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The climate has always changed. What do you conclude?

Filed under: — stefan @ 20 July 2017

Probably everyone has heard this argument, presented as objection against the findings of climate scientists on global warming: “The climate has always changed!” And it is true: climate has changed even before humans began to burn fossil fuels. So what can we conclude from that?

A quick quiz

Do you conclude…

(1) that humans cannot change the climate?

(2) that we do not know whether humans are to blame for global warming?

(3) that global warming will not have any severe consequences?

(4) that we cannot stop global warming?

The answer

Not one of these answers is correct. None of these conclusions would be logical. Why not?

(1) The opposite conclusion is correct: if the climate had hardly changed during the course of the Earth’s history (despite variable incoming solar radiation and changing amounts of CO2 in the atmosphere), then we would conclude that there are strong stabilizing feedbacks in the climate system. The drastic climate changes in the history of the Earth (ice ages, hot ice-free periods) show that the climate system is sensitive to changes in the radiation budget. The measure for this sensitivity is called climate sensitivity: how much global warming will result from a CO2 doubling in the air? For the first time it was estimated by the Nobel laureate Svante Arrhenius in 1896. According to our modern knowledge this climate sensitivity is around 3°C (uncertainty ± 1°C).

Paleoclimatologists determine the climate sensitivity from data from the Earth’s history. A recent review article in Nature on this method showed “a warming around 2.2 to 4.8 °C per doubling of atmospheric CO2, which agrees with IPCC estimates”. In short: the larger past natural climate changes have been, the more vulnerable is the climate system, and the more it will react to the greenhouse gases that humans are adding to the system.

(2) Imagine there has been a forest fire. The police have extensive evidence that it was arson. They know the place where the fire began. They found traces of fire accelerants. Witnesses observed a man whose car was parked nearby. In his trunk the police finds bottles with fire accelerants, and in his house they find even more of it. He has been convicted for arson several times before. Plus some further evidence. In court, he defends himself: forest fires have always occurred lit by lightning, even before there was any man on Earth. Therefore he must be innocent. Does the argument convince you?

The evidence for the human cause of global warming is overwhelming. This is why there has been a consensus among climate researchers for a long time, and almost every scientific academy on the planet has come to the same conclusion. The most important evidence: when it gets warmer, the energy has to come from somewhere (1st law of thermodynamics). It can only come through the radiation budget of our planet. (No, Rick Perry, the energy does not come out of the ocean. To the contrary, measurements show heat is going into the oceans). The changes in this energy balance are quite well known and are shown near the front of any IPCC report – see Fig. 1. The biggest factor is the increase in CO2 concentration as well as a few other greenhouse gases, also added by human activities. The incoming solar radiation has changed just a tiny bit in comparison – since 1950, by the way, it has even decreased and thus offset a small part of the human-caused warming – hence humans have probably caused more warming than is observed (best estimate is 110% of observed warming).

Fig. 1 Radiative forcing is the cause of global temperature changes. Red bars show warming, blue bars cooling effects. I am showing the diagram from the fourth IPCC report of 2007, because it is easier to understand than the more recent from the 5th IPCC Report of 2013, which Gavin discussed here. The overall human-caused radiative forcing, which is given here as 1.6 watts per square meter, had already risen to 2.3 watts per square meter by the year 2011 according to the 5th IPCC report. Source: IPCC report 4 Fig. SPM.2.

Overall, humans have caused an additional heating (radiative forcing) of 2.3 watts per square meter of Earth surface – as of 2011. It has increased further since.

(3) Those who can’t deny that humans are causing warming often seek refuge in the hope that the consequences might not be so bad, so we might just adapt rather than having to stop further warming. The climatic changes in Earth’s history do not support this point of view. As a result of the global warming by around 5 ° C from the last ice age 15,000 years ago to the mid-Holocene, global sea levels rose by 120 meters until 5,000 years ago! At that time hardly a problem – but for today’s humankind even a rise of two meters would be a disaster, bringing devastation to coastal cities and small island states. We still have enough ice on Greenland and Antarctica to raise the sea level around the world by 65 meters. Both ice masses are losing ice more and more quickly. The West Antarctic has probably already crossed its tipping point and is unstable. Greenland could soon follow.

Fig. 2 Ice loss of Greenland measured by GRACE satellites. Source: NASA .

