Les sciences du climat forment une discipline dans laquelle qui que ce soit, indépendamment de son expertise ou de sa compréhension, se sent qualifiée pour présenter ses observations sur de nouveaux articles et polémiques en cours. Ceci peut se révéler frustrant pour les scientifiques, comme nous-mêmes, qui lisont des ‘commentaires’ sur le web dictés par des préjugés politiques qui ne tiennent compte de la rigueur des observations scientifiques.
(suite…)Beaucoup de scientifiques participent aux efforts de vulgarisation, et réfutent et/ou analysent soigneusement certaines découvertes fantaisistes ou fausses en écrivant dans des magazines populaires tels que EOS, New Scientist ou dans les sections débats des journaux. Cependant, ceci prend du temps à publier, et souvent, bien avant leur publication, l’attention des médias est souvent sur un autre sujet. Puisque ces réfutations apparaissent dans la littérature scientifique, passée en revue par des pairs avant publication, ces efforts sont à long terme utiles. Cependant, une réponse plus rapide est parfois utile pour s’assurer que le contexte des actualités est largement diffusé.
Les journalistes à cause de dates-limites, et de leur connaissance limitée dans ce champ de recherche ne savent souvent pas où aller pour avoir le contexte de travaux soutenus par certains “think-tanks” partisans ou autres. Ceci peut mener certains médias majeurs à publier par manque de temps et de compréhension du contexte, des idées douteuses et fallacieuses.
RealClimate est un site de discussion sur les sciences du climat pour le public et les journalistes, site animé par des scientifiques actifs dans ce domaine. Notre objectif est de fournir une réaction rapide aux actualités, et de fournir le contexte scientifique souvent absent dans les médias.
La discussion est ici limitée aux sujets scientifiques, afin de rester sur des problemes sur lesquels nous sommes compétents. Ainsi nous ne impliquerons pas dans les questions politiques ou économiques ayant trait au changement climatique. La validité de l’information scientifique est complètement indépendante de ce que la société décide de faire (ou ne pas faire) au sujet de cette information. Les questions et commentaires constructifs sont les bienvenus, ainsi que les articles de la part de scientifiques qui peuvent choisir de contribuer occasionnellement.
Question: Regarding the current trends of arctic melting, what is the chance that we will see an effect in the North Atlantic current anytime soon? What are the predictors that a result of a change to the NAC will bring (0%
i.e, no real effect or “The Day After Tommorrow” effect?) Any thoughts?
Response: We are working on a piece precisely on this subject. Soon. – gavin
Finally!
Someone’s needed to do this for years.
Well, for a while I thought something like the Talk.Origins site would be enormously useful, but these days blogs (like The Panda’s Thumb) are great, too.
So, thanx very much for doing this.
Great to see a site dedicated to this topic.
I have added your site to the permanent listings on my weblog. I am very glad to see you making this effort, and wish you every success.
My question is what about the entrapped methane in the permafrost that is being released into the atmosphere. Will it make the climate changes occur at a more rapid pace? Will it make the drilling that is planned for the Artic National Wildlife Refuge more difficult or impossible? How about the increased melting of the glaciers in Antartica? The loss of significant portions of the ice shelf that retarded the seaward movement seems to be absent in certain areas and that might presage a more rapid deterioration of the glaciers there. What is the outlook for world sea level rise given the combined effects of these phenomena?
Great idea
Thanks for this much-needed blog. We’ve long needed a site where information like this is readily available and digestible for the lay person.
Great idea. I hope you are able to enact some reform on how science is reported in the popular media. I will be interested to see if you are able to help reduce the unintended bias you refer to in this paragraph:
I hope you are successful. People I talk with outside the climate community really feel ambivalent. I commonly receive the question “Is climate change really happening?” I am sure you do too.
You state you won’t be discussing economic issues but your first post out of the box makes reference to economic issues. Frankly, I don’t see how you can separate the two, but perhaps I don’t understand what you mean by economic issues.
Response: The subtle distinction is that we won’t discuss the economic implications of the science. Obviously most of man-made impacts on climate are related to economics (industrial development for the most part) . Sorry if that wasn’t clear. – gavin
Great idea and a great start. I look forward to future posts and will be recommending this site widely.
It was wonderful to learn of this site. I have already informed my local newspaper of its existence. I suggest that if everyone who visits this page would also take the time to notify their local news outlets, we just might start getting some more accurate reporting (ok, my idealist side is being exposed!!).
Again, thank you, thank you, thank you.
Wonderful idea and I hope your group will not be daunted by the sheer work that may develop.
