# How do we know that C02 is a greenhouse gas? **URL:** \ **Category:** Great Debates\ **Created:** [February 27, 2010, 3:01am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602 "2010-02-27T03:01:44Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![figure9](https://avatars.discourse-cdn.com/v4/letter/f/f0a364/32.png) [@figure9](https://boards.straightdope.com/u/figure9)\ **Post date:** [February 27, 2010, 3:01am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/1 "2010-02-27T03:01:44Z")
Everyone knows that carbon dioxide absorbs infra red radiation and warms our planet. But how do we know? Has anyone ever done an experiment that shows CO2 absorbing infra red? ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [February 27, 2010, 3:13am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/2 "2010-02-27T03:13:29Z")
> [@figure9](#): > > Everyone knows that carbon dioxide absorbs infra red radiation and warms our planet. But how do we know? Has anyone ever done an experiment that shows CO2 absorbing infra red? Yes. You do realize that several billion dollars have been spent through the years in the study of planetary atmospheres, along with just basic studies of physics and chemistry? :dubious: We didn’t just skip over the one test that could be done in a laboratory environment. > **[Carbon dioxide (data page)](https://en.wikipedia.org/wiki/Carbon_dioxide_%28data_page%29)** > > This page provides supplementary chemical data on carbon dioxide. > The handling of this chemical may incur notable safety precautions. It is highly recommended that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source such as SIRI, and follow its directions. MSDS for solid carbon dioxide is available from Pacific Dry Ice, inc. > 2.534 J/(mol·K) at 15.52 K (−257.63 °C) > 47.11 J/(mol·K) at 146.48 K (−126.67 °C) > 54.55 J/(mol·K) at 189.78 K (−83.37 °C) > 33.89 J/(mol ... **Infrared** Major absorption bands: 2350 and 667 cm−1 (4.25 and 14.99 um) ---
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [February 27, 2010, 3:14am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/3 "2010-02-27T03:14:42Z")
> [@figure9](#): > > Everyone knows that carbon dioxide absorbs infra red radiation and warms our planet. But how do we know? Has anyone ever done an experiment that shows CO2 absorbing infra red? Er. Yes. ETA: You can also try to find serious studies that show that CO2 does not influence the temperature/climate. Good luck - really, nobody is denying it, and it’s an extremely simple experiment. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [February 27, 2010, 3:16am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/4 "2010-02-27T03:16:49Z")
> [@](#): > > Received 7 January 1953 > > Line width in the 15-micron band of atmospheric carbon dioxide has been determined by direct observation of line contour. The influence of finite width of slit has been eliminated by numerical correction. 0.12 cm-1 is an upper limit for the CO2 absorption coefficient half-width at half-height. [http://prola.aps.org/abstract/PR/v90/i6/p1024\_1](http://prola.aps.org/abstract/PR/v90/i6/p1024_1) ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [February 27, 2010, 3:26am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/5 "2010-02-27T03:26:33Z")
And anybody that has ever taken an IR of an organic compounds sees those nuisance peaks for themselves. That’s a pathlength of less than a meter, so imagine how much is being absorbed over several miles from the surface to space. Since symmetry rules tend to prohibit other absorptions in that region, getting the actual measurement of what is being absorbed by CO2 is pretty easy. ---
**Author:** ![Animastryfe](https://avatars.discourse-cdn.com/v4/letter/a/8797f3/32.png) [@Animastryfe](https://boards.straightdope.com/u/Animastryfe)\ **Post date:** [February 27, 2010, 3:34am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/6 "2010-02-27T03:34:15Z")
We even tested it in an undergraduate chemistry lab. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [February 27, 2010, 3:47am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/7 "2010-02-27T03:47:27Z")
> [@figure9](#): > > Has anyone ever done an experiment that shows CO2 absorbing infra red? You’re just a little bit behind the curve on this one. The fact that CO2 absorbs infrared was determined by [John Tyndall in experiments conducted in 1859.](http://www.aip.org/history/climate/co2.htm) The fact that atmospheric gases might trap heat and cause a “greenhouse effect” was theorized by Joseph Fourier in the 1820s. This is not breaking news.😉 ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 27, 2010, 3:59am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/8 "2010-02-27T03:59:38Z")
