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Comments 9551 to 9600:

  1. It's not us

    MA Rodger

    Thanks for the response.  I will look into the IPCC and NASA references.

    "The graphic on this webpage suggests 30% reduction 1980-2010 and other data suggests reductions do continue but less strongly."

    Yes.  If anything, particulate concentrations may rise for the rest of the century.  The graphic shows a very small contribution from Africa.  U.N. Population projections for Africa show 4 billion people by the end of this century, comparable to Asia.  That could ramp up worldwide average particulate concentrations and spread them more equally across the globe.  Qualitatively, the competition between GHG warming and particulate cooling could be the biggest uncertainty in the future.

    "One reason that this may be so is that aerosols are very short lived and thus their effects dependent on the region of their emissions"

    I see your point, but wouldn't the total amount of solar reflection be the most important variable, no matter where it occurs?  Wouldn't the resulting cooling eventually even out across the globe?  I will take your suggestion and look at the IPCC reference.     --Richieb

  2. Fermin Francisco at 18:28 PM on 4 October 2019
    Landmark United in Science report informs Climate Action Summit

    Urgent world-scale action has long been needed to address climate change, and the most effective tool to use is the profit motive.  Here's the vision: 1st World green citizens in their millions persuade their contact companies to partner with 3rd World co-ops and companies starting with the Philippines as modeling country to set up high-profit green industries.  Projects: Ethanol distilleries fed by sweet sorghum farms.  Thousand-hectare agroforests with processing factories for export production.  Geothermal plants.  Mini-dam hydropower nets.  Methane digesters and E85 engines for on-site power generation.  E85 & electric transports.  Low-cost solar cells.  Forest resorts. All-electric metals industries.  Agroforest water supply, toll roads, etc.  Current billion-dollar Green Funds should finance the projects at 75% levels due to sure repayment plus interest income incident to the projects' high profitability.  Spread out tropics wide, the projects should sequester atmospheric CO2 at billion-ton levels each year for all time, while employing millions of poor and creating huge markets for all involved companies.   Details: https://fermin4greenearth.blogspot.com.

  3. It's not us

    richieb1234 @106,

    It is correct that there has been a substantial reduction on SO2 emissions over recent decades. The graphic on this webpage suggests 30% reduction 1980-2010 and other data suggests reductions do continue but less strongly. Yet when the aerosol forcing is shown (eg IPCC AR5 AII Table 1.2), we see a peak in 2000 and a very minor decline.

    One reason that this may be so is that aerosols are very short lived and thus their effects dependent on the region of their emissions. NASA data (since 2005) allows the latitude of emissions to be easily quantified. Since 2005 thre have been small reductions in higher northern latitudes (eg USA & Europe), quite large reductions in lower northern latitudes (eg China) while emissions in the tropics and the southern latitudes have remained roughly constant. I would suggest that there is little relationship between global totals for SO2 emissions and the global size of the resulting climate forcing. The location of the emissions has a big effect on the overall forcing levels.

  4. 2019 SkS Weekly Climate Change & Global Warming News Roundup #39

    The death of science in America: The silenced: Meet the climate whistleblowers muzzled by Donald Trump

  5. It's not us

    richieb124 - the IPCC reports each have a chapter on attribution which is what the literature calls it. I agree that your analogy is a good one but doing real-world attribution is a very complex task. The "fingerprints" in this post I think is about as good as it gets without using a physics-based model. Each individual one is ambiguous, but the sum is telling.

  6. It's not us

    :As I mentioned earlier, I am a trainer.  As I read and reread the original post, I think a good analogy to use is the way in which police organizations identify the source of an illicit drug.  A drug that's intercepted on the street could come from anywhere: Colombia, Bangladesh, a rooftop in New York.  "You just can't tell for sure."  But international law enforcement agencies have developed the forensic methods to identify the source by examining its physical and chemical signatures.  It works for natural and synthetic drugs.  One can even identify where drugs have been "cut" by the signatures of the chemicals used.  The same approach is used to distinguish natural causes of warming from man-made causes.  I think this is a good analogy that most adults can identify with.  Once they understand the approach, their minds will be much more open to hearing about the 10 signatures of anthropogenic warming.

  7. It's not us

    David Kirtley:  I did get into the Bloomberg link using Google.  Very intereting.  But I was surprised that it shows a negative trend on temperature effect of aerosols all the way to 2005.  The information I have shows worldwide aerosol concentrations dropping by about 30% between 1980 and 2010.  Shouldn't that have caused somewhat of a reversal in the temperature contribution?

  8. 2019 SkS Weekly Climate Change & Global Warming News Roundup #39

    This video by Sir David King is well worth a look on a history of the science, and some interesting and novel mitigation ideas : New Tools for Climate Repair...

  9. It's not us

    richieb1234 - As MA Roger pointed out, volcanic activity adds complexity to any kind of curve-fitting. Climate response to volcanic aerosols is quite fast compared to other forcings. 

    Tamino did an excellent article on using a combination of a simple 2-box model (one fast response, one slow) along with ENSO, and and showed an excellent fit to the observed climate response, see Once is not enough. Two time constants (2 and 26 years) and one large oscillation appear to be sufficient parameters to map the climate response to forcings. 

