About the SA Blog Network



Opinion, arguments & analyses from the editors of Scientific American
Observations HomeAboutContact

Climate Change Has Helped Bring Down Cultures

The views expressed are those of the author and are not necessarily those of Scientific American.

Email   PrintPrint

sumerian-cuneiformHumanity has weathered many a climate change, from the ice age of 80,000 years ago to the droughts of the late 19th century that helped kill between 30 and 50 million people around the world via famine. But such shifts have transformed or eliminated specific human societies, including the ancient Sumerians and the Ming Dynasty in China, as highlighted in a review paper published January 30 in Proceedings of the National Academy of Sciences.

Epidemiologist Anthony McMichael of Australian National University surveyed how human societies fared during previous episodes of extreme weather brought on by climate shifts. The big threat is changes to food production, or as McMichael puts it “the drought-famine-starvation nexus.” And we’ve never weathered a climate change so big, so rapid and so widespread as the one we are now busily creating by burning fossil fuels, notes McMichael.

Long-running climate changes have often brought about the downfall of cultures, including foiling the earliest human attempts at settled farming nearly 13,000 years ago. Around that time, a major millennia-long climate cooling event known as the “Younger Dryas” coincides with the end of most settlements along the Nile Delta and in modern-day Syria. Skeletons from the era evince “an unusually high proportion of violent deaths, many accompanied by remnants of weapons,” McMichael noted. More recently, three back-to-back decades-long droughts afflicted Mayan society in Central America between roughly 760 and 920 CE, and marked the end of that culture’s regional dominance.

Shorter term climate changes have proven equally devastating. Decade-long droughts in 17th century China led to starvation, internal migration and, ultimately, the collapse of the Ming Dynasty. A seven year span of torrential rains, attendant floods and cold in the early 1300s helped cause a famine that may have killed as much as 10 percent of the people in northern Europe—a generation that would then face the Black Death a few decades later.

Even a single bad summer can be enough—like the hot summer of 1793 in Philadelphia that, paired with an influx of refugees from modern day Haiti, saw an outbreak of yellow fever that killed tens of thousands.

Of course, none of these societies had the benefits of modern technology or modern energy, whether medicine or air conditioning. But even that may not be enough to offset the roughly 2 to 4 degrees Celsius of warming in average global temperatures the world is on pace to achieve via emissions of greenhouse gases. “Such a change will surely pose serious risks to human health and survival,” McMichael wrote, “impinging unevenly, but sparing no population.”

Image: Sumerian cuneiform via © / Michael Fuery


David Biello About the Author: David Biello is the associate editor for environment and energy at Scientific American. Follow on Twitter @dbiello.

The views expressed are those of the author and are not necessarily those of Scientific American.

Rights & Permissions

Comments 39 Comments

Add Comment
  1. 1. priddseren 7:54 pm 01/30/2012

    Amusing how the entire article is about past climate change that killed millions and it was NOT caused by humans but somehow today’s climate change has only one source of change, us Humans and CO2 as the only possible cause.

    Really you warmists are better off just suppressing information like this and stick to your cherry picked data from your make believe computer model planets. Real information mixed in with your speculation just confuses everyone.

    Link to this
  2. 2. the Gaul 8:48 pm 01/30/2012

    Question prid: Why do you use a public forum like this to display your ignorance?
    Time and again you’ve been shown that humans are not the only possible cause, but that the contributions by humans are at least an impenetrable catalyst, at most, an insurmountable destabilization.
    Time and again you’ve read that methane is an even more problematic greenhouse gas, but you insist on your CO2 fixation.
    We would ALL be better off if you semi-literate deniers shut up, stayed in the background, and ceased your pointless caterwauling. Apparently it is not that difficult to confuse you.

    Link to this
  3. 3. Bops 9:35 pm 01/30/2012

    Not sure what planet you are from…can’t be earth.

    Maybe you think all the climate news items are a silly joke.
    The rise in skin cancer must be a another unproven scam too.

    Read the news about the Dutch, the dikes, and what they have to do about it.
    Maybe you are not seeing the TOTAL picture.

    You don’t read about all the water problems…
    WINTER flood warnings where we live this month… melting from where?

    What about a snow storm that came when the leaves were still on the trees in New England.
    We lost power for five days in October…our home went down to 38 degrees inside. We lost all our food.
    All the fish in my tank died. Big Joke. You should experience this some time.. People on oxgen…no power…

    I could go on with so many items, but the point here is that:
    YOU don’t want to recognize the problems because YOU
    are part of the BIGGEST cause and too cheap to accept
    financial responsibility for your part in the pollution.
    You shame yourself.

    Link to this
  4. 4. Bops 9:43 pm 01/30/2012

    There’s a book that James Watson wrote called,
    Lessons learned from a life of science
    Avoid stupid people.
    He wasn’t just kidding, they are for real.