By the way: the just mentioned 5°C rise within ten thousand years at the end of the ice age are among the fastest global temperature rises documented in the Earth’s history. That is 0.05 degrees per century. In the last hundred years we have caused the twentyfold rise. This pace of change overtaxes the adaptability of many ecosystems and will lead to their collapse as the warming progresses. In coral reefs this is already in progress.

The pace of the completely man-made CO2 increase (by now the CO2 concentration is higher than at any time in the past three million years) leads to a rapid acidification of the world’s oceans, because it overcomes the buffer capacity of the oceans. The last major acidification event 250 million years ago has apparently led to a massive extinction of species in the world’s oceans.

(4) Often I hear that the aims of the Paris Climate Agreement are absurd, because humans cannot stabilize the global temperature – after all, our climate changes even without human intervention. This argument is also wrong. As already mentioned, without human interference there would have been no global warming since the middle of the 20th century. If anything there would have been a slight natural cooling. The fluctuations in the sun’s activity are causing variations of 0.1 or 0.2 °C in global temperature in the last thousand years (e.g. at the Maunder Minimum of solar activity in the years 1645 to 1715). In the longer term, the astronomical Milankovitch cycles of the Earth’s orbit and the Earth’s axis dominate the natural climate changes (hence the ice ages). The shortest of these cycles has a period of 23,000 years – for the next hundred years, it practically does not matter. However, our fortune would last much longer than that: the Milankovitch cycles can be calculated over millions of years with astronomical precision (and incidentally be used to predict the beginning of all the past ice ages), and according to that, the next major climate change would arrive only in about 50,000 years. Namely the next ice age.

So if we weren’t doing something really stupid, we could benefit from another 50,000 years with a stable climate. Nothing in our knowledge of paleoclimatology suggests that natural factors could prevent us from limiting global warming to below 2°C. Only our own dithering, our own inertia can do that. Or that we prefer to be lulled into fatal complacency by the reassuring fairy tales of the “climate skeptics” rather than confronting the danger.

Among the most ill-informed claims of those “skeptics” is the assertion that climate researchers do not know or consciously ignore the fact that the climate has always changed. Utter nonsense, of course. Almost all of the authors here at Realclimate have done substantial work in paleoclimate for decades, as you can see from our publication lists (including the textbook Paleoclimatology). A lot of other climate researchers do the same. This May, three of us were at a conference of almost one thousand paleoclimatologists in Zaragoza (see photo below). These researchers know more about the natural, past climate changes than anyone else. Nobody there expressed any doubts about the ongoing human-caused global warming. On the contrary, many paleoclimatologists are particularly concerned about anthropogenic warming, especially in view of our findings about Earth’s history. Already when I was working as lead author on the paleoclimate chapter of the 4th IPCC report more than a decade ago, some of the discussions within IPCC revolved around us paleoclimatologists regarding some risks as considerably more serious than the colleagues specializing in the modern climate, such as the risk of rapid sea level rise or instability of ocean currents and ice sheets.

Whoever tells you that the fact that “the climate has always changed” is somehow reassuring, does not know what he is talking about – or he is trying to con you.

Paleoclimatologists: participants in the PAGES Open Science Meeting in Zaragoza in May 2017

243 Responses to “The climate has always changed. What do you conclude?”

  1. 201
    patrick says:

    @152 Donna: I’m sure your comment speaks for many others too. Thanks for your input.

  2. 202
    Thomas says:

    200 nigelj, You’re right. Many excellent things have been done by individuals and teams and the global body of scientists including via the IPCC and the UNFCCC paris agreements and those you mention above.

    and true ‘facts’ do get scrambled even by the best and even by those with best intentions get things ass up now and then. Imperfection is the norm iow.

    As faulty as it may be, my view is that the artful doubters have successfully filled a vacuum and taken full advantage of that with their deep pockets and highly motivated ideologies etc. These pushing such things have quite effectively garnered the fear factor and turned it into a modern day art form.

    eg “we’re supposed to go live in caves” meme is a fear factor tool they use to shore up their “doubts” and latent conspiracy theories of all those evil greenies and greedy climate scientists sucking on the govt teat over nothing – that too is another fear factor.

    Hey guess what? It works and it is getting stronger not weaker despite all the mounting “facts” you mention that were not as clear as they were as recently as 2000 say.

    Fear sells especially when you make it personal and HOOK it into people’s/groups/nations base beliefs, cultural norms and world views.