  10. It's not us

    For a purely empirical fit of ENSO, Volcano, solar to temps since 1950, try here. Unlike other curve-fitting exercises which try to show warming is due orbit of jupiter, rise of irrigation etc, this uses half the data as training set and then uses the result to model the other half.

    Benestad & Schmidt 2009 challenged Scafetta nonsense with naive empirical analysis of effects of forcing which I think may be closer to what you want.

  11. Ice sheet melting: it’s not just about sea level rise

    Just wondering. What percent of deep water formation is caused by the freezing of surface water on the surface of the Arctic and Antarctic oceans with the accompaning creation of brine.  The amount of ice formed each year in the Arctic has remained more or less constant over the years as reduced ice cover allows more heat to be vented to the atmosphere due to the lack of an overlying insullating cover of ice.

  12. It's not us

    The Bloomsberg link is not to an "article" as such but to a set of graphs beneath which is set out the methodology behind the graphs. And within that methodology is a link to what could be construed as the underlying "article" - Miller et al (2014) 'CMIP5 historical simulations (1850–2012) with GISS ModelE2' although it has broader coverage.

  13. It's not us

    Hmmm...that's odd. The link works for me. Maybe try google?

  14. It's not us

    David Kirtley and MA Rodger

    Thank you both for the responses.  David, the Bloomberg link did not get me to the article, and neither did their search option.  Do you happen to have a copy?

  15. It's not us

    richieb1234 @98,

    The basic problem you face trying to simply show a tight correlation between forcing & temperature is the impact of large short-term changes in climate forcing caused by volcanoes superimposed on the slower changes in climate forcing, as shown here in IPCC AR5 Fig 8-18. (The numbers are available in AR5 AII table 1.2.)

    IPCC AR5 Fig 8.18

    Because of these more dynamic changes, I have found the task involves far more than forcing and sensitivity. Even using a simple Climate Response Function (the timed progression of a warming resulting from a forcing based on the sensitivity - see for instance Hansen et al (2011) who discuss these at some length.) doesn't overcome the problem. You would end up having to set up what is undeniably a model to convert forcing into the resulting global temperature change. (I would add here that in 1910 the climate system was far from in-balance and so 1910 is not a good date to begin such modelling.) And for such a model not to be actually emprirically-based, you would probably end up with a full GCM model whose credibility has, as you say, been criticised by climate denialists.

    This is what is being shown in the link @99. But I would ask if you need the modelling to present the message that the climate forcing of recent times forcing is overwhelmingly anthropogenic with the only significant effect from natural forcing being those short-term volcanic forcings. If the forcings are overwhelmingly anthropogenic, it is surely difficult to argue that it is not the same for the warming.

  16. It's not us

    richieb1234--Bloomberg Businessweek (of all places!) had a really good look at this a few years ago: What's Really Warming the World which is based on NASA-GISS modelling.

  17. It's not us

    I am engaged in developing and delivering training courses on AGW to teens and senior citizens in the Washington D.C. area. I find useful text and graphics in all three levels (basic, intermediate and advanced) of this post. Great job!

    What would be good is a credible and scrutable discussion and graphic presentation of how the various forcing factors affected the global temperature since 1910; i.e. the steady increase from 1910 to 1940, followed by the slight downward trend from 1940 to 1975, followed by the sharp increase from 1975 to the present. Citing model calculations is useful, but skeptics have done a good job of casting doubt on the credibility of models, and models sound like black-box mumbo-jumbo to a non-technical audience.

    A more understandable story emerges if you just examine the trends in sunlight, GHGs and aerosols and relate them to the shape of the curve. Your post does some of that, and I plan to use the insights from it. In addition, I have looked at the graphs of trends in GHGs, aerosols and sunlight since 1910, and I can tell a pretty good qualitative story. But has anyone done a simple quantitative analysis to try and reproduce the shape of the temperature curve?

    From the reading I have done, there appears to be some good analysis of the sensitivities of global temperature to changes in GHGs, aerosols and incident sunlight. Has anyone with access to all the basic data simply multiplied the sensitivity times the amount of change for each of these factors and summed them up for each year since 1910? Would an analysis like that produce something that looks even vaguely like the temperature curve? Is it necessary to include other factors? Or is it a futile exercise?

    Thanks for the great work you are doing to keep this issue in front of the public.

  18. One Planet Only Forever at 13:58 PM on 1 October 2019
    Welcome to Skeptical Science

    TungstenX,

    As you read the CBC article I refered to, pay attention to the mentions of John Cook, the same John Cook who authored this "Welcome to Skeptical Science".

  19. One Planet Only Forever at 12:52 PM on 1 October 2019
    Welcome to Skeptical Science

    TungstenX@63

    I offer the following points to supplement the responses from Eclectic and KR:

    1. In Eclectic's@62 list of groups I would add a group between B and C. This group likes to benefit from fossil fuels more than they care about understanding how harmful it is for them to benefit that way. That makes them like the A and B, but they are not super rich because of it or paid by the super rich to create misleading marketing for their benefit. I personally believe this is the largest group. And they are obviously easy to impress with misleading marketing. And they are propaganda foot-soldiers, readily repeating the nonsense they like.
    2. The CBC News website article "How 'organized climate change denial' shapes public opinion on global warming" may help you understand why there are still so many deniers and delayers regarding climate science (because of the required corrections of developed popular and profitable activities that it has exposed).
  20. Welcome to Skeptical Science

    TungstenX @63 ,

    Margaret Thatcher was very much an economic conservative, and pushed for privatisation of Britain's coal mines in the early 1980's.  Hence her big clash with the unions 1984/85 ~ where she was victorious.  Over the next decade or two, most of the mines closed (being uneconomic) . . . and Northern England became an older version of West Virginia, as Americans might say.  So Thatcher was rather "the opposite" in coal policy, compared with a more recent US President's ideas.

