plate tectonics and climate science.

19666. scaddenp at 12:48 PM on 5 May 2017
       Is the climate consensus 97%, 99.9%, or is plate tectonics a hoax?
       

       And in answer to question, at first look James Maxlow still seems to carry the baton of alternative theory from carrey et al. Last publication I can see in 2001 though did a book in 2005.

       Oh, yes Jan Koziar, a pole maybe. Published this in 2016.

19667. scaddenp at 12:35 PM on 5 May 2017
       Is the climate consensus 97%, 99.9%, or is plate tectonics a hoax?
       

       I think you need to be more specific. By "published", I assume you mean published in peer review journal. Plate tectonics is a vast theory with many aspects to it and some have been considerably more controversial than other. (The current theory of climate is similar). Criticizing some critical aspect of plate tectonics would be a while a ago, but in detail there is a lot of work to do.

       Skepiticism about AGW can take many forms.

       - skepticism about the GHE would be like skepticism of mobile plates and it would indeed be a long time since a paper like that showed up in proper peer review.

       - that man is responsible for CO2 increase is just about in same category but there is indeed a recent publication ( a serious failure of peer review) doing just that. I doubt you can find an actual climate scientist who doubts it however.

       - the GHG is primarily responsible for current climate change and that climate sensitivity is significant are much more focus of published peer reviewed science papers. Got one that hasnt been shot down?? This is the camp of any vaguely respectable scientist with any expertise on climate (Lindzen, Curry, Peikle, Spenser, Christie, Tsonis, who else??).

       The one big difference between plate tectonics and climate science is that plate tectonics does not imply a policy response and furthermore not a response that is antipathetic to entrenched ideology and vested interests. Got a "skeptical" scientist that does have motivated denial?

19668. green tortoise at 11:43 AM on 5 May 2017
       Is the climate consensus 97%, 99.9%, or is plate tectonics a hoax?
       

       When was the last article skeptical of plate tectonics published?

       I remember vaguely someone in the Soviet Union doing that some decades ago.

19669. nigelj at 09:55 AM on 5 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       Tom Curtis @40, yeah I agree with pretty much all that, especially your points about most of the dominant climate change deniers being unreasonable people, and your strategies to deal with them (and the general public) in your last paragraph.

       I think it's definitely a combination of exposing logical flaws in rhetoric as much as it is about science, and that the first approach should be polite and reasoned. If they still dont "get it" then shaming some of these people for their misleading rhetoric a little might work.

       But what do you do with people with no shame, conscience or sense of public duty? Christopher Moncton? Some media "personalities"?

       Its a rhetorical question. Maybe some people are beyond hope. There is still a flat earth society.

       Just as an aside, personalities also differ. I did some basic  psychology at university and have to also deal with clients in my work. One thing I have noticed (learning the hard way) is different people respond to different techniques of people management. Some respond to diplomacy, or praise, some need to actually be bossed around, some to humour, and its important to find out which way they are, and reaslise people are different. It seems obvious, but many managers and professionals just don't get it, and assume one approach will work for everyone.

19670. Tom Curtis at 09:02 AM on 5 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       nigelj @30, over time I have come to the conclusion that treating the majority of active climate change deniers who make a point of public commentary as reasonable people is a mistake.  That is partly because long experience has shown that they are in fact completely unwilling to be persuaded - as evidenced by their epistemic hypocrissy, their accepting as valid critisms of AGW where they do not accept the parellel argument as a valid criticism of their beliefs, even when those beliefs are far more vulnerable to the criticism.

       Keeping the discussion on topic, a classic example of the later is the "do not acknowledge the uncertainty argument" as mounted by Stephens and Curry.  When you look closer, you find the IPCC make statements qualified for uncertainty in two dimensions, ie, how certain it is given what we know, and how robust it is, ie, how likely is it that future knowledge will change our view on the topic.  There uncertainty margins are also quite large, ranging, for climate sensitivity, from 1 to more than 6 C 95% confidence interval for a doubling of CO2.  Their critics who insist the proponents of climate science are too dogmatic, in contrast do not give any indication of how robust they consider their views, and typically have much narrower confidence intervals for climate sensitivity (tending to range from 1-4.5 or less).  Simple logic tells us that if the IPCC is too dogmatic, those critics are also too dogmatic - an argument they will not even consider.