    But it’s more broader than just fear – business and political parties and govts spend $billions each and every year on advertising. Why? Um, it works. Behind the word is human psychology and communication techniques that HOOK people’s attention …. 99% of the time it is always “logical fallacies” being used, or juts plain myth making BS … but whatever the case “people buy into it all” to varying degrees because they get hooked emotionally and personally.

    eg the series of comments/refs I made about politics surrounding that Century of the self doco … the doco isn’t a big deal, but the “message” and “proofs” it contained in it are.

    So Nigelj you ask: “I’m struggling to know what more scientists can do in terms of communication.”

    My answer is very simple one …. HIRE EXPERTS IN COMMUNICATION …. or beg them to volunteer their services asap.

    The science need some decent salesmen on their team and the scientists need to surrender the communication process to them no different than Ford hires an EXPERT AD Company to run their PR advertising campaign for the next 5 years.

    I could be wrong, but as each year ticks by I see nothing has happened to change mind. It’s a 15 year old “opinion”. My depended on good sound Marketing Principles and decent expert Advertising methods.

    No one can effectively communicate to the Public without such expertise. It’s pure Psychology at it’s core. One can sell DDT and Cigarettes or one can sell the survival of Nature and Human civilization …. or gosh, even serious practical action to address AGW/CC.

    Nothing wrong with climate scientists, it’s not their fault for not being expert marketers or psychologists or cognitive scientists —- horses for courses?

    anyway. that’s how I see it, no worries if people disagree or have a better idea. Go for it.

  3. 203
    Thomas says:

    200 nigelj, ps a cpl of examples. If it was only about the “facts” then Ronald McDonald would be selling toothpaste and men in white coats would be selling hamburgers on your TV. And McDonald’s and Burger King and Wendys would not have so much red and yellow in their logos and buildings and wrappers. And Subway would not have so much Green in theirs.

    This stuff goes very deep. And it is totally unnoticed by all except the “experts”. See what I mean?

    Al Gore and Leonardo DiCaprio and so most of the very well intended agw/cc doco makers and UN bureaucrats are not experts in communication, advertising or primary human psychology.

    Coca Cola’s AD Companies are… and Coke always hires the best there is. And they never mention the facts about what’s in the drink … not once, not ever in it’s history. Think about that. :-)

  4. 204
    Thomas says:

    PS and the deniers ad campaign is so damned effective that even RC gets suckered into using their very slogans …. The climate has always changed.

    I simply direct any one curious back to the many refs I provided to George Lakoff who explicitly explains this trap and the solution – based on cognitive science, linguistics and psychology. He’s been on this topic since the 1990s. World’s best kept secret maybe? :-)

    iow this is not new science or new communication techniques. It’s been available for a very very long time, even BCE.

  5. 205
    Thomas says:

    Socrates was brilliant. Yet his lousy communication skills ended up getting him killed. Now Plato on the other hand. Now he was a Salesman!

    Plato was an expert communicator. He changed the entire western world a thousand years later, such was the power of his Word.

  6. 206
    alphagruis says:

    zebra (#194)

    But I am always open to being enlightened on the internet, so why don’t you explain why things that have already been built can’t be built?

    Basic flaw in your logic and ridiculous straw man ! First, I never said that such “things” cannot be build. The first car was an electric one more than a century ago and maybe (if you really had a sane background in physics) you might find out why the thermal engine won the race. Moreover I similarly never said that electric cars or buses are not an alternative in urban transport !!!!
    I was talking about agriculture and trucks ! Right ?
    Second, many “things” have been build in the history of science and technology…. And it’s of course not because a “thing” can be build and/or has been build that it’s really useful and can or will be put in massive use and may replace the “things” you wish it should replace…
    And by the way if you knew indeed something about physics, energy storage per weight unit in batteries versus hydrocarbons for instance, you would have seen since long why in case of trucks, tractors, airplanes or merchant navy for instance it’s “carbon forever” or nothing. Synthetic fuels must replace fossil fuels either because we run out of them or because we make the decision to leave the fossil fuels in the ground.
    Whether you like it or not.
    And neither you nor nigelj nor any politicians or human being will ever be capable to change the laws of physics behind this reality in international meetings or instances. So funny !
    But as nigelj you obviously don’t like neither the facts nor the reality and prefer wishful thinking and dreams
    So it’s definitely useless to continue this debate as far as I’m concerned.
    And remember the facts are very stubborn.
    Some food for thought

  7. 207
    alphagruis says:

    Zebra, I almost missed your “link” to the electric tractor !