Response:< /b> Thanks for your support. We will try hard to keep up, though we may not be able to respond to all posts. -mike
Right now it would be very helpful to non experts (like me) to have a super simple explantion of what exactly Von Storch has done in his article in Science on noisy data and whatever was wrong with the Mann group methods.
Response:< /b> von Storch et al purport to test statistical methods used to reconstruct past climate patterns from “noisy” proxy data by constructing false proxy records ( “pseudoproxy” records) based on adding noise to model gridbox temperature series taken from a climate simulation forced with estimated past radiative forcing changes. Several other researchers have published similar studies in the past. One thing that makes the von Storch analysis different is that they use a simulation that exhibits larger forcing, and more variability than most simulations, the very same “GKSS” simulation (Gonzalez-Rouco et al, 2003) discussed here. In their commentary on the paper, Briffa and Osborn note that the results may not generalize to the actual world, where the forced variability may be much smaller than in the GKSS simulation. While von Storch et al focus on the Mann et al (1998) reconstruction method, they argue that their results generalize to other proxy reconstructions methods as well. -mike
I keep re-reading Von Storch’s articles on what climate models are, and so on, but also keep on coming out with the idea that Mann did just what Von Storch says shold be done. So then I scratch my head wondering, well, if you kick the model hard enough (50%) why should you be surprised if it then produces increasing amplitudes, like a pinball machine will default into “tilt” if you hit it hard enough, and 50% sounds pretty hard.
Response:< /b> The von Storch paper has appeared too recently for responses to have made their way through the appropriate peer-review process. While we are already aware of some recent work arriving at very different conclusions from von Storch et al, it is premature at this time to comment on that work. We hope to be able to comment more fully on the matter when this other work has appeared in the peer-reviewed literature. Respecting the peer-review process, however, we prefer not to post any further comments on this matter until it has played out more fully in the peer-reviewed literature -mike]
It is my opinion that media outlets and policy makers often cite controversy rather than consensus with regard to anthropogenically induced climate change. In recent years, the IPCC, AGU, NAS, and AAAS have all issued statements arguing for the existence of evidence for such change. In a recent Science essay, Naomi Oreskes provides a survey of scientific abstracts (from isi) relevant to climate change and reveals that the overwhelming majority of scientific literature does not refute this position. I think that this disparateness between scientist’s conclusions and people’s interpretations of them is a worthy topic for this website, and that Oreskes’s essay is valuable evidence for such discussion.
Thanks for the site!
I have a couple of questions off the top of my head which don’t fit in anywhere nicely.
1) The IPCC models don’t seem to include possible future contributions from methane hydrates. Does this omission have a sound scientific basis (with respect to short term models)? If an anthropogenic thermal anomaly this century will eventually (and inexorably) propogate to and destabalize significant amounts of methane hydrates in future centuries — shouldn’t this be a consideration for policy makers?
Response: It’s not the IPCC models that don’t include this, rather it is the scenarios that are used to estimate future atmospheric composition. Methane hydrates are just one of the current unknowns that are missing, there are many others. Modellers are working on including at least some of the more important projected changes (such as emissions from wetlands, or the effect of climate on the oxidisation of methane), but we still have some way to go before these are all pinned down. – gavin
2) How well accepted and understood are astronomical forcing models and mechanisms. In particular, are the frequencies of these cycles sensitive to the discovery of new planetoids beyond Pluto? Is the paleoclimate record long enough and precise enough to convince scientists that astronomic forcing is real? Are the mechanisms by which astronomic forcing acts understood and has it been modeled? Eccentricity seems like the weakest one to me. It’s period is relatively long relative to the climate record and theoretically it shouldn’t really have that big of an impact on insolation. Are there alternative explanations for the 100,000 year cycle? In particular — something that explains why it is the dominant period in the last million years and is absent from many or most climate records that cover the previous million years?
[Response: Orbital forcing is among the best known and understood features of climate forcing. We have accurate calculations for these changes going back or forward millions of years. After that, the degree of chaos in the solar system precludes accurate estimates. However, we still have some way to go before we fully understand how the climate reacts to this forcing, and in particular why 100,000 yrs has dominated for the last 8 cycles, but before that it was more like 40,000 years. Other ideas have been suggested, but current thinking is still that it is related to the orbital parameters in some way. – gavin]
Great site. One question, do you have any insight into the phrase “global warming” vs. “climate change”. It seems to me like “climate change” has only started being used relatively recently. I wonder if this is an atempt by the disinformation types to make global warming sound less sinister, a la “estate tax” vs. “death tax”.
