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So What’s A Teacher to Do?

Filed under: — group @ 4 February 2012

Guest Commentary by Eugenie Scott, National Center for Science Education

Imagine you’re a middle-school science teacher, and you get to the section of the course where you’re to talk about climate change. You mention the “C” words, and two students walk out of the class.

Or you mention global warming and a hand shoots up.

“Mrs. Brown! My dad says global warming is a hoax!”

Or you come to school one morning and the principal wants to see you because a parent of one of your students has accused you of political bias because you taught what scientists agree about: that the Earth is getting warmer, and human actions have had an important role in this warming.

Or you pick up the newspaper and see that your state legislature is considering a bill that declares that accepted sciences like global warming (and evolution, of course) are “controversial issues” that require “alternatives” to be taught.

Incidents like these have happened in one or more states, and they are likely to continue to happen. Teachers are encountering pushback from many directions as they try to teach global warming and other climate science topics.

The importance of climate change education is, to the RealClimate community, a no-brainer. Numerous professional science organizations, from the American Chemical Society to the American Geophysical Union to the Geological Society of America have stressed the imperative of climate science being an integral part of science education.

So What’s a Teacher to Do?

Long a defender of the teaching of evolution, the National Center for Science Education has recently launched an initiative to support and defend the teaching of climate change science.

The “support” part has challenges all its own. Unlike evolution, which easily fits into biology and other life science courses, climate science spans multiple disciplines and can fall through disciplinary cracks in biology, chemistry and physics, or appear briefly in more specialized disciplines like ecology or Earth sciences. Moreover, climate science is complex and often non-intuitive, and students (and all too often teachers) stumble over misinformation and misconceptions that are hard to overcome. Many educational institutions are wrestling with how to support climate science in the K-12 curriculum.

But the “defend” part is where NCSE will make a unique contribution. Our experience over the decades helping teachers and school boards resolve the problems that have arisen over the teaching of evolution should stand us in good stead in helping them deal with this newer “controversial science”. Of course, there are many perspectives affecting the objections to climate science education, and each requires its own response.

Some of the denial is literal (It’s not happening! The science is bad!), some of it may be interpretive (it’s maybe happening but people aren’t to blame), and some of it stems more from the implications of climate change (it’s happening and maybe humans are responsible, but someone else is to blame and/or there’s nothing I can do about it). We’re going to help teachers understand where pressure against climate science education comes from, as the first step in helping them construct a response. From the evolution education controversy we learned long ago that one does not solve these problems merely by piling on more or better science: the underlying, motivating issues must be addressed. The science is essential, but not sufficient.

Climate change education should be an integral part of science education. Students should graduate from high school and certainly college with at least a basic understanding of the foundational concepts of climate science so they can understand human activities and how they are impacting climate and other aspects of the earth system.

This is no small task, and obviously NCSE as a relatively small non-profit can only do so much. We need your help.

We have been successful because we marshal allies, like scientists, teachers, parents, and other citizens, at the grassroots. NCSE’s success over recent decades in defending the teaching of evolution has been due in large measure to scientists and others who are willing to support good science education locally and at the state level. We also need scientists to provide us with their scientific expertise.

If you are a climate scientist, please give us your contact information so we can consult with you. Also, your contact information will be helpful to us if something occurs in your region or state where we need a scientist to write a letter, testify before a committee, support a teacher, or help in some other way.

Of course, an obvious way you can help is to join NCSE, but even if you don’t, your expertise will be helpful to us.

Visit our website, and contact our new Programs and Policy Director, Mark McCaffrey, who will be helping spearhead the new initiative, to let us know you support our effort. Teachers will thank you.

217 Responses to “So What’s A Teacher to Do?”

  1. 51
    Ron R. says:

    Sorry, I need to qualify my previous comments. I said that I think that evidence for things like evolution or climate change should be powerful but brief. That’s for general science classes which I suspect most students take. For higher classes, though, where an understanding of the controversial subject is expected and necessary to understanding that particular science as a whole (such as evolution/biology) more detailed discussion of the science is, of course, necessary.

    One other important point. Teachers should never mock a student’s religious beliefs. Nothing will turn a person off faster, possibly for life. In general science classes simply lay out the facts calmly and let the students draw their own conclusions. Discussion of “the controversy” is better reserved for civics classes where one can elaborate on the forces behind it.

    It’s a pity that we live in a world where one has to apologize for teaching science in a science classroom.

  2. 52
    Buck Smith says:

    I think we could have a better debate if both sides would be more specific about the separate parts the global warming and the degree of certainty in the parts. By which I mean

    1. Has the temperature warmed over the last 150 years. Yes, very certain
    2. Have CO2 levels warmed over the last 80 years. Yes, very certain.
    3. Is warming due to CO2 amplified by positive feedbacks (water vapor) Not so certain.
    4. Is projected warming the biggest threat we face? Much less certain and a bigger questions than the science.
    5. Do we have to act now? Again this gets beyond the science..