       This has focussed on the more "reasonable" critics of AGW.  As you know, there are many more far less reasonable critics out there.

       In any event, I have come to realize that dispassionate debate with those critics merely serves as a false marker that their criticisms are reasonable. An unknowledgable person viewing a debate between a climate scientist and one of these disengenuous (or at least, hypocritical) critics will assume that they represent the range of rational debate.  Instead, however, it is an example of political necessity forcing a debate of thoroughly irrational views which have no impact on research because they are, typically, unable to be framed in a way that is not transparently nonsense to those most informed about the issues.

       In that situation, the greatest service we can provide to our reader is to clearly mark the views we are criticizing as, in fact, irrational.  Where the person we are arguing against has a repeated history of mounting irrational arguments, and not accepting rational criticism, we owe it to our readers to indicate that also.

       This strategy has to vary with circumstances.  First, if we are dealing with somebody for the first time, we should indicate the argument is irrational, but not the person.  They may have been merely grossly misguided.  Further, when somebody is given a clear institutional marker of irrationality (Professor at a major university; columnist at a major newspaper), unless you clearly set the context you will come of as irrational if you relly to heavilly on this strategy.  In rebutting such people, you need to show why they are irrational.  But, you still need also to make the case that they are betraying the readers trust by presenting views that are actually irrational, cloaked with rhetoric, and rellying on the readers ignorance to make them plausible.

19671. nigelj at 08:29 AM on 5 May 2017
       Is the climate consensus 97%, 99.9%, or is plate tectonics a hoax?
       

       What you say makes complete sense to me. Lamar Smith means well, but his methodolgy doesn't make sense. The Cooke study methodology makes more sense to me.

       You also have to apply the commonsense test to any methodology. You would expect a few more sceptics in climate change than geology given issues such as vested interests, politics, and ideology that are not remotely as dominant in plate techtonics. So 90 - 97% sounds right to me and 99.7% would seem unlikely. More importantly this means 90-97% is a powerful number, in the circumstances.

       The real issue is more related to the media. They don't report so much on the consensus studies, and perhaps this is becasuse they prefer to keep a rather false or exaggerated debate going. This, if its true, is outrageous as it's putting the safety of the entire planet at risk.

19672. nigelj at 08:08 AM on 5 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       We seem to have this debate about should we politely reason with climate denialists, or be tougher on them, for example call their thinking idiotic?

       (I'm ruling out really nasty vicious insults, as it's unproductive and inappropriate)

       I think we are fooled into thinking its an either / or answer. I think maybe it requires a mix both polite reason and a few harsher words or assessments at times, depending on the individual sceptic.

       It's basic psychological operant conditioning, or carrot and stick. Trump is actually quite good at using these techniques, moving rapidly from praise to harsh criticism, even though I disagree with virtually all his policies.

       The police do a good cop bad cop routine, which is based on the same psychology.

       Frankly Stephens has such a wide range of dubious views on so many things, that you have to say theres a pattern there, and it looks irrational and cranky. He has to be called out on this. You can't just ignore it.

       Yes the NY Times has done some good articles on climate change and this needs praise, but they have made a mistake appointing Stephens in this particular role. It would be equally inappropriate to appoint Al Gore. You want someone respected for their balance, and as neutral as possible. 

19673. nigelj at 07:19 AM on 5 May 2017
       New publication: Does it matter if the consensus on anthropogenic global warming is 97% or 99.99%?
       

       JARWillis @3, I agree I can't see the point of nitpicking over the exact figure. Anything over 90% is a convincing consensus to me. If the split was nearer 60 / 40 I would be concerned.