    Congratulations! You made my day !

    Hilarious !

    130 kWh in the battery pack with 2 X 150 kW motors. That’s the equivalent of about 13 litres of diesel fuel Barely enough to work half an hour on the field…
    For info a diesel tractor of this power has typically a fuel tank of 500 litres ….
    Probably another similar “thing” is expected to tow every 30 minutes the first “thing” home and recharge the battery pack ? While the farmer get’s a sleep ?

    Never seen that much idiocy before.

  8. 208
    nigelj says:

    Thomas @202 -205,

    “The science need some decent salesmen on their team and the scientists need to surrender the communication process to them no different than Ford hires an EXPERT AD Company to run their PR advertising campaign for the next 5 years.”

    I can go along with that, at least to some good extent. They do need some communications experts involved, desperately.

    There’s nothing worse than a scientist, obviously gifted at their job, but stumbling through a public presentation, getting lost in detail, overcomplicating things, etc, and tripped up by difficult, curved ball questions from denialists. Some people have a flair for public speaking, some don’t myself included.

    However it depends how its done. If the IPCC put out information through some public relations agency, this may not make a great impression with the public.

    However the IPCC and climate scientists fronting the public would be well advised to at least get in depth public relations and marketing advice. I have had to learn the art of diplomacy and selling ideas in my job. Nobody should be above this, and it made a huge difference for me. Its very much a learned skill and huge improvement is possible, and the same goes for debating skills.

    Its sad we need all this, but its the reality of life if you want to survive.

    Aristotle also wrote well. So does the modern author Yuval Noah Hariri. They are engaging, easy to read and convincing.

    In contrast Immanuel Kant was incomprehensible, confusing, and dry as dust. The modern author Micheal Shermer writes some great books in their content, but hes not not an engaging sort of writer.

    Al Gore is an ok writer, in his shorter books. The long ones are very tedious.

  9. 209
    Doug Payne says:

    This helps simplify the vision of where we are in this nation.

  10. 210
    nigelj says:

    Alphagrius @207

    So your claim that renewable energy is not practically possible due to the “physics” comes down to claims for example that the new prototype John Deere electric farm tractor is no good, and only lasts half an hour.

    Well this article below says it gets 4 house use, so I’m not sure about your calculations.

    Regardless of that, its really the first of its type. Nobody is claiming its ideal. Battery technology will almost certainly improve further. Aluminium based batteries have already been developed in the laboratory and charge within seconds. There’s no “physics” that says better batteries are not possible and with respect physics cant really design a better battery by itself. A lot comes down to trial and error.

    I’m not a blind optimist on technology either, but there’s seems to be a lot of sound opinion that battery technology will improve. The hard physics limits have not been reached by a long way.

  11. 211

    For the tractor with a 30 minute battery, I would have the battery pack on a rack under the vehicle, so it could be easily removed and replaced. The old battery goes in the charger while the new one is being used. Then switch again. Or have 16 batteries lined up for an eight-hour day. Very time-consuming and costly, of course, but we’re talking prototype, and future versions will get better and easier.

  12. 212
    zebra says:

    niglej 210,

    It is always disappointing for me when someone claims to be “a physicist” but is clueless about the physical world– kind of a contradiction in terms. But, celebrity has accrued to the people we used to call “mathematical physicists”, who have made significant contributions, but whose work could have been done in a Chinese Room where they were kept from birth. (Not all, but many working these days.)

    I had great hopes of hooking up alpha with Killian and Scott and letting them handwave at each other about different scales of agriculture…that could easily power at least one wind turbine. ;^)

    The thing is that of course, contrary to alpha’s Nirvana and No True Scotsman fallacies, smaller-scale and local agriculture are a perfect fit for electrification. I pointed out previously that shipping produce from a distance is probably more CO2-efficient than lots of smaller local farms with smaller tractors and smaller trucks. But, that problem goes away in an electrified farming with on-site/local wind and solar generation paradigm.

    Anyway, alpha has flounced off so he cannot be educated about real-world physics. I will try to get back and discuss the more on-topic question about “educating the public”, but duty calls.