    My $0.02

  3. 53
    DSL says:

    David Hagen @ 22 — Yes, critical thinking should be encouraged and modeled. Yet this is not as simple as letting the kids look at all the alternatives and then showing them how each of the alternatives fails a critical physical or logical test. In the case of climate change, unlike the case of evolution, there are too many alternatives. The “alternatives” are embodied in attacks that aren’t based on any comprehensive physics- and observations-based theory. Ten kids may come up with ten different “alternatives” based on listening to recognized authorities (parents, pastors, FOX, other teachers, etc.) who looked briefly at WUWT or listened to Rush’s latest drivel. The question, then, is how to address every attack, or indeed whether to address every attack. Most climate scientists understand that actual alternative theories (It’s natural, it’s a violation of the 2nd law, or it’s the sun) that attempt to be comprehensive can’t be taught because they fail at the fundamental level. If your building blocks are made out of smoke, it’s tough to build anything on them. Try teaching kids that microscopes don’t actually work the way scientists tell us they do; microscopes are, in fact, part of the lie that B ig P harma is bankrolling to scare us into buying drugs to combat alleged “bacteria” causing sickness that is, in fact, caused by B ig G overnment putting chemicals in the water supply. It’s an alternative theory that is equal to the level of most of the garbage spewed around unchecked in the global warming comment streams where many non-scientists’ minds are influenced. Without some limitation at the level of fundamentals, teachers would never get past the crackpot stuff and actually arrive at the second- and third-tier issues (cloud feedback, aerosols, modeling) where there are a few alternative views and where the debate doesn’t resemble the comment streams of WSJ or The Weather Channel (“God would never allow it!” “a cold atmosphere will not radiate toward a warmer surface!” “Climate scientists are all in cahoots to steal our tax dollars!”).

    The bottom line, I guess, is “What alternative theories?”

  4. 54
    Pedrito says:

    “What is a teacher to do?”

    Have the student(s) write a report why he believes Climate Change/Global Warming is a hoax.

    Maybe start with a report on the origins of the terms Global Warming and Climate Change.

  5. 55
    Jeff L says:

    I teach Physics and Geology/Astronomy at an independent high school in NY state. I have been able to incorporate climate change topics into the curriculum with varying degrees of success, but because of the broad nature of the course, I can only afford to devote a couple weeks to the subject. Despite my best efforts, I find that students still confuse the greenhouse effect and global warming, and few understand radiative forcing. Topics like albedo and sea level rise are a little easier to grasp. I do a lab in AP Physics C: Electricity & Magnetism on the Stefan-Boltzmann equation, where students use a Variac to vary the voltage of an incandescent light bulb in 5V increments; they use a multimeter to measure the current, which enables them to measure resistance and power. From a plot of normalized resistance versus temperature for tungsten, they can determine the temperature of the filament at each voltage increment. When they plot log(power) versus log(temperature), they get an exponent very near 4. We then go on to talk about how one can calculate the equilibrium surface temperature of each planet, assuming it had no atmosphere.

    What seems to be more effective is to make sure that students know how the scientific process works. They should know that scientists don’t pursue research to become rich or to ride some sort of gravy train. They should realize that fundamental research is important and not a waste of money, even if it isn’t immediately obvious what sort of benefit it has to the community at large. Finally, I think posting articles, posters and news items to bulletin boards around the science wing has more of an impact than teaching it in class; it serves as a permanent reminder that climate change is important, long after we have switched to a different subject.

    Luckily, I haven’t had any issues with parents, even though I am aware that some students aren’t convinced that climate change is a problem. Science teachers should be able to use peer-reviewed science articles in the classroom. It boggles the mind that there are some school districts who would reject that approach.

  6. 56
    Ron R. says:

    Hank Roberts — @ 11:00 AM

    Understood, but you need to understand that what is good enough evidence for you, publication in Science, may not be to many others, people who have been cynically and methodically conditioned to doubt. Remember, ‘doubt is their product’. Thus the feeling of a lot of people is that anything can be faked in writing. Additionally they’ve been burned before by putting blind trust in some authority only to have his/her ideas overturned, thus confirming their skepticism. They are absolutists, and think that true science is, or should be, a static thing – once something is “true” it can never change, and are unfamiliar with the fact that it’s actually an ongoing process. So expecting them to accept some “theory” just because it’s found between the pages of magazine is not going to work, hasn’t been working. Like they say, pictures don’t lie.

    Clear, concise evidence is best imo. BTW, images are not only pictures.