       I think James Powell means well, but has got things wrong. He certainly can't assume that papers that dont express any opinion on cause, support agw. You are unlikely to get a 99.9% consensus, because you have various vested interests types of issues, and political / ideological issues absent from the plate techtonics issue. We know Willie Soon got funding from certain vested interests and could have vested interests himself as well.

       Just purely on my observations of climate scientists opinions, anything from 90 -97% certainly sounds right. I admit that's rather anecdotal, but it's consistent with the findings of various polls. The methodology used by Cooke looks very sensible to me.

       Regarding your comments, would we move and do something if sceptics admitted there was a 5% chance the planet was in danger? Hard to say, and interesting question. I dont know that it would be check mate for everyone as some people are just crazy. It would probably be checkmate in many peoples minds, if things were expressed the way you have expressed them.

       However I doubt you would get a sceptic to put a probablility on how right they think there are. Firstly you have a point that admitting say a 5% risk immediately becomes a significant question given the huge degree of risk. 

       Secondly once a sceptic admits any quantity of uncertainty, even a tiny degree, they will have to provide reasons, which will draw them into a rational debate, where they will have to accept they might have to alter their position on the science, which is what they are trying to avoid. It's similar to the way Trump never admits error, because if he does the whole house of Trump cards comes crashing down. The bluff is exposed.

19674. JARWillis at 05:16 AM on 5 May 2017
       New publication: Does it matter if the consensus on anthropogenic global warming is 97% or 99.99%?
       

       In spite of (or perhaps because of) being a complete amateur in this field - a British family doctor in fact - it seems to me that quibbling about the exact size of the majority of climate specialists who urge action to mitigate climate change is beside the point and merely playing into the hands of the denial industry.
       It seems to me that the only question for serious consideration is whether or not we should act on the warnings being given by an overwhelming majority of climate scientists. Surely, since we are talking about a threat to the future of civilisation on this planet, sensible people would respond to warnings even if they came from a much smaller proportion of experts in the field than 97%. I would respond if it was 50%, or probably much less.
       The thing we should be asking the deniers is how CERTAIN they are that they are right and that global climate science is wrong.Ask them to put a figure on it.

       Are they, let's say, 90% certain? They are not going to say 100% because we could write them off immediately if they said that because nothing in science is certain.

       Perhaps they settle for being 95% certain they are right.
       OK, we say, so you are urging us to accept a 5% risk that our civilisation is in peril and you say we should carry on with business as usual because that is OK.
       Surely, this is check-mate. Or am I missing something?

19675. macquigg at 04:14 AM on 5 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       Michael@34,  I disagree with your assessment of the NY Times.  They have been a great source of factual information on climate change, presented with excellent visualizations that non-scientists can understand.  Here are two of my favorites: 1) 2016-hottest-year-on-record   2) how-much-warmer-was-your-city-in-2016 

       Tom@35, I like the piece at And Then There's Physics.  It doesn't dwell on attacking Stephens, but offers the best counter argument I've seen so far.  Maybe that could be the basis for an opposing op-ed in the NY Times.

       John@36, I don't think conservatives will buy that climate change is a "pro-life" issue.  Pro-life is about punishing women for having sex, not minimizing abortions, or anything to do with promoting life.

19676. Daniel Bailey at 02:40 AM on 5 May 2017
       New publication: Does it matter if the consensus on anthropogenic global warming is 97% or 99.99%?
       

       "it seems the most ardent "deniers" are getting really old"

       Science advances, one funeral at a time.  As it ever has.

19677. knaugle at 00:38 AM on 5 May 2017
       New publication: Does it matter if the consensus on anthropogenic global warming is 97% or 99.99%?
       

       Most of the time when I look into this, at a purely amateur level, I find that there are maybe 80 really active, publishing climate scientists.  From this list, I can count less than a handfull of scientists whom I know are critical of AGW.  Roy Spencer, John Christy, and Judith Curry come to mind.  Interestingly Curry has retired and so is no longer on my list.  As is the case with Richard Lindzen and William Gray, and for that matter Christopher Moncton and Fred Singer (who aren't really climate scientists) it seems the most ardent "deniers" are getting really old and I'm not seeing their replacements.  The eternal problem of being a contrarian is always that while you might be right, it is really hard to convince anyone.