    Link to this
  5. 5. priddseren 10:07 pm 01/30/2012

    Hey at the Gaul, are you sure you ready my posts? I am a total denier, how did you miss that one? CO2 is not the cause of anything other than arguments because a select group of people have put together a computer model and think it represents reality better than the actual planet.

    The CO2 fixation is you warmists. I have no idea why they insist on it. However, since all the pointless laws and taxes warmists want to make and the only target for mitigation they have is CO2, why talk about anything else. As far as warmists are concerned methane is not a factor at all. I would be amazed if the warmists actually considered it possible for second factor or a combination of conditions could be the cause, including natural ones.

    As far as human contributions, humans are certainly contributing to pollution. It may be possible the number of humans at 7 Billion and the larger number of domesticated animals, the billions of homes, factories, buildings and burning forests and fuels are all contributing to warming simply because all of this stuff produces actual heat and maybe the atmosphere is unable to handle so much extra heat.

    My point on this article was the warmists even talked about this at all. It sort of proves that the climate changes and kills or benefits life on the planet and it can do this instantly, over time and without the need for a human catalyst. So why would warmists want to publish an article that really proves this current warming is more likely natural or at least the human factor is not so great. After all, the computer model predicted warming for the last 10 years, did not happen.

    Link to this
  6. 6. Bops 12:09 am 01/31/2012

    Sure sounds like you go CheapCheap instead of CleanUpCleanUp!
    Good name for climate change deniers, CheapCheaps

    CO2 is not the only target. Why?
    It is a gas at standard temperature and pressure and exists in Earth’s atmosphere in this state, as a trace gas at a concentration of 0.039% by volume.

    CO2 is toxic in higher concentrations: 1% (10,000 ppm) will make some people feel drowsy.[7] Concentrations of 7% to 10% cause dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour.

    Prolonged exposure to moderate[clarification needed] concentrations can cause acidosis and adverse effects on calcium phosphorus metabolism resulting in increased calcium deposits in soft tissue. Carbon dioxide is toxic to the heart and causes diminished contractile force.

    Methane is a target too. Why?
    It is a relatively potent greenhouse gas. The concentration of methane in the Earth’s atmosphere in 1998, expressed as a mole fraction, was 1745 nmol/mol (parts per billion, ppb), up from 700 nmol/mol in 1750. By 2008, however, global methane levels, which had stayed mostly flat since 1998, had risen to 1,800 nmol/mol.

    Methane is not toxic; however, it is extremely flammable and may form explosive mixtures with air. Methane is violently reactive with oxidizers, halogens, and some halogen-containing compounds. Methane is also an asphyxiant and may displace oxygen in an enclosed space.
    From Wikipedia

    Different people have different main issues.
    As a whole they ALL agree, that’s it’s not a ONE fix for all problems.
    People are cleaning up in all areas, from soaps, foods, water, and fuels. The list goes on. Are you one of the problem people standing in the way of clean changes? or a CheapCheap?

    Link to this
  7. 7. Elegia 1:44 am 01/31/2012

    “Even a single bad summer can be enough—like the hot summer of 1793 in Philadelphia that, paired with an influx of refugees from modern day Haiti, saw an outbreak of yellow fever that killed tens of thousands.”
    “modern day Haiti”?? Really?
    Were they time travelers? Did the author mean ‘contemporary’, but why add an adjective anyway? Am I misunderstanding the author’s intent? Refugees from Haiti brought yellow fever; there wasn’t any other time for them to BE from, neh?

    Link to this
  8. 8. sault 3:33 am 01/31/2012

    If CO2 has no effect, why is Venus’ average temp 30K HIGHER than the MAX temp on Mercury, despite Venus having a higher albedo and MUCH lower solar irriadiance? How can CO2 have no effect when we know its absorption bands rather well and have seen increasigng absorption of outgoing longwave radiation? If you don’t know what I’m talking about, why are you even bothering to comment on this issue?

    Link to this
  9. 9. jdey123 6:27 am 01/31/2012

    “And we’ve never weathered a climate change so big, so rapid and so widespread as the one we are now…notes McMichaels”.

    In the rest of the article, McMichaels cites many short term climatic changes occurring all over the world that have wiped out previous civilisations.

    I’ve come to the conclusion that climate scientists have an arts/humanities background, as logic, correlation or the ability to read data or graphs seems to not to have been grasped.

    Link to this
  10. 10. jdey123 6:32 am 01/31/2012

    There’s a direct correlation between CO2 and temperature increases since 1880 (131 years) apart from:-

    1) 1880 to 1910 (30 years)
    2) 1940 to 1978 (38 years)
    3) 1998 onwards (13 years)

    Yeh, 50 years out of 131 years the world has warmed like the warmists climate models said it would. 81 years it didn’t because of:-

    1) Volcanoes
    2) Aerosols
    3) Solar Lulls
    4) ENSO events
    5) Some other reasons deniers wouldn’t understand.

