Lowercase theories, uppercase Theories, and the myth of global cooling


"Fifteen hundred years ago everybody knew the Earth was the center of the universe. Five hundred years ago, everybody knew the Earth was flat, and fifteen minutes ago, you knew that humans were alone on this planet. Imagine what you'll know tomorrow."

Men In Black's Agent Kay isn't exactly a great public philosopher, but I think he does do a good job of summing up the reason why some people don't like the idea of applying the science of climate change to the realm of political policy. Science changes, after all. Who's to say that 100 years from now we won't find the results of 21st century climate modeling as ridiculous as a map of a flat Earth?

This argument isn't totally off-base. Scientific theories are frequently overturned by new evidence. But, just as often, the new evidence changes one part of a theory, while leaving the big picture intact. That's because scientists use the same word--"theory"--to describe two very distinct classes of ideas. Gravity is a theory. But so is the existence of Gliese 581g--a wobble in the light given off by a distant star which may, or may not, turn out to be a planet. One of these things is not like the other. Of the two, new evidence is much more likely to disprove the existence of Gliese 581g.

Scientists still study what gravity is and how it works. It's a living theory, not a cold, unchanging edifice. In fact, there's a lot of weird, little anomalies that tell us we don't have this gravity thing totally figured out just yet. But as new evidence comes in, it tends to refine the details, not demolish everything we thought we knew. Einstein revolutionized the theory of gravity, but he didn't make apples start to fall up.

With that in mind, I want to tell you a story. There are a lot of climate myths out there—misconstrued facts and frank deceptions used to discredit good climate science. But one of those myths is particularly interesting to me, because it's a very good example of the difference between little lowercase "theories" and uppercase "Theories". The myth of global cooling is the kind of thing that happens when people get the two mixed up.

Let's start at the beginning, with a quick summary of the myth itself.

According to the standard version of this story, everybody in the 1970s thought that the Earth was actually getting colder, and that we were in for a new Ice Age. Animals like armadillos were migrating southward, fleeing the encroaching cold. The Arctic ice pack was unexpectedly thick. Scientists warned of massive crop failures, and wrung their hands over the fate of the millions who would die in our frozen future. They urged governments to take action, either by stockpiling food, or with more disturbingly drastic measures--such as intentionally melting the Polar ice caps. All the same people who, today, tell us that the Earth is heating up were, once upon a time, singing a very different tune. The implicit message about scientists that people get from this story: You just can't trust 'em.

It would be nice if the myth of global cooling were a fringe belief. But it's not.

Influential, big-name talkers push the story. Lots of average people listen to them. The author Michael Crichton worked it into his last novel. Senator James Inhofe told the tale in Congress. Rush Limbaugh believes in the myth. So does George Will. And, consequently, so does at least one of my uncles.

But they're all wrong.

In reality, global cooling was never a broadly accepted Theory. It's reasonable to assume that a good chunk of Americans never heard about it at all. And global cooling never had the support of most climate scientists, let alone scientists in other disciplines, like biology and public health, which are linked to climate change in many important ways today.

We know all of this thanks to the work of two scientists, Thomas Peterson and William Connolly, and a journalist, John Fleck. In 2008, they published a detailed history of this myth in the Bulletin of the American Meteorological Society. So that's another thing that makes the myth of global cooling stand out from the pack. Unlike a lot of myths, the path from fact to fiction is very well-documented.

A Myth is Born

The truth is, for a short period in the mid-1970s, the idea of global cooling was somewhat trendy--as measured in newspaper and magazine stories, but not scientific evidence.

In 1975, both Newsweek and Time ran articles about the coming Ice Age. The next year, National Geographic published a more detailed story about climate science, in general. It touched on global cooling as one of several possibilities for the future of climate.

But all of these stories were based on the same small handful of peer-reviewed papers. In fact, Peterson, Connolley, and Fleck found that, between 1965 and 1979, only 7 peer-reviewed papers were published supporting the idea of global cooling. (In contrast, during that same time period, 44 published peer-reviewed papers found that the Earth was getting warmer. And 20 were neutral on the subject.)

All those papers were the work of scientists who were, for the most part, trying to understand the basics of how the climate system worked, not expanding and refining an already accepted big idea. These were, in other words, lowercase "theories".

Cause and Effect

The issue was inputs.

These are the variable factors--like levels of greenhouse gases, or particles of dust and soot in the atmosphere--that can impact how the natural processes of the climate system play out. In the 1970s, scientists didn't understand variable inputs very well. They knew, based on ice cores and tree rings, that the Earth was probably coming due for a cold snap. In fact, the Northern Hemisphere had been cooler than average between 1940 and 1970. And they knew that particulate matter--the smoke of volcanoes, the soot of factories, the obvious air pollution--could reflect light from the sun and have a cooling effect.

But they also knew about the greenhouse effect.

This is the almost 200-year-old idea at the heart of the Theory of climate change. For a quick refresher, the greenhouse effect describes the cycle of heat transfer that keeps our planet from becoming a frigid ball of dirt, no more habitable than Mars. First, heat from the Sun passes through our atmosphere. Some is absorbed by the ground and oceans, and some of that heat gets reflected back towards space. But the gasses in our atmosphere don't let all that reflected heat out. Instead, atmospheric gasses bounce most of the heat back down again. It's kind of like turning on a laser pointer in a hall of mirrors. Because of the greenhouse effect, Earth is able to trap enough heat to sustain life-as-we-know-it. We've known about this effect since 1824.

