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Launching the Climate Science Project (with your help)

By Joe Romm  

"Launching the Climate Science Project (with your help)"


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Part 1: Why increasing CO2 is a significant problem

I am launching the Climate Science Project — and I need your help.

At the suggestion of journalists, commenters, and others, I am going to assemble the best explanations of different aspects of climate science and post them.  Or repost them, in this case.  Then I’ll create an overview post for the sidebar that organizes them.

So I’m hoping you’ll help me identify the best articles, blog posts, videos, and the like on all areas of climate science from attribution to water vapor feedback (strangely, there are no “z” words in climate glossaries).  It doesn’t matter if the subject matter overlaps.  People need to hear and see things many times from different perspectives.

For instance, if you want a very good and uber-credible written primer on the science, I would suggest, “Understanding and Responding to Climate Change:  Highlights of National Academies Reports 2008.” If you want to understand why scientists are so certain that CO2 is such a big driver of our climate, you should watch Richard Alley’s lively talk AGU video, explains “The Biggest Control Knob: Carbon Dioxide in Earth’s Climate History.”

UPDATE:  Just to be clear, the explanations I’m looking for are not inherently aimed at one audience.  Obviously, my primary interest is explain things to my readers, but I am also interested in explanations for a more general audience.  Basically, I’m looking for the best stuff.

For “an easy-to-understand explanation for why increasing CO2 is a significant problem,” NASA scientist Gavin Schmidt has an excellent 2007 post, which I re-reprint below:

The CO2 problem in 6 easy steps

We often get requests to provide an easy-to-understand explanation for why increasing CO2 is a significant problem without relying on climate models and we are generally happy to oblige. The explanation has a number of separate steps which tend to sometimes get confused and so we will try to break it down carefully.

Step 1: There is a natural greenhouse effect.

The fact that there is a natural greenhouse effect (that the atmosphere restricts the passage of long wave (LW) radiation from the Earth’s surface to space) is easily deducible from i) the mean temperature of the surface (around 15ºC) and ii) knowing that the planet is roughly in radiative equilibrium. This means that there is an upward surface flux of LW around [tex]\sigma T^4[/tex] (~390 W/m2), while the outward flux at the top of the atmosphere (TOA) is roughly equivalent to the net solar radiation coming in (1-a)S/4 (~240 W/m2). Thus there is a large amount of LW absorbed by the atmosphere (around 150 W/m2) – a number that would be zero in the absence of any greenhouse substances.

Step 2: Trace gases contribute to the natural greenhouse effect.

The fact that different absorbers contribute to the net LW absorption is clear from IR spectra taken from space which show characteristic gaps associated with water vapour, CO2, CH4, O3 etc (Harries et al, 2001; HITRAN). The only question is how much energy is blocked by each. This cannot be calculated by hand (the number of absorption lines and the effects of pressure broadening etc. preclude that), but it can be calculated using line-by-line radiative transfer codes. The earliest calculations (reviewed by Ramanathan and Coakley, 1979) give very similar results to more modern calculations (Clough and Iacono, 1995), and demonstrate that removing the effect of CO2 reduces the net LW absorbed by ~14%, or around 30 W/m2. For some parts of the spectrum, IR can be either absorbed by CO2 or by water vapour, and so simply removing the CO2 gives only a minimum effect. Thus CO2 on its own would cause an even larger absorption. In either case however, the trace gases are a significant part of what gets absorbed.

Step 3: The trace greenhouse gases have increased markedly due to human emissions.

CO2 is up more than 30%, CH4 has more than doubled, N2O is up 15%, tropospheric O3 has also increased. New compounds such as halocarbons (CFCs, HFCs) did not exist in the pre-industrial atmosphere. All of these increases contribute to an enhanced greenhouse effect.

Step 4: Radiative forcing is a useful diagnostic and can easily be calculated.

Lessons from simple toy models and experience with more sophisticated GCMs suggests that any perturbation to the TOA radiation budget from whatever source is a pretty good predictor of eventual surface temperature change. Thus if the sun were to become stronger by about 2%, the TOA radiation balance would change by 0.02*1366*0.7/4 = 4.8 W/m2 (taking albedo and geometry into account) and this would be the radiative forcing (RF). An increase in greenhouse absorbers or a change in the albedo have analogous impacts on the TOA balance. However, calculation of the radiative forcing is again a job for the line-by-line codes that take into account atmospheric profiles of temperature, water vapour and aerosols. The most up-to-date calculations for the trace gases are by Myhre et al (1998) and those are the ones used in IPCC TAR and AR4.

These calculations can be condensed into simplified fits to the data, such as the oft-used formula for CO2: RF = 5.35 ln(CO2/CO2_orig) (see Table 6.2 in IPCC TAR for the others). The logarithmic form comes from the fact that some particular lines are already saturated and that the increase in forcing depends on the ‘wings’ (see this post for more details). Forcings for lower concentration gases (such as CFCs) are linear in concentration. The calculations in Myhre et al use representative profiles for different latitudes, but different assumptions about clouds, their properties and the spatial heterogeneity mean that the global mean forcing is uncertain by about 10%. Thus the RF for a doubling of CO2 is likely 3.7±0.4 W/m2 – the same order of magnitude as an increase of solar forcing by 2%.

There are a couple of small twists on the radiative forcing concept. One is that CO2 has an important role in the stratospheric radiation balance. The stratosphere reacts very quickly to changes in that balance and that changes the TOA forcing by a small but non-negligible amount. The surface response, which is much slower, therefore reacts more proportionately to the ‘adjusted’ forcing and this is generally what is used in lieu of the instantaneous forcing. The other wrinkle is depending slightly on the spatial distribution of forcing agents, different feedbacks and processes might come into play and thus an equivalent forcing from two different sources might not give the same response. The factor that quantifies this effect is called the ‘efficacy’ of the forcing, which for the most part is reasonably close to one, and so doesn’t change the zeroth-order picture (Hansen et al, 2005). This means that climate forcings can be simply added to approximate the net effect.

The total forcing from the trace greenhouse gases mentioned in Step 3, is currently about 2.5 W/m2, and the net forcing (including cooling impacts of aerosols and natural changes) is 1.6±1.0 W/m2 since the pre-industrial. Most of the uncertainty is related to aerosol effects. Current growth in forcings is dominated by increasing CO2, with potentially a small role for decreases in reflective aerosols (sulphates, particularly in the US and EU) and increases in absorbing aerosols (like soot, particularly from India and China and from biomass burning).

Step 5: Climate sensitivity is around 3ºC for a doubling of CO2

The climate sensitivity classically defined is the response of global mean temperature to a forcing once all the ‘fast feedbacks’ have occurred (atmospheric temperatures, clouds, water vapour, winds, snow, sea ice etc.), but before any of the ‘slow’ feedbacks have kicked in (ice sheets, vegetation, carbon cycle etc.). Given that it doesn’t matter much which forcing is changing, sensitivity can be assessed from any particular period in the past where the changes in forcing are known and the corresponding equilibrium temperature change can be estimated. As we have discussed previously, the last glacial period is a good example of a large forcing (~7 W/m2 from ice sheets, greenhouse gases, dust and vegetation) giving a large temperature response (~5 ºC) and implying a sensitivity of about 3ºC (with substantial error bars). More formally, you can combine this estimate with others taken from the 20th century, the response to volcanoes, the last millennium, remote sensing etc. to get pretty good constraints on what the number should be. This was done by Annan and Hargreaves (2006), and they come up with, you guessed it, 3ºC.