    Link to this
  11. 11. jdey123 6:40 am 01/31/2012

    sault, CO2 has a warming effect, the argument is how much of an effect. Warmists like yourself claim it’s massive due to a feedback effect. Analysts like me say there’s no correlation between the ever increasing amounts yet still a tiny percentage of CO2 in the earth’s atmosphere and a temperature record which shows a high degree of variablity in a natural warming trend. If you look at the Central England Temperature record which goes back to 1659, the long term warming of central England is only 0.02C per decade, 1/10th that predicted by the climate models. Hence, climate models are rubbish. In order for a hypothesis to become a thory, definite testable predictions need to be made (not projections) and observations need to match the predictions (they don’t).

    Link to this
  12. 12. geojellyroll 11:37 am 01/31/2012

    Bring down ‘cultures’. Hmm? We’re moving towards a pan world culture so no chance of this. Folks shop at Walmart in minus 25c in Canada and plus 35c in Australia. Kids eat at Macdonalds in Santiago and Helsinki. The same IPods are used in Jakarta and Cairo.

    ‘Cultures’ are long gone as we know them. Cultures in the last 50 years (many in only 25 years) are being ‘universalized’. In another 20 years there will be a couple dozen Walmarts in North Korea…and when Cuba opens up, Starbuck’s will be there.

    Link to this
  13. 13. mihondo2010 12:52 pm 01/31/2012

    @Elegia: Take a history lesson: “modern day Haiti” was created in 1804. The event described was in 1793. Perhaps it could be better stated: “from what is now modern day Haiti”.

    Link to this
  14. 14. CopperCowboy 2:38 pm 01/31/2012

    Not much point in splitting hairs with the monkey minds folks. Most of the denier position can be attributed wilful ignorance or greed. Afraid that they and the corporations whose “scientists” they listen to, might not be able continue to pile up the money and political power now destroying our country or they have an inate need to spew their resentment and anger at their own impotence in life. God so loved the ignorant that he filled the world with them, and they vote. Praise Jesus and Koch.

    Link to this
  15. 15. Catamount 5:14 pm 01/31/2012

    priddseren, as opposed to our other resident denialist here, who is yet again building his arguments on intentional distortions of the science, assigning claims to climate scientists that they’ve never once made, avoiding a balanced evaluation of the various kinds of evidence in favor of selling cheap “gotcha” points, I’m going to assume that you’re actually trying to be sincere here.

    “Amusing how the entire article is about past climate change that killed millions and it was NOT caused by humans but somehow today’s climate change has only one source of change, us Humans and CO2 as the only possible cause”

    The strawman argument implicit in this statement is amazingly bad, I’m not going to lie.

    Yes, climate has changed for all sorts of reasons, and even now, changes for all sorts of reasons. Even over the last 150 years, there was large periods when solar changes or aerosol infusions were much more significant than then at-the-time piddling addition of GHGs by humans (which, unlike the intentional-misleading picture JDE123 paints, largely fits into climate models very well, whence why they recreate the last 150 years without a problem, within a fairly small margin of error).

    In fact, even during some recent warming periods, such as during the 1920s, the primary agent of warming was the sun (and our models would break down if the sun wasn’t a strong influence then, because our estimates for the Co2 forcing are just not enough to make the 1920s work without an increase in TSI).

    The reason we think humans have been primarily responsible for the past several decades, specifically, is not because anyone has EVER claimed that ONLY humans can change the climate, as, again, no one has ever claimed that. Rather, it’s because we’ve LOOKED at all the natural causes that have historically been big agents, and they aren’t doing anything on multidecadal timescales.

    Solar output (and with it, cosmic rays), volcanic activity, global albedo, none of them correlate with temperature since the 1970s. The only thing that has been changing that we know of is atmospheric composition.

    Now, as opposed to the impression given by a certain other poster here (not you) that “warmists” ONLY acknowledge atmospheric composition as important, and deny everything else, it is, in fact, denialists who don’t’ acknowledge ALL of the forcings in play.

    “Warmists”, which is basically like saying “every working climate scientist alive” (it’s tantamount to saying “evolutionist”), acknowledge all of the climatic agents as important, and try to include all of them in their calculations. Denalists acknowledge all of the same agents, minus one, because they refuse to acknowledge that GHGs might be ONE of the important forcings.

    The fact that it’s the only known thing changing in any way that correlates with the past several decades is, itself, considerable circumstantial evidence that it is important, no the sole factor (again, contrary to JDE123′s blatant and intentional misrepresentation of the position of scientists), but the particular agent, one of many, that happens to be changing at this moment.

    Of course, circumstantial evidence only goes so far, even if it’s worth consideration. Afterall, our understanding of climate is considerable, but not perfect. There are still components that we don’t 100% understand the behavior or influence of, and maybe even agents we haven’t discovered.