19678. John Hartz at 00:34 AM on 5 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       Yesterday, Liz Spayd, the Public Editor of the NY Times, posted a rather insipid defense of the Times decision to hire to hire Bret Stephens. She also weakly defends his first op-ed. Needless to say, her article has attracted numerous comments (445) — including one fom me. 

       Bret Stephens Takes On Climate Change. Readers Unleash by Liz Spayd, New York Times, May 3, 2017

19679. John Hartz at 00:24 AM on 5 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       Two of the better critiques of the Stephens Affair...

       The New York Times should not have hired climate change bullshitter Bret Stephens by David Roberts, Energy & Enviornment, Vox, May 1, 2017

       Could making climate change a 'pro-life' issue bring conservatives on board? by Ben Rosen, Energy/Environment, Christian Science Monitor, May 2, 2017

19680. Tom Curtis at 23:18 PM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       macquigg @33, there have been a number of responses to Brett Stephen's opinion piece, some of which are listed by Greg Craven and some by And Then There's Physics.  Dana's piece was an opinion piece for the Guardian, and others have also been in prominent forums.  Had the NYT been interested in a debate, they would easilly have found a suitable columnist to counter Stephen's nonsense.  That they chose not to is itself telling.

       As an aside, it turns out that climate science is not the only area in which Stephen's thinks the role of intellectual argument devolves to that of trolling.  Sarah Jones notes (in yet another OP in response to Stephens):

       "At this point the case against the New York Times’s decision to give Bret Stephens an op-ed column is well-known. His comments on race—he has warned of “the disease of the Arab mind” and believes Black Lives Matter contains “thuggish elements”—are atrocious. He doubts the validity of campus rape statistics, and is a climate change skeptic. In an interview with Vox’s Jeff Stein, he insisted that it’s “not true” that one in seven Americans experience hunger. (He’s wrong.)"

19681. HK at 21:50 PM on 4 May 2017
       SkS Analogy 2 - Ferrari Without Gas
       

       gnmw:

       The lapse rate is expected to decrease somewhat because surface warming leads to increased evaporation of water. When this water vapour condenses in the middle and upper troposphere it dumps its content of latent heat and causes extra warming there. This impact is expected to be strongest in the tropics and give rise to the so-called tropospheric hot spot.
       Read more about that topic here.

19682. michael sweet at 21:07 PM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       Macquigg,

       There are many real scientists who would be willing to write your op-ed but the NYT will probalby not print them.

       There is another op-ed from Bret Stephens today.  I only read the title, but it appears to argue that if we take action to control climate change it may cause economic damage.  Presumably he does not care about the damage that will certainly be caused by climate change if we do nothing.

       Bret Stephens is simply a denier who has changed his tune because the data has proven his previous position incorrect.  Now he says he thinks the climate is changing but his message is the same: take no action.

19683. macquigg at 19:43 PM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       The problem with Dana's article is that is too easily dismissed as unfair advocacy (see #20 above), and it is here in an obscure website, rather than in the NY Times.  I would write the op-ed myself, but I have no expertise in climate science.  Even if Stephens is as far beyond reason as you believe, his readers are not.  Let's assume these readers are where I was a year ago. They accept that climate change is real, and it is us.  The next step is to convince them it is bad, very likely really bad, more than just an increment in their summer electric bill.  That is where my floating ball analogy might be helpful.  We need to counter the argument that a 1 degree rise is no big deal, and even if that is the result of averaging larger changes, there will be almost as many cooler areas we can move to.

19684. John Hartz at 13:45 PM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       macquigg @31: You wrote:

       So that's what I would do with Bret Stephens, especially since he has an influential forum, the NY Times. Let's engage him on this topic. Start with an op-ed counter to his April 28th piece.

       Doesn't Dana's article (OP) qualify as such? 