Converting the estimate for doubled CO2 to a more useful factor gives ~0.75 ºC/(W/m2).

Step 6: Radiative forcing x climate sensitivity is a significant number.

Current forcings (1.6 W/m2) x 0.75 ºC/(W/m2) imply 1.2 ºC that would occur at equilibrium. Because the oceans take time to warm up, we are not yet there (so far we have experienced 0.7ºC), and so the remaining 0.5 ºC is ‘in the pipeline’. We can estimate this independently using the changes in ocean heat content over the last decade or so (roughly equal to the current radiative imbalance) of ~0.7 W/m2, implying that this ‘unrealised’ forcing will lead to another 0.7—0.75 ºC – i.e. 0.5 ºC.

Additional forcings in business-as-usual scenarios range roughly from 3 to 7 W/m2 and therefore additional warming (at equilibrium) would be 2 to 5 ºC. That is significant.


And let me add Step 7On our current emissions path, we’re going to blow past 550 ppm, a doubling of CO2 (See U.S. media largely ignores latest warning from climate scientists: “Recent observations confirm “¦ the worst-case IPCC scenario trajectories (or even worse) are being realised” “” 1000 ppm and M.I.T. doubles its 2095 warming projection to 10°F “” with 866 ppm and Arctic warming of 20°F).

I will come back to Step 5 in a later post “” for now, see “Another “Must Read” from Hansen: ‘Long-term’ climate sensitivity of 6°C for doubled CO2.”  Indeed, I’m going to come back to most of these steps this year.

And that’s where you come in.  Please identify in the comments the best articles, blog posts, videos, and the like on all areas of climate science.  I’ll pick out the best and repost them.  Then I’ll organize them in one place.

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72 Responses to Launching the Climate Science Project (with your help)

  1. This is a great idea!I have long relied on the site “How to talk to a climate skeptic” but I believe you have the resources to do a much more sophisticated and up to date version for people like myself who often need to deal with these issues in a very public fashion.

  2. The Wonderer says:

    I am curious what audience you are targeting. I am a big fan of RC, but if this is intended for the general audience, it’s way too technical. I think it was Stephen Hawking’s editor who told him that each equation would reduce book sales by 50%.

    If you are just trying to assemble references to other writings, I recommend that you at least use an equation editor to pretty things up.

    Also, Eli is working on a good technical description of the greenhouse effect, complete with figures, that you might find helpful.


    [JR: I don't have a general audience readership, so, no, this is not aimed at a general audience, per se. Some of the best things are, and I'll repost those, others aren't, and I'll repost those, too. This is material for people to pick and choose from.]

  3. Ron Broberg says:

    This is my attempt at it:

    [1] Humans add CO2 to the atmosphere
    Global, Regional, and National Fossil Fuel CO2 Emissions

    [2] The CO2 content of the atmosphere is increasing
    CO2 Concentration at Mauna Loa Observatory, Hawaii

    [3] CO2 is a greenhouse gas (a gas which helps warm the surface of the earth)
    Radiative Heating Due to Increased CO2: The Role of H2O Continuum Absorption in the 12-18um range.
    Kiehl, Ramanathan, 1982

    [4] The temperature of the earth is rising
    GISS Surface Temperature Analysis

    Temperature (Hadley Center Research Unit – HADCRU)

    [1] -> [2]
    The Global Carbon Cycle: A Test of Our Knowledge of Earth as a System
    Falkowski, et al, 2000

    [2]+[3] -> [4]
    Radiative Transfer Within the Earth’s Troposphere and Stratosphere: A Simplified Radiative-Convective Model
    Ramanathan, 1976

    Global climate changes as forecast by Goddard Institute for Space Studies three-dimensional model
    Hansen, et al, 1988

  4. Barbara says:

    My two cents: eliminate the use of acronyms unless they are first decoded. Skeptic’s eyes glaze over. Also, have a science writer simplify the science. We’re often dealing with people who don’t appreciate the facts or physics. There was a GW program on PBS awhile back showing how ice water in a beaker over a bunsen burner won’t increase appreciably in temperature–taken at short intervals–until the ice is melted, at which time the temp. increases quickly to the boiling point. A very concrete illustration and the visual equivalent of a soundbite. Many of the skeptics don’t read, remember, unless it’s something filtered through FOX or the like.

  5. Wit's End says:

    Best ever video about ocean acidification: http://witsendnj.blogspot.com/2009/10/you-cant-fish-and-not-have-hope.html from the Natural Resources Defense Council – although, I ordered a dvd “A Sea Change – Imagine a World Without Fish” but it hasn’t arrived yet.

  6. this is a very good idea. it exists in bits and pieces, but a good central clearinghouse will be a big help

  7. DreamQuestor says:

    Wouldn’t it be simpler just to link to John Cook’s website Skeptical Science?

    I entirely concur that this is much too complicated. Science education in America is a bad joke and most of the language in that guide will go straight over the head of the typical American.

    [JR: No. I have something different in mind.]

  8. George says:

    Jeff Masters post on the manufactured doubt industry was the best I’ve seen on the reasons why scientists are not being heard by politicians.


  9. Lore says:

    I agree that John Cook’s website, Skeptical Science, has pretty much covered the aspects of climate change from the researched scientific perspective.

    I would concentrate more on short, easy to understand explanations of how the science should implicate our actions and why. Spending the next few years trying to get off of square one leaves even less time to create a list of meaningful plans.

    I feel that just shouting fire… fire, without a clear exit strategy only results in a turnoff and apathy by those who would yet be convinced to listen.

  10. Ron Broberg says:

    One of the important points to stress is that AGW arises from the radiation properties of the CO2 molecule. It is a physical theory in which “warming” is the prediction. AGW was not some recent scam invented to explain warming … warming is the prediction from a set of theories reaching back to the 19th Century.

    1827: Joseph Fourier, 1827, Mémoires de l’Académie Royale des Sciences de l’Institut de France VII., 1827, pages 570–604

    1861: John Tyndall, 1861. On the Absorption and Radiation of Heat by Gases and Vapours, and on the Physical Connection of Radiation, Absorption, and Conduction. Philosophical Magazine ser. 4, vol. 22, 169–94, 273–85.

    1896: Svante Arrhenius, 1896b, On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground, London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science (fifth series), April 1896. vol 41, pages 237–275.

    1938: Guy Stewart Callendar, 1938, The artificial production of carbon dioxide and its influence on temperature, Quarterly Journal of the Royal Meteorological Society, vol 64, no 275, pages 223-240

    1956: Gilbert Infrared Radiation in the Atmosphere, 1956, American Journal of Physics, May 1956, Volume 24, Issue 5, pp. 303-321
    (see also: American Scientist: Carbon Dioxide and the Climate)

  11. Ron Broberg says:

    Joe: check your spam bucket for an abbreviated timeline.
    Too many links I suppose.

  12. mike roddy says:

    Biological feedbacks from land use changes, particularly logging, are understudied and overlooked. This is due to their complexity, and the preponderance of atmospheric scientists in the major climate research organizations.

    Deforestation accounts for 20% of CO2 emissions, but it’s worse than that: industrial logging dries out the affected sites and their soil, and nutriets degrade. This leads to hot microclimates that can no longer support the large trees capable of sequestering major amounts of carbon. The hydrological cycle is affected. We have seen this in climatically marginal forests in Southern Oregon, Greece, and Brazil, where savannah takes over and forests never become reestablished. Numerous studies have confirmed this pattern, and it is getting rapidly worse as the earth warms.