    Thatcher's passionate interest in environmental conservatism (her major speeches to world leaders in 1988/89) seems to have developed subsequent to her coal-mining victory.  So no, I'd have to disagree with the suggestion of her using the AGW/environmental concerns as a lever against the coal miners' union.

    Thatcher had a Bachelor of Science degree in chemistry (according to Wiki, she was the first British Prime Minister to have a science degree) ~ so she was no novice or dummy in matters of science.  And her strong advocacy for world action against climate change, is apparently completely genuine (just as it should be, for a true conservative).

  21. Ice sheet melting: it’s not just about sea level rise

    Interesting coincidence: Massive iceberg breaks off Antarctic ice sheet

  22. Welcome to Skeptical Science

    Thank you Eclectic & KR. It seems that the (m)asses falls in the group that doesn't like/fear change (and usually the same ppl that blames everyone else for their situation).

    Btw, I've got one for the list, told to me: "It was Margaret Thatcher that first came up with the concept of Global Warming to get support for her breaking up the (coal mine) unions in the 1980's"

  23. Welcome to Skeptical Science

    (continued)

    TungstenX, you ask #1. What is in it for the deniers?

    I could respond on this (with another large coffee to help) . . . but the basic answer is: "emotional reasons".   And yes, there's nothing in it, for the deniers' grandchildren.  Excepting a load of unpleasant consequences for the grandchildren and their descendants.

    Deniers - denialists - call them what you will - come in several categories.

    Group A ... the 0.1 percenters who got very rich on oil & coal, and who wish to keep it that way.  When your personal wealth is 20 billion$ . . . then something inside you dies a (big) little, when you think you might gradually be reduced to only 10 billion$ .   Life can be hard, sometimes.   So, by covert means, you finance tame thinktanks & strategic propagandists & astroturfers & Heartland institutes & GWPF's etcetera . . . to create a public sense of unease and doubt about the facts.  And/or suspicion of scientists.  And you don't stop at untruths & half-untruths.  All to achieve political paralysis on climate issues.

    If you are especially unethical, you would more directly manipulate/suborn politicians ~ but fortunately this has never yet occurred ( I gather).

    Group B ... the clientele of Group A.  Meaning the professional propagandists.  Some of whom spent decades in a rear-guard battle denying the tobacco/cancer link.  They know they are being "exceedingly economical" with the truth about AGW.  But they don't care.  It's a business, like being a defense attorney ~ no matter that you are defending someone who's guilty as sin.  Just use Doublethink, to calm your conscience (if any).

    Group C ... the unthinking reactionaries.  They see the (social) world is changing and they don't like change (for various emotional reasons).  They are easy meat for the propagandists ~ easily gullible that all changes must be bad for them socially & financially.  Change ~ to renewable energy ~ must be resisted, because it is a change.  And/or it's a start to a slippery slope.

    Many of these people are angry people.  Angry that their life is not perfect.  Pleased to find a scapegoat, like the issue of AGW / climate change, which can be "denied" and resisted.

    Group D ... the scientific crackpots, who hold that CO2 has little or no effect on climate.  And that modern scientists are clueless.  Essentially, the crackpots are an intellectually-insane subgroup of Group C.

    Group E ... the tinfoil hatter Conspiracists.  Fearful of the Illuminati, of World Marxists, or whoever.  Also angry.  Also a subgroup of Group C and often overlapping with Group D.

    TungstenX , perhaps you can define other groups to add here !

  24. Welcome to Skeptical Science

    TungstenX:

    I'll offer my opinion on the second question first. Climate change science over the last couple hundred years, involving >90% of scientists, isn't a conspiracy; that nutty idea is just a hook to hang highly motivated objections upon.

    "What's in it for deniers?": Simply delaying regulations by a few years is immensely profitable for fossil fuel companies; the tobacco industry managed decades of delay by induced doubt and demands for 'sound science' that came down to 'nothing will ever be evidence enough'. And that delay translated into money. Others appear driven by ideology; objecting not so much to the science as to the government oversight required to addressing a 'Tragedy of the Commons' scenario.

    In my very personal opinion, climate deniers fall into four major groups: Loons (pet theories unsupported by evidence, many are emeritus physics professors), lobbyists (objecting for pay, often the very same lobbyists who previously objected to tobacco regulations), ideologues (such as libertarians, against any regulation whatsoever), and opportunists (because it's professionally better to be a frequent Congressional witness than, say, just another 2nd-3rd rate climate scientist), with varying mixes thereof.

  25. Welcome to Skeptical Science

    TungstenX @59 ,

    Being presently at leisure and well fed and well coffeed** . . . I shall have a stab at replying to your questions #1 and #2.

