Archives par mot-clé : CO2

Molecular fossils from phytoplankton reveal secular Pco2 trend over the Phanerozoic

by C.R. Witkowski et al., November28,  2018 in SciAdvances


Here, we reconstructed Phanerozoic PCO2 from a single proxy: the stable carbon isotopic fractionation associated with photosynthesis (Ɛp) that increases as PCO2 increases. This concept has been widely applied to alkenones, but here, we expand this concept both spatially and temporally by applying it to all marine phytoplankton via a diagenetic product of chlorophyll, phytane. We obtained data from 306 marine sediments and oils, which showed that Ɛp ranges from 11 to 24‰, agreeing with the observed range of maximum fractionation of Rubisco (i.e., 25 to 28‰). The observed secular PCO2 trend derived from phytane-based Ɛp mirrors the available compilations of PCO2over the past 420 Ma, except for two periods in which our higher estimates agree with the warm climate during those time periods. Our record currently provides the longest secular trend in PCO2 based on a single marine proxy, covering the past 500 Ma of Earth history

Fig. 2Ɛp calculated from phytane in Witkowski et al., 2018

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Man-Made Global Warming? Where’s The Evidence

by H. Schreuder, November 28, 2018 in ClimateChangeDipsatch


After decades of alarm calls over the impact of human emissions of carbon dioxide (CO2) on global temperatures and climate change, a glaring lack of factually demonstrated and scientifically proven evidence remains.

The evidence presented has been based on computer modeling of temperatures from global weather stations, a larger percentage of which are sited in towns and cities and no data, numerous studies show.

For the 70% of oceans, seas, and lakes, satellite measurements are routinely adjusted to take account of anomalies and sea level rise alarm, expressed in measurements of millimeters per century, does not quantify in that tidal gauges are subjected to landmass upheavals and/or subsidence, none of which can be taken to represent empirical evidence. See Also: New study shows coastlines gaining land despite sea level alarmism

Taxe carbone : le jeu en vaut-il la chandelle ?

by Rémy Prud’homme, 26 novembre 2018 in MyhtesManciesMath


La raison d’être de la taxe carbone qui pèse sur les carburants est qu’en augmentant le prix des carburants en France, cette taxe va diminuer la consommation de carburant, et les rejets de CO2 qui vont avec. Le raisonnement est solide. Mais la question est : de combien ? C’est l’enjeu. L’augmentation de cette taxe met le pays à feu et à sang. C’est la chandelle. Le jeu en vaut-il bien la chandelle ?

Pour y répondre il faut connaître la sensibilité de la consommation au prix, ce qu’on appelle l’élasticité-prix. C’est le rapport de l’effet, la variation de consommation (mesurée en %) sur la cause, la hausse de prix (également mesurée en %). Si une hausse des prix de 10% entraîne une diminution de consommation de 8%, l’élasticité est de -0,8.

Human ancestors not to blame for ancient mammal extinctions in Africa

by University of Utah, November23, 2018 in ScienceDaily


New research disputes a long-held view that our earliest tool-bearing ancestors contributed to the demise of large mammals in Africa over the last several million years. Instead, the researchers argue that long-term environmental change drove the extinctions, mainly in the form of grassland expansion likely caused by falling atmospheric carbon dioxide (CO2) levels.

The study is published today in the journal Science.

“Despite decades of literature asserting that early hominins impacted ancient African faunas, there have been few attempts to actually test this scenario or to explore alternatives,” Faith says. “We think our study is a major step towards understanding the depth of anthropogenic impacts on large mammal communities, and provides a convincing counter-argument to these long-held views about our early ancestors.”

To test for ancient hominin impacts, the researchers compiled a seven-million-year record of herbivore extinctions in eastern Africa, focusing on the very largest species, the so-called ‘megaherbivores’ (species over 2,000 lbs.) Though only five megaherbivores exist in Africa today, there was a much greater diversity in the past. For example, three-million-year-old ‘Lucy’ (Australopithecus afarensis) shared her woodland landscape with three giraffes, two rhinos, a hippo, and four elephant-like species at Hadar, Ethiopia.

See also here

Carottes de glace, CO2 et micro-organismes

by Paul Berth, 22 novembre 2018, in ScienceClimatEnergie


Les microbulles de gaz emprisonnées dans les carottes de glace sont fréquemment utilisées pour estimer le taux de CO2 de l’atmosphère du passé. Il s’agit de méthodes de mesure indirectes. Par exemple la carotte de glace EPICA Dome C en Antarctique nous suggère que le CO2 de l’atmosphère a varié entre 180 et 300 ppmv pendant les derniers 650 000 ans (Brook 2005). Cependant, le taux de CO2 observé dans ces carottes de glace représente-il vraiment l’atmosphère du passé? Nous allons montrer ici qu’un paramètre est souvent négligé par les glaciologues, et que ce paramètre pourrait avoir un effet considérable sur le résultat des analyses : il s’agit de la présence de micro-organismes dans la glace et les microbulles.