    By using less wood, we can embark on serious afforestation and preservation projects. Timber industry corruption is preventing this, and it’s as bad here in the US as in countries like Indonesia. I took a shot at this in an article that appeared in an enviromental journal. Here’s the link- http://www.tinyurl.com/yc8ncuq, background research by a post doc student at http://www.tinyurl.com/ycxfsqu.

    As Stern pointed out, moving rapidly toward halting deforestation and restoring forests is the fastest and most cost effective short term emissions reduction strategy available.

  13. Kevin Meaney says:


    I think that it is essential that the water vapour feedback is included. The greenhouse gases emitted by humans by themselves do not add to the greenhouse effect that much. I think it is necessary to be clear about how big the water vapour feedback is. Warm the atmosphere a little bit and it holds more water vapour, which warms the atmosphere even more, which holds more water vapour and so on, we are just lucky the water vapour feedback coefficient is less than 1, otherwise we would have runaway warming or cooling

    We can see from measurements taken at the time and modelling of the effects of volcanic eruptions how large the water vapour feedback is. The aerosols from the volcano cool the atmosphere slightly resulting in a reduction of water vapour which cools the atmosphere even more. We know how important this is.

  14. EMTguy says:

    Barbara (4): “… Many of the skeptics don’t read, remember, unless it’s something filtered through FOX or the like.”

    If the idea is to educate and convert skeptics, I would suggest losing the snark. It’s constructive of nothing.

  15. Jeff Huggins says:

    Simplicity is Beauty (in some senses anyhow)

    Rather than searching all the existing materials — some of which are too technical, or come across that way — I’m going to offer a few thoughts in a different way, for what it’s worth.

    There are a few aspects of the science of the matter, and also of the ethics of the matter, that I like to try to explain in very simple terms, without any technical jargon, using metaphor and example, in a way (hopefully) that a fifth-grader could understand.

    So, periodically, I’ll just write one of those and post it (as a comment) and/or send it in. These won’t be formal, and they’ll be in simple unpolished narrative form. If someone else wants to polish/edit, put them into better form, or make a short video piece on one or more of them, go for it. I don’t have a “production” shop here, nor time for editing. But, I have some concepts and ideas that might prove helpful in explaining some of the matters in a non-technical way. So, I’ll just write them and offer them to the collective universe of ideas.

    So, as time here allows, I’ll periodically write a few of them.

    (Tell me “no” if this is not a good idea, and I’ll save the time.)



  16. sarah says:

    1. A critical point that is implicit in Alley’s excellent presentation at AGU it that “natural” does not mean “without cause”. Yes, previous warming events were “natural”, but they were still caused by increases in CO2; humans have simply introduce a new mechanism to increase atmospheric CO2.

    2. An aspect that’s hard to communicate is the balance between the facts that (i) models are unanimous in predicting warming, and (ii) it is much more difficult to predict the extent of some important feedbacks. i.e. impacts of methane release from melting permafrost; ability of vegetation to absorb CO2 as biomes shift and precipitations patterns change; rates of ice-sheet moving/breaking in Greenland and Antarctica.

    What I try to explain is that while these effects are difficult to model precisely, virtually all are positive feedbacks. It’s just a question whether they will make things somewhat worse or catastrophically worse.

    The deniers’ arguments haven’t changed much, even as the science advances. Tim Lambert’s concise 2005 summary in the form of a bingo card is still mostly relevant (just substitute Roger Pielke, Jr for Michael Crichton).

  17. Wit's End says:

    Ron Brogurg’s links reminded me of this interactive graph from the NYT, which is super for giving a non-scientist an overview of the history of climate science:


  18. Wit's End says:

    ack! Broberg, sorry!

  19. Mim says:

    For fairly good overviews and rebuttals to common arguments, John Cook’s SkepticalScience is very good and he keeps it up to date. I concur with Eli Rabett’s site being worth a visit. As is Tamino’s site: http://tamino.wordpress.com/

    Realclimate.org is a must.

    For those with more time and an interest in refreshing their high school science, David Archer’s video’s of his Fall 2009 course at UChicago is an excellent comprehensive overview of the science but needs to be viewed in order and entirety:
    U Chicago Climate Science Lectures

    His site has some models to play with as well as a couple of chapters from his book, which looks to be worth getting.

  20. prokaryote says:

    Please provide translations aswell – once someone has the time.

  21. Deep Climate says:

    The Richard Alley AGU lecture is a great choice. Unfortunately there doesn’t seem to be a full transcript available of that talk.

    Two summaries I have come across (or been pointed to):

    Summary from Alex Smith of Radio Ecoshock, explaining Alley’s “Rock-Weathering Thermostat” including key verbatim extracts:


    Steve Easterbrook’s summary from his AGU diary:


    At least one of these would be a useful companion to the full video, which is great but somewhat daunting for those short on time. A full (or edited) transcript, when available, would be even better.

  22. Andy Gunther says:


    I think it would be most effective if you link your primer on climate science to Cook’s (or other’s) debunking of the basic denier points. This would really make it a “one-stop shop” for journalists and other’s seeking information.

    I concur with Ron Broburg that incorporating the history of the theory is important (or key links to Spencer Weart), as many people do not understand how much science is behind our present understanding. When I speak I point out that Arrhenius published 20 years before Alfred Wegner produced the theory of continental drift, and yet the latter is not very controversial anymore.

    The Union of Concerned Scientists’ web site also has some valuable summary presentations: http://www.ucsusa.org/global_warming/science_and_impacts/science/

    [JR: Yes, Cook's site is good. I feature it a lot and certainly will make it a highlight here.]

  23. prokaryote says:

    This project should have it’s own website domain.

    Some ideas

    “Climate Change What you need to Know.”

    “Earth Climate System and Implications.”

    “Earth Climate Change Knowledge.”

    “Understanding Earth Climate System.”

    Scientific knowledge on climate change for everybody.
    Gathering of explantions, studys, general media about earth climate system, models, scenarios and solution. To understand earth climate system and human implications better. Information should be provided in a simple and imageable way (text + media).

    Consensus and state of science should be stretched (disclamier).
    Cooperation with governmental bodys if possible. Cooperation with filmmakers and environmental groups. User comments for interactive communication.

    Please acknowledge that flash, pdf – closed formats, many scripts mean less access and security. There are alternatives for flash for embedding movie clips – html5.

    Download section with studys, plans, model/data and media.

    I find http://climate.gov is a good example for a good presentationm of current climate system states.

  24. Barbara says:

    EMTGuy–truly my comment wasn’t intented in a “snarky” way. I know how important this topic is. But of the skeptics I speak with my comment holds true. It’s my experience, in the world I currently occupy at work and among family. They are not technically inclined, or apt to read something too lengthy or dense. I’m merely trying to get a different approach out there as well as all the scientific ones available. We really need to get everyone on board, not just who they would call the intellectual elitists.

  25. Alan says:

    Please check out http://www.ucsusa.org/global_warming/ , especially their Global Warming FAQ which is under the Global Warming 101 link. They have done a great job of explaining the science, complete with explanations of unfamiliar terms like radiative forcing, and no equations.

  26. Doug Bostrom says:

    Prokaryote’s suggestion resonates for me.

    There is so much duplication of effort in the progressive climate science communications community, an abundance of sites covering this topic from slightly different perspectives but all acting more or less alone.

    This situation reminds me of a bunch of people who all know soccer really well, can play the game, are well trained, are on the same field and indeed actually in a game but can’t seem to act as a team.