  7. 57
    Thomas says:

    I think we get caught up in a larger issue. Methods of thinking are not orthogonal to current,
    and concievable political and cultural change. Major parts of our society are engaged in a
    cultural/political war. The tendency to view teaching of such essentials as critical thinking,
    the scientific method, epistemology in general, as an ideological battleground is overwhelming.
    Those that raise a stink about teaching climate science, or evolution, aren’t interested in fact,
    or critical thinking, they are overwhelming interested in winning a culture/political war. It is
    obvious to me at least, that if we had a population who paid attention to the search for truth,
    and to methodoligies to avoid being misled because of our human cognitive weaknesses, that our
    politics would be quite different. And I think those on the other side realize this as well. Efforts
    to improve or correct the current generally por quality of thinking and decision making will run
    headlong into this war.

  8. 58
    Ray Ladbury says:

    Buck Smith: “3. Is warming due to CO2 amplified by positive feedbacks (water vapor) Not so certain”

    Really? You expect that somehow, magically, CO2 loses it’s greenhouse nature at 287 ppmv? You choose to ignore/deny a dozen different lines of evidence that establish CO2′s sensitivity at 2-4.5 degrees per doubling? You don’t want to pay attention to the fact that the stratosphere is cooling even as the troposphere is warming–a sure sign of greenhouse gasses? You choose to ignore all the other latitudinal, diurnal, seasonal, altitudinal… signatures of greenhouse warming?

    Is deigning to consider 10% of the evidence really your idea of a compromise position?

  9. 59
    Jim Eager says:

    Kamimenive wrote @ 32: “Be honest about the desire here: to have students be activists for a global warming agenda.”

    Thus nicely demonstrating the type of inculcated ignorance science teachers are up against.

  10. 60
    Hank Roberts says:

    I recall once in the mid-1950s, a new student in our grade school brought his previous year’s history book to class. He wanted to know why part of it was so different from textbook our school was using. Same publisher. Same year.

    His old history book — used by a Northern state school system — gave one short chapter to the “Civil War” — and the version used in our — Southern — state school had three times as much about the “War Between the States” with pictures and biographies, weighted toward the Confederacy.

    That provoked some fascinating discussion.

    The teachers made a good lesson of it — that students were being given a very simplified version of a complicated history, and that often different students in different school systems were taught rather different history.

    Today, you can find material to teach the same lesson about biology and physics. Kids need to know this stuff. They’ll use the information.

    “Analysts need to take neoliberal theorists like Hayek at their word when they state that the Market is the superior information processor par excellence. The theoretical impetus behind the rise of the natural science think tanks is the belief that science progresses when everyone can buy the type of science they like, dispensing with whatever the academic disciplines say is mainstream or discredited science….”
    Mirowski, Philip, “The Rise of the Dedicated Natural Science Think Tank” (New York: Social Science Research Council, July 2008).

  11. 61
    caerbannog says:

    I had been dabbling with the GHCN (and CRU) raw temperature data off and on lately. Found that it is surprisingly easy to get global-average temperature results that are very similar to what the “pros” publish.

    In my latest little experiment, I selected a very small number of rural temperature stations (fewer than 50, and for most years, much fewer than 50). Looked for rural temperature stations with long temperature histories, scattered roughly evenly around the globe. Simply averaged the anomalies together (no gridding/area-weighting computations — station distribution sparse and uniform enough to make area-weighting irrelevant). Got results surprisingly close to the NASA land temperature index — details here:

    The posted results were from my “first try” — no trial-and-error “cherry picking” involved.

    So I got to thinking — would it be feasible to put together a set of “user friendly” temperature data processing tools (where the students don’t have to deal with the nitty-gritty details of data handling — accommodating data gaps and such) that would allow students to “explore” the global temperature record and generate/plot their own global-average temperature estimates based on their own station selection?

    With tools like Google-Earth/Google-Maps, it is easy to “zoom in” and explore a station’s environment (rural, urban, whatever). Google provides all the documentation needed (and others have already done this) to overlay station locations onto global satellite imagery.

    I’m thinking of some open-source software that allows students to use GoogleEarth/Maps to go all over the world and “click on” selected temperature stations. As the student does so, the global-average results (produced by a straightforward gridding/averaging procedure) would updated “on the fly” as students add stations.

    My experience with the GHCN raw data indicates that students would see a global-warming signal pop out of the raw (with the emphasis on RAW) data *very quickly* as they selected stations (with the instructor cautioning them not to “cherry pick” but to ensure good global coverage).

    If I had the wide-ranging programming talent, I’d consider tackling a task like this — but my programming talents are too much along the lines of “seat of the pants”, just getting by to get the job done” to be able to put together a “killer app” that non-programmer students could actually use.