  13. 213
    Loyd Clary says:

    Your story was very interesting with all of the figures, graphs, and calculations until you fell back on the lie about Antarctica shrinking and causing sea levels to increase. You should read the NASA report dated 30 Oct 2015 Entitled: “Mass Gains of Antarctic Ice Sheet Greater Than Losses” This information was based on tens of thousands of years of information gained from ice cores taken and from current research. The report shows that the ice growth currently on Antarctica actually causes the sea levels to decrease by 0.23 millimeters per year. It also shows that the ice thickness on East and interior Antarctica has been increasing by an average of 1.7 centimeters per year for thousands of years. Although I agree that we need to closely work to control destruction of our environment, once an environmentalist publishes an exaggeration (or Lies), then everything they say is a lie to the unconvinced readers. This report that I referenced is the NASA report that came out a couple of weeks before our president’s gloom and doom speech in Paris. When you lie once, from then on you’re always a liar and everything you report or say is suspect. This is one of the reasons so many people fluff off anything that environmentalist say. If you want to work toward getting everyone onboard to help the environment, STOP THE LYING and EXAGGERATIONS.

    [Response: Can you try, just once perhaps, to consider that some people may actually know more about a topic than having seen a headline two years ago? And that, just perhaps, you might want to consider the totality of the evidence rather than an outlier study that just happens to coincide with your preconceptions? Go on… gavin ]

  14. 214
    zebra says:

    BPL 211,

    It’s more like 4 hours, not 30 minutes, because the electric motors do not operate at maximum capacity continuously, as our “physicist” friend alphagruis apparently believes. It is not a simple calculation, actually, but this is why you build prototypes and put them through real-world paces.

    However, you are correct that the battery-swap idea, which is problematic for passenger vehicles at this point, is perfectly suited for the farm application.

    Farmers do that kind of thing all the time, for heaven’s sake! They are constantly hooking and unhooking heavy equipment to the tractors, they have equipment sheds, which can be covered with solar panels…so, a couple of extra batteries and a little planning will get them through a 12-hour day.

    What’s not to like.

  15. 215
    CCHolley says:

    Loyd Cary @213

    You should know that the author of this piece that you accuse of lying is the preeminent oceanographer and climatologist Stefan Rahmstorf. He is one of the top scientists in his field and has certainly shown that he knows what he is talking about and should be beyond reproach, unless, of course, you just don’t like what he says. And I’d be very surprised if he is not very aware of the paper you reference and has studied it in depth. But go ahead and call him a liar and exaggerator if it makes you feel better, but you’d be wrong.

    As for thisGavin dude, I suspect he should know something about the *NASA* paper you are referring to.

  16. 216


    BPL: Stop assuming that anyone who disagrees with you must secretly agree and be lying about it. If you can’t imagine that someone could honestly disagree with you, it probably means you don’t understand the subject under discussion.

    It’s not “a lie” that the Antarctic ice cap is shrinking. The GRACE satellites say so, and I trust them over the one article you managed to turn up to the contrary.

  17. 217
    Mal Adapted says:

    Loyd Clary just accused Stefan of lying. Is that actionable?

  18. 218
    Digby Scorgie says:

    Loyd Clary @213

    Are you aware of the connection between Gavin and NASA?

  19. 219
    nigelj says:

    Lloyd Clary @213

    There was no lie in the discussion over Antarctic ice mass, as has been pointed out above.

    And dismissing an individual or entire group of people over one lie or mistake is obviously childish. You would have to dismiss the entire human race.

    Scientists have a good deal better record of integrity than politicians for example. Look at the truly prolific lies currently coming out of the White House. But I suspect that doesn’t bother you.

  20. 220
    Phil Scadden says:

    Clary – perhaps you might like to ask Zwally whether he thought the speech was lying and exaggerations? When he put the paper out, he was concerned that people would abuse the findings exactly the way you have? Also, dont confuse scientists with environmentalists. You can be both, but dont assume it.

  21. 221
    jgnfld says:

    @213 Presenting information in its full context is not a denier attribute. Nor could it be or the conclusion would be that there is warning. Hence the constant cherrypicking and presentation of singular, out-of-context factoids exactly as we saw with tobacco, acid rain, etc.

  22. 222
    Mal Adapted says:

    The Koch Club’s investments in AGW-denier propaganda has paid off handsomely, by convincing gullible culture warriors like Loyd Clary that AGW is an ‘environmental’ issue, rather than an immense and growing economic cost that literally everyone on Earth will have to pay for one way or another.