Thank you so much for putting this blog together.
Thank you for bringing these topics to the masses!
To all involved in this project: THANK YOU so much. I have been wishing for just such a venue as this where serious dialog can take place between climate research scientists and a genuinely interested public. I can assure you that this is a much-needed and greatly-appreciated service you are offering. This URL has been added to my “short list” of reference sites.
Miguel — you are correct in your guess about “climate change” vs. “global warming.”
From http://www.ewg.org/briefings/luntzmemo/ :
[Republican communications guru Frank] Luntz advises that, “Climate change” is less frightening than “global warming.”… While global warming has catastrophic connotations attached to it, climate change suggests a more controllable and less emotional challenge” (p. 142).
This leads nicely into my questions for the site authors: While I understand your interest in avoiding “political or economic implications”, will you be willing to call politicians on the carpet when they take stances that contradict well-understood science?
Response: Yes.
In response to post 17, I think using the phrase climate change may be a more accurate way of describing what we are observing. For one, the warming may not necessarily be global such that some regions may not face appreciable change in seasonal temperatures while others may be significantly warmer. Another reason to favor “climate change” is that it does not have the shelf-life that “global warming” does. By this, I imply that some sort of negative feedback may prevent the planet from persistent warming, thus making “global warming” innacurate. As we cannot be certain of continued warming, yet we are certain that our climate is changing, “climate change” versus “global warming” is a more accurately description. I don’t think that the use of either phrase strengthens or weakens either side of the greater debate, rather we are trying to say exactly what we mean.
This site is great news. Just do not let it become a battleground between lobbyists and scientists. Expert commentary of popular (and arising) misconceptions is most important – responding to every comment is not and may even turn counterproductive.
I would like to offer a suggestion for a discussion topic. Specifically an overview of climate models and simulation techniques.
Regards
Emil
In response to post 23:
I agree and disagree with alex. On the one hand, climate change is a more accurate term. But it is also a sort of ‘cop-out’, in the sense that climate is always changing, always has, and always will. Global Warming gets at the fact that the current ‘global warming’ is human induced. At least that’s how it’s perceived in the public lexicon. Yes there may be negative feedbacks and the thermohaline circulation may shut down causing Europe to slide into a deep-freeze but it is still caused by ‘global warming’ caused mostly by humans. However, I find myself using the term climate change and if people ask me, ‘is the climate changing?’. I reply ‘yes and it’s getting warmer and it’s because of people.’ Global warming has become a political term, so I feel hesitant to use it in a scientific context, but it is still an accurate term that does well to getting the public to think about the consequences of our society.
Congrats to a great site, important function and content.
Keep it up…
Hurray!
This site has been needed for a long time. Thanks to all you climate scientists for taking the time to respond quickly to the naysayer misinformation.
Your site is already a gem!
I wouldn’t be surprised if you guys already had in mind what I want to suggest, but just in case, let me suggest that you write and collect a bunch of “explainers” that you provide as links from the home page, plus in particular an explainer about modeling. Not climate modeling. Just modeling. I think ordinary folks easily mush together models with parameters with parameter values or “settings” with exact predictions of runs under specific settings and with general predictions that pertain to runs over a range of settings (which settings, may or may not encompass the universe of plausibility or “reasonability” and can be its own source of controversy), etc. I also think most people don’t really appreciate the various motivations for building models, running models, the process of testing and validating models and hence in the end why some models and some predictions are more worthy or credible than others. I suppose in the abstract this would be dull as doornails if not unhelpful, and so probably it’s best to explain it with examples and in the context of climate modeling, but I wanted to describe it in the abstract, just because I think what keeps a lot of people from appreciating climate science (or even why it’s hard to appreciate) has to do with very basic ideas about not just “the scientific process” but with the narrower or perhaps more easily describable process of modeling.
Thank you!
You are filling a void which has concerned me for quite some time.
Would you please explain radiative forcing and how existing atmospheric CO2 infrared opacity _will not_ substantially limit global warming caused by the additional emissions of CO2?