    So you need direct evidence that GHGs, particularly CO2, are among the myriad of powerful influences. Fortunately, there are plenty of ways to estimate how powerful CO2 is, by looking at all the other forcings, seeing how powerful they seem to be, and seeing what that leaves for the CO2 influence. You have to make assumptions there, so your estimate could be wrong if you incorrectly estimate everything else, so what you do is you do different analyses, with different assumptions, and if you consistently come to the same CO2 forcing, you’re probably correct.

    If you want to look at those efforts, there are plenty of papers in the scientific literature which give good discussion of that. I personally like Annan and Hargreaves’ 2006 GRL paper, not just because it’s a unique methodology (which comes to yet again the same answer), but because it discusses a lot of other papers, making it a good starting point.

    Time after time, analysis after analysis, we come to the same influence from CO2: 2.5-4.5C for 2xCO2 (at our concentration; it’s not linear), with a high probability of the actual value lying near the middle at 3C.

    Without that strong CO2 forcing, our entire understanding of climate falls apart.

    This consistency is precisely what makes a theory robust.

    So contrary to your assertion, which I hope was simply innocent misunderstanding, the assumptions you attribute to climatology are not at all the basis for our understanding. We know many things change climate, but there’s plenty of evidence that GHGs are ONE of those things (again, denialists acknowledge all the OTHER influences, based on similar evidence, but then reject that one particular influence), and it’s the only influence we know of that’s changing at present on any timescale that would amount to causing a climatic trend (a statistically significant trend being ~30 years).

    “As far as human contributions, humans are certainly contributing to pollution. It may be possible the number of humans at 7 Billion and the larger number of domesticated animals, the billions of homes, factories, buildings and burning forests and fuels are all contributing to warming simply because all of this stuff produces actual heat and maybe the atmosphere is unable to handle so much extra heat”

    No, you don’t have to worry about this, because all the convection and conduction humans emit really amounts to very little when we’re talking about the Earth’s radiation balance.

    Let me put it into numbers for you. Humans consume about 15TW of energy, and of course, what goes in must come out, some of it as light that simply bleeds off to space, but a lot of it as waste heat.

    Now, let’s assume that 100% of it came out as waste heat. I’d guess the real value is more like 30-50% (a lot comes out as EM radiation), but let’s just say 100%.

    The Earth’s surface is roughly 51,007,200,000,000 square meters. That means that the total forcing would be ~0.294WM^2 (yes, I know, forcings are measured at TOA for the purposes of climate sensitivity, so the below figure will overestimate sensitivity, but I don’t have a surface area to work with for TOA, so I apologize for the inaccuracy; this is just rough demonstration).

    Climate sensivity is roughly 0.75°C/W/m^2. So the total contribution to temperature we could make would be 0.2205C, even if 100% of ALL the energy we consumed went JUST to heat production. In reality, it’s probably more like half that (and even that’s not really accurate, and probably high-balling), so if we grew by 15TW of just heat output a decade, then you might have cause to worry.

    Did I miss anything?

    Those seemed like your two biggest points of inaccuracy.

    Link to this
  16. 16. Catamount 5:16 pm 01/31/2012

    …where’s Carlyle?

    He’s usually the first to gravitate towards these kinds of discussions, and one of the most interesting skeptics I ever have the pleasure to have discussions with (because he builds arguments on sincere attempts to discuss science, often making goods points).

    SciAM climate articles are a sad place without him :(

    Link to this
  17. 17. sofistek 5:32 pm 01/31/2012


    “After all, the computer model predicted warming for the last 10 years, did not happen.”

    Oh yes it did. All of the years since 2000 have been warmer that all other previous recorded years, bar one (1998). The warming trend has continued over that time, though the last few years has seen a levelling (but 2010 was still the warmest, statistically tied with 2005). Last year was the 8th warmest on record. The longer term trend is still up.

    I see this meme from deniers all the time. It’s as though if they say it often enough, it becomes true. Why bury your head in the sand? Go look at the data.

    Link to this
  18. 18. Catamount 5:52 pm 01/31/2012


    There have been pauses several times since 1970, yet warming continued right along after they ended, which is why it’s silly for denialists to claim there’s anything unusual going on here. This is the fourth pause in warming that I know of in relatively recent history; if the last three ended with continued warming, why do they think this one is any more important? Do they really have nothing better to argue?

    It just astounds me.

    Link to this
  19. 19. jgrosay 11:50 am 02/1/2012

    Probably a series of years with weather changes producing bad crops, with the resulting shortness of food and increases in bread prices was in the origin of the french “revolution”, I’d say better the ” XVIIIth century french genocide”. It would be interesting knowing if the amount spent in necklaces and other luxury goods was able to buy grain somewhere, or just, if the amount of wheat for sale was limited, would have generated only an aditional increase in prices. It seems that during the great Irish potato famine that killed thousands, Ireland remained a net wheat exporter, if this were true, it would be one of the darkests shames for mankind.

