Archives par mot-clé : History

LES EVENEMENTS CLIMATIQUES EXTREMES DU PASSE (19)

by John Moreau, 20 octobre 2018 in Belgotopia


« Le contenu de la mémoire est fonction de la vitesse de l’oubli »

Désormais, chaque inondation quelque peu catastrophique, chaque tornade, chaque anomalie météorologique est rattachée au réchauffement climatique qui parait-il nous menace, mais dont en plus l’homme serait responsable !

Pourtant, la consultation de chroniques ou récits anciens est révélatrice de précédents tout aussi apocalyptiques,  et relativise la notion même de « changements climatiques », ainsi que la définition d’un « climat stable » qui n’a jamais existé mais qu’on voudrait instaurer à tout prix.

 

AUX ENVIRONS DE 1850, FIN DU « PETIT AGE GLACIAIRE » et début d’un réchauffement du climat, surtout perceptible en hiver.

Pour l’ensemble des épisodes :

https://belgotopia.wordpress.com/2015/02/27/sur-les-evenements-climatiques-extremes-1/

https://belgotopia.wordpress.com/2015/04/01/sur-les-evenements-climatiques-extremes-2/

https://belgotopia.wordpress.com/2015/04/15/sur-les-evenements-climatiques-extremes-3/

https://belgotopia.wordpress.com/2015/05/05/sur-les-evenements-climatiques-extremes-4/

https://belgotopia.wordpress.com/2015/06/01/sur-les-evenements-climatiques-extremes-5/

https://belgotopia.wordpress.com/2015/06/15/sur-les-evenements-climatiques-extremes-6/

https://belgotopia.wordpress.com/2015/06/24/sur-les-evenements-climatiques-extremes-7/

https://belgotopia.wordpress.com/2015/08/20/sur-les-evenements-climatiques-extremes-8/

https://belgotopia.wordpress.com/2015/09/04/les-evenements-climatiques-extremes-dans-lhistoire-9/

https://belgotopia.wordpress.com/2015/09/30/les-evenements-climatiques-extremes-du-passe-10/

https://belgotopia.wordpress.com/2015/10/28/les-evenements-climatiques-extremes-du-passe-11/

https://belgotopia.wordpress.com/2015/11/25/les-evenements-climatiques-extremes-du-passe-12/

https://belgotopia.wordpress.com/2017/03/10/les-evenements-climatiques-extremes-du-passe-13/

https://belgotopia.wordpress.com/2017/03/21/les-evenements-climatiques-extremes-du-passe-14/

https://belgotopia.wordpress.com/2017/05/23/les-evenements-climatiques-extremes-du-passe-15/

https://belgotopia.wordpress.com/2017/09/04/les-evenements-climatiques-extremes-du-passe-16/

https://belgotopia.wordpress.com/2017/09/06/les-evenements-climatiques-extremes-du-passe-17/

https://belgotopia.wordpress.com/2018/03/25/les-evenements-climatiques-extremes-du-passe-18/

https://belgotopia.com/2018/10/20/les-evenements-climatiques-extremes-du-passe-19/

 

Ocean Temperatures Have Been Rising Since 19thC

by P. Homewood, October 12, 2018 in NotaLotofPeopleKnowThat


https://www.sciencedaily.com/releases/2012/04/120401135345.htm

 

The significance of course is that the warming of the oceans began long before any impact from CO2 emissions.

HH Lamb has written extensively about how sea temperatures in the Atlantic fell radically during the LIA. Is the warming trend since then merely a return to earlier conditions?

Addressing on Abrupt Global Warming, Warming Trend Slowdown and Related Features in Recent Decades

by Indriani Roy, September28,  2018 in FrontiersinEarthScience


  • College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom

The puzzle of recent global warming trend slowdown has captured enough attention, though the underlying cause is still unexplained. This study addresses that area segregating the role of natural factors (the sun and volcano) to that from CO2 led linear anthropogenic contributions. It separates out a period 1976–1996 that covers two full solar cycles, where two explosive volcanos erupted during active phases of strong solar cycles. The similar period also matched the duration of abrupt global warming. It identifies that dominance of Central Pacific (CP) ENSO and associated water vapor feedback during that period play an important role. The possible mechanism could be initiated via a preferential alignment of NAO phase, generated by explosive volcanos. Inciting extratropical Rossby wave to influence the Aleutian Low, it has a modulating effect on CP ENSO. Disruption of Indian Summer Monsoon and ENSO during the abrupt warming period and a subsequent recovery thereafter can also be explained from that angle. Interestingly, CMIP5 model ensemble, and also individual models, fails to comply with such observation. It also explores possible areas where models miss important contributions due to natural drivers.