19685. Bob Loblaw at 11:31 AM on 4 May 2017
       Evidence Squared #10: Debunking William Happer's carbon cycle myth
       

       A definition of "pollutant" that I like is "the wrong thing in the wrong place at the wrong time".

       Ozone is a good example. Important and beneficial in the stratosphere as a UV-blocker, but nasty stuff at ground level where it rapidly reacts with many things biological (such as lung tissue).

19686. macquigg at 10:46 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       I could be wrong about Stephens, and I know that some people are beyond reason.  I have debated a self-proclaimed "atmospheric science" expert in a public forum az-2-forum, and I relied heavily on material from  SkepticalScience.com to counter his arguments.  I was seriously tempted to call him a crackpot, but I held off, and I think that was the most effective way to demonstrate his irrationality.

       So that's what I would do with Bret Stephens, especially since he has an influential forum, the NY Times.  Let's engage him on this topic.  Start with an op-ed counter to his April 28th piece.  Resist the temptation to call him dishonest.  Acknowledge that there is plenty of uncertainty even after we accept the basic facts that the globe is getting warmer because of man-made CO2.  Show why this uncertainty should be a call for action not delay. Use the airplane analogy.

       As for further study, maybe some statistical simulations would help.  We can't predict local climates, but if we run our best models with random inputs, and we see that in 98 out of 100 simulations, the results are disastrous in some part of the world - a drought in California, flooding in Missouri, etc., maybe that will help convince people who read the NY Times, that with near certainty, we have a serious problem in a few decades.

19687. gnmw at 10:20 AM on 4 May 2017
       SkS Analogy 2 - Ferrari Without Gas
       

       HK— Why would the lapse rate decrease?

19688. Tom Curtis at 07:49 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       macquiqq @22, that quote just looks like more denial to me.  He is equating uncertainty in predicting climate (changes a century from now) with changes in weather (changes in a year).  

       Nor, despite his rhetoric, is he taking uncertainty seriously at all. Uncertainty cuts both ways.  Temperatures may be cooler than the IPCC median projections, but they also be warmer.  Indeed, it is more probable that they will be 50% greater than median than 50% less than the median increase.  Consequently, we should be more cautious in the face of uncertainty - ie, do more to prevent the potential changes. 

19689. Tom Curtis at 07:41 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       The temperature record for the Apache Powder Company, which according to Berkely Earth is the nearest station to Benson carrying a temperature record after 1973:

       

       The BEST record for Tucson, Arizona - which according to them is the nearest major city:

       

       With the qualification that both show annual temperatures, rather than summer temperatures, they are quite similar.  In particular the increase in temperature since the 1960s is approximately the same in both cases.  The variations from the trend seem to last longer in Benson, however, than in Tucson.  Part of the reason for that may be that Tucson temperatures are stabilized by being more open to air from the Gulf of California and/or the Colorad River valley.  I do note that warming in summer in Arizona has been less than for the other three seasons. 

       What that means for Benson in 80 years time with BAU is that like the rest of Arizona, it will be much hotter and much drier.  It will likely continue to have more persistent short term variation.  Any idea that Benson will retain a late twentieth century 30 year mean temperature or precipitation 80 years from now is unwarranted.  Its changes in both will be very close to those for Arizona as a whole.

19690. nigelj at 07:32 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       Macquigg @22, I'm in agreement with many of your comments on agw, but  a little mystified by your comments in this post on Stephens. You claim Stephens is taking a more reasonable position, but the material you quote Included:

       "Seemingly tiny differences in terms of inputs can make dramatic differences in terms of results. We should be humble about what we can know a year into the future, never mind a century, and we should be refining our assumptions continuously. That calls for more"

       This is just more delay and denislism. I have heard the same claim in different forms for 20 years and it subtly suggests we need far more research. Dont you see he will still be saying the same thing when sea level has risen 3 metres? 

       Sure modelling is complex and small things have big implications, but this doesn't make it just guesswork. He words this in a way to try to undermine peoples faith in the modelling. It's all just sophistry.