    On the other side, people who recognized early they needed to form a team and now have first mover advantage and are scoring goals way disproportionate to their basic skill level.

    I suppose this could be simply an organic feature of how this scenario has played out with no way to address it.

  27. Jim Prall says:

    The past two years I’ve run a three week seminar on climate change and geoengineering for engineering undergrad; with advice from Prof. Danny Harvey I assigned several articles in the first session as background on the reality and seriousness of climate change. Most are paywalled, but this one is open access:
    “Squaring up to reality”, Martin Parry and colleagus,
    Nature Reports Climate Change
    Published online: 29 May 2008 | doi:10.1038/climate.2008.50
    “Both emissions reduction and adaptation will need to be much stronger than currently planned if dangerous global impacts of climate change are to be avoided.”

    Another good overview of the ocean acidification problem is here:

    On the topic of the urban heat island effect, and whether it has been factored out in detecting and attributing recent greenhouse warming, here’s a good recent review article by Dr. David Parket of the UK Met Office:
    This is from a new e-journal called “Wiley Interdisciplinary Reviews Climate Change” (or WIREs Climate Change for short, in their terms.) There is another article in the first issue by Judith Lean recapping the science on solar-climate links. I haven’t read all of that one but she is a leading expert in the subject and has in the past helped push back the “climate change is all solar” line of argumentation.

    This open access publication looks worth following for more such accessible review articles that sum up the lay of the land and recap recent research results. I found this one at least quite accessible reading, on par with Scientific American, e.g., as opposed to specialty journal articles that dive right into technicalities. Space and word-count restrictions force most journal articles to skip all the background that would allow non-specialist readers to understand where their work fits in to the bigger picture.

  28. Dennis says:

    I don’t have links — perhaps others do — but two things that must be addressed in the project:

    1. When raising the matter of CO2 increases because of human activity, be sure to include something about how the differences in carbon isotopes is the “smoking gun” for fossil fuel CO2 emissions.

    2. Be sure to mention the tiny percentage (relative to the entire atmosphere) that naturally occuring GHG’s make, and how much of a difference that makes in the Earth’s natural greenhouse effect.

  29. Baerbel Winkler says:

    I think that Peter Sinclair’s video-series “Climate Denial Crock of the Week” should be included:

    As far as translations go (suggested by prokaryote), there is currently an effort underway to translate John Cook’s SkepticalScience list of arguments into various languages:

  30. Glenn Meyers says:

    Barbars makes an excellent point: “My two cents: eliminate the use of acronyms unless they are first decoded. Skeptic’s eyes glaze over.”

    Individuals without backgrounds in climate science, must be provided with methods for understanding what is occurring. When they are equipped with practical, easy to understand building blocks, they will then be better equipped to expand their knowledge base.

  31. Bob Wright says:

    Recent articles conclude that when adding in the forcings of methane and other minor GHG’s we are almost at the equivalent of 450 ppm CO2 already. Considering things being roughly additive, we would then be at equivalent 500 ppm when CO2 hits 450?

    Is it correct to assume that aiming for a peak at 450 considers the addtional contribution of the other GHG’s?

  32. Doug Bostrom says:

    BTW, if there’s one particular messaging effort that absolutely must be handled competently, it’s explaining why the C02 added to the atmosphere by human activities is a pollutant.

    Unless and until C02 added to the atmosphere by humans is labeled a contaminant and is understood by the public as such, effective policy response to this pollution will much more difficult than necessary, nearly impossible.

    The amount of pushback already occurring in connection with EPA’s effort to tackle C02 is directly proportional to the importance attached to this matter by fossil fuel interests. They’re well aware this single battle will have significant impact on the outcome of this war.

    Look at commonly accepted definitions of pollution, then look at the cognitive pretzels baked by opposition PR flacks to get an idea of how vulnerable they are.

    C02 is naturally occurring in the atmosphere. So is C0, but C0 is accepted as being a pollutant in excessive quantities and was the subject of a massive engineering intervention to reduce tailpipe emissions of C0. There’s nothing complicated about this matter.

  33. Lamont says:

    I really love that post in RC since in steps #1 and #2 it lays out why CO2 must be a greenhouse gas.

    All the arguments which try to attack the role of CO2 as a greenhouse gas, and deny the utility of any kind of modeling or deny the temperature record are going to have a hard time with that approach.

    OBSERVABLE FACT: Something causes a greenhouse effect from the LWR budget.
    OBSERVABLE FACT: IR lines for CO2, H2O, CH4, O3 are measurable from space and explain the greenhouse effect in the LWR budget.
    OBSERVABLE FACT: Those lines have increased with increasing concentrations of those gases.

    Aliens observing from Mars could easily figure out that increasing CO2 was having an impact on the LWR budget of the Earth and causing warming at lower layers with these observations.

  34. Lou Grinzo says:

    Joe: I also had a post with multiple links not appear–please check your spam catcher thingie.

  35. CJ Martin says:

    This effort to consolidate the science seems somewhat redundant with there being so many other good sources of information. But due to the massive failure of the population to grasp the consequences of our failure to act on our knowledge I believe that this project is needed.

    Please supplement this research with scientific studies regarding our common refusal to adopt ideas that conflict with our beliefs. Understanding the power of denial, propaganda and lobbying to prevent the critical changes in policy and economic development would be a valuable addition to the scope of your project.

  36. Pagodroma says:

    I agree with Doug’s soccer player analogy. We don’t need more lists (Skeptical Science is now even available as an iPhone App!) but better strategies to provide correct and usable information to media, policymakers, politicians and not to forget our friends, colleagues and neighbors.
    When teaching complicated subjects it is often a good thing to rely on PBL, problem oriented learning. What I think we need is a site focused on something similar for climate science and politics. It should also be multidimensional and not a list of subjects. You should be able to start at any end, eg ocean acidification, perhaps in this way:

    Oceans seems to be getting more acidic – is that true – if so what is cause and trend – what problems does it cause short and long term – possible interactions with other areas of climate science – time for natural system to revert to normal if left alone – are there ways to mediate this – etc

    or another area

    Is it true that freshwater glaciers are melting – what data is available -time series – possible explanations (temp/soot/sun/human interactions/buldings etc) how long till gone, effect on freshwater availability etc etc

    Of course there will be a lot of interactions and overlap but I think this way of addressing the problem would bring something new and make it easier to communicate with those who are not science literate.

    Please comment! Is this is a workable idea?

  37. shopa says:

    I think it is a great idea.

    Let me make a suggestion.
    We need somebody to make, and maintain, a list of the different climate change problems that different countries are experiencing.

    Some Americans won’t be swayed by small annual increases in CO2 or global temperatures, but they might be surprised at the many droughts around the world.

    Our news media does not report on drought problems outside of the USA,
    and few report on the severity of the droughts in California and the American West.

    I feel that concrete examples are the only way to reach some people.

  38. Cornhusker says:

    I haven’t read the comments, but…

    Any list of core documents must include the most up to date graph of CO2 and temperature over the past several hundred thousand years. An example is here http://www.sierraclub.ca/national/programs/atmosphere-energy/climate-change/ten-myths.html#cc7

  39. prokaryote says:

    IPCC errors: facts and spin
    Currently, a few errors –and supposed errors– in the last IPCC report (“AR4″) are making the media rounds – together with a lot of distortion and professional spin by parties interested in discrediting climate science. Time for us to sort the wheat from the chaff: which of these putative errors are real, and which not? And what does it all mean, for the IPCC in particular, and for climate science more broadly?