@UCSUSA “Union of Concerned Scientists” doesn’t understand what “unprecedented” means when used with the word “warming”

by Anthony Watts, August 30, 2018 in WUWT


Earth’s surface has undergone unprecedented warming over the last century, and especially in this century.

Every single year since 1977 has been warmer than the 20th century average, with 16 of the 17 warmest years on record occurring since 2001, and 2016 being the warmest year on recorded history. A study from 2016 found that without the emissions from burning coal and oil, there is very little likelihood that 13 out of the 15 warmest years on record would all have happened.

Source: https://www.ucsusa.org/global-warming/science-and-impacts/science/human-contribution-to-gw-faq.html


First a definition of the word “unprecedented”:

Note that “in this century” isn’t part of the definition. it says “never done or known before”

So in that spirit, here’s some other “unprecedented” warming in Earth’s history, via the Vostok Ice Core dataset:

Napoleon at Waterloo versus the volcano – Napoleon lost

by Anthony Watts, August 23, 2018 in WUWT


Napoleon’s defeat at Waterloo caused in part by Indonesian volcanic eruption

Electrically charged volcanic ash short-circuited Earth’s atmosphere in 1815, causing global poor weather and Napoleon’s defeat, says new research.

Historians know that rainy and muddy conditions helped the Allied army defeat the French Emperor Napoleon Bonaparte at the Battle of Waterloo. The June 1815 event changed the course of European history.

Two months prior, a volcano named Mount Tambora erupted on the Indonesian island of Sumbawa, killing 100,000 people and plunging the Earth into a ‘year without a summer’ in 1816.

Now, Dr Matthew Genge from Imperial College London has discovered that electrified volcanic ash from eruptions can ‘short-circuit’ the electrical current of the ionosphere – the upper level of the atmosphere that is responsible for cloud formation.

The findings, published today in Geology, could confirm the suggested link between the eruption and Napoleon’s defeat.

Greenland Temperatures In 2017

by P. Homewood, July 1, 2018 in NotaLotofPeopleKnowThat


As we all know, Greenland is warming up rapidly, causing the ice sheet to melt faster and faster.

Well, according to the BBC and New York Times, at least.

Only one slight problem – the temperature record shows quite a different story.

There is certainly no evidence of rising temperature trends, and every likelihood that temperatures will plummet again when the AMO turns cold again.

Sécheresses (Grandes), étés caniculaires à travers les siècles

by La France Pittoresque, 1 août 2013


Quel est le degré de température de nos grands étés ? Ici revient l’insurmontable difficulté de fixer au juste, avant l’usage du thermomètre, l’intensité du froid ou de la chaleur. Un artifice fondé sur les rapports reconnus entre certains phénomènes naturels et les mouvements du thermomètre, fournit les mesures approximatives de nos grandes chaleurs et sécheresses.

De Humboldt a posé en principe que la végétation des arbres exige au moins une température moyenne égale à 11°. Le chiffre de cette température répond encore au point où la chaleur de l’air commence à devenir sensible. Ce degré assez fixe peut être pris pour le premier terme d’une échelle de nos grandes chaleurs. Messier a quant à lui constaté que le maximum de la chaleur à Paris, le 8 juillet 1793, a marqué 40°. C’est à peu près la plus haute température, excepté celle de l’été 1705 à Montpellier, observée en France, le thermomètre au nord, isolé, à l’ombre, à l’abri des réverbérations et à l’air libre.

