22 oct. 2007

L'arnaque du Global warming ? (2/3)

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Avant de lire ce post je recommande à ceux qui ne l'on pas encore fait de prendre 10-15 minutes pour regarder le début du fim documentaire "la grande aranque du global warming", disponible ici.
Donc voilà, ce qu'il faut savoir concernant ce fameux documentaire c'est qu'il a été en partie discréditer par des journalistes au cours d'un débat sur la télé australienne donnant suite à la diffusion du dit film. Certains graphiques présentés dans le films étant incomplets, certains datant de 1970 etc...

En confrontant les deux films (celui d'Al Gore et celui-ci) j'en suis arrivé à deux constats:
1) Un documentaire tend facilement à "manipuler" le spectateur
2) Il existe bien un débat sur la validité de la théorie du Global Warming.

La dissertation que j'ai rendue se penche sur ce second point et je vous la retranscrit ici même pour ceux que ça intéresse. Je sais c'est très long et en anglais. Les titres des différentes parties figurent en gras, n'hésitez pas à feuilletez tout ça et à ne vous arrêter que sur les parties qui vous intéressent. Les chiffres entre paranthèses renvoie au références bibliographiques, c'est essentiel.

Je publirais un dernier post sur le sujet avec ma conclucsion sur ce que je pense de tout cela avec du recul. En lisant la disserte, gardez à l'esprit le fait que mon objectif premier était de décrocher une bonne note, pas d'exposer mes profondes convictions. Bonne lecture.

Climate change essay

"The Great Climate Change Swindle' and 'An Inconvenient Truth' present
opposing views on the effect of anthropogenic carbon emissions on global
warming. Comment on the validity of the arguments expressed in both
documentaries and present your own opinion in this debate.”

Intoduction

Nowadays, global warming is in every mind. Almost everybody has heard about it in the media and it seems that now, global warming is the only thing to blame when any single natural catastrophes or climate disorder occurs. According to CNN, “global warming will lead to rising sea waters, droughts and agriculture disasters in the future if unchecked” (1)
The Al Gore movie, “An Inconvenient Truth” (AIT), shares the same level of alarmism on climate change and defends the IPCC views on global warming. In the other hand, the movie “Great Global Warming Swindle” (GGWS) defends a very different thesis, claiming that CO2 has nothing to do with global warming and uses every common climate change skeptics arguments to prove is point. It is clear that both movies are going too far on their own directions. However, a quick research on the Internet reveals that, contrarily to what Al Gore claims in his movie, there is no consensus at all among scientists regarding climate change science.
In this essay, after debating about the relevance of both pre-cited movies, arguments against the CO2 causing global warming thesis will be examined in order to prove that CO2 has little to do with climate change. IPCC reports relevance and seriousness will be discussed and so would be the question of how hazardous and alarmist is global warming. Then element in favor with the IPCC thesis will be brought into the discussion before making the final conclusion which will be answering the following question: is CO2 the main cause of global warming and is global warming as threatening as the IPCC and Al Gore’s movie are claiming.


Relevance of AIT and GGWS movies.

The two following movies “the great global warming swindle” (GGWS) and “An Inconvenient true” (AIT) shares dramatically opposed views on global warming. This second movie was shown during a TV broadcast and the projection was followed by an argument that mainly discredits the movie. It appears that several parts of graphs and figures were missing and old graphics were sometimes used to prove a point that new available graphics would have discredit. Basically, what the filmmaker did consist of using only a part of a data set that agrees with is point to prove is theories. This process is commonly use by journalist and filmmaker to prove their point. Michael Moore’s movies, as brilliant as they could be, use the same kind of process: only focus on information that proves the filmmaker point of view. Using this kind of process is human and does not necessarily discredit the whole movie. But this is not science.