    [ **coffeed not to be confused with covfefed. Excuse American joke. ]

    #2.  Yes, it's a bit of a stretch to make a global AGW conspiracy.  But all things are possible to the Conspiracist mind !

    Firstly, you go back to 1896 and influence the Swedish scientist Arrhenius and his CO2 global warming calculations.  [ check V ]

    Then jump forward 40 years to the 1930's and influence the British engineer/scientist Callendar and his analyses on global temperatures & radiative absorption of CO2.  [ check V ]

    Then forward to 1956, to influence the Canadian scientist Plass, with his similar findings on "climatic change".  [ check V ]

    Then to the 1960's 1970's 1980's ... through up to today, as you influence & control thousands then millions of American / European / Japanese / and other international scientists, in a hundred nations and in thousands of universities / military laboratories / and other organisations.  You get them to fabricate & falsify decades & terabytes of data, and get them to integrate ALL previous physics - seamlessly - into the modern pseudo-science of climatology, in a devilishly meticulous and clever manner.  All without any whistleblowers, ever.  [ check V ]

    Then you bribe Russian & Canadian Eskimoes, Lapplanders, and Himalayan mountain-dwellers to report extensive ongoing ice-melt.  Also without whistleblowers.  [ check V ]

    Then you bribe countless mariners, harbormasters, and other coastal dwellers ~ to report rising sea levels for a century.  Again, no whistleblowers about this.  [ check V ]

    All easily done, whilst keeping your tinfoil hat on.

     

    BTW, TungstenX : all or most countries agree on quite a number of international issues, actually.  They needn't be in perfectly harmonious synchrony re AGW ~ but they should aim to achieve minimal fossil fuel usage by around 2050 (preferably nett zero CO2 emission by then, or sooner of course.)

  26. Welcome to Skeptical Science

    (Disclaimer; I'm still reading but) I have not came across answers to the following:


    1. What is in it for the deniers? (Why fight so hard to misinform, or fight so emotionally against scientifically proven facts?) I can't see the return for the effort? 


    2. How can Global Warming / Climate change be a global conspiracy (haven't read this statement here)? Does anyone really think all the countries will agree on this and nothing else? (Image the lunch order at the UN... ;-) )

    (Do not take science as gospel, but then use the scientific process to disprove it, right?)

  27. There is no consensus

    ERRATA @830,

    A quick response to your specific enquiry regarding our global carbon emissions. You suggest that I talk of "almost no progress in cutting down emissions."

    With or without AGW, the emissions from our use of fossil fuel is ever being lessened by the pursuit of fuel efficiency measures. There is also the drive towards renewable power sources which is obviously driven by a desire to combat AGW. Folk can point to the UK where we have reduced our carbon emissions to well below the 1990 levels (I hear the denialists talk of UK carbon emissions being the lowest since the 1890s.) Yet this was achieved very much by exporting those emissions to China and adopting gas rather than coal with fuel efficiency playing a minor role.

    It is the global emissions that are important. Sadly these continue to grow. In successive 5-year periods since 1985 (with 2015-17 extrapolated to a 5-year period) the global growth in carbon emissions (GCP data) has been 6%, 6%, 10%, 18%, 13%, 6%. Until those figures become negative, there is every reason to, well, to be pessimistic or to take the argument to the public/government or to jump up and down and scream at politicians for being useless or to superglue yourself to an underground train to get your message onto the evening news.

    I have not been apart of the direct-action campaigns but have for a quarter of a century been apart of the other three.

  28. There is no consensus

    Errata @830 ,

    no, those "500 scientists" are not fully 100%  wrong.  But if they were an aeroplane . . . then they'd be so far from flightworthy, that no engineer would let them out of the hangar ~ for fear that they'd crash just moving along the taxiing strip.

    In less humorous terms: the "500" letter is so error riddled, that it would take a large number of paragraphs to detail it all.  Not just errors, but deceptive rhetoric.

    Politics :- as of those extremists who think that all the world's scientists are in a century-long plot/conspiracy to impose a communist world government, and are faking all the data to that end.

    Religion :- as of those extremists who think that the Christian Deity is/will step in to correct any significant global warming.   And Prof Lindzen who takes an [Old Testament] view that Jehovah won't allow more than slight warming (at least, that was his view during a 2006? interview with a sympathetic interviewer ~ and I haven't detected any change since.)

    All these guys are intelligent (though the vast majority do not research or publish in the climate field) and all are so strongly influenced by Motivated Reasoning (political/religious) that they end up producing nonsense.

    Errata, if you are not inclined to some hours of heavy reading at websites like NASA, AAAS, U.K. Royal Society, etc . . . . then you might enjoy some youtube videos by Potholer54 (science journalist) on climate matters.  He debunks a lot of the common myths which have been circulating.

    Potholer54 is polite & amusing [ how refreshing ! ].

    You will be especially amused by his 5 short videos exposing the "Monckton Bunkum" mendacities of Lord Monckton (who is a sort of pop star among denialists . . . denialists who fawn on him, especially at WattsUpWithThat website.)

    The partisan "Green New Deal" is just local American politics, and is not a consequence (or reflection) of genuine climate science.  Best to first understand real climate science: and only then give thought to remediation of the AGW situation.