Climate change is really just an exaggeration of the greenhouse effect. Carbon dioxide is better than a lot of other gasses at bouncing heat back down to Earth. The more carbon dioxide in the atmosphere, the more heat gets trapped, and the higher our global average temperature rises. We've known about the way rising carbon dioxide levels enhance the greenhouse effect since 1896.

By the 1970s, climate scientists knew cars, power plants, and other aspects of modern energy use were releasing unprecedented amounts of greenhouse gases into the atmosphere. The question everybody was trying to answer: Which input was more powerful? In other words, would particulate matter beef up a natural cooling trend to the point that the greenhouse effect was merely a pleasant distraction? Or, would the impact of carbon dioxide and its greenhouse gas cousins outpace both natural and anthropogenic cooling, and take us to a warmer world?

The Way It's Supposed To Work

In the 1970s, nobody really had a solid answer to those questions. In a given year, one scientist would publish a paper that supported cooling, while another two or three would publish results that favored warming. And journalists would report on all those papers.

In 1975, the same year that Newsweek and Time warned of a coming Ice Age, Peterson, Connolley, and Fleck found that The New York Times actually ran two climate science stories. The first was titled "Scientists Ask Why World Climate is Changing; Major Cooling May be Ahead." The second: "Warming Trend Seen in Climate; Two Articles Counter View that Cold Period is Due."

If you saw both Times stories, you'd have a pretty good idea that scientists weren't totally in agreement on this issue. But not all journalists provided that kind of context. Every peer-reviewed climate science paper was like a part of a mountain range. The only way to make sense of the topography was to zoom out, and look at the whole thing. But, some journalists had a tendency to report on each new study that came out as though it were an isolated hill of fact in the middle of an empty plain.

One group actually did review the big picture of climate science in 1975. That was the U.S. National Academy of Sciences. The NAS is sort of like a cross between a professional organization and a medieval court adviser. Not all the scientists in the United States are members. Instead, current members elect new ones, based on the quality, importance, and influence of their research. Think of it as the Science Hall of Fame. Getting in is a big deal. But it's more than just symbolic. That's because the NAS plays a role in American politics. Most politicians aren't trained scientists. Even if they are, they can't be expected to be experts on everything. So, instead, when politicians need to know what's going on in a particular field of science, they turn to the actual experts at the NAS. Every year, the Academy puts together many reports summarizing the state of scientific research on a wide array of topics and offers their advice about what politicians should do with that information.

The 1975 NAS report on climate science reflects the confusion that surrounded the field at that time. In fact, the introduction flat out says, "...we do not have a good quantitative understanding of our climate machine and what determines its course. Without the fundamental understanding, it does not seem possible to predict climate..." There wasn't anything close to a scientific consensus on climate in 1975. But that was about to change rapidly. Over the next five years, research methods improved, more papers were published, and all those little theories began to add up to a single big Theory--the Earth was getting hotter.

By 1979, it was already clear that the effect of greenhouse gases had a bigger impact than the effect of dust particles. When the NAS came back to the subject of climate science that year, the state of research had changed enough that their summary was now very different. Instead of uncertainty, the 1979 NAS report emphasized a message that was, basically, the same as what we still hear today: The Earth is warming, and that fact should not be ignored. The popular press liked the story of global cooling. But their interest in that story didn't reflect what scientists were actually thinking. There was no flip-flop of science here.

Instead, what happened in the 1970s was that science worked the way it's supposed to work.

Researchers identified an important question. They studied it. They figured out how to study it better. And, slowly, between roughly 1970 and 1980, they came up with a broad, generalized answer. They went from a jumble of lowercase theories to an uppercase Theory.

Since then, the uppercase Theory hasn't changed. No new evidence has surfaced to challenge it. Instead, researchers have busied themselves with the details—studying the lowercase theories within climate change to try and make that big Theory more specific. What they've learned has made them more and more certain that the big Theory is correct. So, in a way, the scientific consensus certainly has changed since 1975. But it changed from, "We don't know," to "Climate change is definitely happening.

Image: Frozen World, a Creative Commons Attribution (2.0) image from laszlo-photo's photostream


  1. “That’s because scientists use the same word–“theory”–to describe two very distinct classes of ideas. Gravity is a theory. But so is the existence of Gliese 581g…”

    Nope. Scientists don’t use the word “theory” to describe the second phenomenon; existence of Gliese 581g is a hypothesis.

    1. A hypothesis is a proposed explanation for a phenomenon. In what way is the suggested existence of Gliese 581g a hypothesis?

      1. A hypothesis is a proposed explanation for a phenomenon. In what way is the suggested existence of Gliese 581g a hypothesis?

        Its existence is presumed based on interpretation of available data. We’re not working with color photos and soil samples from exo-planets.

      2. In the way that it is the proposed explanation for the observed wobbles in the orbit of the Gliese 581 star.

      3. A theory is the result of gathering lots of evidence which is based on testing hypotheses. Gloster nailed it.

        1. No, a theory does not spontaneously arise from the “gathering of evidence acquired while testing hypotheses”. Too complex.