In the same way, AIT also contains a lot of false information. More than simplifying the link between CO2 emission and temperature increasing, it is on the effect of global warming that the movie goes to far. Among the numerous errors, several are now going to be examined.
The pictures of mount Kilimanjaro suggest that global warming is the cause of the melting snow. But studies have shown that glacier of mount Kilimanjaro started to disappear in 1880 (2), a long time before greenhouse gas emissions started. These studies also show that the average temperatures of the air never went above the melting point (2). Thus, the glacier is not melting but only shrinking. According to Kraser et al (3), what causes the decrease of ice cop is a modification of local climate that started in the early 20th centuries. Precipitation decrease involves not enough snow to replace the glacier ice. This has nothing to do with global warming.
Other pictures of European glacier are shown in the movie to prove global warming effects, not taking in account the fact that those glaciers started to disappear during the middle of this century, before anthropogenic C02 emission started to rise (4). An other fraud consist of showing images of the supposed current melting of the Perito Moreno Glacier (Pantagonia) which is only the normal process of a glacier moving from the mountain to the sea (5). Glacier had always been moving, this is basic knowledge.
More closely to our times, Al Gore uses recent natural catastrophes to enforce the global warming threat. According to him, hurricane Katrina is due to global warming, no matters that a climatologist working for IPCC has claimed that there was no evidence of any links and that the damage caused to New Orleans where due to dams default of conception (6). List of such false facts is long.


Effect of CO2 on global warming

Now that the point that both movies can’t be taken as scientific serious work and both contains false or partial wrong statement has been established, let’s move on the very topic of this discussion: the effect of carbon dioxide on global warming. The GGWS gives several arguments against the thesis that carbon dioxide drives climate changes. Those arguments are now going to be discussed.

First argument: CO2 concentration has been driven by increase in temperature in the past.

The major hypothesis in global warming thesis is that increasing carbon dioxide concentration in the atmosphere will increase the global temperatures. But if we look at the past ice records, it appears that temperature always increased in the first place, and that CO2 increasing follows by 200-800 years (7,8,9). One of the explanations of this increase of CO2 is that when temperatures increase, oceans get warmer and release more CO2 into the atmosphere (10). Even members of IPCC did acknowledge that. Those observations imply that no evidences that CO2 concentration drive climate change can be found in the past. Nevertheless, that does not necessarily means that CO2 has no effect of climate change. CO2 can still be a factor of aggravation in temperature increase, as it is suggested during the debate following the projection of the GGWS movie.

Second argument: During 1950-1970, no warming was observed, despite CO2 increase.

Another common argument used by skeptics is that during the economic growth period that followed the world war two, temperatures does not increased, even if CO2 concentration did. There is nothing about this anomaly in the last IPCC report and, as a mater of fact, there is no graphs showing CO2 concentration during this precise period (only graph related to the 1970-2005 and last 650 thousand years ago periods). On the other hand, the fact that temperatures didn’t increase during this period is clearly established in the IPCC report (11). The following figure from IPCC report 2001 (12) clearly shows this point.


The point is that if CO2 emissions drive climate change, why temperatures didn’t increase when CO2 concentration started increasing? As the IPCC reports are quite quiet about that, having doubts on this matter seems perfectly justified.

Third argument: Atmospheric temperatures from satellite and balloon data set.

The third important argument against the IPCC thesis is that temperatures of the atmosphere did not increase in the same way that the surface temperatures and they are indeed, below the surface temperature. According to the green gas effect theory, these temperatures should be more important in the atmosphere than in the surface, or at least about the same.
Indeed, atmospheric temperatures records from satellite are available since 1979. C.R. de Freitas explains that those data are more reliable and accurate than surface sample data (13). He also evocate the fact that those data are subject to discussion, as effect such as satellite orbital aren’t very well known. Thus, temperature measures from balloon match with satellite data. The results of all those measures (from satellites and balloons) show that atmospheric temperatures did not scientifically increase in the past twenty years and, moreover, that atmospheric temperatures are bellow surfaces temperature (on average). This has been confirms by the studies of the IPCC member J. Christy (14,15,16).
Those anomalies are present in the 2001 IPCC report and the following pictures are from this report.

But the summary for policymakers of the 2001 IPCC report doesn’t talk about those anomalies, only the full report mentioned them.