  29. Postma disproved the greenhouse effect

    Brian Hughes - Your description of "induced emission" matches the textbook definition of "stimulated emission"; I think you have two terms for the same phenomena. 

    Stimulated emission (to be of any significance) requires several things: You need a population inversion, with more molecules at higher energies than statistically normal when undisturbed - this requires additional energy pumped in. The emission will quickly die off without an optical resonating cavity, as photons leave the pumped site. And to make use of that energy, one end of the resonating cavity should be 'leaky'. The result is a projection of coherent light powered by the 'pumping'. Without these supports any stimulated emission results in just one (fairly infrequent) photon exchange. 

    In short, you need a laser. Or for microwave frequencies, a maser. 

    Stimulated emission just isn't a factor in GHG energy exchanges. Spontaneous emission over a molecularly associated characteristic spectra, on the other hand, is.

  30. There is no consensus

    Hi again and thanks a lot for all the answers and links, I extremely appreciate it!
    Unfortunately, I didn't go through all the links and I didn't read a lot since it's a bit late and I'm dead tired and have to wake up early for work. I definitely will read it as soon as I catch some time, but I'll take some time to at least put my thoughts here, hope that you'll feed me with more material so I won't have a chance to be bored tomorrow :)

    First, about the "500 scientist" paper. To be honest, I didn't recognize a single name from people signed there, I'm still fairly new in this whole topic, and I recognize just some names from IPCC, however, before sharing links with you here, I did a bit of a homework and tried to look up names from "500 scientist" letter and the very first name on the list (Professor Guus Berkhout) already did arise some suspicion ((...) once worked in the oil and gas industry and became a respected professor after that. Berkhout started his career working for Shell. — Wikipedia). But digging deeper and deeper, I came across the thing which I really don't like (from any side) - articles which "prove" that some of the conclusions of non-deniers (how do we call them anyways?) were driven by money, greed, political or personal agenda. I don't have links now, but I'll give my best to share them eventually with you. This I find extremely disturbing, because whenever I come across such article/statement, my personal conclusions just fall apart and divert me from logical thinking (I suppose that's the whole point of those in the end). I simply cannot believe that people who we call "scientist" are able to degrade them to such a low level to try to discredit others by silencing them or by using silly "arguments" like pointing out their work history. Both of you (MA Rodger and Eclectic) concluded your comments by completely discrediting their letter. This is exactly what I tried to point out in my previous comment — there is no "questioning" whatsoever. How so? Are you saying that everything stated there is 100% incorrect (well, some of the statements sounds dumb even to me tbh)?
    I tried to look up a bit about Lord Mockton and GWPF, but I'm really tired now and will try to continue with that tomorrow. What I found interesting in that letter what the sentence in the first paragraph on second page - Climate science should be less political, while climate policies should be more scientific. It really might be just a propaganda trick, but that sounds honest to me in some way, and I don't understand why non-deniers sit with them and give them a chance to talk (or did this happen already in the past)?

    About Myles Allen's message... I didn't even notice the comment section, might go through it tomorrow a bit, although I tend to avoid such things just because of mentioned "opinion-fest". But his article somewhat triggered my skepticism again. The first time, it was this particular article which I still cannot explain to myself whether is it true or not?
    (Just a quick digression, while searching for this one, I came across this link in comments section. Is this really true?)

    Anyways, to cut my story short and get to some direct questions, looking forward for your answers!

    @MA Rodger:
    I might be wrong, but you sound a bit more pessimistic than others? Are you saying that in last couple of years there is almost no progress in cutting down emissions, because I personally believe that western world is really giving its best (well, to some extent) to do so.

    To any of you:
    As I said, you discredited completely the "500 scientists" letter with labelling it "unscientific nonsense", "extremist political/religious positions", stating that "they still don't have any actual evidence", "unsupported assertions, none of which stand up to scrutiny", etc. Now, pardon my ignorance, but I personally didn't get and impression that this is politically/religiously motivated and also that there might be "scrutiny material" there (e.g. "Warming is far slower than predicted" or "Climate policy relies on inadequate models"). On the other hand, current "solutions" to climate change problem (e.g. "Green New Deal" or "Climate Strike") have hidden political agendas all over the place (even SR15 report, which I didn't read yet, has a part "efforts to eradicate poverty" in the title description. I still cannot understand what "getting rid of poverty" or has to do with climate change, this sounds very political to me).

    And finally, maybe a bit off topic here, but the thing which is bothering me for some time now is, how comes that no one in this climate change topic is mentioning SOx or NOx emissions? To my understanding (again, pardon my ignorance), those are directly contributing to GHG chemical reactions and we don't have enough knowledge of direct impact on climate, however, they are massively emitted from cargo ships which still make more than 90% of world's transport.

    Thanks again for your time and effort, apologies for any errors/typos and general stupidity, it's getting pretty late now, I should avoid commenting at this hour :)

  31. Postma disproved the greenhouse effect

    Brian Hughes @93,

    I'm not familiar with "induced emission" but...

    "Spontaneous emission" is the mechanism where an excited molecule drops to a lower energy state and doing so emits a photon. The direction is any-which-way because the reason for the excited state is almost always due to collision with fellow gas molecules. These collisions happen in micro-seconds so an excited molecule (be it by the absorption of a photon or by collision) will have very little chance to undergo spontaneous emission which on average takes tenths-of-a-second but there are a great number of molecules entering that excited state due overwhelmingly to collision.