Climate Scientists Reject Wind And Solar, Demand Nuclear-Powered Future

by Stop These Things, November 20, 2108 in ClimateChangeDispatch


In the climate alarmists’ worldwide crusade against carbon dioxide gas, only the most delusional still believe that wind and solar power add anything to their arsenal.

As we have said repeatedly, nuclear power is the only stand-alone power generation source which is capable of delivering power on demand, without CO2 emissions being generated in the process.

Perversely, notwithstanding that Australia is in the top three uranium exporters, it’s the only G20 country with a legislated prohibition on nuclear power generation…

Evolutions récentes du CO2 atmosphérique (3/4)

by J.C. Maurin, 12 novembre 2018 in ScienceClimatEnergie


L’IPCC (GIEC en français) fut créé en 1988 par l’UNEP (United Nations Environment Programme) et le WMO (World Meteorological Organization). Dans les principes régissant les travaux du GIEC (1) on lit : Le GIEC a pour mission d’évaluer … les risques liés au changement climatique d’origine humaine.  Le GIEC respecte son propre principe fondateur : il attribue l’intégralité de la hausse du taux de CO2 depuis 1958 à une cause anthropique. Nous examinerons ici le modèle anthropique du GIEC et nous le confronterons aux mesures contemporaines, puis à un modèle mixte. Cet article fait suite aux deux précédents publiés sur le site SCE au cours des mois de septembre (1/4) et octobre 2018 (2/4).

C.   Modèle anthropique GIEC

C.1   Les contraintes des modèles (Fig. 1)

Le paragraphe A (article 1/4) a montré qu’en 1980 le taux de CO2 atmosphérique était de 338 ppm et le  δ13C de -7.6 ‰. En  2010 le taux de CO2  atmosphérique était de 388 ppm et le δ13C de -8.3 ‰. Il existe une modulation annuelle de ce taux, très marquée dans l’hémisphère Nord.

 

Interview exclusive: Henri Masson, Université d’Anvers, déclare les modèles du GIEC « aberration statistique »

by Henri Masson, 10 mars 2012, in Contrepoints


Des modèles, cela fait 40 ans que j’en fais », précise d’emblée Henri Masson. Ingénieur chimiste de formation (Université Libre de Bruxelles), docteur en sciences appliquées, professeur émérite à l’Université d’Anvers, expert globe-trotter (notamment pour la Banque Mondiale et l’ONU), l’homme est, de surcroît, doté d’un sérieux sens de la vulgarisation. Lorsque Contrepoints lui propose d’analyser les modèles prédictifs du GIEC, le Belge est catégorique : « Si mes étudiants me présentaient de tels modèles, je n’hésiterais pas à les recaler ! »

Contrepoints : Quelle confiance peut-on accorder aux modèles du GIEC, qui prévoient, parmi d’autres choses, un réchauffement planétaire dû aux émissions humaines de CO2 ?

Evolutions récentes du CO2 atmosphérique (3/4)

by J.C. Maurin, 12 novembre 2018 in  ScienceClimatEnergie


L’IPCC (GIEC en français) fut créé en 1988 par l’UNEP (United Nations Environment Programme) et le WMO (World Meteorological Organization). Dans les principes régissant les travaux du GIEC (1) on lit : Le GIEC a pour mission d’évaluer … les risques liés au changement climatique d’origine humaine.  Le GIEC respecte son propre principe fondateur : il attribue l’intégralité de la hausse du taux de CO2 depuis 1958 à une cause anthropique. Nous examinerons ici le modèle anthropique du GIEC et nous le confronterons aux mesures contemporaines, puis à un modèle mixte. Cet article fait suite aux deux précédents publiés sur le site SCE au cours des mois de septembre (1/4) et octobre 2018 (2/4).

C.4.  Conclusions

  • Un modèle qui décrit un monde fixe, en équilibre, un modèle où l’homme est central, un modèle qui parvient à reproduire certaines observations mais pas toutes, un modèle unanimement soutenu par les autorités politiques ou morales, enfin un modèle qui pose a priori un principe intangible… est le type même de modèle qui fut développé  par Ptolémée (6) pour le système solaire. Ce modèle fut jadis l’objet d’un consensus  à  > 97%.

  • L’atmosphère actuelle comporte environ 20 ppm de CO2 anthropique correspondant à 20/400 soit 5% du CO2 atmosphérique. En un siècle les hommes ont donc modifié la composition de l’atmosphère de 20 ppm soit 0,002% : sur ce sujet également, il semble que nous ne soyons pas au centre du monde.

  • Les évolutions récentes du CO2 atmosphérique ne peuvent pas avoir une cause uniquement anthropique: les observations du δ13C l’interdisent. Les causes sont anthropiques et naturelles. Le modèle purement anthropique du GIEC est donc à rejeter.