    Something like this, of course, would be completely open-source — parents who object could be invited to scrutinize the source for themselves to try to find out where the alleged “data-manipulation” takes place. ;)

  12. 62
    Nick says:

    @MalcolmT Post 30
    there is gradual change, and then there is rapid change.

    The Younger Dryas massive cooling event took place on the scale of decades.

    Rapid climate change may in fact have been a common occurrence in earth’s history. have a look at the paper “Sudden climate transitions during the Quaternary” by J Adams et al.

    This is part of the reason why people are concerned that our carbon inputs may “flip a switch” so to speak. it has happened many times before.

    The upside of that is that life on earth is probably more accustomed to rapid climate change than a lot of people think…

  13. 63
    Tietjan Berelul says:

    Most teachers are left from center, they should leave their ideoligy at home.

    I dont see how a teacher would teach about global warming without leaving politics out of it. I dont want my children to be taught that the only way to save the planet is to subscribe to far left wing liberal values.

    My children do not know the difference between consensus and proof. I doubt they will be told about cap and trade or that is is okay to polute as much as you want if you can have hollywood buy carbon credits. The UN will be portrayed as a scientific institution and they will not see any climategate emails.

    [Response: As a demonstration about all that is wrong with the current discussion, this comment can not be bettered. It excludes from the world view that there is anything which might in fact be simple fact - such as for instance, the radiative impact of CO2, or the planet's energy balance. Instead, global warming is thrown together with the various paranoid fantasies related to Hollywood and the UN and 'far left liberals' promoting cap and trade (a Republican idea originally). Can anything be done here? Can right wing scientists and teachers reach these people on the basis of their shared values? (Oh, and Tietjan, they do exist). - gavin]

  14. 64
    Adrian Smits says:

    But teacher wasn’t the UHA temperature of the entire planet almost a tenth of a degree colder than it was thirty years ago for the whole month of January! That sure does sound cold. I heard there is hundreds dying of cold in Europe in the past week!

  15. 65

    [edit: I believe I said no more on it didn't I? Jim]

  16. 66

    caerbannog 61: Excellent work.

  17. 67
    Selgovae says:

    Any science teacher who wants to teach student the “facts” of climate change should look for another job. And that applies whatever your views on the topic are. Teach students how to measure temperature, how to graph results, how to deal with experimental results that don’t match the textbook numbers (oh, chemistry class, how I miss you). Kids aren’t going to believe you anyway, unless you have a cool voice. Please stay out of their heads. If you really want to impress them, show them how to turn ten volts into a thousand volts, make water run uphill, and on special occasions, how to make alcohol out of potatoes. I remember learning about evolution in the religion class. It seemed appropriate at the time. We couldn’t measure it or blow it up so it had no place in the science lab.

  18. 68
    Jonathan says:

    I happened upon this discussion and just want to tell people what’s it’s like when science education at the middle school level goes right: My kid goes to public school and they have a year of Earth Sciences at the 6th grade level. They teach all about global warming and other exigencies of the earth system, and they have projects to seek out current events, which there are many, and explain them within the scientific paradigm. This way, global warming material is covered in a very matter-of-fact way. Personally, I would have to have a shot of wiskey to teach my kids these things, but the kids absorb it naturally as it is the only thing they know and the teachers are trained to deliver this material. My hat goes off to them for this. Fortunately, the parents are generally scientifically literate or don’t want to embarrass themselves, so there is not much controversy over it. That’s is how it should be.

  19. 69
    Buck Smith says:

    Ray Ladbury – The 2.5 to 4C sensitivity number is obtained by adding positive feedbacks to the much smaller sensitivity due purely to CO2. I am not doubting the CO2 warming at all. The positive feedbacks come from more water vapor in the air. But water could also cause negative feedbacks – more clouds and / or more precipitation. Water is very different from CO2 – its phase transitions are inherently non-linear. An increase in global precipitation is a negative feedback that would effectively short circuit the whole global warming effect from CO2.

  20. 70
    Ray Ladbury says:

    Buck Smith,
    The derivations of climate sensitivity are actually empirical constraints, having little to do with models. Things like climate responce of glacial and interglacial periods, response to volcanism, etc. You would know this if you bothered to consult the evidence before forming an opinion.

    In the unlikely event you are actually interested in consulting evidence and upgrading from pseudoskeptic to real skeptic, this page has plenty to keep you busy. Hint: don’t cherrypick. Look at the evidence in its entirety and the consensus of results:

  21. 71
    David B. Benson says:

    Nothing is better, not lasts so long in memory, than an well done laboratory exercise. I still remember my high school biology and chemistry experiments despite never in the intervening 55 or so years having any occasion whatsoever to apply what was direstly learned there.