    Link to this
  20. 20. jgrosay 11:58 am 02/1/2012

    Also the disappearance of the Indo valley culture, the towns of Mohenho-Darho and Harappa was caused by a climate change that make dry the rivers this cities were placed next to, and not as some say “the aryan hords”, if such a thing really exists. A drought was also the cause of the fall of the amreican Puebla indians, some peruvian cultures, and some eggyptian dynaties, it was discovered in Egypt under the ruins of a wall, the skeletons of one young man having a rat in is hand, and three other people after,that were supposedly runnig to take the edible rat from the boy; many captured Napoleon soldiers were left in a small balearic island, they received just a monthly visit of a boat to bring there water and food. Can you imagine what happened ?

    Link to this
  21. 21. Dredd 12:34 pm 02/1/2012

    Anthropogenic global warming induced climate change is obviously new, seeing as how it has never happened before.

    Trials in Europe held individuals guilty for ecocide.

    Kinda difficult to do that to climate itself.

    Link to this
  22. 22. d3mocritus 4:33 pm 02/1/2012

    I have never understood how anyone, can truly and sincerely believe, that the hypothesis about global warming due to a dramatic increase of anthropogenic emissions of greenhouse gases, can be a global orchestrated conspiracy?

    And that only they, have the intelligence and intellectual acuteness to see thought it?

    How anyone with a modicum of knowledge in basic physics, chemistry and climatology can not at least grasp the basic, and internally consistent logic of the principle?

    And that in absence of any final data and experiment that would settle the full scope of the risks beyond doubt, don’t at least see the reason and logic behind adopting the cautionary principle?

    That does truly astound me, but also make me think of Carl Sagan, and his worries about the low level of scientific understanding in the population at large, and what that could mean for the future of our world :(

    Link to this
  23. 23. Catamount 6:21 pm 02/1/2012

    d3mocritus, the thinking isn’t that they’re the ONLY ones who can see through this imaginary conspiracy; they think a lot of people can.

    Here’s what’s stupid though:

    Let’s assume for a moment that there’s a scientific conspiracy involving EVERY SINGLE CLIMATE SCIENTIST (oh, and Richard Muller, too!), and it’s TWELVE DECADES in the making (ever since Arrhenius).

    Do they honestly think that

    A.) These climate scientists would make the error that produced the incorrect result something so transparent, that people without college degrees in science, let alone climatology, would be able to see it?

    B.) That the few “skeptic” scientists left who would be able to see this error would all be pointing out that actual problem, rather than harping on irrelevant points, distorting facts, and committing logical fallacies?

    To elaborate on B. Let’s call this secret of the climate scientists Fact X. Fact X is a well-designed flaw in climatology, intentionally hidden in the deep technicalities of the science (if millions of these scientists spent 120 years doing this, they’d at least be capable of that much).

    Now let’s take Patrick Michaels, a real climate scientist. As a climate scientist, why does he make his arguments out of lies, such as distorting Hansen 1988 in front of Congress, instead of spending all his time pointing to the ACTUAL flaw, our Fact X?

    The same goes with Roy Spencer, John Christy, and Richard Lindzen, and maybe even non climate-scientists who still understand science like Ian Plimer.

    Why does Spencer write incorrect scientific papers throwing the ocean’s mixed layer depth to the wind (he claimed it’s a kilometer; it’s about 50m in reality)? Why does John Christy harp on isostatic adjustment, claiming it’s some kind of fraud (when it’s not only useful, but the scientists who do it give you all the data to “unadjust” it, even if you disagreed with it)? Why does Ian Plimer base a book off of a fraudalently doctored graph from The Great Global Warming Swindle (which the graph’s own author, Friis-Christensen, called fraud)? Why does Richard Lindzen build his case on forcings and feedbacks (collectively known as the infrared iris hypothesis) based on cherry-picked data for an area not typical of the topics for clouds?

    If there’s some gross flaw in climatological methodology as part of a vast conspiracy, they should all be in a concerted effort, all pointing to that one ACTUAL flaw.

    So why, instead, do all the skeptics spend time lying, distorting facts, or perpetrating logical fallacies?

    The only explanation I can think of is that there IS NO flaw in climatological science, so these people are lying, distorting facts, and perpetrating logical fallacies to invent one.

    “How anyone with a modicum of knowledge in basic physics, chemistry and climatology can not at least grasp the basic, and internally consistent logic of the principle?”

    It’s my experience that most of the people who oppose global warming theory do NOT have these things, and data backs me up there.

    Not only does basically 100% of the climate scientist community back AGW theory, but 84%, or 5 out of 6, scientists in ANY field agree with AGW theory (

    Link to this
  24. 24. Catamount 6:34 pm 02/1/2012

    “And that in absence of any final data and experiment that would settle the full scope of the risks beyond doubt, don’t at least see the reason and logic behind adopting the cautionary principle?”