    "Stimulated emission" is when a passing photon 'drags' a photon out of an excited mollecule and this will be in the same direction as the passing photon. This will occur within the GH-effect but as photons have a comparatively short path-length, they are themselves going any-which-way and thus these extra "stimulated emissions" will not constitute some extra directional flux of energy.

    I am no expert but I have a feeling that "induced emission" is just another name for "stimulated emission."

  32. There is no consensus

    My apologies to MA Rodger.  I was overly brief in my comment above ~ I meant that the sort of "discussions" usually following on the tail of the "12 years" statement (wherever it gains headlines) . . . are discussions/posts which turn into an opinion-fest.

    The statements by author Myles Allen were very calm and reasonably objective, and illustrate how very little time we have to get things on the right path.  The exact amount of time & tonnage of burnt carbon we can "afford" is, of course, rather fuzzy ~ as is the 1.5C figure itself.  It's a reasonable best estimate . . . and we shouldn't let rhetoric (by denialist propagandists) conceal the unpleasant reality of it all.

    The comments following the Myles Allen OP were fairly civil, but slid off into an opinion-fest.  But it was extraordinary to see that the comments were not bombarded by avalanches of bots & intellectually-insane trolls & rabid political extremists & CO2-physics-denying crackpots.  It's almost as though a sensible moderation policy was in full effect !

    OTOH, there's no getting away from the conclusion that "the 500 scientists" was an example of scientific nonsense & false/misleading propaganda . . . so typical of anything involving the hand of "the error-prone Lord Monckton".  Or anything involving the hand of the Heartand Institute or the GWPF or their ilk.  Nothing new, there.

  33. Postma disproved the greenhouse effect

    I'm asking here because I can't see a better place.

    Einstein (1917) "A Quantum Theory of Radiation" described 3 types of emission; spontaneous emission, induced emission, and stimulated emission.

    For an induced emission of a photon, the emission of an identical photon is simultaneous and in the same direction as the incident adsorbed photon due to the conservation of momentum, no matter how small. Same for stimulated emission (?).

    Pierrehumbert (2011) says the momentum goes into changing the internal energy of the molecule which then undergoes spontaneous emission at some random time in some random direction and thereby he seems to be saying there can be no induced emission. At least that is my understanding of the two papers. (Given the usual boundary conditions, i.e. ideal gas, thermodynamic equilibrium, etc.)

    My confusion is why is there no induced emission when a GHG molecule adsorbs an incident photon and conservation of momentum can be ignored like Pierrehumbert says. Also, wouldn't there be some stimulated emissions from an excited GHG molecule from the passing of a photon of the required frequency?

  34. There is no consensus

    ERRATA @826,

    I would disagree with Eclectis @827 in that the Myles Allen OP is correctly explaining why the simplistic message “the Intergovernmental Panel on Climate Change (IPCC) says we have 12 years” is being used unscientifically.

    However I would entirely agree with Eclectic @827 that the letter from  "500 prominent scientists" is entirely non-scientific nonsense.

     

    The message from Myles Allen is that this 12 years concerns the time it takes before potentially we hit the +1.5°C of global warming. The adoption of +1.5°C at the COP21 meeting in Paris in 2018 was a wake-up call to global governments from science and it does show that we were potentially 12 years away from breaching that limit although a more likely timing would have been 22 years. Yet the significance of the SR15 report failed to spur governments globally into appropriate action. The wake-up call was given but the world hit the snooze button, again.

    Mind I was using a 12 year message even before SR15. My own version of a 12 year message would be that, at current levels of emissions, we had 12 years' worth of CO2 emissions to play with. That was emissions limits set out against a +1.5°C limit within  the 2013 IPCC AR5 Synthesis Report. (The limit of 550Gt(CO2) from 2011 is buried away in Table 2.2 which represents 14 years of CO2 emissions from 2011.) And note we are now halfway through that 12 years' worth of emissions.

    The IPCC message has always relied on politicians picking up on the dry scientific message that we are stuffing the planet's climate. Emissions targets are watered down and hidden away in documents because many politicians are unable to cope with that reality. Although the messages of the Climate Emergency movements are often less than scientific, if they convinces the world that we do have an emergency on our hands, I for one am not bothered that there is a scientific problem with the message.

     

    And then there is the letter from the usual set of denialists.

    They misrepresent thmselves. They are not "a global network of more than 500 knowledgeable and experienced scientists and professionals in climate and related fields." (At least, when they were 400  "independent Climate Scientists and Professionals" almost all were not "knowledgeable and experienced scientists and professionals in climate and related fields.") They make six unsupported assertions, none of which stand up to scrutiny. If you feel any of their bold claims deserve more than this summary dismissal, do say.

  35. There is no consensus

    Errata @826 [perhaps you will later change name to Corrigenda?  ;-)   ]

    the SkepticalScience website is primarily about the science, not "opinion".

    Science is advanced by research - and is published in reputable peer-reviewed journals.  Not every such scientific article is perfect; but en masse and over time the published science has a very good track record (in the "hard sciences" that is ~ not so much in the "medical" or "psychological sciences".)

    That is why opinion is next to worthless ~ except where it is based on real science.