However, in the last IPCC report (2007), new figures are displayed. According to the report, new studies on satellite data has managed to find results that now match quite successfully the surface data. This is shown as a great victory in the last IPCC report, even if some methods are quite disputable. The report acknowledges that huge progress has been made since the 2001 report on interpreting and using satellite data. Different studies are cited and reasons for past mistakes are given. So it seems that new results are more reliable than old ones, even if studies cited are sometimes anterior to the 2001 report. The following figure is from the 2007 IPCC report and shows the new results:

However, it can be noticed that increase in temperature are far less alarming than the famous “hockey stick” figure. Moreover, the whole subject of satellite data interpretation is pretty controversial, even inside the IPCC work team (De Freitas, 13).


Fourth argument: models are not working

Another litigious point is that models that are used by the IPCC group work, the same models that predicts catastrophic future, still can’t predict event that occurred in the past. Lindzen claims in is allocution in front of the US senate in 2001 that “temperature increases observed thus far are less than what models have suggested should have occurred even if they were totally due to increasing greenhouse emissions. The invocation of very uncertain (and unmeasured) aerosol effects is frequently used to disguise this. Such an invocation makes it impossible to check models”. He also evocates the fact that models aren’t able to simulate properly distinct phenomenon such as past ice age and recent heat wave (El Nino) (17). Those problems are also mentioned by Professor P. Michaels (IPCC contributor) (18). The whole point is that if models based on CO2 thesis are correct, then they should be able to explain past climate change. And as they are not, they are probably not accurate, and so are their catastrophic predictions.


Fifth argument: CO2 concentration in the atmosphere is too low to have an effect.

This is a classical argument. It is known that the major green house gas in term of efficiency is not CO2 but water vapor (IPPC reports). Moreover the CO2 only represent 0,5% of the total atmosphere constituent and the CO2 has only increase by 30% over the past 30 years (6). And as C02 is normally a part of the natural green house warming process, thinking that a small modification on only one (and not the biggest) parameter that affect climate could lead to such a modification seems to be not really reasonable. The argument against this idea is that the process of warming through natural green house gas consists of a fragile equilibrium and that modifying this equilibrium (even a little bit) can lead to dramatic consequences. But during the past, CO2 concentration had experienced important change, sometimes without drastic consequences. The theory of this fragile equilibrium is therefore quite difficult to understand has the climate is, by definition, always changing.



The IPCC and Global Warming hazards

So far, critical points regarding effect of CO2 upon global warming have been discussed, and maybe except from satellite data, it has been shown that the CO2 guiltiness in causing global warming has failed to be proven. If CO2 was the only cause, past CO2/temperature records would have shown it. Difficulties of modeling the climate change and anomalies such as the ones encountered during the 1950-70 period also argued against the classic thesis.
Moreover, in addition to the fact that CO2 effects may have been overestimated, global warming effects have also been overestimated in the media, the Al Gore movies and the IPCC reports. Before going into details regarding that matter, it is useful at this point of the discussion to talk more about what is exactly the IPCC.

The IPCC (Inter Panel on Climate Change), thus, is an organization that has been set up by the UN in 1988 with the mission of studying the cause and effects of climate change. The IPCC is constituted by scientist from all the UN countries and divided into three working groups with the following different mission: a) assess available scientific information on climate change, b) assess the environmental and socio-economic impacts of climate change, and c) formulate response strategies (19). The IPCC write reports on their works (the two last ones were released in 2001 & 2007). The main report is more than 600 pages long and two summaries are written, the technical summary and the “for policymaker summary”. It is this last summary which is used by the media and the politician.
The way IPPC is ran involves several problem. The first one is that the summary report is written not only for policymakers but by policymakers (UN government representatives). Actually, the summary disagrees on several points with the main reports, and important facts that don’t agree with the main thesis are left behind in the summary for policymakers (19). Another criticized aspect of IPCC is that scientific contributors are chosen because of their country of origin more than for their competences. It is thus clear that IPCC is more political than scientific. Several contributors are even defending that CO2 may not be the main cause of global warming (P. Reiter, R. Lindzen, P. Michaels, J. Christy…). In conclusion, IPCC does not appear to be the most truthfully source of information, and the influence that it has on media and policymakers is not really based on scientific matter as the summaries do not reflect all the aspects of the main report.

