The Meaning and Utility of Averages as it Applies to Climate

by Clyde Spencer, April 23, 2017

By convention, climate is usually defined as the average of meteorological parameters over a period of 30 years. How can we use the available temperature data, intended for weather monitoring and forecasting, to characterize climate? The approach currently used is to calculate the arithmetic mean for an arbitrary base period, and subtract modern temperatures (either individual temperatures or averages) to determine what is called an anomaly. However, just what does it mean to collect all the temperature data and calculate the mean?

USGS Estimates 304 Trillion Cubic Feet of Natural Gas in the Bossier and Haynesville Formations of the U.S. Gulf Coast

USGS, April 13, 2017

The Bossier and Haynesville Formations of the onshore and State waters portion of the U.S. Gulf Coast contain estimated means of 4.0 billion barrels of oil, 304.4 trillion cubic feet of natural gas, and 1.9 billion barrels of natural gas liquids, according to updated assessments by the U.S. Geological Survey. These estimates, the largest continuous natural gas assessment USGS has yet conducted, include petroleum in both conventional and continuous accumulations, and consist of undiscovered, technically recoverable resources.

How inconstant are climate feedbacks – and does it matter?

by Nic Lewis, April 18, 2017

There is as yet no observational evidence that climate sensitivity increases with time in the real climate system – although this cannot be ruled out – nor is it fully understood why it increases in most AOGCMs. In any event, even if real-world climate sensitivity does increase with time, in the longer run other factors that are not reflected in ECS, such as melting ice sheets, are probably more important. Therefore, while time-varying climate sensitivity is of considerable interest from a theoretical point of view, for practical purposes its influence is likely to be very modest.

L’acidification des océans : causes anthropiques versus variabililité naturelle

Usbek, 13 avril 2017

L’acidification n’est pas une simple réponse statique à l’augmentation de la concentration de CO2 dans l’atmosphère : c’est la résultante de processus biologiques et physico-chimiques qui entraînent une répartition inégale du carbone sur la verticale de l’océan. D’autre part la vie océanique a survécu à des niveaux beaucoup plus élevés de CO2 depuis des millions d’années dans le passé.

Le mix énergétique mondial de 1990 à 2035

by planete energies, 03 février 2016

L’ Agence Internationale de l’Énergie (AIE) a élaboré plusieurs scénarios de l’évolution prévisible du mix énergétique d’ici 2035. Le scénario moyen (« New policies scenario ») met en évidence l’augmentation de la demande en énergie primaire, qui passe de 13 000 Mtep en 2011 à 17 400 en 2035. La part des énergies fossiles (pétrole, gaz, charbon) restera largement dominante : elle passerait de 81 % en 2011 à 76 % en 2035. Les énergies renouvelables (y compris hydraulique et biomasse) seront en croissance : de 13 % en 2011 à 18 % en 2035

La géologie, une science plus que passionnante … et diverse