    Atmospheric physical chemistry isn’t so easy, but there was an earlier comment which might work into a suggestion for a laboratory exercise appropriate for middle school students.

    As for “not believ ing in it”, that issue arose here in the biology class required of all students and the matter of biological evolution. The instructors routinely explain that it is not necessary to “belive in it”, but is is necessary to understand the fundamentals.

  22. 72
    Craig Nazor says:


    Net cloud feedbacks are most likely positive, not negative, which is why the IPCC stated the figure they did for the climate sensitivity with feedbacks (and clouds are not the only feedback). Here is one of any number of good studies that supports this:‘feedback’-affects-global-climate-and-warming/

    Do you really think that the IPCC wouldn’t evaluate this information? Why wouldn’t they?

    Clouds can reflect light, but water vapor also acts as a greenhouse gas to the heat that has already been trapped at the surface. Although different types of clouds have different net effects, depending on altitude, thickness, time of day, etc., scientists have actually looked into this, and the general consensus is that the net feedback is positive.

    Why would you assume that the scientists who are trying to understand climate wouldn’t consider all of this?

    Actually, claiming that cloud feedbacks are too poorly understood to be able to be taken into account when estimating the climate sensitivity is one of the older and more time-worn of the denier arguments. It’s just not true, from the information I have seen.

    Why would we want to be teaching kids things that weren’t true?

  23. 73
    dhogaza says:


    An increase in global precipitation is a negative feedback that would effectively short circuit the whole global warming effect from CO2.

    Gotta love statements like this, totally unquantifed.

    So, Bucko, a 0.0000000000000000000000!% increase in global precip would effectivley short circuit the warming effect of increased CO2?

    Or did you mean a 0.000000000000000000000000000000000000000000000000000000000000001% increase?

    Enquiring minds want to know.

  24. 74
    Ron Wecht says:

    One approach that I have found helpful in discussing the issue with skeptical friends is to use some universally accepted facts and demonstrate a logical route to an obvious conclusion, such as:
    1. Earth receives energy from the sun in the form of radiation,
    2. Earth radiates energy outward to space, also in the form of radiation,
    3. Radiation is the only way energy comes into the Earth from space and the only way energy can leave Earth and travel through space,
    4. If Earth radiates less energy than it receives, Earth must warm,
    5. CO2 is a greenhouse gas, which slows the outward bound radiation,
    6. The amount of CO2 in the atmosphere has been increasing in the last @ 150 years as the result of man’s use of fossil fuels,
    7. The increased amount of CO2 is slowing the outward bound radiation of energy from Earth.
    8. As less energy radiates out to space, Earth must warm.

    I do not believe that any of the enumerated facts are controverted by any skeptics, at least not by any who have even a basic idea of the physics involved.

    Details can be explained in response to questions and as part of a discussion, for example, depending on the level of the students, explain why the increased CO2 does not increasingly block the inbound radiation.

    The students can at least be exposed to the basic building blocks of climate science.

  25. 75
    Tietjan Berelul says:


    Thanks for your reply to my post. I am a white married pickup driving employed male. I hold 2 degrees, I have been on the UN(HCR) payroll for most of the nineties, and I am do not believe in crazy conspiracy stories. I visit this website on a daily basis. Needless to say I consider myself a conservative.

    If you want to reach me with your message about climate change, people like you need to talk to people like me.
    Alarmists tell me I am anti-science, or a pickup idiot, or ridicule me, or tell me I must believe cigarettes are healthy and then want to educate my kids.

    Put yourself in my conservative shoes, the same liberal teachers that wont allow my children to hug their friends or sing a christmas carol, are now going to teach them the facts about global warming. I hope you see why that would worry me.

    [Response: These are the teachers who are teaching your children to read, do maths, get inspired, and strive for things they care about and want to achieve. Not sure I see the problem. - gavin]

    [edit - this topic is OT here, sorry]

    I will admit that I am not educated enough to argue the science behind global warming. Why cant the global warming community not admit or see that most of what they have been doing just will never pass the smell test of the average Joe. Whether it is the climate gate emails, or Al Gore in a private jet or not wanting to admit mistakes.