       Climate models are doing just fine. Predictive ability is the best way to ascertain if modelling works. I know very little about climate modelling, but enough to know its based around clusters of differential equations that calculate atmospheric changes. Equations are still equations across all fields of science, they make predications and are tested by results of those predictions. The more important thing is that temperatures over the last 50 years are tracking close enough to models predictions which shows the models have value in terms of at least global scale changes.

       I get your ping pong ball analogy by the way. I just think your wording was a little unfortunate, and created an impression that you felt 'all' climate modelling was hopeless, when I think you meant it's just hard to calculate what happens on a city by city basis? (I think that would actually always be pretty hard but scientists can only try I suppose).

       Regarding Brett Stephens, I based my comments on what I have read, and I did read the links in the original article. I don't think its helpful calling people names or swearing, but if somebody makes certain pronouncements we are entitled to draw conclusions on their mental state and must tell it as we genuinely see things and sometimes this means being critical.  Yes we should try and politely reason with people, and I do this most of the time. I think you are  generally right to promote this as you generally have. The trouble is some people are just obviously beyond reason, and with them its a waste of time trying and you need to be a bit blunter. 

19691. scaddenp at 07:23 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       What what I have read, the issues with local climate are not due to chaos (your floating ball) but with sub-scaling in GCMs and the difficulty predicting how warming will affect structural elements in the earth weather system (eg behaviour of jet streams - which influence local storm tracks - and particularly the ENSO system). Will the Hadley cells expand etc. Time and research is likely to improve prediction. Improving computer grunt will smaller cell size as well.

       However, I think it is also useful to remember that you can say with confidence that practically all local climates will get warmer. Wetter or dryer is harder. Some places are easier to predict that others as well.

19692. nigelj at 06:48 AM on 4 May 2017
       Evidence Squared #10: Debunking William Happer's carbon cycle myth
       

       I think both analogies in the posts above are good. I think almost anything can become a pollutant, dependent on circumstances and quantities, etc. We currently have a big problem with cow urine introducing excessive nitrates into rivers, and in this instance its dependent on quantities.

       But it might be better to say CO2 is a pollutant dependent on circumstances. When we exhale CO2 it becomes part of the natural carbon cycle, so doesn't raise atmospheric concentrations, where burning fossil fuels does increase concentrations,so it's reasonable to call it a pollutant if it originates with fossil fuels.

19693. John Hartz at 06:28 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       macquigg @25: You ask:

       Will more research be helpful in predicting local climates?

       I am by no means an expert on this matter, but, based on what I know about GCMs, they probably will never be refined to the point they can produce a forecast of what the climate of Benson, Arizona will be in the year 2100 under a given scenario of input variables. Some of the GCMs can currently produce forecasts for mult-state regions such as the Southeast US. Assuming that an adequate stream of funding is avaialble to do so, I suspect that some GCMs will be refined to make forecasts for smaller areas such as states. 

       A couple of follow-up questions for you:

       What is the current population of Benson?

       What is Benson's source of potable water?

19694. Evan at 06:26 AM on 4 May 2017
       SkS Analogy 2 - Ferrari Without Gas
       

       For those brave souls who have made it this far down the comment list, one more comment. Yes, the analogy may be interpreted as crude and does not hold up under all considerations of the actual greenhouse effects. The purpose was to draw attention to the fact that it takes more than just CO₂ to cause warming. It also takes infrared radiation. If we try to draw too much from an analogy it can become confusing, and the purpose of these analogies is not to educate the well-educated commenters, but to educate people who may be new to the science of global warming.

       That said, I am always open to modifying and improving these analogies, so thanks all for the many constructive comments. I will consider them all and will consider how we can improve this analogy and make it more effective.

19695. macquigg at 05:46 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       John@23, Daniel@24: Arizona as a whole is getting warmer, and Tucson is part of the region that is impacted by the drought we've seen for the last few years.  Tucson gets its water from the Colorado River, and will be the first city to be cut off if the water levels fall a little further.  The climate in Benson is much different.  We have no problem with water, but if I understand climate science correctly, that could all change with a small shift in the jet stream, which could happen with the predicted global warming.  My point in using Benson as an example is not to argue that global warming is good for Benson, but rather that the problem lies in the uncertainty, even with local climates that seem to be moving in good direction.