Don’t listen to them! They’re all liars, under the pay of Big Nitrogen! There’s never been a study of CO2. There never will be. You know why? It doesn’t exist! The glaciers are just hiding waiting to pounce! You’ll see. You’ll all be sorry when you’re sitting under a mile of ice in your skivvies! ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [February 27, 2010, 4:10am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/9 "2010-02-27T04:10:03Z")
On one of the science channels there was a woman who demonstrated the heat-retaining properties of CO[sub]2[/sub]. She had two bell jars; one filled with air, and the other with CO[sub]2[/sub]. Each had a thermometer. She set them in the sun, and the thermometer in the jar of CO[sub]2[/sub] displayed a higher temperature than the one in the jar filled with air. ---
**Author:** ![figure9](https://avatars.discourse-cdn.com/v4/letter/f/f0a364/32.png) [@figure9](https://boards.straightdope.com/u/figure9)\ **Post date:** [February 27, 2010, 4:18am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/10 "2010-02-27T04:18:39Z")
I try to keep my opening posts short, but sometimes I leave out some important details. I guess I was looking for an experiment that visually demonstrated CO2’s heat trapping ability, (a demonstration that the average person could understand). I was thinking that if there was a demonstration that showed people that C02 traps heat they could get a better understanding of the problem. I really don’t understand how C02 absorbs heat but I guess its like a microwave oven. Only instead of microwaves making water molecules flip around IR is making C02 dance around. I should have worded my OP as, “Is there any demonstration that shows C02’s ability to cause global warming, that an average person could understand?” ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [February 27, 2010, 4:20am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/11 "2010-02-27T04:20:18Z")
The fact that questions like this even get asked should tell the IPCC exactly where it needs to direct it’s message. If people can’t even see this simple fact, it’s no wonder that so many people are willing to think climate change isn’t happening. ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [February 27, 2010, 4:31am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/12 "2010-02-27T04:31:52Z")
> [@figure9](#): > > Everyone knows that carbon dioxide absorbs infra red radiation and warms our planet. But how do we know? Has anyone ever done an experiment that shows CO2 absorbing infra red? Actually, CO2 (and man-made CO2 in particular) isn’t even the most putatively potent greenhouse gas, and certainly not the only–or even main–ingredient in the earth’s temperature homeostasis. One of the areas of controversy is how linear the effect of CO2 is over the predicted doubling of CO2 concentration through 2100 or so. Climate sensitivity to CO2 forcing is predicted with mathematical modeling. These models (thousands of lines of code attempting to take into account all known variables), by nature, make certain assumptions including best-guess parameters plugged into the models. Right now the general range of expected average temperature gain is somewhere from 1 to 6 degrees C, depending on the model and the parameters. However if it turns out that the relationship between elevated temperatures and CO2 rise is not very linear, all of those models will have overstated the actual change we see. An example of an unknown feedback loop variable is water vapor/clouds. What will the effect of that feedback loop be? Will elevated temperatures increase the amount of clouds and water vapor? Will that effect further raise the temperature, or lower it? See [here](http://online.wsj.com/article/SB10001424052748703939404574567423917025400.html) for an opinion that the climate science around CO2 and its feedback loops is not settled. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [February 27, 2010, 4:46am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/13 "2010-02-27T04:46:45Z")
> [@figure9](#): > > I try to keep my opening posts short, but sometimes I leave out some important details. I guess I was looking for an experiment that visually demonstrated CO2’s heat trapping ability, (a demonstration that the average person could understand). The Mythbusters did an experiment in their Young Scientists episode. [![](https://i.ytimg.com/vi/pPRd5GT0v0I/hqdefault.jpg "Mythbusters tests global warming theory - does CO2 warm air?") ](https://www.youtube.com/watch?v=pPRd5GT0v0I) ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [February 27, 2010, 5:08am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/14 "2010-02-27T05:08:27Z")