          A theory is a provisional statement of relation, a result of thought applied to observations of phenomenon, which may then be confirmed or dis-confirmed by further observations.

          I’m curious – what do you think all of that cruft about ‘gathering evidence’ and ‘hypotheses’ adds to the definition, besides un-necessary complexity?
          That is to say, what precisely necessitates their inclusion in the definition of “theory”?

          Theories arise from the application of human thought to observations made of the world.

          Theories are then tested and refined by the making of further observations, which are usually (chemistry, experimental physics) – but not necessarily ( astronomy, geology, ‘field’ biology, climate studies) – taken or made in the controlled setting of the laboratory.

  2. Yeah, the thing about these attempts to define science is that they’re reactive to creationists and liars–and so they always warp what science actually is. Science is a deeply personal and creative activity, and every scientific genius does it in their own way.

    In any event, you’ve got twelve inches of print here and you never mention that, simply, correlation doesn’t imply causation.

    That you can never establish the truth or falsehood of climate change, but only establish how likely it is. The IPCC is VERY careful to define what they mean by ‘likely’, and to always state the level of likelihood of each statement.

    And, ultimately, that climate change is based on so many unknown variables that is about risk management–not science.

    1. “…you never mention that, simply, correlation doesn’t imply causation.”

      You left out a word, a most important one, too. No worry, I will fix:

      “…you never mention that, simply, correlation doesn’t NECESSARILY imply causation.”

      I mean, good luck proving “causation” where there is NO correlation at all.

      The trick is to design experiments testing explanations which can eliminate all other possible causes of the observed correlation.

      But correlation certainly should always engage our attention, in order to answer the question curiousity always asks: why is any relation at all being manifested?

    2. Hold on….
      from your firast post above:

      “…that climate change is based on so many unknown variables… ”


      If they are “unknown”, how can you know that there are “so many” of them?

      How can you know that there is even one “unknown variable”?

      In summary:

      “Unknown variables”? WTF are you talking about?

      1. Unknown or untold number of conditions of the variables that weather can possible give you would more likely be correct. Far too many variables to test in weather variables when we don’t know what how one weather condition can effect another weather condition to create changes in climate. They are probably infinite…but you can’t figure that out is what is meant?…small mind!

    1. I was just going to say the same. This is great original content. It’s actually something people might want to link to. Way to go Maggie…

    2. Agreed – I thought it was a bang-up job of putting context to this one of many smoke screens offered by some.

  3. When the creationists are beating the “evolution is only a theory” drum, it sometimes makes me wonder if perhaps the word theory is just too confusing when applied this way. We almost always rebut with “gravity is also a theory”, but I’m not sure that is adequately steering the ship away from the rapidly-melting iceberg. I’m not advocating the adoption of a new word, merely acknowledging that it could be improved upon.


  5. I would take this more seriously, except for one little problem:

    William Connolley used to be an administrator on Wikipedia—who was notorious for getting into massive, insane edit-wars with people over global warming and “cold fusion”. They pulled his admin powers as a result.



  6. But it changed from, “We don’t know,” to “Climate change is definitely happening”.

    This is what I mean when I say you’re likely to misrepresent science when you’re purely reactive to liars who are intentionally misleading people.

    It’s really tempting, when you’re in an argument with a global warming denialist, to say something like this. But it’s not true. You won’t find an honest scientist who will say it.

    Climate change is not ‘definitely happening’. It is now, and will forever be–no matter how much more evidence is collected–merely ‘highly likely’. That is the nature of systems where you cannot control all the variables.

    Also, I’d prefer if people who popularize climate change go out of their way to discuss outliers: satellite data which does not show temperature increases, why the southern hemisphere isn’t melting the way the northern one is, the difference between CO2 and other greenhouse gases like methane, or the relative dominance of man-made versus volcanic CO2.

      1. You’ve mistaken me for a denialist. Climate change will never be ‘definitely happening’, until it happens. Can you tell me what the climate will be tomorrow?

        The IPCC has not cleared up the difference between surface and satellite anomalies. Reasonable explanations can be made, but the satellite data simply does not show the same increase in temperature.

        If you’re telling me that the reason Antarctica is not melting is known–I’m sorry, but though reasonable models have been produced it is simply not fair to talk about Greenlands’ melting and not also mention the fact that the same observation is not made on the other pole.

        I DEEPLY believe in climate change. I think it is the most difficult and important problem in science. But telling people that recycling their plastics will affect a problem which will require something in the ballpark of ten to twenty TRILLION dollars in the next few decades–telling them that global warming is a known fact and that it will melt poles on periods of a few years–these things are not true and when people discover they are not true we will lose our credibility.

          1. This’ll be my last post, I know I’m posting too much.

            No. My point is not a grammar correction…I’m talking about the very nature of a field in which you cannot control, or know, the variables, and in which you cannot repeat the experiment.

            Notice that just by pointing this out, people have assumed I’m a denialist. They must reduce climate change to being either true or false. My point is–no such reduction is possible.

            When I say it’s not a grammatical correction, what I mean is that this irreducibility is the fundamental problem with popularizing climate change. There will always be doubt, and unless popular descriptions of climate change address the nature of correlation there will always be people who take advantage of that doubt.

            For those who insist that climate change is 100% known, let me ask you:

            What level of CO2 emission is safe?