Role of atmospheric carbon dioxide in climate change

by M. Hertzberg & H. Scheruder, 2016 in EnergyEnvironment


Abstract

The authors evaluate the United Nations Intergovernmental Panel on Climate Change (IPCC) consensus that the increase of carbon dioxide in the Earth’s atmosphere is of anthropogenic origin and is causing dangerous global warming, climate change and climate disruption. The totality of the data available on which that theory is based is evaluated. The data include: (a) Vostok ice-core measurements; (b) accumulation of CO2 in the atmosphere; (c) studies of temperature changes that precede CO2 changes; (d) global temperature trends; (e) current ratio of carbon isotopes in the atmosphere; (f) satellite data for the geographic distribution of atmospheric CO2; (g) effect of solar activity on cosmic rays and cloud cover. Nothing in the data supports the supposition that atmospheric CO2 is a driver of weather or climate, or that human emissions control atmos- pheric CO2.

The phase relation between atmospheric carbon dioxide and global temperature

by O. Humlum et al., 2013 in Global&PlanetaryChange


Highlights

► Changes in global atmospheric CO2 are lagging 11–12 months behind changes in global sea surface temperature. ► Changes in global atmospheric CO2 are lagging 9.5–10 months behind changes in global air surface temperature. ► Changes in global atmospheric CO2 are lagging about 9 months behind changes in global lower troposphere temperature. ► Changes in ocean temperatures explain a substantial part of the observed changes in atmospheric CO2 since January 1980. ► Changes in atmospheric CO2 are not tracking changes in human emissions.

Also this graph

Paradigm Shift? The ‘Belief’ That Bioenergy Is Climate-Friendly Is Now Recognized As A ‘Major Error’

by K. Richard, November 1, 2018 in NoTricksZone/PNAS


Governments vociferously promote bioenergy as renewable, sustainable, and carbon-neutral. But scientists are increasingly characterizing this “belief” as a “major error”, as bioenergy generates more CO2 emissions per kWh than burning coal does, and the projected rapid growth in bioenergy will serve to ‘increase atmospheric CO2 for at least a century’ as well as clear forests and destroy natural ecosystems.

500 Million Years of Unrelatedness between Atmospheric CO2 and Temperature

by Davis W.J., 2017 in CO2Science


Davis, W.J. 2017. The relationship between atmospheric carbon dioxide concentration and global temperature for the last 425 million years. Climate 5: 76; doi: 10.3390/cli5040076.

Writing by way of introduction to his work, Davis (2017) notes that “a central question for contemporary climate policy is how much of the observed global warming is attributable to the accumulation of atmospheric CO2 and other trace greenhouse gases emitted by human activities.” If you talk to a climate alarmist, the answer you receive from such an inquiry will likely be “almost all.” A climate skeptic, on the other hand, will likely respond that the answer is “likely none.”

Hoping to provide some crucial information on this topic, Davis analyzed the relationship between historic temperature and atmospheric CO2 using the most comprehensive assemblage of empirical databases of these two variables available for the Phanerozoic period (522 to 0 million years before present; Mybp). In all, 6680 proxy temperature and 831 proxy CO2 measurements were utilized, enabling what Davis described as “the most accurate quantitative empirical evaluation to date of the relationship between atmospheric CO2concentration and temperature.” Multiple statistical procedures and analyses were applied to the proxy records and the resultant relationship is depicted in the figure below.

Egalement voir ici

Why CO2 Is Not A Climate Control Knob

by A. Bright-Paul, October 22, 2018 in ClimateChageDispatch


As the Earth rotates on its own axis, one-half of the Earth is cooling while the other half is warming up.

So the Earth is warming and cooling daily and the temperature is changing 3,600 times every hour in every location all over the world, as there are 3,600 seconds in every hour.

As the Earth is traveling around the Sun in an ellipse at 66,000 miles per hour and is tilted and wobbling as it spins, so the Earth has seasons, as the angle to the Sun varies.

So the temperatures in the spring and summer are usually warmer than in the autumn and winter when temperatures decline.

So there is a massive number of different temperatures over the whole Earth, constantly changing and always in flux.

IPCC achieves net zero credibility

by Barry Brill, October 14, 2018 in WUWT


The recently released IPCC SR15 reports (at A1) that global warming is likely to reach 1.5°C between 2032 and 2050 and (at B) will probably bring species extinction, weather extremes and risks to food supply, health and economic growth. If we are to avoid this, net CO2 emissions will need to decline by about 45% from 2010 levels by 2030, reaching net zero by 2050 (C1), followed by extensive removals (C5). The required energy investment alone will be $2.4 trillion per year.

Is this possible?

As at 2015, which was not materially different from 2010, more than half the planet’s total CO2 emissions (36Gt) were sourced from just three countries:

….