> [@Chief\_Pedant](#): > > Actually, CO2 (and man-made CO2 in particular) isn’t even the most putatively potent greenhouse gas, and certainly not the only–or even main–ingredient in the earth’s temperature homeostasis. > > One of the areas of controversy is how linear the effect of CO2 is over the predicted doubling of CO2 concentration through 2100 or so. Climate sensitivity to CO2 forcing is predicted with mathematical modeling. These models (thousands of lines of code attempting to take into account all known variables), by nature, make certain assumptions including best-guess parameters plugged into the models. Right now the general range of expected average temperature gain is somewhere from 1 to 6 degrees C, depending on the model and the parameters. > > However if it turns out that the relationship between elevated temperatures and CO2 rise is not very linear, all of those models will have overstated the actual change we see. An example of an unknown feedback loop variable is water vapor/clouds. What will the effect of that feedback loop be? Will elevated temperatures increase the amount of clouds and water vapor? Will that effect further raise the temperature, or lower it? > > See [here](http://online.wsj.com/article/SB10001424052748703939404574567423917025400.html) for an opinion that the climate science around CO2 and its feedback loops is not settled. As the last debate showed, \*\*opinions \*\*from the Wall Street Journal should not be taken seriously. > **[RealClimate: Lindzen and Choi Unraveled](https://www.realclimate.org/index.php/archives/2010/01/lindzen-and-choi-unraveled/)** > > RealClimate: Lindzen and Choi, Trenberth Fasullo, O'Dell and Wang, tropical ocean temperatures, TOA radiative fluxes, climate sensitivity > [@](#): > > A recent paper by Lindzen and Choi in GRL (2009) (LC09) purported to demonstrate that climate had a strong negative feedback and that climate models are quite wrong in their relationships between changes in surface temperature and corresponding changes in outgoing radiation escaping to space. This publication has been subject to a considerable amount of hype, for instance apparently “[LC09] has absolutely, convincingly, and irrefutably proven the theory of Anthropogenic Global Warming to be completely false.” and “we now know that the effect of CO2 on temperature is small, we know why it is small, and we know that it is having very little effect on the climate”. Not surprisingly, LC09 has also been highly publicized in various contrarian circles. > > Our initial reading of their article had us independently asking, how we could have missed such explicit evidence of the cloud feedback as shown in LC09? Why would such a significant finding have gone undiscovered when these feedbacks are widely studied and recognised as central to the projections of climate change? We discovered these common concerns at a meeting last year and then teamed up to address these questions. > > With the hype surrounding the manuscript, one would think that the article provides a sound, rock solid basis for a reduced climate sensitivity. However, our examination of the study’s methods demonstrates that this is not the case. In an article in press (Trenberth et al. 2010 (sub. requ.), hereafter TFOW), we show that LC09 is gravely flawed and its results are wrong on multiple fronts. > **[Water Vapor Feedback Loop Will Cause Accelerated Global Warming, Professor Warns](http://www.sciencedaily.com/releases/2009/02/090219152132.htm)** > > Here's yet another reason to hate humidity: it expands global warming, says a professor of Atmospheric Sciences writing in the journal Science. He says that warming due to increases in greenhouse gases will lead to higher humidity in the atmosphere.... > [@](#): > > The perspective by Dessler and co-author Steven Sherwood of the Climate Change Research Centre at the University of New South Wales is published in the journal Science. In the article, they review and summarize the peer-reviewed evidence in support of a strong water vapor feedback and conclude that the evidence supporting it is overwhelming. > > “For years, there was a debate over this mechanism, with some even questioning if the water vapor feedback existed at all. But recent work on this feedback has moved its existence and strength beyond argument,” Dessler adds. > > Predictions of significant global warming over the next 100 years by climate models require a strong water vapor feedback. Recent estimates suggest the earth will warm from 2 to 4 degrees Celsius (4 to 8 degrees Fahrenheit) over the next century – a scenario that could have devastating long-term consequences. > > “Everything shows that the climate models are probably getting the water vapor feedback right, which means that unless we reduce emissions, it is going to get much, much warmer on our planet by the end of the century,” he adds. > > Many scientists believe such warming rates are already happening. > > They can point to the summer of 2003, when a prolonged heat wave gripped Europe. According to the Earth