  23. 223
    Mr. Know It All says:

    Comments on the article:

    YOU: “The drastic climate changes in the history of the Earth (ice ages, hot ice-free periods) show that the climate system is sensitive to changes in the radiation budget.”
    YOU: “The most important evidence: when it gets warmer, the energy has to come from somewhere (1st law of thermodynamics). It can only come through the radiation budget of our planet.”

    MKIA: Is there no other way to cause climate changes other than changes to the radiation budget? Vast areas of the western US are covered with lava: Idaho, Colorado, Oregon, Washington, Wyoming; and 80% of earth’s surface above and below sea level is volcanic. If, sudden widespread volcano activity covered vast areas with lava around the world, could that heat produce climate change? What about asteroid impacts – we know of some, maybe there are some we don’t know about? Is it possible that some change in the orbit of the earth around the sun occurs occasionally – maybe some celestial body whizzes by and changes the orbit?

    YOU: “Often I hear that the aims of the Paris Climate Agreement are absurd, because humans cannot stabilize the global temperature…..”

    MKIA: Whether there is an agreement or not, all believers should be living as much as possile, a low-carbon life-style, right? PV on the roof, electric car or no car, bike-carpool-bus to work, work from home, T-stat set at 60 in winter, 80 in summer, mostly vegetarian diet grown locally, no big-screen power hog TV, power off computer when not being used……..right?

  24. 224
    Chris O'Neill says:

    Victor #164:

    I’m also bothered by a theory that attributes cooling to the emission of aerosols and warming to the emission of CO2, both stemming from the same increase in industrialization and indeed from the same coal burning plants.

    The difference of course is that aerosols get rained out in a relatively short time (ever heard of “acid rain”?) whereas around half the CO2 will stay up there for a much, much longer time.

    These concepts must be extremely difficult for someone like you to understand, Victor.

  25. 225
    Chris O'Neill says:

    Victor #120:

    for me such differences confirm a long held suspicion of findings based purely on statistical analyses

    OK so you now don’t disagree that there is a correlation between atmospheric CO2 and global temperature anomaly.

    But now you are “suspicious” of statistical analyses.

    You are a master of moving the goal posts Victor.

  26. 226
    Chris O'Neill says:

    Victor #78:

    the burden of proof is on the defender of the theory

    Where is the defence of the theory that CO2 emissions are harmless?

  27. 227
    Chris O'Neill says:

    Victor #151:

    I’ll bet you say that to all the trolls.

    Thanks for the confirmation.

    Of course, we already knew you were obviously biassed Victor when you claimed a 3.6% increase in CO2 is a “low rate of increase” while a 4.6% increase is “rising sharply”.

  28. 228
    Chris O'Neill says:

    Victor #163:

    What are YOUR credentials?

    Your credentials are almost completely irrelevant to physical sciences.

  29. 229
    I Voted For Trump says:

    Hello All! Yes, it’s true.

    213 Loyd Clary
    Here’s the link to the NASA study you referred to which does indeed claim that increasing Antarctic ice accumulations are contributing to lower sea levels:

    Is the study disputed? By whom?

    [Response: Everyone else working on the issue. -gavin]

  30. 230
    Not_Sure says:

    A useful label to understand and use when appropriate – PALTERING

    Figuring out when someone’s being honest can be exhausting. To stay on your toes, watch for a technique called “paltering” that uses true statements to distort your perceptions.

    Harvard Paper

  31. 231
    Alastair B. McDonald says:

    Re 229 where “I voted for Trump” asks if the study saying the Antarctic is gaining 80 Gt ice per year is disputed.

    Greenland is losing 280Gt ice per year so sea level is not falling!

  32. 232
    Steve E says:

    I’ve been reading your site off/on for several years now, and I’d just like to say…… Wow.

    Thanks for your service.

  33. 233
    Richard Beaumont says:

    Adam Lea says:
    20 Jul 2017 at 5:01 AM
    …I really have my doubts that enough of the global population do, or will take it seriously enough…The hard-wired cognitive biases that worked well for survival in the hunter-gatherer days, but are dreadful in today’s completely different complex civilizations, are too powerful to overcome, we collectively don’t have sufficient intelligence to override…

    Human cognition is not the problem. American culture is.