    And that is why opinion-fests such as the ones you mention ~ '12-years-to-climate breakdown' ; and '500-scientists-no-climate-emergency' ~ have little or no relevance to the important questions regarding the recent rapid warming of the physical world.

    The thread here about consensus is really just an indirect way of examining the mainstream climate science.  As I mentioned in my post #822 [above] . . . there are hardly any "climate-skeptical" scientists remaining.  Forty years ago, there was space for scientists to be skeptical about AGW ~ but the current state of "overwhelming consilient evidence" is so clear-cut that "contrarians" have nothing left apart from empty rhetoric to support their so-called position/positions.

    How and why . . . can you yourself benefit your scientific understanding, by spending time on the two rather political opinion-fests you cited?   This website [ "SkS" ] does have a weekly events section, where opinions can be expressed on more sociological aspects of AGW, if that's what you're wishing.  (But that's not really related to this thread's consensus topic. )

    And you'll find that the "500" scientists are talking a great deal of unscientific nonsense (their Motivated Reasoning comes from extremist political positions and from extremist religious positions . . . and they still  don't have any actual evidence to back themselves up ! ).

  36. Climate's changed before

    MA Rodger @ 788

    Thank you so much!!!!!

  37. There is no consensus

    Hi all!

    First of all, thanks for this magnificent website, lots of interesting material and comments, but still a lot left to read and learn.

    Please, allow me to quickly introduce myself, I live in a place around 66 degrees north and I'd refer to myself as "sceptic", rather than "denier", although I've been labeled in many different ways just because of a different opinion. I would consider myself as some sort of "environmentalist" since I am aware of the planet I live since my young ages and I took care of my actions to preserve my environment as much as possible. Today, I work for a company closely related to environmentalism and I'm trying to teach my child to be aware of our planet, however, in a very different way than other kids of his age are doing every Friday on the street. I am not a scientist of any sort, but I do consider myself fairly smart, especially because I'm in love with scientific method of "question everything" since the same young age, and this is the reason I consider myself a sceptic nowadays, not only when the issue of climate change is in question.

    The same "question everything" method inspired me to register here and ask few questions. I hope that people here are more reasonable and doesn't look at other people's questions as some kind of trolling tactics, as it is happening more and more often in "social media" places. All my questions will be honest and without no bad intentions. They might be silly and "ignorant", but hey, I joined here to learn something new, so apologies in advance for any stupidity coming from my mouth :) Honestly, I am very confused at this point regarding climate discussion because of constant opposing statements, studies, conclusions, I hope I'll get some clarifications here.

    Now, in past 2-3 days, I'm reading a lot around here, especially "Climate Myths" section and all the comments around. Seems like there's lots of smart people here with lots of knowledge about the topic, but what I didn't see often (actually probably never) is someone who would leave an impression of "questioning everything". Why is that so? Especially if someone presents material from contrarian scientists which is trying to "question" the opposing statements. It looks to me like one side is not quite ready to have a debate, while the other one is desperate for it and to send a message which is constantly being silenced. This kind of behaviour is moving me away more and more from my currently shaky belief in climate change, no matter how crazy that sounds.

    I am very happy that I came across this website because it started to bring back some logical conclusions in my mind, but then, just today, I noticed 2 articles which again started forcing me not to take anything written here for granted.

    To make it more interesting, one of the articles is from Myles Allen himself. It's not that he is denying anything, but he is somewhat confirming that lots of people got some things wrong and jumped to wrong conclusions (https://theconversation.com/why-protesters-should-be-wary-of-12-years-to-climate-breakdown-rhetoric-115489). The other article talks about my other point about the debate, and it really sounds to me like lots of other scientists are silenced and no one cares about their opinion. How in the world is that possible in the "science" in the first place? (https://climatechangedispatch.com/500-scientists-no-climate-emergency/). So, I assume that my other question would be, what are your opinios on those 2 articles?

    Thanks for your time and for all the answers!

  38. Water vapor is the most powerful greenhouse gas

    Please update the link to the article from Santer 2007 --> https://www.pnas.org/content/pnas/104/39/15248.full.pdf

    Moderator Response:

    [PS] Thanks very much for that. I have updated the Held 2000 link in the rebuttal as well.

  39. Climate's changed before

    TVC15 @787,

    800,000 RSL

    This graphic has already appeared up-thread and is snatched from the web but originates from this webpage. (You need to click the top-left icon to get the 800,000 year version.) The underlying study is Spratt & Lisiecki (2015).

    If your denier who is "trying to say that Milankovitch Cycles are irrelevant" actually manages to achieve such an assertion, perhaps he should be asked what would trigger ice ages if not milankovitch cycles?

  40. There is no consensus

    JBeez , please also edit/correct: "exacerbated".  If English is not your first language, then you can make a post in your Mother Tongue — but you may be slow to get replies.  There are a few posters who make their post that way; but they are usually wise enough to make an English subscript, even if it comes across a bit clumsily (still, readers are tolerant enough to make the best of it).

    If you wish to improve your knowledge of the relative efficacies of CO2 and H2O, then please make your post in an appropriate thread [not this thread].

    Look at the upper left corner of this page :- "MOST USED Climate Myths" . . . and (from more than 100 threads) choose the best fit.  You might care to select Myth 30 or Myth 36 , perhaps.  Read the Basic (and more Advanced versions) and also look through the 100's of comments (some trashy, some very informative).