  40. Wit's End says:

    shopa, in case you’re not familiar with this blog, you might try checking desdemonadespair.blogspot.com. There’s absolutely no commentary, and it’s not organized the way you suggest, but it’s the best source of empirical impacts from around the world that I know of – just links to real news that the mainstream media in the US generally ignores, much of which is shocking.

  41. Christopher S. Johnson says:

    I want to add something that often gets missed on these kinds of endeavors. Good layout, design, and interface. Please, hire a good web page and application designer. Attractiveness counts for much more than one would imagine. Look at the god-awful redesign over at Grist. One cant even find their “How to talk to a climate skeptic” anymore. And it feels like thorns to graze your eye over their page.

    Go find a site that feels modern, user friendly, inviting colors, attractive photography, and emulate it. Not too crowded. USEFUL search with the ability to set results by date or relevance. Perhaps a combo of Wikipedia and Bing!

    I also want to add to the call for addressing the under appreciated subject of ocean acidification. The anthropogenic element is even clearer than with global warming. It should be a topic that always rests in our brain’s utility belt, and mentioned in the same breath with CO2 regulation.

  42. Jeff Huggins says:

    That Carbon Dioxide Stuff Just Being Its Natural Predictable Self

    You know those neat goggles and cameras that can see things in the dark, like you see in the movies sometimes?

    You know, those things that show humans as being blurry and red, usually, and that show hot things much brighter than warm things, warm things brighter than colder things, and that don’t show downright cold things at all?

    Cold shows up as black. And hotter things appear reddish or orange-ish or yellowish.

    Well, those goggles and cameras are picking up “infrared radiation”, which is just energy that is radiated from things that are fairly hot, or at least warm, but that we can’t directly see. The sun itself is super hot, of course, and it gives off radiation that our eyes can see – because our eyes are well evolved to see the sun’s radiation. Things that are just warm or fairly hot don’t give off visible radiation – light that is seeable, naturally – but they still give off radiation: infrared radiation. Simple as that.

    As you know, if you walk barefoot on the pavement at night, after a hot day, your feet will still feel the warm pavement, if it hasn’t cooled off already. Try it out. In this case, you are feeling the pavement’s warmth directly.

    That pavement is warm even though it looks black or dark at night, to you, if there are no streetlights, that is. What you are experiencing is this: The pavement is warm, but it’s certainly not giving off light that you can see.

    Yet, it is giving off energy in the form of infrared radiation. If you had your own pair of those neat goggles or an IR camera, you could see it, easily.

    Your body is giving off radiation too, but does your body glow to your own eyes? Probably not. When you walk with your friend outside, on a dark night, do you see your friend’s body glow? Probably not. But, your friend’s body is still warm, and you could see it well if you had one of those IR gadgets.

    So, where are we?

    Warm stuff gives off energy in the form of radiation, and (if the stuff isn’t super hot) we humans can’t see the radiation with our own eyes. It’s the kind that’s picked up by those goggles. But it is happening all the time. Just because you can’t normally see it doesn’t mean it’s not there. It’s there. Borrow a pair of those fancy goggles, and take a look!

    Now, as it turns out, molecules of carbon dioxide absorb some of that sort of radiated energy. Just like a dark shirt absorbs sunlight in the daytime, carbon dioxide molecules absorb some of the radiation that we can’t see, that comes from all those warm things like pavement and dirt and so forth.

    Why do carbon dioxide molecules absorb some of that energy? Well, the frequencies and wavelengths of some of that energy are just right to excite the bonds in carbon dioxide molecules. Have you ever seen guitar strings start to vibrate, or a crystal glass start to vibrate, when someone or some instrument is making a certain note? Either way, don’t be confused. It’s nothing magical or unique. Your skin absorbs some visible sunlight. The carbon dioxide molecules absorb some of the other radiation that’s invisible to our eyes. But, natural principles are at work in both cases. Most matter absorbs radiation of one sort or another. Dark shirts absorb many wavelengths, and carbon dioxide molecules absorb some other wavelengths. It’s not magical or unexpected. We should be surprised if it didn’t happen!

    How do we know, you ask? In many ways. And, science has known this for over a century. If you’d like to know how we know, we’ll cover that another time.

    Now, back to carbon dioxide: It’s pretty predictable, once you get to know it. (Molecules tend to be much more predictable than humans, by the way! This shouldn’t surprise us either.)

    When carbon dioxide molecules absorb some of the radiation that comes from warm things – the kind of radiation that we can’t see unless we have those goggles – then they move around faster and bump into other molecules of all sorts. So, all the molecules start moving a bit faster and bumping into each other a bit harder, when they do. And, when molecules in a gas (or in anything) do that, that means that the gas has a higher temperature. It’s hotter. When a gas’s molecules move around faster, the gas has a higher temperature.

    So, in a nutshell, here is this part of the process:

    In the daytime, sunlight comes in through the atmosphere, hits the Earth, and warms up the ground and other stuff on the Earth’s surface, including our dark shirts, pavement, rooftops, dirt, and so forth. Carbon dioxide molecules don’t absorb the visible light: It passes right through them. We humans see the visible daytime light, but carbon dioxide molecules couldn’t give a hoot about it, as it comes in.

    But, anything warm, like stuff on the Earth’s surface, radiates the sort of radiation we talked about earlier, the kind that we can’t see. This happens at night and in the daytime, but we can’t see it with our naked eyes. But it’s there. The carbon dioxide molecules absorb some of that energy, move around faster, bump into other molecules, and heat up the atmosphere. The more carbon dioxide molecules there are in the atmosphere, the more of this invisible radiated energy they absorb, and the more heat they transfer into the atmosphere. Simple as that, pretty much.

    Energy has to have a place to go or something to do. It doesn’t just disappear. If there are more carbon dioxide molecules in the atmosphere, they absorb more of the invisible radiation that comes up from the pavement, dirt, seas, and other things on Earth, and they transfer that heat into the atmosphere, warming it up.

    The question is not whether carbon dioxide molecules do this. They do. That can be shown and confirmed in many ways, and it is consistent with what many other molecules can do too, with radiation of various wavelengths.

    Indeed, if you told a carbon dioxide molecule that it didn’t, and couldn’t, absorb that sort of energy and convert it to heat, it would only think that you were very misinformed, and it might even be insulted! After all, that would be a bit like telling a human that he or she didn’t breathe oxygen and didn’t have any need for a toilet every once in awhile. The human would think you were nuts, right?

    Remember now, if you don’t believe that the sort of invisible radiation that I’m talking about exists, you might try borrowing those fancy goggles or cameras. The military has them, and law enforcement personnel sometimes do, and rangers, and some industries use them as well. Or, if you don’t think that carbon dioxide molecules absorb some of that energy, much like your dark shirts absorb visible sunlight, we explain that more here ___________. Or, if you do understand that carbon dioxide molecules can and do absorb some of that energy, but if you think that they can get rid of that energy without moving faster, bumping around, and increasing the temperature of the atmosphere, we can explain that to you using a bathtub as a good analogy.

    The point here, of course, is that you directly experience the same sorts of things or you at least understand stuff that is caused by the very same sorts of things. None of this is magical. You can see sunlight. You can feel a warm pavement. You know that dark shirts feel warm in sunlight. You realize, if you think about it, that we humans can’t see some types of radiation but that those types still exist. If you wanted to, you could borrow some of those goggles or cameras.

    By the way, can anyone suggest some of the many great movies in which they use infrared goggles or cameras? Predator is one, of many. What about others?