    The reason too few people, particularly in the USA, recognise the severity of the problem is that they are inundated with a campaign of misinformation by cynical interests who know that not everyone has the time or energy to investigate the issue for themselves, or the knowledge to evaluate competing claims.

    Go to Germany, New Zealand, or China and most people do understand. Its time to pinpoint what is exceptional (cough cough) about the USA, with its unbelievable concentration of young earth creationist nutcases, climate science deniers, and various other moronic faith positions…

  34. 234
    Richard Beaumont says:

    MKIA: “Is there no other way to cause climate changes other than changes to the radiation budget? Vast areas of the western US are covered with lava: Idaho, Colorado, Oregon, Washington, Wyoming; and 80% of earth’s surface above and below sea level is volcanic. If, sudden widespread volcano activity covered vast areas with lava around the world, could that heat produce climate change?”

    ME: Sure, huge volcanic eruptions would affect climate in a number of ways, from initial direct local heating (more a temporary weather effect), aerosols (a few years) and CO2 emission (millennia), especially if the lava flow hit a big coal seam or clathrate bed… and yet we have seen over 1K warming over the last century without any giant burst of volcanism.

    MKIA “What about asteroid impacts – we know of some, maybe there are some we don’t know about? Is it possible that some change in the orbit of the earth around the sun occurs occasionally – maybe some celestial body whizzes by and changes the orbit?”

    ME: Why is it so important to you that any amount of grasping at straws is preferable to established science that predicted global warming from CO2 increase back in 1896 based on simple physics and that apart from the details, not much has changed since?

    Why not accept a hypotheses that predicted temperature rise and explains the temperature rise? Your unknown asteroids and non-existent volcanic bursts might as well be fairies in the garden.

  35. 235
    Mr. Know It All says:

    234 Richard Beaumont

    Is it possible that AGW was predicted based on the science in 1896? I thought the basic science involved quantum mechanics as indicated in the video link below. I thought quantum mechanics came later than 1896 – no?

  36. 236

    KIA: Is it possible that AGW was predicted based on the science in 1896? I thought the basic science involved quantum mechanics as indicated in the video link below. I thought quantum mechanics came later than 1896 – no?

    BPL: Yes. The greenhouse effect was discovered in 1824, the gases responsible for it were identified in 1858, and Arrhenius predicted anthropogenic global warming in 1896. But the explanation for HOW it worked, on the molecular level, had to wait until quantum mechanics was developed in 1900-1920 or so.

  37. 237
    Ray Ladbury says:

    To the ironically named Mr. Know It All:
    Do you really presume that everyone else on the planet is as utterly clueless as you? Do you really think that no one else has ever looked at the utterly impossible alternative causes for the warming that you posit? Or is your goal merely to distract and entertain?

    As to quantum mechnanics–not necessary for understanding the greenhouse effect. All you have to understand is:
    1) Greenhouse gasses are transparent in the visible–where the radiative peak for the Sun is–and absorb strongly in the infrared–where Earth radiates.
    2) That atmospheric temperature decreases with altitude (look up adiabatic lapse rate)
    3) That the lifetime of the excited CO2 molecule is sufficiently long that a large proportion of such molecules relax via transfer of momentum to another atom (mostly N2) during collision rather than via re-radiating a photon.

  38. 238
    Marco says:

    MKIA, you may want to consider that Darwin’s theory of evolution was established well before we knew the existence of DNA and genes. Try to find a very recent explanation of evolution that does not reference the latter.

  39. 239
    Chris Ho-Stuart says:

    Specifically, at the time the greenhouse effect was first discovered and described, the capacity of certain gases to absorb the infrared was a property that was measured. Now it is possible to calculate the IR absorption in detail using quantum mechanics.

    It was not necessary to have those detailed calculated spectra to measure IR absorption or to apply basic nineteenth century thermodynamics to understand the greenhouse effect as a necessary consequence.

  40. 240

    #235, KIA–

    Tyndall wrote that changes in the amount of any of the radiatively active constituents of the atmosphere—water vapor, carbon dioxide, ozone, or hydrocarbons—could have produced “all the mutations of climate which the researches of geologists reveal . . . they constitute true causes, the extent alone of the operation remaining doubtful.” Tyndall’s carefully executed laboratory experiments clearly demonstrated that trace atmospheric constituents were active absorbers of heat radiation.