            @canuck: I realize there are models, but if you’ll notice the study is about one year old. This remains an open scientific question.

          2. All statements about the state of the future are subject to doubt.

            man mad e global warming is happening, and you say there’s a significant chance that it is not?

            if that is npot what you’re saying, what’s with the philosophical quibble, a quibble applicable to ANY predictions made outside of a laboratory set up?

            Questions of whether to engage in bloody and vicious war are today being determined on much much less definite probabilities than those which exist for man-made climate change…so why the sudden insistence on the perfection of prediction, before advocating the adoption of effective adaptive action?

            Of course we never “know with s certainty” what the future holds. So what? For that’s no reason whatsoever not to take steps now reasonably calculated to preserve your future happiness, based upon what we know and have observed in the past.

            Man has and is changing the Earth’s climate in ways which our species, and indeed the biological domains and webs we depend on, may not be able to survive in the long term.

            That statement is the truth.
            Note the use of the word “may”.
            Uncertainty yet holds her domain intact!

            So what?

            That is the truth.

          3. Oh, and it is the same theory which is being used to account for both the Antarctic thickening, and the Greenland/Arctic melt.

            That counts, too.

        1. You mis-speak: you don’t “believe”, you are merely convinced, on the present state of the evidence, of the correctness of the present interpretation of the data.

          As always, one remains rerady to change one’s mind, IF sufficient evidence is presented (indeed, if such even exists) to do so.

          Science is a matter not of “belief” – but of demonstration.

          “Prove it!” is the cry…and once that happens – as it has, in the case of anthropogenic climate change – the rules to dis-prove “it” become more strict: for then actual evidence is yet required to be the foundation of any dis-proof, too.

        2. I completely get your point. I too cringe when I hear a bastardization of the science for the purposes of arguing FOR the existence of climate change… because that’s exactly what deniers are doing. (Yes, bastardization is a bit harsh to describe the simplification of the issue in order to support the greater scientific consensus.)

          However, using words like “likely” is suicide to the cause, because if there is a half of the nation that can’t,handle ambiguity or notions of probability, it’s the more conservative half. Ideology drives the debate. And the debate is based on verbal gymnastics rather than a discussion of the science.

          (Still, if faced with the argument I would counter with, “Bullets fail to discharge x out of y times. When I pull this trigger, it is likely that you will be shot in the head. Would you like me to take steps to not shoot you in the head? Or do you want me to pull the trigger so that you may prove my theory wrong?”)

          1. So, you’re in an argument with a denialist of some sort.

            Option #1: You get into a semiotic argument about what a ‘theory’ is, allow your opponent to set the framework for the debate, and wind up miscasting science as something devoid of human inspiration.

            Option #2: You get into an argument about the inability of science to ever truly establish cause and effect. You distinguish between experiments in which you can choose variables and repeat, and those in which you can only observe. You talk about defining levels of likelihood and the central importance of doubt in the scientific method.

            I’d say that option #2 actually gets to the heart of what science is. Option #1, which Maggie is using here, is a semiotic argument and I’ve always felt it misrepresents science.

          2. Honestly, if they are looking for a fight (they always seem to be), I tell them plainly that I don’t have the time to argue something that has zero scientific legitimacy.

            I don’t like stoking their fire.

          3. And how often does the bullet not fire? The chances of that bullet not firing are very slim and only a maniac would play those odds. Can you even put a number on ANYTHING of the probability of the experimental models happening in the future when it seems to me that most of the models tested are now proven wrong and, when, As quoted in another post “the very nature of a field in which you cannot control, or know, the variables, and in which you cannot repeat the experiment?”

    1. Define “definitely happening”. Is the 99% certainty that we have of Global Warming “definite”? How does that compare to our certainty that if we throw a rock over a cliff that it will “definitely” fall down? After all, an eagle could grab it and fly off with it so it’s not “definite”.

      Every “outlier” that you mention is an old canard that was thoroughly discredited decades ago. The oldest is the satellite myth which upon investigation of the (quite proper for once) criticisms of the data turned out to be the result of the previously unadjusted for orbital decay of the satellites.

    2. I believe it is highly likely the sun will “rise” tomorrow. However, it’s only a theory…

  7. Five hundred years ago, everybody knew the Earth was flat

    Right, and Galileo was burned at the stake because the Church hated astronomy.

    There are more people living today who genuinely believe in a flat earth than there were in 1511, or in 1491, which is maybe what was meant. I’m speaking of the greater “West,” but the same thing applies to the Chinese at the time as well.

    Sorry, but the sphericity of the earth was accepted by virtually everyone with an opinion on the subject since the 3rd century BCE, including non-elite traditions (i.e., what people believed who weren’t taught a formal Aristotelian or Platonic cosmology in a medieval university or monastery school). It’s not even a particularly difficult observation to make.

    Science is important enough to get its history right, especially when you’re using it analogically. Not that I disagree with the rest, but zombie historical lies will, like any zombie, eventually try to eat your brains.

      1. What, you mean for saying the sun didn’t go around the Earth? (Around, as in, to the other side?)

      2. Sorry, can’t refresh your memory. It needs to be erased and re-written. Galileo died, apparently of natural causes, on January 8th, 1642. His body is buried in the Basilica of Santa Croce in Florence except for three fingers and a tooth.