    You know, on this point, I would argue that we’ve already settled a lot beyond doubt.

    That humans are warming the planet is one. We have at least a dozen completely independent lines of evidence, reliant on entirely different assumptions, that suggest a strong CO2 forcing, to say nothing for the fact that we not only can’t explain recent warming without that forcing, but about half of all climate science falls apart without it (in other words, it’s a parsimonious explanation for HUGE numbers of observations).

    That this will be dangerous for us, us not just meaning humans necessarily, is also beyond doubt.

    According to a paper by Lobell et al just last year (I could dig it up if you want), food production has fallen measurably just from late 20th century warming, while many other species have been either seriously threatened, or already driven extinct by that same warming (for which our well being is only one reason to care about; we rely on biodiversity as much as the next, but that’s hardly the only issue).

    As for points of uncertainty, I think the world’s national science academies had it right in their joint letter:

    “a lack of full scientific certainty about some aspects of climate change is not a reason for delaying an immediate response that will, at a reasonable cost, prevent dangerous anthropogenic interference with
    the climate system”

    What’s reasonable cost is exactly what we should be discussing, not whether AGW is real, since we’re far past that.

    Link to this
  25. 25. d3mocritus 4:11 am 02/2/2012


    “…the thinking isn’t that they’re the ONLY ones who can see through this imaginary conspiracy; they think a lot of people can.”
    “Not only does basically 100% of the climate scientist community back AGW theory, but 84%, or 5 out of 6, scientists in ANY field agree with AGW theory”
    “It’s my experience that most of the people who oppose global warming theory do NOT have these things, and data backs me up there.”
    Sorry if I cut and paste wildly here, but I think these pieces taken together, light up the core in my bewilderment very well.
    Together with the enormity of the following proposition you draw up…

    “Let’s assume for a moment that there’s a scientific conspiracy involving EVERY SINGLE CLIMATE SCIENTIST (oh, and Richard Muller, too!), and it’s TWELVE DECADES in the making (ever since Arrhenius).”

    Where is the personal humility and reflection regarding the scope of ones personal knowledge, and ability to value and judge upon the matter?

    That I think is where my question really came from, how can they really truly believe they know, and see clearly what so many other individuals, often infinitely better qualified don’t?

    “You know, on this point, I would argue that we’ve already settled a lot beyond doubt.”

    I agree with you, and that the issue now is rather to better understand how much and how fast, and what could happen further down the road.

    But my point was that even if we don’t know for certain all the details of the full scope of the risk we are facing, I would still argue that basic common sense would tell anyone, that we should work very hard to take precautions, with all speed possible.

    What ideas, framework, personal experience or state of mind prevents people from seeing and embracing this?

    You should of course not blindly believe everything anyone tells you, but likewise bad is to stubbornly hold on to an idea, and not to be able to re evaluate and change your mind in the light of overwhelming evidence to the contrary.

    (Sry for my english)

    Link to this
  26. 26. Catamount 9:16 am 02/2/2012

    d3mocritus, I definitely understand where you’re coming from

    It’s like every climate scientist ever, and almost every general scientist, the people who have spent 6-8 years of their life in college in grueling courses (take it from me, hard science majors make you question your sanity regularly), and then spend years or decades in the field, the people who discuss this stuff at such a technical level, that their discussions are to our discussions what a five year old’s discussion of math is to a differential equation course, and they all agree with AGW… and you just have these denialists, with no formal science education or research experience (since almost all the people who do back AGW theory), who don’t even take half a second to ponder that before going “whatever, they’re ALL wrong, and I’M right”

    I’m not sure “bewildered” is the word I’d use, but it’s as good a word as any, because THERE IS NO WORD, not in English anyways, for that level of arrogance.

    You’re right that there’s a difference between being healthily skeptical, not accepting whatever you’re told, or even looking for alternative explanations, and just obstinately refusing to even acknowledge evidence.

    Naomi Oreskes phrased it wonderfully, saying “there’s a difference between being a maverick, and being a mule”.

    I recommend you find her essay sometime and read it; it’s on this exact subject. It’s in Gavin Schmidt’s book:

    Or for another similar take, perhaps Friedrich Hayek?

    Hayek, the poster boy for the political movements behind climate science denial, would be disgusted with these people.

    Oh, and your English is probably better than my typing :)

    accursed laptop keyboards…

    Link to this
  27. 27. llewelly 10:08 am 02/2/2012

    Link to this
  28. 28. llewelly 10:09 am 02/2/2012

    How reliable are climate models?