    That was in 1861.

  41. 241
    Adam Lea says:

    233: “Human cognition is not the problem. American culture is.”

    I strongly disagree. Do you really think that only America is full of people who over-consume, are wedded in a religious like state to neo-liberal capitalism, and dismiss anything that challenges that religion? It is all over the western world, the UK is full of it, why do you think right wing governments are continuously elected whilst the Green party is permanently confined to the fringes with likely no hope of election in mny lifetime? Look at how people live across the rich nations, it is only a bit less worse than Americans, but still well over the limits of sustainability. Even significant parts of the developing world are aspiring to reach Western standards of living and wealth, with all the destructive side effects that will entail. It has nothing to do with which patch of soil on the planet anyone happens to be standing on, it is because climate change and its consequences are, for most people, an invisible enemy. The reason people dismiss it as a problem is because from their perspective they cannot see a problem (or the problem is way off in the future or someone else will cop it), therefore why should they, as they see it, take cuts to their quality of life for no perceptible gain to themselves. Human cognition is terrible at visualising seemingly inivisible threats as a problem, and giving the future any significant value compared to the here and now. This last point is a key issue, people want to enjoy the benefits of capitalism now, and any consequences in the future are of much lower value. No different to people refusing to give up smoking or excessive drinking, the pleasure they get now outweighs the health consequences (which may or may not happen) in the future. Similar in a way to when drivers pull off dangerous manoevres around cyclists, the driver externalises the risk without consequence, the cyclist takes the consequence if it goes wrong, if an accident does happen the driver will often use any excuse to blame the victim. The climate change and consequences issue is just like that but on a global scale and orders of magnitude more severe.

  42. 242
    Thomas says:

    241 Adam, I think you missed the point. “American culture is.”

    Or perhaps more accurately a Culture lacking in “sophistication” and humanity’s highest “ideals”?

    eg Culture – Range of human phenomena that cannot be attributed to genetic inheritance.

    Culture is the characteristics and knowledge of a particular group of people, encompassing language, religion, cuisine, social habits, music and arts.

    The Center for Advance Research on Language Acquisition goes a step further, defining culture as shared patterns of behaviors and interactions, cognitive constructs and understanding that are learned by socialization. Thus, it can be seen as the growth of a group identity fostered by social patterns unique to the group.

    In a world of globalized media connections since the 1960s this ‘group identity culture’ has spread like a virus all over the world infecting almost all other cultures negatively and at times violently and destructively.

    There are very good sound reasons why ground zero for AGW/CC denial is located in the USA and the Washington DC in particular. It’s not an accident nor a coincidence – it’s the manifestation of the predominant power base of the late 20th and early 21st Century American Culture.

    While the USA will eventually go the way of the Roman Empire, and for the exact same reasons as that empire went the way of the dodo, the question is now whether or not this predominantly Dysfunctional Irrational anti-Humanity anti-Reason anti-Enlightenment Culture will take the whole world with it as well.

    Delivering us all unto a Planet of the Apes like existence of subsistence again. That is the question. Ignoring the key driver will not deliver a rational solution, nor a satisfactory outcome for Earth as a whole.

    That Great Generation who moved mountains and who sacrificed all during WWII no longer exists. Nor does the same society and culture out of which the Generation was born into exist anymore.

    Today is a completely ‘New Deal’ – in fact it’s a ‘Bad Deal’ for all the world. Those not aware of it, and those who cannot see it, and those who kind of see it but consciously choose to ignore it (due to cognitive dissonance etc) are as much the problem and as guilty as as the most criminal proponents of AGW/CC denial are.
    And yes, it is that serious and urgent as was went down in Nazi Germany in the 1920s and 1930s. You bet it is.

  43. 243
    bcw says:

    44 is making the “it’s too hard to calculate so the answer is zero” argument, mixed in with “it’s presumptuous for us with our tiny brains to try to calculate this.”

    Come on, it’s conservation of energy: Arrhenius came pretty close in 1896. The one thing we know absolutely is that the answer is NOT zero effect. As a useless physicist, even I can understand this. He then pretends that there is not a substantial literature on matching past climate to models, exactly what he claims he needs to see. With all the 10^9 increase in computing power, the answers haven’t changed that much from when I first peered skeptically at reports on this in the early eighties. The only thing that really changed is we have made some progress getting away from coal.