        1. Yeah, I know…Semiotix had asserted that Galileo had been burnt.

          He’s thinking of Bruno, I bet.

          1. I wasn’t thinking of either Galileo or Bruno. Sorry if the sarcasm didn’t come across, but that was meant to read like “Right, and monkeys might fly out of my butt!” The “story of Galileo” is something everyone “knows” because they heard it in 7th grade. In fact, Galileo wasn’t burnt and you couldn’t swing an astrolabe in 1633 without hitting a church-patronized astronomer.

            Glad we’re all on the same page.

    1. semiotix, citation please? I find it really hard to believe that anyone can say what most people believed before 1500 since the vast majority of those folks were illiterate and lived hundreds or thousands of miles away from any centers of civilization.

      Yes, some educated people knew, but it seems ridiculous to say there are more people who believe in a flat earth now.

    2. semiotix, of course you are correct regarding people thinking the world was spherical 500 years ago and I agree that the history of science is important, but the analogy that you’re addressing is from a quote in a movie. I’m not sure correcting the history is all that useful, especially because here the quote serves as a pithy introduction to an article about myths that people falsely believe about science.

    3. I did not know Galileo was burned at the stake. It is my understanding he was forced to recant his heliocentric beliefs and was subsequently held under house arrest for his remaining days. Or maybe your statement was ‘tongue in cheek’ and I missed it.

  8. And yeah, I know, I just yelled at a movie character. What of it, I’m feisty! It just took me a moment to remember that Men in Black was a movie, not some horrible new schlock-history book that people were reading by the millions.

    But it’s just a nails-on-chalkboard thing with me. Angry historian smash and all that.

    1. At least he didn’t say that we only use 10% of our brains. That’s another pet peeve of mine.

  9. I’ve long suspected that there was some degree of cooling, or at least less apparent warming, back in the days before catalytic converters, coal stack scrubbers, and the like, when we (thinking from a US-centric standpoint) were dumping a lot more aerosols into the atmosphere. The aerosol increased albedo and offset the greenhouse effect at least somewhat. When aerosol production declined as a result of regulation of some emissions, the cooling of atmospheric aerosols was reduced, and things warmed up in a hurry. Granted, this is a gut feeling, and I don’t have any data to back it up, and the effects might have been somewhat local, but I wouldn’t be surprised if there were some truth to it.

  10. I don’t think you actually mentioned thermal radiation, which is pretty important to understanding how the system works. For those of you without the scientific background:

    Everyone knows that if you make something really hot, it glows. Charcoal, pokers, lava, lightbulb filaments, stars, it works with everything. But just because something isn’t really hot doesn’t mean it’s not doing the same thing. Look at your hand. It’s probably around 37 degrees Celsius, or about 310 kelvins. You can’t see it glowing, but it is. It’s just that since it’s so much cooler than the filaments in those bulbs your parents grew up with, the photons it’s spitting out are much less energetic.

    If you’ve ever seen a picture of the electromagnetic spectrum, you know that visible light is only a small chunk of it. If a particular bunch of radiation has less energy than red light, you won’t be able to see it. More energy than violet light, same thing. The thermal radiation coming from your hand is in the infrared (“under-red”) part of the spectrum. And the planet Earth is doing the exact same thing.

    Wherever you are, there are photons flying around and bumping into you. Even if you’re in a cellar without a light, there’s the Earth’s thermal radiation, in the infrared band. Even if you’re in deep space, between galaxies, there’s the odd millennia-old photon from some star or another, but more important than that is the leftover thermal radiation from the Big Bang. It’s called the Cosmic Microwave Background Radiation because it’s mostly in the microwave band by now. That’s because of the redshift as the universe has expanded — it’s like the Doppler effect (which makes things sound higher-pitched if they’re moving toward you and lower-pitched if they’re moving away), but with light.

    Because of conservation of energy, things emitting thermal radiation cool down. Things absorbing radiation, of course, warm up, just like you do when standing outside on a sunny day. If something is surrounded by a vacuum, like a planet, then it warms up if it emits more energy in thermal radiation than it takes in and cools down if it’s the other way around. Teleport a rock halfway to the Andromeda Galaxy and it’ll eventually cool to about 4 kelvins, or -269 degrees C, because at that point it’s not losing any more energy from thermal radiation than it’s absorbing from the CMBR. (That background radiation is thin.) The Earth is a relatively small 93 million miles away from a decent-sized star, so our “equilibrium” temperature is a fair amount more than that.

    Here’s where the greenhouse effect comes in. Normally, the sun warms the Earth, the Earth radiates the same amount of energy away in the infrared, and the whole thing’s in equilibrium. (This is a simplification, but it’s good enough.) But if you add more greenhouse gases to the Earth’s atmosphere, they bounce some of the Earth’s thermal radiation back to the Earth. So suddenly, the Earth’s not emitting as much radiation as before, even though the sun’s just as bright. So it warms up until it’s emitting enough extra radiation to make up for the difference. Might be just a few extra degrees, but the ecosystem is fragile enough for that to make a big difference. That’s what causes global warming.

    And that’s the way it is.