    That will help you in getting up to speed, on the science of Greenhouse.  Starting from your base position, you may well need rather more than that.  But, it will be a good first step in understanding what the scientists are talking about.

  41. There is no consensus

    *their, since i can't edit

  42. There is no consensus

    Unfortunately, CO2's effects on weather are overly exacerbated by scientists who haven't taken the time to study the behavior of matter in depth with respect to radiation. Until they stop talking about CO2 being responsible and move the conversation to H20, they're consensus doesn't mean anything. Study the matter before you make assumptions. CO2 is a miniscule GG compared to H20 and there's not enough of it to make a comparison at this point.

  43. Climate's changed before

    MA Rodger @ 780

    Where can I find easy to understand data that shows that only two of the last 8 eight had sea level rise higher than today?

    Also a denier is trying to say that  Milankovitch Cycles are irrelevant.  Where do they get idea that from I wonder?

  44. CSLDF: Events at NOAA Highlight Strengths and Shortcomings of Agency Scientific Integrity Policies

    More administration interference in good science: Clean-air scientists fired by EPA to reconvene in snub to Trump

  45. CO2 effect is saturated

    What michael sweet said...

    Also, pressure is simply the weight of all overlying gases. If air density were constant, air pressure would drop linearly with height. Air density isn't constant, because pressure drops with height. In the end, air pressure basically decreases logarithmically with height (to a first approximation).

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

    In atmospheric models, they often use pressure as the vertical coordinate. Layers spaced equally in pressure would be roughly equally-spaced on a log(height) scale, or logarithmcially-spaced on a linear height scale.

  46. Using fallacy cartoons in a quiz

    Well-done, as always!

  47. CO2 effect is saturated

    You are progressing a little.

    Concentration is measured as Molarity which is moles per liter.  Ppm is a fraction of particles of dry air and is not concentration . For gases, molarity is directly proportional to pressure.  This varies with height.  Sometime pressure is used for concentration.

    It is a waste of time to attempt to model systems you do not understand.  The system is not saturated.

  48. CO2 effect is saturated

    The model in 542 is wrong I have to admit. It is wrong for two reasons:

    1) My impression was that vibrational energy and the kinetic energy mv2/2 were systems with little interaction. That is not the case. Michael Sweet in post 553 and Bob Loblaw in post 554 correct me here. Here is another reference (which gives a proportion of 10**9 instead of 10**5)
    https://sealevel.info/Happer_UNC_2014-09-08/Another_question.html

    So in the new model the photon at a wavelength of 15 μm travels an average of 25 m before being absorbed by a CO2 molecule which goes into a vibrational state, and which then collides (whatever that means (distance between the centers of the molecules less than the minimum of the two radii?)) with a Nitrogen or Oxygen molecule and falls back into the zero vibrational state (why?) and transfers the vibrational energy into kinetic energy over the two molecules. So CO2 transforms the energy of photons of certain wavelengths into kinetic energy of the atmosphere close (around 25 m) to the position where the photon was emitted.

    2) According to Fig 1 in Zhong & Haigh (2013) of the 239 W/m2 outgoing longwave radiation only 22 W/m2 comes directly from the earth. This is from Trenberth & Fasullo (2012). In Tremberth, Fasullo & Kiehl (2009) it is still 40 W/m2.

    Looking down from outer space for each photon leaving the earth system at TOA (which is 100 km above the surface according to Google. Is that correct?) one should be able to specify its wavelength and the level above the earth surface where it originated. Around 9% originate at the surface. It would seem that 90% originates close to the surface, say less than 1 or 2 km, except for the wavelengths around 15 mm, which originate at 10 km. (In figure 4 in Zhong and Haigh (2013) the red line follows the Boltzmann-curve for 290K rather than 260K, see figure 3, the temperature at 5 km).

    The saturation of CO2 for certain wavelengths shown in the black blue and green graphs in Figure 6(c) in Zhong & Haigh (2013) suggest a transmission which decreases like the inverse of the concentration of CO2 as it approaches the limit value. That agrees with the model in post 542 but I do not see how the new model will give this result.

    I think concentration (ppm) is the variable of interest, not density (parts per m3). The twenty layers of my original model each contain the same amount of matter. Their height may vary. The effective CO2 concentration at 10 or 20 km is the same as at sea level. See for instance Aoki et al. (2003) Carbon dioxide variations in the stratosphere over Japan, Scandinavia and Antarctica. Tellus (2003) 55B, 178--186. CO2 is 50% heavier than oxygen or nitrogen, so one would expect it to settle down at the bottom. If it did it would form a layer of pure CO2 more than three meters high. A hundred years ago that was only a bit more than two meters!

  49. Climate's changed before

    I have to agree with TVC.  The exchanges between the experts and the well informed and the deniers has given me a more detailed look at the different aspects of AGW.  

    I've been here lurkinga couple times a day since the inception of this blog site.  I read most of the articles and love going to the commets where things get fleshed out. 

      

  50. Climate's changed before

    MA Rodger @780 

    Thank you so much. I learn so much from you all when I post the denialist blather that deniers challenge me with.

    Thanks for the link to the Rohling paper.

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