    [Response: Realising one does not know everything is the first step to actually learning something. So here are two little facts - global warming as a function of increasing CO2 was predicted 50 years before Al Gore was born, and whether someone flies in a private jet has no actual connection to whether fossil fuel emissions cause climate change. Science does exist separately from what we might do about the situation - and while I have no interest in getting you to change your fundamental political values, I do have an interest in finding ways for you to get past the (incorrect) lumping of science into a political package of things you dislike. If you don't want to get your science from me, fine, but then find people who you can trust to tell you about it. Katherine Hayhoe is an evangelical Christian married to pastor - read what she has to say. Barry Bickmore is Republican mormon from Utah, Kerry Emanual is Republican, as are Sherwood Boehlert, John McCain, Chuck Hagel etc. Read Jim Manzi in the National Review. None of these people are the people you seem to be concerned about, and yet all of them have a reasonable grasp of the science. Please try and break out of the bubble - you will thank yourself later. - gavin]

  26. 76

    To Dr. James Bouldin,

    I’m not clear on what I did to offend you to the point where you now seem to regard me as a personal enemy. You 1) called me delusional, 2) deleted my attempt to explain my position, and 3) reprimanded me in the angry tones associated with a parent addressing a small, disobedient child.

    If you don’t want me to discuss my research here, fine–it’s your blog. But there’s a polite way to say it. Frankly, I find your conduct in this matter verges on the unprofessional–not to mention inexplicable.

    No doubt you’ll remove this post as well, and perhaps ban me from RealClimate. I’ll make it easy on you and just not come back. Have a nice day.

  27. 77
    jyyh says:

    “Why would we want to be teaching kids things that weren’t true?”

    I think it’s only those who do want to mislead their children who want to do that. Deceit is their prime mode of operation and they want their children to be good at being bad.

  28. 78
    Todd Crane says:

    In my experience teaching evolutionary theory and hominid evolution to college freshmen, I have encountered several students who say the don’t believe in evolution so don’t think they should have to learn about it. I have had some success in telling them that I cannot make them *believe* in evolution, but it is my job to see that they understand the theory and the evidence involved in it.

    Granted, university teaching is somewhat different than secondary school, but emphasizing science as a means of interpretting evidence, rather than establishing belief, is helpful in overcoming these educational hurdles. It also provides an opportunity to teach about what science does and does not do.

  29. 79
    Dan H. says:

    Increasing cloud cover will lead to negative feedback. What the IPCC (and others) claim, is that the warming will reduce cloud cover, thereby generating a positive feedback. This is highly contentious, and the largest area of uncertainty in the climate sensitivity estimates. Ray is correct in that the figure quoted is from empirical estimates. Recent temperature data and paleoclimate estimates result in a much lower range.

    [Response: You will find that people will probably get less frustrated with your comments if you don't over-generalize and actually cite the papers you are obliquely referring to. i.e. cloud cover per se is not determinative of the sign of the feedback - it depends very much on whether it is low cloud or high cloud, IPCC makes no such claim, and 'recent estimates' is referring to the Schmittner et al (2011) paper, whose merits and flaws were discussed here at length. - gavin]

  30. 80
    Dan H. says:

    I would like to add a little to your fact sheet. Number 3 is not necessarily true. There is more interaction through space, but its quantification is largely unknown. Number 5 also slows incoming radiation, the molecules are insensitive to the direction of the radiation, only its wavelength and intensity.
    Students whould definitely be exposed to the building blocks of climate science. Then (as expressed previously), they can further study the impacts of various changes and responses to the climate.

  31. 81
    Ray Ladbury says:

    Dan H.,
    So if clouds provide negative feedback, then why do temperatures drop more on clear nights than cloudy ones?

    Also, since climate sensitivity requires at least 30 years for any hope of estimating sensitivity, I would be interested in your source on this. And your “paleoclimate” estimate is pure fetid dingo kidneys. See Knutti and Hegerl figure 3 for a good graphical summary:

  32. 82
    Craig Nazor says:


    “Increasing cloud cover will lead to negative feedback.”

    Do you have any actual science to show to support that statement?

    So why is Venus so hot?

    Just where, exactly, does the IPCC say:

    “That the warming will reduce cloud cover, thereby generating a positive feedback.”


    Where do you get your information to support this statement:

    “Recent temperature data and paleoclimate estimates result in a much lower range.”


    Dan, are you making things up again?

    The bigger question is, should we be teaching things that some people (like Dan “H.”) happen to BELIEVE are true to children in a science class, or should we be teaching them facts based on actual science? Who is to decide what the “facts” are? Unfortunately, our current system lets all kinds of unqualified people attempt to make decisions as to what the facts are, as I have witnessed up close and personal here in Texas over the past few years.

  33. 83
    Jonathan says:

    What does ‘belief’ have to do with it? They are in school to learn something: Might as well learn science if it’s a science class. They will certainly have to past the tests! This should be the bottom line. Of course, believing the science could be helpful. In fact, I think it is a distraction to the learning process. Didn’t Feymann say “Nobody understands quantum theory.” Understanding and belief can follow.

  34. 84
    Ray Ladbury says:

    Dan H., Oh FFS! No, Dan, energy loss due to “interactions with space” is NOT significant. For all practical purposes–the only energy loss that matters is outgoing IR radiation. Period.