Furthermore, helped by IPCC reports, global warming issues have now taken an important place in the media. In fact, we are now been told that human kind has never been as threaten as it is now. But is global warming such an alarming issue?
First, it can be noticed than projections and models from the last two IPCC reports are becoming less alarming. In the 2001 report, the increase in temperature by 2100 was predicted to be from +1,4°C to +5,8°C. In the 2007 report, the increase is predicted to be from 0,5°C to 3,5°C, even if the global situation regarding the CO2 release is reckoned to be worst than it was in 2001. Second, temperatures are not rising as fast as the “hockey stick” was predicting (see figures from satellite data).
Moreover, consequences of this warming are not as bad as it should be. The following picture is from the 2007 IPCC summary for policymakers and can also been found in the main report. It clearly shows that ocean level started to rise before any green house gas emission started, and that this evolution has been mostly constant since 1950. No global warming effects can really been observed yet.

Evolution of sea level from 1850 to 2005 (IPCC 2007 report)
The fact that sea level are not dangerously increasing is also claims by other scientist such as Singer (20,21) and Church and al. (23)

The last thing concerns the global warming effect on natural disaster. Even according to the 2007 IPCC reports, “Single extreme events cannot be simply and directly attributed to anthropogenic climate change” (IPCC 2007 report p310) and IPCC 2001 Report (IPCC, 2001b, p. 5) states that “no systematic changes in the frequency of tornadoes, thunder days, or hail are evident...” (IPCC, 2001b, p. 5). Moreover, studies based on simulation has shown that an increase of CO2 will product a decrease of frequency of tornados (24) and other studies such as Michaels and al. has shown that warming will not increase the frequency of hurricanes (25,26). That confirms that AIT was a too far alarmist movie.
To go even further, some scientists are claiming that global warming would also have good consequences. Some studies actually have shown that a greater level of CO2 in the atmosphere increases plant growth and is profitable for agriculture (27). The main idea is that measure that should be taken to fight global warming would cost more and would have more negative effect on human kind that global warming consequences (good and bad ones) would have. Even if this point of view is extreme, it counter balance the idea that global warming will lead to the end of the human kind.

Finally, a last publication that adds new argument against the IPCC view has been recently published (28). In his paper, Dr G Stanhill tries to drawn intention to an important factor that should influence the climate and ask the very question: why this important factor has not been taken into account by the IPCC, in none of his reports. The factor is the modification that occur in the sun radiation on earth surface. This is influenced by cloud density and regarding this factor, two periods have been identify. The Dimming where solar radiation was lower that they usually are occurred between 1950-70 and the Brightening that is happening since 1980. Important literatures is available on this subject (29) and the fact that this aspect is not mentioned in the IPCC reports is quite surprising. Dr Stanhill doesn’t draw conclusion on the way these factors affect global warming but mentioned the facts that these factors influence global warming and insist on the fact that they are not mentioned in the IPCC reports.

Additional views

To conclude this discussion, it is important to moderate what have been written before with other perspectives. To summarise, we have seen that CO2 was not as likely as the IPCC was telling us the cause of global warming. IPCC seriousness has been discussed and it appeared that this organisation was at least as much scientific as political. And hazardous effects of global warming have been minimized compare to what the IPCC and mostly the media claim.
Nevertheless, some other consideration should be taken on this very serious matter.
The first point would be that, even if there is more serious so-called sceptic among the scientist community, they are still a minority. That doesn’t mean that they are wrong, but that on certain points (such as the polemic around the satellite data), serious studies proving both theses do exist.
Secondly, even if argument such as the fact that in the past, temperature did increase before CO2 (seen first argument), this does not prove that CO2 has no effect on global warming. That only proves that C02 didn’t have a major impact on climate change in the past. Furthermore, some of the sceptic are not only trying to prove that CO2 has nothing to do with climate change but also argue that global warming does not really exist (6). This point of view is too extreme and even if the IPCC is political, important interests are also involved in the other side. No global warming would be better for economy, at least in short term.
Moreover, even if IPCC is not the most truthfully organisation, the 2007 main report refers to important new studies that agree with the fact that global warming is real. Considering that the last IPCC report only contains lies and false scientific facts would be ridiculous and hazardous.