  43. Wit's End says:

    I think a good analogy for people who don’t want to think about molecules is the car in the sun. Everybody knows not to leave Fido in the car on a hot day with the windows closed, because heat gets trapped and the car gets hotter than the outside temperature – just like the CO2 in the atmosphere traps heat on earth. More CO2, more heat gets trapped. And we know it traps heat, otherwise, the earth would have a climate like the moon.

    And as far as Jeff’s reference to invisible infrared radiation goes, it is important to remind people that just because they can’t see something doesn’t mean it isn’t there.

    And so another good analogy for people who aren’t predisposed to read science is to remind them that if they sit in a closed garage in a car with the engine running, eventually they will die of carbon monoxide poisoning. They won’t smell it, or see it, but it is lethal just the same. It should help them understand that just because the rising level of CO2 and other greenhouses gases isn’t visible, it doesn’t mean it isn’t real, and changing our climate.

  44. Cheryl Rofer says:

    A number of commenters have pointed out that this explanation is much too technical and acronymic for the general public. I’d like to point out that this explanation, the Richard Alley video, RealClimate, and many other sites seem to begin in the middle of things, assuming that of course the reader is more or less on the same page, both attitudinally and technically, as the writer.

    I’m currently preparing an adult-education lecture on climate change. That’s it. One hour-and-a-half lecture, with a half-hour of discussion. The audience will range from general public to retired physicists.

    I’m not a climate scientist, but I am a chemist and have worked for many years with mass- and energy-transport models like those the climate modelers use as well as a lot of molecular dynamics. As I research my lecture, I’m finding an awful lot of explanations opaque.

    The terminology is horrible. “Forcings.” I now know what that means, but it took some work, and it doesn’t describe, for non-modelers, what they’re talking about. “Greenhouse effect” suggests that there’s a layer of something that is reflecting heat back. Some of the explanations sound that way, and there are even illustrations from sources that probably should know better that show a layer of greenhouse gas. I wrote this up a while back.

    And then there’s “water is a feedback.” I’m not entirely convinced I understand what that means or why that approach was chosen, after reading many explanations. I think I’ve got it and will write it up, probably this week.

    But oh my, there’s a lot of work to do to make all this understandable.

    [JR: Just to be clear, the explanations I'm looking for are not inherently aimed at one audience. Obviously, my primary interest is explain things to my readers, but I am also interested in explanations for a more general audience. Basically, I'm looking for the best stuff.

    Those of you who have different audiences can find the stuff that's best for your audience and/or translate the other stuff for them. I do expect to post original material myself for CP readers, which aren't quite as technically oriented as RealClimate.]

  45. Casey says:

    This is meant for the average person – the average young person with very little background in science beyond what is covered in the classroom. It is at the very low end of the scale when it comes to technical language, so it might not be what you’re looking for. But maybe you’ll find it useful.


  46. David B. Benson says:

    I recommend linking to the fascinating “The Discovery of Global Warming” by Spencer Weart:

  47. Doug Bostrom says:

    David B. Benson says: February 14, 2010 at 7:39 pm

    I recommend linking to the fascinating “The Discovery of Global Warming” by Spencer Weart:


    Yes! Comprehensive, and Weart presents it in such an engaging way.

  48. Anna Haynes says:

    Richard Alley also has a more general-audience NSF outreach video – How Do We Know? Physics, Forcings, and Fingerprints – available in video or audio from – http://bit.ly/AlleyNSF
    (fyi, the real NSF site only provided it in video, that made my laptop choke)

    Joe, CliProg’s highest-value new project, IMO, would be to become the go-to Google Image Search for science-based climate graph imagery; I’m already using it for this purpose since Google Image Search returns such dreck.

  49. David B. Benson says:

    Could link to Global Warming Art:
    or to its subsections.

  50. Richard Brenne says:

    The point of effective communication is to say the most with the fewest number of words, to be as clear and concise as possible. A good example of this is none of my comments.

    It’s like finding the lowest common denominator (and not just in the way Fox has found its audience).

    Always be grammatically accurate if you want to write good.

    So Gavin’s first three steps are great, but in the fourth step (and at all my meetings there are generally 12) for a general audience he’d need to find a way to explain radiative forcing in words a fifth grader would understand, something like: “There are a number of different things that can warm the Earth’s atmosphere, like a warming sun or more water vapor preventing more of the sun’s reflected rays from leaving the atmosphere. These are examples of radiative forcing.” (The last sentence should only be used if Gavin feels the term needs to be used – if not, just describe the concept without the term. Technical jargon should always be kept to a minimum, and everything should always be explained with the simplest words possible. Like the propriaceptive process connecting synapses between the neurons of the cerebral cortex.)

    I like Gavin’s use of the lowest common denominator statements combined with showing the math for those who want to see it, but this can be done in footnotes as well.

    Caveats can come in the footnotes where the math is shown. Don’t go all caveat-y on us until the footnotes. First make the clearest and most concise statement that is factual – then add caveats as you need to in the more comprehensive statements or footnotes. Too many caveats in topic sentences, abstracts or summaries are like mentioning that one is unemployed, suffering several very personal diseases and living with one’s mother during a pick-up line.

    Use metaphors as much as possible, but not disgusting ones like my previous sentence. (And for the record, when I was single this didn’t work as well as I might’ve hoped.)

    Just as mathematicians, physicists and other scientists can look at a blackboard to find how to simplify equations, the same process can be put to work here, both by people in the same room and on-line. I nominate Joe and Climate Progress as this clearinghouse of information.

    And my ultimate dream is to see as much synergy in this process between IPCC, NASA, NASA-GISS, NOAA, NOAA-ESRL, NOAA-NCDC, UCAR/NCAR, HADLEY, AMS, GSA, AGU, CIRES, NSIDC, INSTAAR, NREL, 350, RC and CP as possible.

    Also, avoid acronyms.

  51. I like the comment “Food, agriculture and fisheries … etc.” See complete quotation at the end of my comment.
    What we need is to focus on “Joe the Plumber” who has no time to learn or try to understand all the multi-syllable words we are fond of using. Here is where the old KISS Principle comes in, you know: Keep It Simple, Senior!” and both the old and the young are left out by esoteric lengthy complex discourse.
    The other problem is that our key and most important audience has a very short attention span. Therefore, I suggest going for the Simplest and Scariest way of presentin the Truth, call it the SST Principle.
    Here is my first version, a second version to follow, later.

    1. Begin with a description of a forest fire with pictures. Explain how all that burning wood produces smoke and CO2.
    2. Briefly describe how a Greenhouse in a farm works. Why the windows let in the solar radiation heat but keep the plant heat inside. A picture of termometer would suffice. No need to bring in Plank’s, or whoever’s Law.
    3. Move on to the Feedbacks, for example, how the heat from the forest fire leads to future forest fires and the wildfires California had last year. A video would be nice, if there is one. No need to bring up the Carbon previously stored by the tree, etc.
    4. State the obvious in a simple way: Forest fires produce CO2 that increase the Green House Effect, that increases the temperature of the forests, that increases the chances of another fire, elsewhere where there are trees and forest left. A map with the Australian forest fires or some other would help.
    5. Mention a Second feedback: My choice is to describe how the melting tundra brings bacteria that eat the thawing vegetation and produce more Methane. A simple statement that Methane is 20 worse should suffice.
    6. Mention the frozen Methane, the Gigatons of frozen CH4, at the ocean bottom should suffice. Estimated numbers would help.
    7. Clearly and simply describe how these “and other” feedback mechanism WILL (OK, use your word) lead to the last Tipping Point. Which I think is when the Methane comes out of the Ocean. There is no theoretical way to turn back after that point.