       Will more research be helpful in predicting local climates?  Or is this more like the floating balls in the river - no chance of ever predicting which ball will end up where.

19696. Daniel Bailey at 02:58 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       The state of Arizona as a whole has had significantly warmer summers:

       

       Perceptions certainly do not overrule reality.

19697. John Hartz at 02:37 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       macquigg #20: You wrote:

       I live in Benson Arizona, and it looks like the hot summers are getting a little cooler.

       You could easily verify whether your impression is correct or not by analyzing the temperature records for Benson and/or nearby Tuscon. 

19698. macquigg at 01:12 AM on 4 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       Tom @21, I was not aware of Stephens' prior writings on this topic, but if his first two op-eds in the NY Times (April 28 and May 1) are what he currently thinks, it looks like his position has changed.  He now seems very reasonable: "The climate is an intensely complex system. Seemingly tiny differences in terms of inputs can make dramatic differences in terms of results. We should be humble about what we can know a year into the future, never mind a century, and we should be refining our assumptions continuously. That calls for more investment in science, not less."

       A fair criticsim, which appears in the comments to the April 28 column, is that he is not treating the uncertainty with enough urgency.  One of the commenters gave a perfect analogy:  We would not get on a plane if technical experts told us there was a 10 to 20% chance of disaster.  Let's work on refining that estimate and getting better models that will help us know the specifics of what is likely to happen.

19699. BILLHURLEY13951 at 00:31 AM on 4 May 2017
       Evidence Squared #10: Debunking William Happer's carbon cycle myth
       

       I think the analogy is easier than that. Water, like CO2, is natural and life-giving. But too much and you drown.

       Not only do degrees/percentages play a part in the Climate Change issue, but in all environmental issues as well.

19700. Tom Curtis at 22:14 PM on 3 May 2017
       NY Times hired a hippie puncher to give climate obstructionists cover
       

       macquigg @20, I think you are being all together too generous to Bret Stephens.  As recently as 2010 he was writing:

       "So global warming is dead, nailed into its coffin one devastating disclosure, defection and re-evaluation at a time. Which means that pretty soon we're going to need another apocalyptic scare to take its place."

       and reffering to environmentalists as making "quasi-totalitarian demands".

       In 2011 he was writing:

       "Consider the case of global warming, another system of doomsaying prophecy and faith in things unseen.

       As with religion, it is presided over by a caste of spectacularly unattractive people pretending to an obscure form of knowledge that promises to make the seas retreat and the winds abate."

       In 2015 he referred to global warming as:

       "The hysteria generated by an imperceptible temperature rise of 1.7 degrees Fahrenheit since 1880—as if the trend is bound to continue forever, or is not a product of natural variation, or cannot be mitigated except by drastic policy interventions."

       And finished, the article by writing:

       "Here’s a climate prediction for the year 2115: Liberals will still be organizing campaigns against yet another mooted social or environmental crisis. Temperatures will be about the same."

       On that evidence he has consistently considered global warming to be based on hyped and fabricated studies, with what actual warming exists being due to natural variation, a view he is sufficiently confident in as to predict effectively no temperature change over the coming century.

       Three record annual temperatures in a row have made that view untenable for anybody who wants to pretend they are a serious commentator; but I have no doubt he was not convinced by the science (which has not changed over the two years) and hence that come the next La Nina he will revert back to what is essentially AGW denialism.

       Further, it is plain from the articles that he is very happy to insult those pressing for action on AGW, and indeed insult working climate scientists who take no role in the policy debate as well.  Given the liberality with which he insults, he would be a precious petal indeed if he took offense at the comments here.

       In short, I think the evidence shows you are wrong in thinking Stephens is open to persuasion on any terms.  He is prepared to run up and down the levels of denial as suits the circumstance, but nothing will persuade him that AGW represents a serious threat that merits any policy response.

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