CONCLUSION

After considering all the arguments and after taking in consideration the recent studies evocated in the last IPCC report, it is difficult to adopt a clear point of view. Nevertheless, here is what can be suggested.
First, the CO2 causes and influences on global warming are not clear. But CO2 is unlikely to be the only cause of global warming. This hypothesis has failed to gives evidences. Secondly, climate change science is a very complex matter which requires a lot of care and should not suffer from an only single point of view. Understanding the different cause and consequence of climate change is a top issue, but this should not involve political debates and should be let to science.
Third point, it is clear that global warming is less threatening that the media would say. But in the other and, global warming is still real and should not be underestimating. Almost all scientists agree that global warming is real, they just don’t agree on the alarmism that should be applied to the situation (Lindzen). However, the way we consider global warming represent, at is own level, is hazardous. By overestimating this threat, wrong decision will be taken and instead of going nowhere, we might just go in the very wrong direction. Only focusing on CO2 might have dramatic effect on the environment. As far as we know, CO2 is not a pollutant, only a green house gas. For example, nowadays, more and more sugar cane is grown through the world in order to produce bio fuels. This as a dramatic effect on the struggle against starvation in developing countries, lead to deforestation in South America and destroy ecological nests in Western Europe (30).
But in the other hand, assuming than CO2 as nothing to do with global warming and going back to the old habits would have dramatic effect on ecology in general. Sustainable development should be encouraged and putting ecological consideration under the light is a suitable thing.
Science and politics shouldn’t interfere as long as it is not necessary. We should remain very careful on the climate matter but still don’t fall for stupid things because some alarmist people are telling us than in few decades, most of the land will be under the seas.


References:

(1): http://www.climat-sceptique.org

(2): Molg, T., Hardy, D.R. and Kaser, G. (2003), Solar-radiation-maintained glacier recession on Kilimanjaro drawn from combined ice-radiation geometry modeling. Journal of Geophysical Research n°108

(3): Kaser et al, (2004), Modern Glacier Retreat on Kilimanjaro as Evidence of Climate Change: Observations and Facts. International Journal of Climatology. N°24: 329-339

(4): http://en.wikipedia.org/wiki/Retreat_of_glaciers_since_1850.

(5): Wikipedia, Perito Morena Glacier, http://en.wikipedia.org/wiki/Perito_Moreno_Glacier.

(6): Lewis, M., A Skeptic’s Guide to An Inconvenient Truth, September, CEI (2006).

(7): Fischer, H., Wahlen, M., Smith, J., Mastroianni, D. and Deck B, (1999), Ice core records of atmospheric CO2 around the last three glacial terminations, Science 283: 1712-1714.

(8): Pearson, P., and Palmer, M., (1999), Middle Eocene seawater pH and atmospheric
carbon dioxide concentrations, Science, v. 284, p. 1824.

(9): Rothman, D.H., (2002), Atmospheric carbon dioxide levels for the last 500 million
years, Proceedings of the National Academy of Sciences USA, v. 99, p. 4167-4171.


(10): Segalstad, T.V., (1998), Carbon cycle modelling and the residence time of natural and anthropogenic atmospheric CO2: on the construction of “greenhouse effect global warming” dogma. In: Bate, R. (ed.). Global Warming the Continuing Debate. Cambridge, UK. European Science and Environmental Forum, p. 184-218.

(11): Third IPCC report (2001), p34

(12): Third IPCC report (2001), p3

(13): De Freitas C.R., (2002) Are observed changes in the concentration of carbon dioxide in the atmosphere really dangerous? Bulletin of Canadian petroleum geology vol 50, n°. 2, JUNE, p. 297-327.