Policy Institute, more than 35,000 people died that summer, with France recording over 14,000 deaths and Germany more than 7,000. > > Additionally, warmer temperatures are having an adverse effect in the Arctic, where rapid loss of ice is now occurring. > > “The only possible way future warming won’t be significant is if there exists some sort of off-setting negative feedback, which has yet to be discovered,” Dessler notes. > > “Most scientists, myself included, judge that to be a pretty unlikely possibility.” > **[CO2 is the main driver of climate change](https://skepticalscience.com/CO2-is-not-the-only-driver-of-climate.htm)** > > \While there are many drivers of climate, CO2 is the most dominant radiative forcing and is increasing faster than any other forcing.\ > [@](#): > > What the science says… > > While there are many drivers of climate, CO2 is the most dominant radiative forcing and is increasing faster than any other forcing. > [@](#): > > So in summary, there are two reasons for the focus on CO2: > > 1. CO2 is the most dominant radiative forcing > 2. CO2 radiative forcing is increasing faster than any other forcing ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [February 27, 2010, 5:13am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/15 "2010-02-27T05:13:33Z")
It doesn’t even matter **GIGObuster** , they just come back with the same old stuff hoping that THIS time nobody will call them on it. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [February 27, 2010, 5:36am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/16 "2010-02-27T05:36:52Z")
> [@WarmNPrickly](#): > > It doesn’t even matter **GIGObuster** , they just come back with the same old stuff hoping that THIS time nobody will call them on it. Of course, but as a teacher I get into the habit of repeating the lessons, remember, those posts are not only for the ones that ignore what most of the research are telling us. Many have to learn even the basics. One thing is a fact: the best evidence and research conclusions have not changed, regardless of all the “gates” and scandals put forward. For a good introduction regarding this subject it is recommended that all check the Climate Denial Crock of the Week short videos: [http://www.youtube.com/user/greenman3610#p/c/029130BFDC78FA33/5/LAtD9aZYXAs](http://www.youtube.com/user/greenman3610#p/c/029130BFDC78FA33/5/LAtD9aZYXAs) > [@](#): > > One of the most contentious of climate crocks is the role of water vapor in climate change. And climate deniers are always trying to fog the issue. But don’t be scared, Crock of the Week is here, to help make sure you don’t get sucked in. That video does show that from 1953 scientists got the essentials of how CO2 warmed the atmosphere and the Water Vapor feedback with CO2. For more videos: > **[greenman3610](https://www.youtube.com/user/greenman3610)** > > Knocking down the nonsense of Climate denial. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [February 27, 2010, 6:04am UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/17 "2010-02-27T06:04:51Z")
Actually, as I understand it the most potent greenhouse gas is that old standby, dihydrogen monoxide. Fortunately, nature has means to precipitate out an excess of DHMO – people in the North have been shoveling it all winter, and the liquid state precipitating out is familiar to most people. Carbon dioxide, on the other hand, has a much longer stabilization cycle, involving photosynthesis, particularly by trees, and carbonate deposits in shallow seas, wherea rapid buildup cannot be quickly corrected for, only over decades or longer. That’s why it’s of so much concern. ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [February 27, 2010, 2:06pm UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/18 "2010-02-27T14:06:53Z")
> [@GIGObuster](#): > > As the last debate showed, \*\*opinions \*\*from the Wall Street Journal should not be taken seriously. Among the psychologies associated with Great Causes is the willingness to accept opinion which resonates with one’s core position and reject as incompetent and silly those which do not. Of your cites, none is a published paper; they are all essays. From your[third cite](http://www.skepticalscience.com/article.php?a=2584) I might also recommend [this essay’s](http://www.theaustralian.com.au/news/opinion/more-evidence-co2-not-culprit/story-e6frg6zo-1225814230258) concluding comments for digestion: _"Thus we have two geological examples and two satellite data studies pointing towards a lesser role of CO2 in global warming. This argument does not discount the reality of global warming during the past century or the potential consequences should it continue at the same rate, but it does suggest we need a broader framework in considering our response. The Copenhagen summit exposed intense political differences in proposals to manage global warming. Scientists are also not unanimous in claiming to understand the complex processes driving climate change and, more important, scientific studies do not unambiguously point to a single solution. "_ In any case, and to maintain this as much GQ (Gentlemanly Questions) as possible, there is no real debate that among the properties of atmospheric CO2 is a greenhouse effect. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 27, 2010, 2:58pm UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/19 "2010-02-27T14:58:33Z")