    1. Here’s the problem. Just because a bit of a problem is well understood (thermal radiation and the greenhouse effect), it doesn’t follow that the whole problem is understood, or “beyond doubt”, or even close to being beyond doubt.
      If the earth was just an inert sphere with some CO2 in its atmosphere and nothing else, then it probably would be possible to model matters quite accurately, but that isn’t a very good model of the place we call home. There are a myriad of effects that each will have an impact, many of them poorly understood or not at all, and many of which interact with each other in complex ways. Reference has been made in this thread to pollutants and the resultant “global dimming” impact, but that’s only one example.
      A better understanding of everything would be a great help to us. Trying to close down the debate by vilifying any departure from orthodoxy would not.
      The article suggests we’ve been through that process and come out the other side. Perhaps. But I wonder what bias the prospect of being labelled a “denier” would exert on a researcher?

  11. This is a really excellent essay, but “Scientific theories are frequently overturned by new evidence,” could be phrased better.

    Scientific Theories (uppercase) are not overturned, they’re upgraded, refined. Flat-Earth is actually a pretty darn good approximation when your corner of the world is at most a few hundred miles across. The Earth is only very slightly curved on that scale. Spherical earth is a better approximation once you can carry out simultaneous measurements in Greece and Egypt (thanks, Eratosthenes). Add in gravity and rotational fictitious forces and you’ve got an oblate spheroid. And so it goes- new theories capture old ones as approximations in a certain range of conditions.

    That’s why scientists, except sometimes when talking informally or to the public, distinguish between theories and hypotheses.

    1. Spherical earth is a better approximation once you can carry out simultaneous measurements in Greece and Egypt (thanks, Eratosthenes).

      Actually, Eratosthenes was using data from two locations in Egypt, though your point remains valid.

  12. So if Global Cooling was the minority scientific opinion when compared to Global Warming at the time, why did the media seize on the former instead of the latter?

    What made them imagine that they would sell more newspapers and tune in more Nielsen viewers by proclaiming “We’re all going to freeze to death” rather than “We’re all going to burn up”?

    Global Cooling may not have been the scientific consensus, but it was certainly the media consensus, and Carl Sagan wringing his hands about it in prime time convinced a lot of people who today look at Al Gore and his PowerPoint slides with deep suspicion.

    At any rate, thank you Maggie for addressing this bit of history that most of the AGW faithful insist never happened at all.

    1. TUS – John Fleck here, co-author of the paper Maggie cited. In response to your question about why the media in the ’70s seized on “global cooling”: It’s not clear the media did, in fact, seize on global cooling to the exclusion of global warming. While a thorough media analysis was beyond the scope of our project (we were focused on the scientific literature), we did read a lot of media coverage. We found that there was a great deal of coverage of the global warming hypothesis as well.

      What *is* clear is that those who, for whatever reason, have been propagating the “’70s global cooling” meme found it advantageous to repeat and amplify the coverage of global cooling while excluding the coverage of global warming. Much as they’ve done with the scientific literature.

  13. Your own government (whichever one you’re in) most assuredly believes Climate Change is real, and they’re licking their chops…

    5 WikiLeaks Hits of 2011 That Are Turning the World on Its Head — And That the Media Are Ignoring


    #4) World leaders are practically lighting a fire under the Arctic. As Secretary of State Hilary Clinton met with the Arctic Council last month to discuss oil exploration, WikiLeaks, with impeccable timing, published a new trove of cables highlighting a race to carve up the Arctic for resource exploitation. Nations battling to poison the arctic with oil drilling include Canada, the US, Russia, Norway, Denmark, and perhaps even China, which all have competing claims to the Arctic.

    Clearly, banking on the melting of the polar ice caps has taken priority over halting or even reversing the catastrophic effects of climate change. The Arctic contains as much as one quarter of the world’s gas and oil reserves, once hidden under huge masses of ice and inaccessible through frozen seas. However, ice is melting faster than predicted, presenting profitable business opportunities which are leading the Arctic countries to lose sight of longer-term climate issues. Greenpeace oil campaigner Ben Ayliffe underscores the danger of this mentality:

    “These latest Wikileaks revelations expose something profoundly concerning. Instead of seeing the melting of the Arctic ice cap as a spur to action on climate change, the leaders of the Arctic nations are instead investing in military hardware to fight for the oil beneath it. They’re preparing to fight to extract the very fossil fuels that caused the melting in the first place. It’s like pouring gasoline on a fire.”

    Why are the Lunatics always running the asylums??

  14. Speaking of Michael Crichton, I started ignoring him after he wrote this article for Parade Magazine in 2004. His solution to worrying about global warming? Don’t worry about it, “they” were saying the earth was freezing before “they” were saying the earth was warming.

    – social_maladroit @ work

  15. As an aside, we will never stop global warming until we stop using fossil fuels, and how likely is that? There’s to much money in it, and humans (Americans in particular) are too in love with their cars. All the conservation and bicycling and green talk isn’t going to amount to squat (and this is ignoring the organized effort by moneyed interests to sew doubt about global warming.) If you really want to stop human’s contributions to global warming then either find a way to slow human population growth, or come up with better, cleaner energy production (like cheaper and more powerful solar cells and longer lasting batteries.)

  16. Arguing about global warming is like arguing about what kind of a knife the butcher might have used when he sold you bad meat.

    Global warming is just one metric of a vastly larger, incredibly important problem – pollution.