    Link to this
  29. 29. Thierry Gaudin 11:47 am 02/2/2012

    Despite all its claims,modern science is utterly clueless as to the real causes of abrupt climate reversal in the past.Yet it is fully recorded and astronomically measured in the literary record of all ancient civilizations.
    The only obstacle is modern science total inability to decipher these records correctly.Science denigrates what it cannot understand at the expense of all humanity to whom these records belong and more often than not will do its utmost to suppress any and all attempts at bringing this record to a full light for all to see.
    Case in point:past violent climate change was recorded by the Sumerian like this:

    When the second year arrived
    They had depleted the storehouse.
    When the third year arrived
    The people’s looks were changed by starvation.
    When the fourth year arrived
    Their upstanding bearing bowed,
    Their well-set shoulders slouched,
    The people went out in public hunched over.
    When the fifth year arrived,
    A daughter would eye her mother coming in;
    A mother would not even open her door to her daughter. . . .
    When the sixth year arrived
    They served up a daughter for a meal,
    Served up a son for food. (Dalley 25-26)

    One therefore may ask: what could possibly have caused such a drastic state of chaos to even include cannibalism?

    The answer is contained in their chronological scheme known as Sumerian king lists as well as in the Torah in chapter 7:11 verse 1 7 1 describing the deadly return-transit of the planet venus to its point of departure.

    Let bring science to the fore to explain the astronomy behind these two notations 7 1 1…1 7 1:

    The orbits of Earth and Venus line-up thru a series of 5 superior conjunction and 5 inferior conjunctions between the sun and the earth during a period of 8 years.

    And during these 8 years and 5 inferior conjunctions,the planet venus conjuncts with the earth at five equally spaced points around the ecliptic.

    To test and measure the planet’s reappearance to point
    1 of 5,we have wait another 584 days (one synodic revolution)to find that venus will return very close to point “1″ of this cycle in exactly “6″ synodic revolutionsof 584 days or:

    3504 days
    —- = a prototypal ratio of “9.6″years= 6×1.6

    The importance of this natural cycle 6×1.6=9.6 rests on the astronomical fact that the planet venus is also in one of her 10 conjunction with the earth every 9.6 months or 292 days which in sumero-akkadian lunar months of 30 days shall translate:
    9.6 x 30= 288 = 1 7 1…1 1 7. Verse 1 7 1 of the Torah
    7 1 1 and the natural and logical third sequence 1 1 7 giving a complete synodic track of the planet venus as:

    7 1 1…1 7 1 ..1 1 7.

    In the Epic of Atrahasis destruction arrives in 1200 year increment that is in the senary system “6″ = 288=
    1 7 1 …1 1 7.

    Then in the 11th tablet of the Epic of Gilgamesh we find
    the return of the morning star Ishtar venus and the black cloud in exactly Line 98 of the line by line transliteration :

    98 has exactly “6″ divisors “1,2,7,14,49 and itself 98 for a total of 1 7 1.
    The original council of the gods”

    Anu 60
    Enlil 50
    Enki-Ea 40
    Ishtar 15 for a total of 165 in 6= 171 in the year 165-6
    of the Torah verse 171.

    Here is the climate change in past.

    please note this material is copyrighted.

    The same holds true for the mayans as another cluelessness of science the infamous totuguero inscription;

    The descent from 9 supports in the 13:

    from superior conjunction 9 points 72 648 to 819 of their calendar round 1 7 1.13 at inferior conjunction x72 = 936-819 =1 1 7.
    From 648 to 936 9 to 13 =288 =171…117.

    Link to this
  30. 30. Catamount 7:13 pm 02/2/2012

    d3mocritus, I had a response, but apparently either my browser or SciAm at it. Either way, I agree.

    The arrogance displayed by these people, who don’t miss a beat claiming to know more than all the climate scientists, and most of the general scientists, on Earth, is beyond words.

    @Thierry Gaudin, I don’t think I could do much better than your post when it comes to injecting a bit of humor into these topics, but you might want to be careful; tone doesn’t translate well over text, and someone MIGHT end up thinking you’re serious ;)

    Link to this
  31. 31. Catamount 7:14 pm 02/2/2012

    *ate, not at

    Link to this
  32. 32. jgrosay 4:28 pm 02/5/2012

    Don’t know why, but the sentence “Helped bring down cultures” reminds me of an assertion by Goebbels: “When I hear the word culture, I put my hand on my pistol”

    Link to this
  33. 33. FSDAQ 11:37 am 02/6/2012

    Precisely. Climate change will always be with us, which explains why the CO2 nonsense is political, rather than scientific, hype.

    Link to this
  34. 34. Jeromiah 9:38 pm 02/6/2012

    I think this sums it up,

    Link to this
  35. 35. JacobSilver 5:16 pm 07/5/2012

    In earlier climate changes they did not have the knowledge and technology we now have. But what good is it doing us? In the face of indisputable, scientific fact, a large percentage of our leaders still deny climate change. This leads to political paralysis of action. The consequence will be the more rapid onset of drought and the early dying of millions. So, what good is our knowledge and technology?