    And your objection to # 5 might be significant if there were appreciable incoming IR radiation. As there is not, I do not see the relevance of this objection.

    Dan, where do you come up with this [edit - please stay polite]?

  35. 85
    Dan H. says:

    You may need to check your sources on incoming radiation.

  36. 86
    David Karoly says:

    I will try to get back on topic from an Antipodean perspective. Ian Plimer, an economic geologist with a strong climate change denial media profile in Australia and author of “Heaven & Earth” has recently released another climate change denial book in Australia directly aimed at teaching of climate change in schools, and the parents of school children. It is called “How to get expelled from school: A guide to climate change for pupils, parents and punters”. It was launched in Australia by the former Prime Minister of Australia, John Howard. Yes, this is an issue in Oz and it is great to see the resources available from NCSE.

    There are reviews of this book available at

    It appears to be at the same “scientific” (????) standard of his previous book, and therefore not worth buying.
    However, there are now many teachers in Australia who will need to resources available through NCSE, Skeptical Science, and other sites. Thanks.

  37. 87

    Hi Fred,
    there is a textbook on global climate change that was published in 2008 by Germanwatch in the Westermann Verlag. Unfortunately, it is in German. Is there no English language textbook for schools? If not, would it be of interest to translate a text book from German into English?

  38. 88
    Hank Roberts says:

    > interactions through space

    Wouldn’t it be nice if the HAARP system could somehow pump heat off the planet, priming the pump by tickling the ionosphere?

    That notion seems to show up along with revelations about secret US-USSR plots to warm the planet, chemtrails, and suchlike.

  39. 89
    Dan H. says:

    You better check on your source for incoming infrared radiation, unless you think values in the 40-60% range are negligible.
    With regards to clouds, I thought we settled that on this site last year, where the issue was whether cloud cover would increase or decrease. An increase in cloud cover, unless it very specific to certain cloud types, has a general cooling effect.

  40. 90
    John West says:

    Ray Ladbury says:

    “energy loss due to “interactions with space” is NOT significant. For all practical purposes–the only energy loss that matters is outgoing IR radiation. Period.”

    Agreed, however, sequestration of CO2 and H2O are important processes in regard to atmospheric composition on Earth. It’s not only Earth’s magnetic solar wind deflector that minimizes loss thus avoiding being like Mars but also the sequestration of CO2 and H2O that helps keep Earth from being like Venus. “Sequestration of heat” (lol) could be important to “global average temperature” over a long time frame and therefore also long term equilibrium sensitivity, not just heat loss (radiantly) to space. Instead of heat (transfer of energy), Id rather use the term Internal Energy (IE) in regard to the concept commonly called “heat content”. Assuming a radiant imbalance, that energy could be sequestered into increasing the internal energy of the deep ocean and then that internal energy could be decreased by work done by the deep ocean (i.e.: expansion, currents, etc.) thus nullifying the radiant imbalance as would be expressed in “global average temperature” over long time periods (equilibrium sensitivity).

    Change in Internal Energy of a system equals Heat added to the system minus Work done by the system. (1st Law of Thermodynamics)

  41. 91
    Hank Roberts says:

    > John West

    Where did you get your First Law definition? I’d like to have a look at your source and see if it’s giving you accurate information. Cite please?

    You left off part of the definition; here’s a bit more from one definition:

    “… internal energy is equal to the total heat added and work done. If the system is isolated, its internal energy cannot change….”
    – Wikipedia

    No matter how much work the ocean or atmosphere do, they don’t lose energy, they don’t cool off by doing that work.

    Take a planet surrounded by vacuum. Is it isolated? If not, how not?

  42. 92
    Ron Wecht says:

    Dan H,

    Re your #79.

    I believe that your assertion that the GHG’s also slow inbound radiation is incorrect, at least as it would apply to solar radiation. The GHG’s each react to radiation in specific frequency ranges, all in the IR band. Solar radiation, which emanates from an extremely hot source is high frequency radiation. Our atmosphere is generally transparent to incoming solar radiation, except for reflection by clouds, aerosols and such.

  43. 93
    numerobis says:

    @Ray: pedagogically, it’s probably useful to discuss that greenhouse gases don’t know which way radiation is going — so the way they work is that the energy comes in, is absorbed by the atmosphere, ocean, and ground, then re-emitted at different wavelength. And that change in wavelength is how you can build a greenhouse gas.

    The experiment with an IR camera mentioned above would be pretty neat. They’ve gotten much cheaper of late. A field spectrometer is also fun to play with on a sunny day. It took until college before I got to use any real toys; my high school barely had Bunsen burners. What climatology-relevant physical experiments can be run on a shoestring budget? A website is nice but I suspect a lot of kids would tune it out more easily than if they get to touch the science.