    We need to stop wasting money on bullshit and spend every cent we’ve got, as a nation, on sustainable energy – a program would make us all rich beyond our wildest dreams in the long run.

  17. This is an extremely well-written piece. Well done.

    I’m ready for part 2 of 37 parts, however…

  18. First the ‘scientists’ tell us the earth is flat. Now the earth is getting hotter. What a crock!

  19. semiotix… “Right, and Galileo was burned at the stake because the Church hated astronomy.” I got it from the get go….your sarcasm-meter is not broken.

    This is an informative piece. I liked the info about the NAS…tho’ to quibble I’d call it the science All-Star team, as, well. . .you have to be finished with your career to be in the HOF. Anyways…

    I like the term ‘climate change’ as opposed to ‘global warming’ as it encompasses much more of the interesting and oft surprising weather phenomena we are seeing on a regular basis. . .or, like some barroom bathroom graffiti I read yesterday: “Mother Nature Wins!”

    And so; as Nero fiddled whilst Rome burned, we type as the whole world simmers. A commenter above blamed Americans for our love of the auto as Usual Suspects of CO2 crimes, but I do believe last year China bought more autos than the US did: conspicuous consumption is not solely encompassed by our national character…yay?

    As Charles Dudley Warner once said: ‘everybody talks about the weather but nobody does anything about it’. . .

    Except we do. We make it worse. How very droll…

  20. This all sounds like a flip-flop of theory to me

    “By 1979, it was already clear that the effect of greenhouse gases had a bigger impact than the effect of dust particles. When the NAS came back to the subject of climate science that year, the state of research had changed enough that their summary was now very different. Instead of uncertainty, the 1979 NAS report emphasized a message that was, basically, the same as what we still hear today: The Earth is warming, and that fact should not be ignored. The popular press liked the story of global cooling. But their interest in that story didn’t reflect what scientists were actually thinking. There was no flip-flop of science here.”

    Then this…..

    From: http://www.huffingtonpost.com/2011/07/04/global-warming-china-air-pollution_n_889897.html

    “People normally just focus on the warming effect of CO2 (carbon dioxide), but during the Chinese economic expansion there was a huge increase in sulfur emissions,” which have a cooling effect, explained Robert K. Kaufmann of Boston University. He’s the lead author of the study published Monday in Proceedings of the National Academy of Science.”

    On top of all this THEORY that S02 increases(the dust)is that the S02 levels from he US decreased by 71% since 1980.

    From: http://www.rightsidenews.com/2011071814086/life-and-science/energy-and-environment/global-warming-and-global-cooling-report-july-18th-2011.html

    “A check of the EPA web site showed that under existing regulations, from 1980 to 2010, SO2 emissions have declined by about 12,490,000 from 17,260,730 tons to 5,119,700 tons. NOx emissions have fallen by about 3,963,000 from a high of 6,026,524 tons in 1997 to 2,061,098 tons in 2010, or about 66%. Obviously, by 2010, major reductions in emissions of these gases have been achieved under existing regulations – 71% for sulfur dioxide since 1980 and 66% for NOx since the high in 1997.

  21. Maggie, thank you so much for coming to Boing Boing. You have elevated the level of wonderful things and I look forward to your long articles and your snippet posts. I enjoy your work, and share it often. Thanks again!

  22. I like the article.  Well written and researched, except for one thing:

    “Fifteen hundred years ago everybody knew the Earth was the center of the
    universe. Five hundred years ago, everybody knew the Earth was flat…”

    Carl Sagan fully and completely debunked the idea that a flat Earth was a commonly held belief.  In his tv show _Cosmos_, Sagan tells the story of how the ancient Greeks amassed quite a bit of knowledge, and part of that was that the Earth was known to be round, and they even had accurate estimates for the size of the Earth.  It was only years later when much of this knowledge was lost or destroyed that the myth of the ancients believing in a flat earth emerged.  And let us remember that this myth is being quoted in a comedy movie.
    Thanks to the Church, a great many myths were created.
    Thanks to the Celts and their monastic universities, some of the knowledge of the ancients survives, debunking those myths.
    We here in the United States are suffering through yet another wave of anti-science, pro-rigid-belief-system dogma.  It’s tiresome.

    1. Christian, that flat earth bit… that was a movie quote and not intended as evidence of anything.

  23. From the perspective of this space scientist, mentored by an extremely talented scientist at the Imperial University of Tokyo – Professor Kazuo Kuroda- who was sent to find the nature of the weapon that vaporized Hiroshima on 6 Aug 1945,The history (1945-2011) of consensus science, global climate concerns, and the current economic and social unrest leads to very unpleasant, but seemingly inescapable, conclusions:



    I would appreciate finding a more palatable conclusion.

    With kind regards,
    Oliver K. Manuel
    Former NASA Principal
    Investigator for Apollohttp://myprofile.cos.com/manuelo09

  24. Re: the Celts and the ancient Greeks. Why don’t the Arabs of southern Spain get the credit they deserve? The texts the Irish had came from those Arabs. Is it that Cahill book? Or is it something similar to the way that all the folk songs/tales of Appalachia get attributed to the “Scots Irish,” with no mention of the African peoples who gave us the banjo, many of the Jack tales, and good old Brer Rabbit?

