Tous les articles par Alain Préat

Full-time professor at the Free University of Brussels, Belgium apreat@gmail.com apreat@ulb.ac.be • Department of Earth Sciences and Environment Res. Grp. - Biogeochemistry & Modeling of the Earth System Sedimentology & Basin Analysis • Alumnus, Collège des Alumni, Académie Royale de Sciences, des Lettres et des Beaux Arts de Belgique (mars 2013). http://www.academieroyale.be/cgi?usr=2a8crwkksq&lg=fr&pag=858&rec=0&frm=0&par=aybabtu&id=4471&flux=8365323 • Prof. Invited, Université de Mons-Hainaut (2010-present-day) • Prof. Coordinator and invited to the Royal Academy of Sciences of Belgium (Belgian College) (2009- present day) • Prof. partim to the DEA (third cycle) led by the University of Lille (9 universities from 1999 to 2004) - Prof. partim at the University of Paris-Sud/Orsay, European-Socrates Agreement (1995-1998) • Prof. partim at the University of Louvain, Convention ULB-UCL (1993-2000) • Since 2015 : Member of Comité éditorial de la Revue Géologie de la France http://geolfrance.brgm.fr • Since 2014 : Regular author of texts for ‘la Revue Science et Pseudosciences’ http://www.pseudo-sciences.org/ • Many field works (several weeks to 2 months) (Meso- and Paleozoic carbonates, Paleo- to Neoproterozoic carbonates) in Europe, USA (Nevada), Papouasia (Holocene), North Africa (Algeria, Morrocco, Tunisia), West Africa (Gabon, DRC, Congo-Brazzaville, South Africa, Angola), Iraq... Recently : field works (3 to 5 weeks) Congo- Brazzaville 2012, 2015, 2016 (carbonate Neoproterozoic). Degree in geological sciences at the Free University of Brussels (ULB) in 1974, I went to Algeria for two years teaching mining geology at the University of Constantine. Back in Belgium I worked for two years as an expert for the EEC (European Commission), first on the prospecting of Pb and Zn in carbonate environments, then the uranium exploration in Belgium. Then Assistant at ULB, Department of Geology I got the degree of Doctor of Sciences (Geology) in 1985. My thesis, devoted to the study of the Devonian carbonate sedimentology of northern France and southern Belgium, comprised a significant portion of field work whose interpretation and synthesis conducted to the establishment of model of carbonate platforms and ramps with reefal constructions. I then worked for Petrofina SA and shared a little more than two years in Angola as Director of the Research Laboratory of this oil company. The lab included 22 people (micropaleontology, sedimentology, petrophysics). My main activity was to interpret facies reservoirs from drillings in the Cretaceous, sometimes in the Tertiary. I carried out many studies for oil companies operating in this country. I returned to the ULB in 1988 as First Assistant and was appointed Professor in 1990. I carried out various missions for mining companies in Belgium and oil companies abroad and continued research, particularly through projects of the Scientific Research National Funds (FNRS). My research still concerns sedimentology, geochemistry and diagenesis of carbonate rocks which leads me to travel many countries in Europe or outside Europe, North Africa, Papua New Guinea and the USA, to conduct field missions. Since the late 90's, I expanded my field of research in addressing the problem of mass extinctions of organisms from the Upper Devonian series across Euramerica (from North America to Poland) and I also specialized in microbiological and geochemical analyses of ancient carbonate series developing a sustained collaboration with biologists of my university. We are at the origin of a paleoecological model based on the presence of iron-bacterial microfossils, which led me to travel many countries in Europe and North Africa. This model accounts for the red pigmentation of many marble and ornamental stones used in the world. This research also has implications on the emergence of Life from the earliest stages of formation of Earth, as well as in the field of exobiology or extraterrestrial life ... More recently I invested in the study from the Precambrian series of Gabon and Congo. These works with colleagues from BRGM (Orléans) are as much about the academic side (consequences of the appearance of oxygen in the Paleoproterozoic and study of Neoproterozoic glaciations) that the potential applications in reservoir rocks and source rocks of oil (in collaboration with oil companies). Finally I recently established a close collaboration with the Royal Institute of Natural Sciences of Belgium to study the susceptibility magnetic signal from various European Paleozoic series. All these works allowed me to gain a thorough understanding of carbonate rocks (petrology, micropaleontology, geobiology, geochemistry, sequence stratigraphy, diagenesis) as well in Precambrian (2.2 Ga and 0.6 Ga), Paleozoic (from Silurian to Carboniferous) and Mesozoic (Jurassic and Cretaceous) rocks. Recently (2010) I have established a collaboration with Iraqi Kurdistan as part of a government program to boost scientific research in this country. My research led me to publish about 180 papers in international and national journals and presented more than 170 conference papers. I am a holder of eight courses at the ULB (5 mandatory and 3 optional), excursions and field stages, I taught at the third cycle in several French universities and led or co-managed a score of 20 Doctoral (PhD) and Post-doctoral theses and has been the promotor of more than 50 Masters theses.