> [@figure9](#): > > I try to keep my opening posts short, but sometimes I leave out some important details. One of my pet peeves is that nobody knows how to ask a proper question, and this particular example is one for the ages. Why do you even think that OPs should be short? You wasted your time and all of ours by leaving out one whole sentence. But that lack turned your question from something meaningful into nonsense. Who did that help? In general, don’t expect us to read your mind. Give us all the details. The better your frame your question, the better we can frame our answers. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [February 27, 2010, 3:51pm UTC](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602/20 "2010-02-27T15:51:20Z")
> [@Chief\_Pedant](#): > > Among the psychologies associated with Great Causes is the willingness to accept opinion which resonates with one’s core position and reject as incompetent and silly those which do not. I’m biased towards science as demonstrated by my acceptance of Nuclear power and nanotechnology, Stop your insults. > [@Chief\_Pedant](#): > > Of your cites, none is a published paper; they are all essays. Made by climate researchers, but do not let that fact get in the way of an opinion piece from the WSJ. As for your comment for digestion: > **[RealClimate: PETM Weirdness](https://www.realclimate.org/index.php/archives/2009/08/petm-weirdness/)** > > RealClimate: Paleocene-Eocene thermal maximum, climate sensitivity, PETM, Earth System Sensitivity, methane hydrates, climate models. > [@](#): > > The problems probably started with the title of the paper “Carbon dioxide forcing alone insufficient to explain Palaeocene–Eocene Thermal Maximum warming” which on it’s own might have been unproblematic. However, it was paired with a press release from Rice University that was titled “Global warming: Our best guess is likely wrong”, containing the statement from Jerry Dickens that “There appears to be something fundamentally wrong with the way temperature and carbon are linked in climate models”. > > Since the know-nothings agree one hundred per cent with these two last statements, it took no time at all for the press release to get passed along by Marc Morano, posted on Drudge, and declared the final nail in the coffin for ‘alarmist’ global warming science on WUWT (Andrew Freedman at WaPo has a good discussion of this). The fact that what was really being said was that climate sensitivity is probably larger than produced in standard climate models seemed to pass almost all of these people by (though a few of their more astute commenters did pick up on it). Regardless, the message went out that ‘climate models are wrong’ with the implicit sub-text that current global warming is nothing to worry about. Almost the exact opposite point that the authors wanted to make (another press release from U. Hawaii was much better in that respect). > > What might have been done differently? > > First off, headlines and titles that simply confirm someone’s prior belief (even if that belief is completely at odds with the substance of the paper) are a really bad idea. Many people do not go beyond the headline – they read it, they agree with it, they move on. Also one should avoid truisms. All ‘models’ are indeed wrong – they are models, not perfect representations of the real world. The real question is whether they are useful – what do they underestimate? overestimate? and are they sufficiently complete? **Thus a much better title for the press release would have been more specific “”Global warming: Our best guess is likely too small” – and much less misinterpretable!** > [@Chief\_Pedant](#): > > In any case, and to maintain this as much GQ (Gentlemanly Questions) as possible, there is no real debate that among the properties of atmospheric CO2 is a greenhouse effect. I guess the evidence by researchers that were basically ignored 50 years ago overwhelmed the “big cause” that the scientists had back then: that we should not worry about CO2 levels in the atmosphere. History has demonstrated that the change of position among scientists on this subject did not come by faith. [Next page](https://boards.straightdope.com/t/how-do-we-know-that-c02-is-a-greenhouse-gas/530602.md?page=2)