(14): Christy J., Goodridge J.D., (1995) Precision global temperatures from satellites
and urban warming effects from non-satellite data. Atmospheric Environment, 29, 1957-1961.

(15): Christy J., Parker D.E., Brown, S.J., Macadam, I., Stendel M, and Norris W.B., (2001)
Differential trends in tropical sea surface and atmospheric temperatures since 1979, Geophysical Research Letters, v. 28, no. 1, p.183-186

(16): Christy J., Spencer R.W. and Braswell W.D., (2000), MSU tropospheric temperatures:
dataset construction and radiosonde comparisons, Journal of Atmospheric and Oceanic
Technology, v. 17, p. 1153-1170.

(17) : Testimony of Richard S. Lindzen before the Senate Commerce Committee on 1 May 2001, USA. http://www-eaps.mit.edu/faculty/lindzen/Testimony/Senate2001.pdf

(18): Patrick Michaels, (2006) “Hot Tip: Post Misses the Point!” World Climate Report, January 31, , http://www.worldclimatereport.com/index.php/2006/01/31/hot-tip-post-misses-the-point

(19) : De Freitas C.R., (2002) Are observed changes in the concentration of carbon dioxide in the atmosphere really dangerous? Bulletin of Canadian petroleum geology vol 50, n°. 2, JUNE, p. 297-327.

(20) : Singer, S.F., Climate change and consensus, Science, v. 271, p. 581 (1996).

(21) : Singer, S.F., (1999) Hot Talk, Cold Science: Global Warming’s Unfinished Debate (2nd edition). The Independent Institute, Oakland, CA., p110, (1999)

(22) : De Freitas C.R., (2002) Are observed changes in the concentration of carbon dioxide in the atmosphere really dangerous? Bulletin of Canadian petroleum geology vol 50, n°. 2, June, p. 300.

(23) : Church, J. A., (2006) Estimates of the regional distribution of sea-level rise over the 1950-2000 period, Journal of Climate n°17 p. 2609-2625

(24) : Nguyen K.C., and Walsh, K.J.E., (2001) Interannual, Decadal, and Transient Greenhouse Simulation of Tropical Cyclone-like Vortices in a Regional Climate Model of the South Pacific. Journal of Climate, v. 14, p. 3043-3054


(25) : Michaels, P.J. and Knappenburger, P.C. (1996) Human effect on global climate, Nature, v. 384, p. 522-523.

(26) : Michaels P. J., Balling, R.C., Vose, R.S. and Knappenburger, P.C. (1998) Analysis of
trends in the variability of daily and monthly historical temperature measurements, Climate Research, v. 10, p. 27-33.

(27) : Friends of science website (http://www.friendsofscience.org) and more specifically: http://www.friendsofscience.org/assets/FOS/FOS4.mov

(28): Stanhill G., (2007) A Perspective on Global Warming, Dimming, and Brightening, Eos, Vol. 88, No. 5, 30 January

(29) : http://www.greenhouse.crc.org.au/crc/research/c2_bibliog.htm

(30) : Nicolino F., La faim, la bagnole, le blé et nous, une dénonciation des bio-carburants, Fayard (Ed), October 3 (2007)





7 commentaires:

Nadia B a dit…

Snif ! C'est en anglais !

Aurais-tu ça en français please ?

(Si non, tant pis pour moi...)
En tout cas bravo pour ton blog !

Nours a dit…

et beh fillot, le moins que l'on puisse dire c'est que t'y a mis du tiens! c'était dans le cadre de quelle matière?
je me demande comment ça se passerait si on nous demandais ça à l'A7... le peu ou on nous demande de réfléchir sans être technique, c'est en anglais "éthique" et c'est pas du lourd... "Mickael l'ignoble capitaliste a fait des économies sur la sécurité. Pédro le petit mexicain surexploité meurt à la suite d'un accident. qui a tort?" (véridique: le tout avec comme support vidéo un genre de sitcom encore plus mal joué que les machins du club dorothée).