Reconstructing a Temperature History Using Complete and Partial Data

by Mark Fife, April 19, 2018 in WUWT


In today’s post I am going to go over how I went about creating a reconstruction of the history of temperature from the GHCN data sets using a variable number of stations reporting each year for the years of 1900 to 2011. Before I go into the details of that reconstruction, let me cover how I went about discarding some alternative methods.

I decided to create a test case for reconstruction methods by picking five random, complete station records. I then deleted a portion of one of those records. I mimicked actual record conditions within the GHCN data so my testing would be realistic. In different trials I deleted all but the last 20 years, all but the first 20 years or some number of years in the middle. I tried normalizing each station to its own average and averaging the anomalies. I tried averaging the four complete stations, then normalizing the fourth station by its average distance from the main average. In all cases when I plotted the reconstruction against the true average the errors were quite large.normalizing the fourth station by its average distance from the main average. In all cases when I plotted the reconstruction against the true average the errors were quite large.

Four questions on climate change

by Garth Paltridge, April 18, 2018 in ClimateEtc.

An essay on the state of climate change science.

(1) Is the science of climate change ‘settled’?

The scientific uncertainties associated with climate prediction are the basis of most of the arguments about the significance of climate change(25), and as well are the basis of much of the polarized public opinion on the political aspects of the matter. Perhaps the most fundamental of the uncertainties can be illustrated by reference to a simple ‘thought experiment’ as follows.

(…)

(2), (3), (4)


 

Studying oxygen, scientists discover clues to recovery from mass extinction

by Arizona State University, April  17, 2018 in ScienceDaily


About 252 million years ago, more than 90 percent of all animal life on Earth went extinct. This event, called the “Permian-Triassic mass extinction,” represents the greatest catastrophe in the history of life on Earth. Ecosystems took nearly five million years to recover and many aspects of the event remain a mystery.

A research team, led by scientists from Arizona State University and funded by NASA and the National Science Foundation, is helping to understand why this extinction event happened and why it took life so long to recover. The study, published in Science Advances, was led by ASU School of Earth and Space Exploration graduate student Feifei Zhang, with direction from school faculty member Ariel Anbar.

23 années de pause des températures de la stratosphère selon le rapport 2017 du GWPF

by Uzbek, 2 avril 2018 in ClimatoRéalistes


La Global Warming Policy Foundation (GWPF) a publié son rapport sur l’état du climat pour 2017. Etabli par Ole Humlum, Professeur émérite à l’Université d’Oslo, ce rapport est un examen complet du climat mondial.

En voici les 10 principales conclusions :

1. Il est probable que 2017 ait été une des années les plus chaudes depuis le début des mesures instrumentales en 1850, moins chaude cependant que 2016.

2. À la fin de l’année 2017, la température moyenne à la surface de la planète avait retrouvé les niveaux antérieurs à l’épisode El Niño. Cela montre que la hausse récente des températures mondiales a été causée principalement par ce phénomène océanographique dans le Pacifique. Cela suggère aussi que le  « hiatus » se poursuivra dans les années à venir.

(…)

Can Humans Melt the Antarctic Icecap?

by Julius Sanks, April 16, 2018 in WUWT


When discussing climate with people who do not have technical backgrounds, I have learned much of the climate discussion is a foreign language to them.

So, I take them through a few examples of how much energy is involved and how miniscule human activity is by comparison. Done properly, this lets a non-STEM person grasp the huge amounts of energy involved.

One of my favorites is Anthony’s essay that debunks the Hiroshima equivalent alarmism:

https://wattsupwiththat.com/2013/06/23/getting-cooked-by-hiroshima-atomic-bomb-global-warming/

CHALLENGING THE SCIENCE BASIS OF THE PARIS CLIMATE AGREEMENT

by Antero Ollila, April 16 in WUWT


 

COP21 does not define the scientific basis of the agreement for the warming effects of the anthropogenic emissions, but it refers to a scenario. This scenario has not been defined in the COP21, but it can be found. The scientific resource of United Nations as well as of the COP21 is IPCC. The exact specification of IPCC is (Summary for Policymakers. In: Climate Change 2014. Mitigation of Climate Change”): “Baseline scenarios, those without additional mitigation, result in global mean surface temperature increases in 2100 from 3.7 °C to 4.8 °C compared to pre-industrial levels (range based on median climate response; the range is 2.5 °C to 7.8 °C when including climate uncertainty)”. Even though IPCC refers to multiple scenarios in the text above, the surface temperature increase to the average value of 4.25 ⁰C means one scenario only.

