by A. Préat, 4 septembre 2020 in ScienceClimatEnergie
SCE a plusieurs fois rapporté que la période actuelle de réchauffement n’est pas exceptionnelle, qu’elle fait partie de cycles décennaux à pluriséculaires de refroidissement et réchauffement qui ont lieu dans des fourchettes de température fort modestes, de l’ordre de 0,15°C par 10 ans. SCE a aussi montré que le CO2 tant incriminé dans ces changements, et surtout l’actuel, n’avait pas de raison d’être, ce gaz venant après l’augmentation de température. Le ‘bouton CO2 ‘ à même d’expliquer ou de ‘justifier’ le battage médiatique quasi-quotidien est donc à ‘la remorque’ de la température et, l’hypothèse de l’effet de serre reste avant tout une hypothèse (exemple ici).
Enfin SCE a souvent rappelé (ici et ici) que la concentration atmosphérique de CO2 n’a jamais été aussi basse dans l’histoire géologique de notre planète, qui a connu la plupart du temps des concentrations jusqu’à 25 fois supérieures au cours du Phanérozoïque (à partir du Cambrien, il y a 541 millions d’années), et même encore bien plus élevées au cours du Précambrien. Nous partirons de ce dernier point, puisque les médias et scientifiques sont toujours à nous rappeler, de manière assez dramatique, que la teneur actuelle est plus élevée que celle des ‘derniers’ millions d’années (articles médiatiques presque quotidiens, exemple ici parmi une pléthore d’articles). Est-ce bien le cas? et si oui –et toujours pour ces ‘derniers’ millions d’années– quid de la température ?
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by Dr. S. Lüning & Prof. F. Vahrenholtz, in NoTricksZone
How do today’s temperatures fit into the climate-historical context?
This is one of the main tasks of today’s climate research. A group of researchers led by Milos Rydval have presented a reconstruction of summer temperatures in Scotland over the past 800 years. The results were produced from tree ring examinations.
Surprisingly, the scientists found that the current level of heat in Scotland had been reached and even exceeded several times in the past. These heat spells occurred in the 14th, 16th, and 18th centuries and each spanned over several decades (Figure 1). In between there were cold phases that fit well into the context of the Little Ice Age.
What follows is the abstract of the study published in November 2017 in the journalClimate Dynamics:
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by P. Homewood, August 19, 2018 in NotaLotofPeopleKnowThat
Booker commented the other day how one scientist claimed last week that we now have “the highest temperatures on Earth since the last ice age”. The BBC failed to even challenge this statement.
This certainly is not the first time I have heard claims (presented as fact) to this effect.
We have already seen concerted attempts to disappear the MWP, so it is time to reclaim the Holocene Optimum (so named for good reason), which is generally accepted to have run from about 9000 to 5000 years ago
Obviously we had no thermometers around in those days, so nobody knows what the average temperature of the Earth was then. There again, nobody really knows now either.
But there is plentiful evidence that many places were significantly warmer than now. I present some of this evidence below, though this is probably only skimming the surface: …
See also here
by Tim Ball, July 31, 2016 in WUWT
Hypsithermal, Altithermal, Holocene Optimum, Holocene Thermal Maximum, Holocene Megathermal, Anthropogene;
There is frustration and reward when an article appears on the same topic of an article you are completing – in this case the Holocene. Such was the case this week with Andy May’s article “A Review of temperature reconstructions.” Andy points out the basic problems of reconstruction using proxy data for the most recent half of the Holocene – an issue central to historical climate and climate change studies. His paper did not alter my paper except as it reinforces some arguments.
This article examines the entire Holocene and illustrates the history that influenced the studies. There are two distinct parts to the studies, the pre and post Intergovernmental Panel on Climate Change (IPCC). The former is a genuine scientific struggle with issues of terminology and reconstruction, and the latter a scientific struggle to impose a political perspective regardless of the evidence. Because of the damage done to climatology by the proponents of anthropogenic global warming (AGW), both parts require explanation.
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La géologie, une science plus que passionnante … et diverse