  44. 94
    Hank Roberts says:

    “Time Required: In under half an hour you can measure the temperature of the sky and clouds and learn how clouds tend to stabilize the temperature on the ground below. You can learn much more by spending a few hours reviewing this project, visiting the links it lists and performing some experiments of your own….”

    Infrared thermometers cost under $15 nowadays.

    Also very handy for figuring out where your building insulation isn’t up to par.

    To use it, you need to teach about emissivity and why it’s important in measuring things with a remote infrared thermometer.

  45. 95
    Hank Roberts says:

    More on emissivity, including a “Kids don’t do this at home” experiment (use an infrared thermometer on a skillet that has a shiny back and a dark nonstick inside surface; compare the results with various amounts of heating.

    Do you know what the emissivity of human skin is?

  46. 96
    Susan Anderson says:

    For you delectation and entertainment (sic), DotEarth has borrowed this post:

    Personally, I’d love to see a few real scientists weigh in before the little clique that has dominated that blog forever gets in full voice.

  47. 97
    Susan Anderson says:

    What Mike Roddy said


  48. 98
    Jim Eager says:

    Re Dan’s comment about greenhouse gas absorption of incoming solar longwave radiation, see:

    Note that everything to the right of “visible” is longwave, and the almost total lack of overlap between the incoming solar spectrum and earth’s outgoing spectrum. Now note the bands at which H2O and CO2 absorb.

    Increasing atmospheric CO2 should have negligible impact on absorption of incoming longwave as its only bands in the incoming spectrum are far out in the toe. However, an increase in atmospheric H2O due to warming would appear to have considerably more impact given that it has several unsaturated bands in the deeper portion of the incoming spectrum.

    Clouds aside, this doesn’t exactly support the argument that increasing water vapour will have a negative, or cooling effect.

  49. 99
    Chris Colose says:

    Ron Wecht- “I believe that your assertion that the GHG’s also slow inbound radiation is incorrect, at least as it would apply to solar radiation. The GHG’s each react to radiation in specific frequency ranges, all in the IR band. ”

    Actually, this isn’t quite true, but it doesn’t help Dan H’s argument in the slightest. It is certainly true that GHG’s are dominant in the longwave portion of the spectrum, but some (especially water vapor, and ozone in the UV) also interact to a large degree with incoming energy. The increase in water vapor in a warming world could actually cause some degree of global dimming (even overcompensating for expected aerosol decreases as air gets cleaner in the future, e.g., Haywood et al., 2011; JGR).

    But actually it doesn’t matter all that much whether the absorption is occurring directly at the ground layer or absorbed throughout the lower troposphere and then communicated to the surface through energy fluxes/convection; thus, you need to look at more than just the energy balance at the surface and see how these fluxes might cancel or add when viewing the whole climate system (at the top of the atmosphere). Even some scientists haven’t gotten this right, leading some to conclude erroneously for example that several watts/m2 decrease in surface solar flux per decade during the global dimming era was just as competitive with the CO2 forcing.

    As for this cloud feedback stuff, there has been no robust explanations for why cloud feedbacks should be strongly negative, but there have been good explanations proposed for why the longwave component tends to be robustly positive (see e.g., Dennis Hartmann’s FAT hypothesis), in theory and is ubiquitous across the CMIP3 models, though difficult to constrain observationally. The shortwave component is more uncertain, but clouds do not simply respond to “more water vapor in the air” but to saturation and the underlying dynamics (e.g., much of the subtropics is expected to dry in a future climate or a poleward shift in the storm track would bring clouds to lower solar zenith angles), or e.g., a change from ice to liquid particles.

  50. 100
    Craig Nazor says:


    The many aspects of cloud feedbacks are complicated. Maybe you know this, and are taking advantage of the confusion in the attempt to win an argument. Or maybe not. It’s hard to tell.

    There is the effect of clouds as physical entities. They “block” (scatter) light and other radiation. Because clouds tend to be highly reflective, overall, clouds reflect heat, so it can be said that clouds have a cooling effect.

    But that doesn’t explain Venus. If it did, Venus’ heavy cloud cover would make Venus cool. Venus is hot due to the physical properties of the molecules of the compounds that comprise Venus’ clouds. On earth, clouds are mostly water vapor, which is a strong greenhouse gas. A greenhouse effect is present when water vapor is present.

    This is an oversimplification, but this is what I mean when I say that the NET effect of clouds (including all types of clouds, and the molecular properties of the water vapor itself) is most likely a positive feedback. The 2010 Dressler paper that I linked to supports a net positive feedback for clouds. The AR4 does not claim that cloud feedback is negative. From what I have read, it seems that GCMs support a net positive feedback from clouds, also.

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