    Some subjects to avoid:
    1. Skip the history of the evolution of the Earth. People want to know what will happen, not what did happen. I found it fascinating and hard to follow.
    2. No equations, no multisyllable words, minimum of pictures. A video would be most effective but not of one person talking. Only voice overs.
    3. Obviously, I am way out of my field, feel free to disregard parts or all of this.
    But, thank you for the opportunity to write these words.
    Wish you the best, the survival of my, and your, grand children is at risk, grave risk. The ultimate temperature is like that of our next door neighbor Venus’ CO2 Atmosphere, 845 Deg. Faherenheit, about twice the temperature of the Auschwitz’ ovens. What a way to go…
    “Food, agriculture and fisheries. The well-being of the human society fundamentally depends on the availability and distribution of food. Lobell and Field (2007) demonstrated that the warming trend in global temperatures since 1981 has already led to the reduction in global yields of wheat, maize and barley. This has resulted in annual total combined losses of roughly 40 million tonnes or US$5 billion (€3.2 billion) per year. Under continued warming, Lobell et al (2008) predict that south Asia and southern Africa are the two regions that will likely suffer significant reductions in the yields of several crops that are important for their large populations. Tubiello and Fischer (2007) showed that reduction of greenhouse gas emissions could reduce the global costs of agricultural losses from climate change by 75-100%, and that the number of additional people at risk of malnutrition would be reduced by 80-90%. Brander (2008) concluded that the productivity of fisheries may suffer regional, and possibly global, decline as a result of global warming, and that this decline may have already begun.”
    Closing remarks (maybe): But there is some benefits from Global Warming the initial increase in temperature will reduce food production (seme examples would help) which will lead to famine in Africa, South America and Central Asia. About two or three Billion people. After they die, the forests they were cutting to survive may be restored, if it is not too late, and the human race, minus a billion or two, will survive.
    Have nice day!

  52. Dick Veldkamp says:

    Good site on how we know that CO2 in the atmosphere is on the rise, and why the extra CO2 is due to human activity. Graphs of measurements and further references.


  53. prokaryote says:

    50. there is nothing on sea ice?

  54. LT says:

    Great idea, Joe.

    The following audio or video files immediately spring to mind.

    1. Talk by Naomi Oreskes available via University of California TV
    “The American Denial of Global Warming”

    2. An arresting 15 min audio by Charlie Veron, former Chief Scientist of the Australian Institute of Marine Science, Townsville QLD Australia, PLEADING for the Great Barrier Reef. Suitable for a general audience.

    “A plea for the Great Barrier Reef”. on ABC Radio National Ockham’s Razor, 08/04/2008. http://www.abc.net.au/rn/ockhamsrazor/stories/2008/2207734.htm

    I suggest including all the consensus statements from the various national Science Academies issued over the last few years.

  55. Baerbel Winkler says:

    Richard Brenne said “..Also, avoid acronyms”

    While avoiding them is fine, it’s not always possible or feasible. A neat list of the most often used acronyms would therefore come in handy as well, perhaps even with some additional information of where the instituation (if it’s an acronym like eg. NOAA) is located.

  56. James says:

    Good job Joe. But is it possible to stop the flood of inaccurate information coming from the media? Just today the UK Times website is running the non-story about the urban heat island effect causing global warming:


  57. Mim says:

    I think my latest suggestion might have ended up in the spam filter. Anyway, do a search on you tube for potholer54. It’s a series of eight climate change videos (so far) and they are good for non-scientists.

    (I’ll not provide a link because it could be why the message doesn’t appear, I’ve tried a couple of times.)

  58. WAG says:

    I’ve written a couple posts that I think are good ways of making the climate argument very very simply. The first is here:


    The second I’ve written in the comments below, and can be found here:


    Fact #1: Global temperatures have risen by about 0.8 degrees C (1.4 degrees F) since records began, with the ten warmest years on record all occurring from 1997-2008. This is not disputed.

    Fact #2: CO2 is a greenhouse gas; a basic physical property of CO2, repeatedly measured and confirmed since the 1890s, is that it absorbs and emits infrared (heat) radiation, so CO2 in the atmosphere traps heat from the sun. This is undisputed.

    Fact #3: CO2′s concentration in the atmosphere has risen by 35% since the Industrial Revolution, and is now at its highest level in at least 450,000 years (measured in bubbles of air trapped in ice cores). CO2 measured at the Mauna Loa observatory in Hawaii shows an uninterrupted increase since records began in 1959. This is undisputed.

    Fact #4: The amount of extra CO2 in the atmosphere matches almost exactly with the amount released from fossil fuels (minus the amount that would be taken up by natural carbon sinks). That sounds like a big claim, but miners, drillers, factories, and utilities are, after all, businesses who keep careful records of the fuel they burn, so it’s relatively easy to measure. So we know with 100% certainty that the extra CO2 comes from human emissions. This is undisputed.

    So we know for certain that humans are adding significant amounts of CO2 to the atmosphere, that CO2 is a heat-trapping greenhouse gas, and that temperatures are rising. The logic is inescapable… to logically prove that humans are NOT causing the observed increase in temperatures, you would need to prove both of two things:

    First, you need to show how it could be possible to pump more of a known greenhouse gas into the atmosphere WITHOUT temperatures increasing. How can the earth absorb more energy from the sun without its temperature rising?

    Second, if CO2 is not causing the observed warming, you need to show what IS. Long-term global temperature change is only caused by an external forcing that causes either more energy to come in from the sun, or less energy to escape back into space; absent a forcing, there’s no temperature change. We know that temperatures are rising, so if it’s not the greenhouse effect causing that increase, what is?

    The first question regards the sensitivity of the earth’s climate to changes in CO2, which requires a scientific background I don’t have. If you’re interested in learning more, check here and here.

    The second is easier to deal with, as long as you can read a graph. The most common alternative to greenhouse gases is the sun. Solar activity, the argument goes, is correlated with past climate changes; therefore, the sun must account for the global warming we see today. The problem is, solar activity has decreased since the 1970s, just as global temperatures have risen the most. So while the sun may have caused PAST climate changes, it cannot be causing TODAY’S.

    Remember, a climate skeptic must answer BOTH claims to have a credible point.

    But what about the evidence FOR global warming—is there a smoking gun? Well, there are several, but here’s one that involves no complex calculations, correlations, or models. As it turns out, greenhouse gas-induced warming has a telltale signature, based on how different layers of the atmosphere heat up. If you imagine the earth and its atmosphere as a person covered by several blankets, there are two ways the person can get warmer: either more heat comes in from the outside (i.e. you turn up the heat in the room), or less heat escapes through the blanket (i.e. you throw another blanket on). If you crank the heat up, the extra heat passes through all the blankets, heating them all up. But if you throw another blanket on, you trap more heat in the lower layers, and the top blanket doesn’t warm up much.

    That’s basically how the atmosphere works. If the increase in global temperatures were due to more energy coming INTO the earth (i.e. the sun was getting hotter), you would expect to see warming of ALL layers of the atmosphere. But if warming were caused by greenhouse gases trapping more heat, you’d expect to see warming of only the lower layers of the atmosphere where the heat was being trapped. When you look at the data, what we actually see is that while the lower atmosphere (the troposphere) is warming, the upper atmosphere (the stratosphere) is actually COOLING. That’s the smoking gun, proof that global warming is definitively caused by extra greenhouse gases, which we know to be from human activity.