    Link to this
  36. 36. tsnell 5:41 pm 07/5/2012

    From the way I see it, there are four primary factors that, taken together, add up to a new and dramatic change in our climate that’s coming down the tracks at us like a run-away freight train.
    First, Population. It took 10,000 plus years of human history to get half a billion of us on the planet, but only the most recent 400 years to gain 15 times that, or an added six and a half billion of us. Why? The industrial age and modern medicine.
    Second, the discovery of oil in the 1860s (therefore none burned before that date.)
    Third, the industrial Age with the discovery of electricity and the use of steam, diesel, and gas engines. Over a very short period we began burning vast quantities of coal, oil, and natural gas, with carbon dioxide (CO2) as a primary byproduct.
    Forth, a key characteristic of CO2: That it acts as a partial blanket for heat energy but not for sunlight. Essentially, sunlight comes through the atmosphere and warms the earth, but some of that warmth cannot pass back through the atmosphere because CO2 blocks it. Until now this has been good because it helps stabilize the Earth’s temperature and makes life as we know it possible.
    So, as our modern industrialized world, driven by the needs of 7 billion of us, pumps unbelievable amounts of additional blanketing CO2 into our atmosphere, our Earth can’t do anything but warm up.
    How does a warming Earth affect climate change?
    Our Earth’s climate is a hugely complex system and complex systems can make radical changes with seemingly very little outside pressure. These are called “tipping points”. What do I mean? Let’s say your standing next to someone and they reach up and lightly push against your shoulder. You shift your weight slightly and nothing happens. But let’s say you are standing on top of a narrow fence post with nothing to hold on to and someone pushes you. Almost guaranteed you will fall off the post. Climates are like you on the fence post – subject to dramatic change with the smallest push.
    So, in conclusion, it is my belief that only a small rise in temperature, thanks to our burning all these fossil fuels, may very well cause catastrophic change in our climate. So if we don’t do something soon, that run away freight train will get us.

    Link to this
  37. 37. tsnell 6:28 pm 07/5/2012

    I should also add that the climate change I’m talking about hasn’t happened yet – may not happen for 20,30 or 40 years. The reason I’m concerned is that, if we’re to effectively stop it, we have to act now and act in very big ways. If we wait 20 years it will be too late. I want to keep climate change from happening, not for myself, but for my children and grandchildren. At 73 I probably won’t be around long enough, but they will, and I care about them and their future.

    Link to this
  38. 38. GreenMind 1:23 am 07/6/2012

    Humans have destroyed their environments over and over again for thousands of years, on ever-increasing scales. First it was simply overhunting, and the need to go find better hunting grounds or more firewood. Then humans found Australia, and somehow as a result it became desert. Then humans found the Americas and somehow all the megafauna went extinct. Then agriculture was invented, and it destroyed many local environments, such as the Fertile Crescent (now desert), the Gobi Desert, and the Sahara.

    Ironically, when the irrigation system for the Central Valley in California was planned, scientists said that they had to include a way to drain the water or the Central Valley would turn salty like the Fertile Crescent. But then it was built, and the farmers paying for it said, no, we don’t want to pay for the drainage part. As a result, the Southern part of the Central Valley is now too salty to be used for agriculture, and that area is growing.

    But there are success stories. The Dust Bowl was starting to destroy agriculture all over the the Midwest, but then the government started regulating farming practices, and the Dust Bowl receded. The Ozone Hole is no longer growing because governments prevented the manufacture of the chemicals that were destroying it. Lake Erie has fish in it again because governments prohibited the pollution that killed them. Are there any examples, any at all, in which the people started to destroy their environment and then saved it again without the intervention of government? Does anyone know of an example?

    Modern civilization is so widespread, and modern technology so powerful, that it is capable of destroying agriculture and fisheries everywhere in the world, in the name of efficiency. The more subsistence economies are pulled into the global economy by the World Bank and the governments it influences, the worse the crash will be.

    Link to this
  39. 39. karenalcott 10:58 pm 12/16/2012

    It seems obvious to me, that our population and its distribution are way out of whack. The proof isn’t just malnutrition and the occasional outright famine, but the ongoing need to ship food and pipe water into areas that cannot support the local population. We need fewer people in areas with less resources. If we are going to avoid the fate of our cultures forerunners, we need to exercise some restraint. Nobody that I know of has suggested that there aren’t any natural factors involved in climate change. Also there is plenty of literature from climatologists concerning the release of ever increasing amounts of methane, due to the loss of permafrost and ice cover particularly. So I don’t understand why the paranoid denialist folks think there is some kind of conspiracy to hide those facts. The fact is we cannot move the planet around and we can’t control solar activity or volcanoes. We can however change what we are doing. We can stop adding to the problem, we can curb our own population and we can either assist the people who are in areas that will no longer support them to control their population or redistribute some of them. For example, there already too many people in the arid areas of our southwest. If it turns out that the models are right and the area is going to be even dryer in the future, we will either need to ship water in or move people out.

    Link to this

Add a Comment
You must sign in or register as a member to submit a comment.

More from Scientific American

Email this Article