10 new islands formed in the last 20 years

by Sidney Stevens, July 5, 2016 in mother.nature.network


Yes, islands are disappearing — most recently the five Solomon Islands lost to rising sea levels. But don’t despair just yet. For every island that goes the way of the dodo bird, the Earth is busy creating new islands.

Some erupt into being through volcanic activity. Others grow from ocean sandbars. Still others reveal themselves after glaciers retreat. A few are only temporary, while some materialize and erode on a regular basis. However they’re birthed and however long they last, island-building is part of the amazing mystery of our living, breathing planet.

Here are 10 of Mother Nature’s newest islands formed in the past two decades (and one still in the embryonic stage).

(…)

Largest High-Arctic Lake Melting From Geothermal Heat, Not Global Warming

by James E. Kamis, April 16, 2018  in ClimateChangeDispatch


Recent changes to Lake Hazen, the world’s largest high-Arctic lake, are from increased heat flow from the area’s known geological features, and not from global warming as per the many alarmist media reports.

Evidence supporting this is abundant and reliable.

Northeast Canada’s Lake Hazen lies adjacent to the world-class Greenland/Iceland mantle plume.

Unusual climate during Roman times plunged Eurasia into hunger and disease

by S. Writers,  April 16, 2018 in TerraDaily


A recent study published in an esteemed academic journal indicates that volcanic eruptions in the mid 500s resulted in an unusually gloomy and cold period. A joint research project of the Chronology Laboratory of the Finnish Museum of Natural History and Natural Resources Institute Finland (Luke) suggests that the years 536 and 541-544 CE were very difficult for many people.

Also here in Nature, University of Helsinki

Easter Island’s “ecological suicide” – myths and realities

by Dennis Avery,  April 7, 2018 in WUWT


In a recent New York Times column, Nicholas Kristof misleads us about the awful history of Easter Island (2,300 miles west of Chile), whose vegetation disappeared in the cold drought of the Little Ice Age. In doing so, he blinds modern society to the abrupt, icy climate challenge that lies in our own future.

Kristof repeats the archaeological myth that Easter Island’s natives committed “ecological suicide,” by cutting down all their palm trees. They supposedly used the logs as rollers to move their famous huge statues. Afterward, they could no longer build canoes to catch the fish that were their key protein source. Worse, he says, clearing the trees resulted in so much soil erosion that most of the population starved and/or killed each other in famine-driven desperation (…)

Solar activity over nine millennia: A consistent multi-proxy reconstruction

by C.J. Wu et al., April 5, 2018 in Astronomy&Astrophysics


.pdf (13 pages)

The solar activity in the past millennia can only be reconstructed from cosmogenic radionuclide proxy records in terrestrial archives. However, because of the diversity of the proxy archives, it is difficult to build a homogeneous reconstruction. All previous studies were based on individual, sometimes statistically averaged, proxy datasets. Here we aim to provide a new consistent multi- proxy reconstruction of the solar activity over the last 9000 years, using all available long-span datasets of 10Be and 14C in terrestrial archives.

Sea level rise acceleration (or not): Part VII U.S. coastal impacts

by Judith Curry, April 15, 2018 in Climate.Etc.


Global mean sea level (GMSL) has increased by about 8–9 inches since 1880, with about 3 inches occurring since 1993. As discussed in Part VI, scientists expect that GMSL will continue to rise well beyond the 21st century because of global warming that has already occurred and warming that is yet to occur.

The recent NOAA Report Global and Regional Sea Level Rise Scenarios for the United States has stated that even the relatively small increases in sea level over the last several decades have been associated greater storm impacts at many places along the U.S. coast. Further, the frequency of intermittent flooding associated with unusually high tides has increased rapidly in response to increases in local sea level, becoming a recurrent and disruptive problem.

Svensmark: “Global Warming Stopped And A Cooling Is Beginning” – “Enjoy Global Warming While It Lasts”

by H.. Svensmark, June1 , 2016 in Principia.Sci.International


The star that keeps us alive has, over the last few years, been almost free of sunspots, which are the usual signs of the Sun’s magnetic activity. Last week [4 September 2009] the scientific team behind the satellite SOHO (Solar and Heliospheric Observatory) reported, “It is likely that the current year’s number of blank days will be the longest in about 100 years.” Everything indicates that the Sun is going into some kind of hibernation, and the obvious question is what significance that has for us on Earth.

If you ask the Intergovernmental Panel on Climate Change (IPCC) which represents the current consensus on climate change, the answer is a reassuring “nothing”. But history and recent research suggest that is probably completely wrong. Why? Let’s take a closer look.