  59. adrian says:

    When introducing my Rhet/Comp 101 students (at a community college) to researching and writing about a concept, I use global warming as an in-class model. We begin with “How Global Warming Works” on the “How Stuff Works” site. It has pretty clear explanations and pictures.

    They then proceed to other sites, but as a beginning for non-science-literate, non-climate-change-informed persons, this site works well in my experience. I link them directly through Blackboard. (I also provide a link to “Climate Progress,” which those whose interest is sparked will often read.)


  60. We need a “poster child”!
    Please consider a quick survey of your specialists and your readers and ask them to nominate the best location with dramatic impact to illustrate the earliest and worst effects of Global Warming. Surely, (a) Bangladesh, with its millions on land overrun by the ocean waters, (b) Maldivas (Sp?) the first nation about to drown in the Indian Ocean and (c) the Aral Sea in Central Asia (my choice) will be in The Top Ten List. Russia is rushing construction of a canal to the Aral Sea lake to bring water to this inland lake but the consequences are already evident. The race is with the rapidly evaporating glaciers in Tijikistan, north of Mt. Everest.The survival of a lot of residents, farming itself and farmers is in the balance.
    The Aral Sea, an inland lake, once the fourth largest lake in the world lost over two thirds of its water, already.
    Lake Mead is not a good example, although it lost 80 feet of water, some people look forward when the first billboard appears with “Will the last Las Vegas resident please turn off the light? Thanks!” Will local politicians be re-elected when the water loss begins to hurt? It’s best to keep politics out of the issue.

  61. Yoram Bauman says:

    If you’re looking for more of an economics angle on the tragedy of the commons, I’m immodest enough to suggest two of my “stand-up economics” videos: Mankiw’s Ten Principles, and the follow-up on global warming.

    PS. If you’re looking for a big-picture introduction to climate science, here’s a draft of the PowerPoint we use in the Introduction to Environmental Studies class I co-teach at the University of Washington. (Comments welcome! And here’s a smaller PDF version.)

  62. _Flin_ says:

    An OpEd in the Boston Globe by Kerry Emanuel from MIT sums things up nicely and understandable, although not only about CO2 but more about what is agreed on and what isnt:


  63. Richard Brenne says:

    Michael F. Sarabia (#62) writes that we need a “poster child” and nominates Bangladesh first, and I think this is a great choice and I know just the image to use.

    The world’s ultimate photographer of the myriad impacts of climate change is Gary Braasch, who I just heard speak on Saturday. Al Gore projects Gary’s stunning images up to 70 feet across on screens, they hang in the American Association for the Advancement of Science in Washington, D.C. (Joe, how about taking your family?) and they appear in his great 2007 book, “Earth on Fire: How Global Warming is Changing the World.”

    From a small boat Gary took a picture of 90 people in Bangladesh crowded onto a rapidly-eroding outcrop of mud just a few feet above water as the road to the village had eroded away. He points out that all 90 combined probably have a smaller carbon footprint than just the average American.

    While the Maldives and Tuvalu are also important and heart-breaking, they have about 1/400th the population of Bangladesh. India is building a Lou Dobbs-sized wall (maybe not the size of Dobbs himself, but the size of the wall he’d like to see built along our southern border) to keep out political, economic and soon climate refugees from Bangladesh, which suffered the deaths of an estimate half a million during a tropical cyclone in 1970 and an estimated 35 million people were left homeless when heavy Himalayan run-off, deforestation and monsoonal rains combined to flood two-thirds of Bangladesh in 1998, the year after I lived in rapidly-deforesting Nepal upstream.

    Braasch is a wonderful speaker, has great command of the totality of climate science (despite my ability to pick more nits on climate change talks than anyone I know) and like McKibben and so many other experts is a big Climate Progress fan.

    This one photograph is so powerful it should become iconic, because it speaks to the rapid melting of Himalayan glaciers and lessening snowpack affecting stream and river flow, including the Ganges into Bangladesh, and of course to sea level rise, which will probably impact more people more adversely in Bangladesh than any other single place of the same size on Earth.

  64. Mal Adapted says:

    Dennis @29:

    1. When raising the matter of CO2 increases because of human activity, be sure to include something about how the differences in carbon isotopes is the “smoking gun” for fossil fuel CO2 emissions.

    I think this is important, also. It’s especially helpful to counter the “volcanoes emit CO2″ denier talking-point.

  65. Chris Winter says:

    I have Gary Braasch’s book in front of me and I second Richard Brenne’s recommendation. It is an excellent work, with many powerful photographs. (This is the updated edition, published 2009.)

    What impresses me most are the time-interval photos, like the ones of Athabasca Glacier 1917-2005 that lead off the book.

    It would be really something if we could get some time-lapse videos of such scenes. Of course, that would take phenomenal patience.

  66. Chris Winter says:

    Another good choice comes from Reader’s Digest. It’s called Global Warning: The Last Chance for Change. (Publ. 2007; ISBN 978-0=7621-0876-3)

  67. TheMoron says:

    Here is a suggestion for a “Step 8, if you don’t believe you are capable of assessing how valid the scientific case is given all the controversy”.

    The Joint Science Academies G8+5 statement presented to each head of state at the 2008 G8 meeting in Japan sums up what scientists believe and what they think should be done, in my mind at a more authoritative level subject to less potential or real political influence than the IPCC. Its only two pages long.

    Its for people who want to know what the most prestigious and accomplished scientists in the world believe about the present state of knowledge of climate change.


    I use this to show how unified the top flight scientists of the world are about the evidence and theories put forward by climatologists.

    I point out the signatures. These are the heads of the most prestigious and hard to be accepted into science groups in China, India, Russia, the US, the UK, Japan, Germany, France, Italy, Canada, Mexico, Brazil, and South Africa. Anyone skeptical of what is said in this statement must ask themselves, how do they think the top scientists in China were persuaded to sign this, if climate change science is so shaky? How were the top scientists of the US, the UK, Germany and Japan taken in if the theory is so unsound? How could a worldwide conspiracy of the scientists in one mere scientific discipline, i.e. climatology, spread to the most reputable scientific organizations all over the world?

    I sometimes mention, for instance, what the National Academy of Sciences in the US is. The other organizations are aiming to be this august. From the NAS website:

    “The Academy membership is composed of approximately 2,100 members and 380 foreign associates, of whom nearly 200 have won Nobel Prizes. Members and foreign associates of the Academy are elected in recognition of their distinguished and continuing achievements in original research; election to the Academy is considered one of the highest honors that can be accorded a scientist or engineer”.

  68. lemar says:

    This link “IR spectra taken from space” does not work

  69. Mike says:

    I am soliciting this forum for help. I am a scientist with a strong background in Chemistry and Physics but have been on the sidelines of the climate debate. Frankly I have seen a lot of hype on several sides of this climate issue but I am not a climate change skeptic. There is clearly a ton of material published on the subject of climate change from highly credible scientists. I am looking for a handful of best references that clearly demonstrate the anthropogenic link to climate change. I’m interested in papers with the evidence, NOT conjecture, NOT something watered down for journalists/politicians or for those with a rudimentary knowledge of science.

    What would you recommend? Thanks in advance.

  70. prokaryote says:

    Mike, check the links which has been posted again.
    Here is something for the “skeptics”, a collection from RealClimate – a blog from climate scientists and now with a wiki page.