    The Arabs are responsible for much of Western European culture, including the medieval romances, which seem likely to have derived from the Arab Udhrite school of poets.

  25. Your personal palatable-ness level with regard to conclusions is entirely irrelevant.  What matters is if the conclusion turns out to be true.  

    By the way, just because your link document is formatted vaguely like a scientific paper doesn’t mean it’s scientific. 

  26. The value of any scientific theory or Theory comes from its ability to predict.  Theories that seek to “explain” have little of no value, because new explanation will be found as new information comes to light.  However, a theory that can predict successfully today will continue to predict successfully tomorrow, even after the new information is discovered.

    Thus Newton’s is still widely used to predict the effects of gravity today, even though Einstein is more accurate.  Both these theories work even though we don’t know how gravity works, or even how fast it travels.

    In contrast the IPCC climate models all predicted that temperatures would accelerate upwards after 2000.  Instead global temperatures have leveled off.  Had Newton or Einstein theories made such a glaring mistake in prediction, their theories would have been immediately called into question.

    1. Actually, not true. Thirty years is really required to clearly see long term trends in climate changes, but the graphs from 1900 to the present show an increase in warming, and an increase in the rate of warming.  2010 tied with 2005 for the warmest year on record, with 2011 threatening to be even more destructive. See this webpage on the NOAA web site:

  27. The ‘prediction’ of the theory in this case is that in a general way it predicts the global rise of temperatures in step with the global increase in man-made CO2 production. That it doesn’t predict the weather in detail is down to the fact that weather prediction is a very complicated business, much more so than the simple movement of comets, planets and spaceprobes. The atmosphere is not a simple system, and failure to predict in detail is a failure of the models used rather than failure in the theories of thermodynamics and other physical phenomena. And on the scale of these things, a decade is small-scale. After all, one of the inputs is the Sun’s 22-year sunspot cycle, and it has been a quiet decade for sunspots, for reasons no-one has a grasp on.

    As Maggie pointed out, the physics behind the greenhouse effect are nearly two centuries old; there’s nothing wrong with that theory. If there had been no global warming alongside the increase in man-made CO2 production, then that would indicate that there was something wrong with the theory. But there has been and there isn’t. Just as your favoured theory of economics can’t predict how much money will be in your wallet precisely a year from now, but can (sometimes) predict how the economy will be performing a year from now, climate scientists can’t predict how many inches of snow you’ll get in a given year, but can say that the average global temperature will increase if things go on as they are.

    Edit: This was meant as a reply to Fred_berple.

  28. Dr Trenberth said increased temperatures had led to more water
    staying in the atmosphere. “What we are seeing throughout the world is
    when it rains, it pours.”
    Over the oceans there was now 4 per cent more water vapour than in
    the 1970s, and sea surface temperatures had increased by about 0.55
    degrees Celsius.
    “The environment in which all storms form now is different to 30 or 40 years ago because of climate change.”


  29. This is not a rhetorical question:  I hear very little about how the element Sulphur is incorporated into these climate models.  Can anyone shed a little light on that?

    1. Recent reports indicate that the sulfur compound emissions from coal plants have been blocking some of the sunlight, and therefore mitigating the warming effect of trapped heat from sunlight. As coal plants reduce this pollution (which is damaging for other reasons, such as inducing asthma and causing acid rain), then the heating up effects from greenhouse gases will speed up.

    2. Sulphur compounds can form short-lived aerosols which directly reflect solar energy and also affect cloud behavior by acting as surfaces for the condensation of water (can affect cloud brightness).  Sulphur can also be directly injected into the Stratosphere by volcanic eruption, leading to the formation of the acidic “Junge Layer”, a layer of high altitude aerosols which can affect solar input and stratospheric ozone chemistry.

  30. Conservative Media Downplay Extreme Heat Wave

    July 26, 2011 8:55 am ET by Jocelyn Fong

    On his radio show yesterday, Rush Limbaugh declared that
    “almost no temperature records were broken” during the recent heat wave and
    that media outlets who reported on “record-breaking” heat were telling “a bunch
    of lies” to “advance a political agenda of liberalism.”

    Limbaugh’s remarks echo a Newsbusters post in which Noel Sheppard claims that “almost no
    temperature records were actually broken.” He came to this conclusion by
    ignoring most of the temperature records. Nevertheless, Sheppard’s claim was
    picked up not only by Limbaugh but also Fox Nation:

    1. Everybody with at least half a brain knows that whatever blowhard Limbaugh says – you should believe the exact opposite.  And you will be right about 99.78% of the time.  For those with less than half a brain (his listeners, e.g.) his word is gospel.

  31. It’s Not the Heat, It’s the Stupidity: Limbaugh Calls Heat Index a Liberal Government Conspiracy
    Joe Romm

  32. The only people who I have read describing CO2 as a pollutant are the so-called skeptics. Everyone knows that plants use CO2 as part of their energy cycle, even climate scientists, and nobody is calling for the total elimination of CO2 from the atmosphere. It should be remembered that the greenhouse effect is responsible for about a 30 kelvin shift in temperature on the Earth’s surface and without it the Earth would be a frigid snowball of a world.

    On the other hand, one should bear in mind the physicians’ maxim: the difference between a medicine and a poison is the size of the dose. If some CO2 is good for us, that doesn’t mean that more CO2 would be better.

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