Gerald Marsh offered this opinion in “A Global Warming Primer”
(page 4 -excerpt)
“Radiative forcing is defined as the change in net downward radiative flux at the tropopause resulting from any process that acts as an external agent to the climate system; it is generally measured in W/m2. Examples are variations in the amount of solar radiation reaching the Earth and changes in the concentrations of infrared-absorbing gases in the atmosphere. Increasing the amount of carbon dioxide in the atmosphere by, for example, a factor of two does not double the amount of infrared radiation
absorbed by this gas. The reason for this is as follows: Carbon dioxide has three absorption bands at wavelengths of 4.26, 7.52, and 14.99 micrometers (microns).13 The Earth’s emission spectrum, treated as a black body (no atmospheric
absorption), peaks at between 15 and 20 microns, and falls off rapidly with decreasing wavelength. As a result, the carbon dioxide absorption bands at 4.26 and 7.52 microns contribute little to the absorption of thermal radiation compared to the
band at 14.99 microns. Natural concentrations of carbon dioxide are great enough that the atmosphere is opaque even
over short distances in the center of the 14.99 micron band. As a result, at this wavelength, the radiation reaching the tropopause from above and below the tropopause is such that the net flux is close to zero.
If this were the whole story, adding more carbon dioxide to the atmosphere would contribute nothing to the greenhouse effect and consequently could not cause a rise in the Earth’s temperature. However, additional carbon dioxide does have an influence at the edges of the 14.99 micron band. Because of this marginal effect, the change in forcing due to a change in carbon dioxide concentration is proportional to the natural logarithm of the fractional change in concentration of this gas. Specifically, the IPCC gives
dF = 6.3 ln (C/C0) W/m2
where dF is the change in forcing, and C0 and C are the initial and final carbon dioxide concentrations. This approximation breaks down for very low concentrations and for concentrations greater than 1,000 ppmv, but is valid in the range of practical interest. The Earth’s temperature is therefore relatively insensitive to changes in carbon dioxide concentrations, a doubling leading to a dF of only 4.4 W/m2.”
A clear explanation of radiative forcing, CO2 infrared opacity and how additional atmospheric CO2 will contribute to significant warming would be important to many of trying to explain the physics of global warming.
Please see Ground Truth Investigations to see a list of references and that I’ve added your site to my list of climate change resources.
I am thrilled about this website: kudos, and keep it up.
I have just sent the URL to many people in my own network, including folks who helped to run the Howard Dean campaign. Not to add a partisan edge; rather to suggest that — as Dean’s campiagn showed in the realm of politics — you all may be able show in the realm of science the power of building networks and sharing infromation on the web.
GOOD LUCK, and thanks.
Very interesting. I hope that you can keep those of us who are well informed amateurs abreast of the facts. I would be interested in hearing your opinions on the effects of the natural climate change cycles vs. manmade factors. I have recently attended a lecture by Dr. David Dallmeyer of the U.of Ga. concerning data availble from ice cores concerning the natural patterns of heating and cooling.
Very interesting site
I am intrigued by the satellite timperature data. Do you plan on explaining why the sat temps and surface temps are not consistent
Response: You can find a discussion of these issues in our “glossary” entry on the “MSU Temperature Record” and the associated links including this discussion in “Wikipedia”. -mike
Currently RealClimate appears to be correcting errors by rewriting. The blogosphere frowns upon this, preferring corrections be done by updates in such a way that the original material remains visible. See for example Rebecca Blood’s Weblog Ethics . Is there a good reason RealClimate is not following standard blogging conventions?
[Response: Fair point. We’re thinking about it – William]
You write: “… the discussion here is restricted to scientific topics. Thus we will not get involved in political or economic issues that arise when discussing climate change.” Please, could you give on your website some addresses on “political or economic issues that arise when discussing climate change.”
A skeptic of global warming recently pointed me toward an article by Richard S. Lindzen, the Alfred P. Sloan Professor of Meteorology at the Massachusetts Institute of Technology. The guy clearly has a bit of an attitude problem, and I am not particularly enamored with the Cato Institute to begin with, but as layperson I am unqualified to refute him. He certainly does not agree with the majority of climate experts. Would any of you wizzes do me (and my bulletin board buddies) the fine service of assessing Lindzen’s haughty assertions? The article is here: http://www.cato.org/pubs/regulation/reg15n2g.html
Many thanks for this interesting board, and any comments you care to provide on the article.
This is a fantastic development, everyone. Best wishes and I look forward to a lively, active series of discussions.
Lindzen has failed to appreciate the electrical and biological aspects of CO2 on cloud behaviors.
Congratulations on the great idea for this blog, and what a pity I only learned about you through Science magazine and not on, say, CNN. I’ll try to help publicize you by posting a link on my links page http://www.aip.org/history/climate/links.htm
(it gets 200 or so visitors a month, every bit helps).
If you need help in answering any historical question, please feel free to call on me or to add a link to the most appropriate essay(s) at my “Discovery of Global Warming” site http://www.aip.org/history/climate .