Bon, sinon, n'ayant pas un nain ternet performant chez moi, je n'ai pas pu regarder les 2 films. ayant trainé sur le net, j'immagine que dans le meilleur des cas je serais retombé sur une conclusion du genre, "Ok le CO2, on sait pas trop si ça pose un grave problème, mais il y a surement d'autres emission gazeusez humaines aux conséquences peu réjouissantes. Et il parait logique de réduire au maximum notre influence sur le monde qui nous entoure".
sur ce dernier point, c'est plutot mal barré aux vues de la croissance humaine... mais on a le droit de rêver, non?

Sinon, donc trainant sur le net en cherchant 2/3 trucs sur le sujet, je suis tombé sur une recherche aux conclusions interessantes... peut être que tu en a déjà entendu parler, il s'agit du club de rome et du rapport Meadows:
http://www.manicore.com/documentation/club_rome.html

tu lira ça si ça t'interesse, mais globalement, l'étude semble s'attacher, sans vouloir faire la morale, à étudier les limites de la politique de croissance à tout prix qui attire tant les hommes: si notre monde est fini et si on ne fait que grossir, n'y a t'il pas un moment où on va atteindre ses limites? qu'est ce qu'il se passera à ce moment là?
Je n'ai pas lu ce fameux rapport, juste quelques pages de commentair sur internet qui en parlent. Mais l'idée de base est plutot logique, quand on y pense...

Chris a dit…

Ah parain ça fai plaisir de te croiser ici! je prendrais surement le temps de lire le rapport dont tu parles plus tard (la il est 1h30 du mat et je suis encore en train de bosser sur le rapport "qu'il serait bien de rendre demain", un truc avec une colonne d'absorption, c'est que du bonheur !

Chris a dit…

Nadia, désolé mais comme mes cours sont en anglais, so is my disserte ! Et comme je l'expliquais à mon chère nounours, je nai pas beaucoup de temps libre en ce moment, et guère l'envie de tenter une traduction de mon anglais approximatif.

Nadia B a dit…

Ok, pas de problème.
Je n'ai plus qu'à me mettre à la langue de Shakespeare !
Et ça m'apprendra à n'avoir rien écouté en cours d'anglais ! (c'est fou comme les actes peuvent avoir des conscéquences tardives parfois ! Et pas seulement au niveau écologique, tu vois !)
En tout cas merci d'avoir pris la peine de me répondre.

Bonne continuation.

Anonyme a dit…

Waaah ! Je suis clouée de voir tout ce que tu as écrit en anglais ! J'avoue que je n'ai pas eu le courage de tout lire mais ça m'intéresse, j'y reviendrai ! Et finalement, tu as eu combien ?

Xabier a dit…

allez ça faisait longtemps...j'ai juste survolé le texte mais même si je trouve que tout ce foin que les média font autour du global warming est un peu ridicule, ce genre de réflexion est toute aussi perverse. Car si l'étendue de l'implication dans le réchaffement du CO2 n'est pas connue elle n'en est pas moins inexisatnte. Réduire la production de CO2 n'est pas une mauvaise chose, ce qui l'est c'est de transposer le problème sur un autre gaz.Et loin de moi l'idée de reprendre tous les arguments point par point, je te ferais la remarque toute simple sur la concentration de CO2:

c'est certes très mince en comparaison avec la vapeur d'eau mais toi qui a fait de la chimie tu sais très bien que les équilibres chimiques ou thermiques ne suivent pas des lois linéaires. Pour faire plus simple, l'eau boue à 100°C et non pas à 99,9°C. Aussi infime que soit la variation de CO2, elle peut avoir un grand effet sur le climat, il n'y pas de modèle clair le prouvant de la même façon qu'il n'y en a pas le discréditant. Tout ça pour dire que cet argument, c'est un peu du flan.

la limite globale de tes arguments résident à mon avis dans le fait que tu n'as fait qu'essayer de discréditer la théorie sur le CO2 sans penser à intégrer celui ci dans ta pensée. Tu es passé d'un extrême à l'autre.