DATES DE NOS GRANDS ÉTÉS ET GRANDES SÉCHERESSES :

* VIe siècle : 580, 582, 584, 585, 586, 587, 589, 591
* VIIe siècle : 675, 700
* VIIIe siècle : 783
* IXe siècle : 874, 892
* Xe siècle : 921, 987, 994
* XIe siècle : 1078, 1094
* XIIe siècle : 1137, 1183, 1188
* XIIIe siècle : 1204, 1212, 1226, 1287
* XIVe siècle : 1305, 1306, 1325, 1331, 1334, 1361, 1384, 1392
* XVe siècle : 1473
* XVIe siècle : 1540, 1553
* XVIIe siècle : 1632, 1674, 1684, 1694
* XVIIIe siècle : 1701, 1712, 1718, 1719, 1726, 1727, 1767, 1778, 1793
* XIXe siècle : 1803, 1811, 1817, 1825, 1842, 1858, 1875, 1893

La canicule d’ici et l’hiver de là By: Martin Pettitt – CC BY 2.0

by Martin Pettitt, 8 août 2018, in Contrepoints


S’exprimer, sans recul, sur une canicule localisée à l’échelle du climat mondial constitue une erreur déontologique.

Il est regrettable que certains utilisent la vague de chaleur actuelle — qui au demeurant n’a rien d’anormal — afin de faire de nouveau miroiter la catastrophe climatique annoncée depuis 1992.

Le livre Des changements dans le climat de la France : histoire de ses révolutions météorologiques, du Dr Fuster, est sorti en 1845, alors qu’on ne produisait pas encore de pétrole. Dans ces 500 pages richement documentées, l’auteur passe en revue les aléas du climat en France depuis la conquête de la Gaule par Jules César jusqu’à son époque.

Voici quelques exemples tirés de ce livre, afin de montrer que la canicule que nous vivons n’a absolument rien d’anormal …

US Instrumental Records Indicate More Heat Waves Occurred In the 1930s Than Today

by K. Richard, August 6, 2018 in NoTricksZone


During the 1930s, when the atmospheric CO2 concentration was about 100 ppm lower than today (310 ppm vs. 410 ppm), United States heat waves were just as if not more common than recent decades.

Recently there has been much ado about heat waves and the hottest-ever-recorded-temperatures making their rounds in Northern Hemisphere summer.

Yet scientists have determined that heat waves are largely driven by natural variability, not anthropogenic CO2 emissions.

..

‘This Is How Global Warming Will Play Out:’ 1931 Ocean Temp Record Broken By…0.2 Degrees?

by Mike Bastach, August 5, 2018 in WUWT


….

But while Scripps is trying to tie the record-high ocean reading to the broader wave of media coverage on global heat waves, there are a few caveats to note about what the scientists found.

First, these measurements are taken from a pier that’s near the shoreline, which would not necessarily make it representative of the entire Pacific Ocean, and therefore easily influenced by local weather events.

The “anomalously warm temperatures for the past week” that Scripps researchers observed at their pier somewhat mirror the temperature pattern in 1931, and indeed, the daily records broken in the past week have been very close to readings from 87 years ago.

There is an upward trend in temperature readings from Scripps’ pier, but the trend seems to also broadly coincide with the flipping of a natural ocean cycle, the Pacific Decadal Oscillation, to its warm phase. That flip occurred around 1976.

The Completely Fake Time Of Observation Bias

by Tony Heller, July 30, 2018 in ClimateChangeDispatch


In 1999, NASA’s James Hansen was concerned that the very high-quality US temperature record didn’t match Hansen’s fake global warming trend.

How can the absence of clear climate change in the United States be reconciled with continued reports of record global temperature? Part of the “answer” is that U.S. climate has been following a different course than global climate, at least so far. Figure 1 compares the temperature history in the U.S. and the world for the past 120 years.

in the U.S. there has been little temperature change in the past 50 years, the time of rapidly increasing greenhouse gases — in fact, there was a slight cooling throughout much of the country …

June Solar Update

by David Archibald, July 6, 2018 in WUWT


We have only 300 years-odd of detailed solar observations with telescopes, half that of magnetic records, half again in the radio spectrum and less than that for most modern instrument records (and 12 years of Watts Up With That to interpret it). So as the months pass our knowledge of solar activity is still growing appreciably. The evidence points to a major transition of activity in 2006 which has returned us to the solar conditions of the 19thcentury. 19th century-type climate is expected to follow.

Figure 1: F10.7 Flux 1948 to 2018

New paper shows issues with temperature records: Comparing the current and early 20th century warm periods in China

by Dr. Willie Soon et al., June 13, 2018


Recently, a new paper which we co-authored with five other researchers was published in Earth-Science Reviews entitled, “Comparing the current and early 20th century warm periods in China”. The paper is paywalled, but the journal has kindly allowed free access to the article until 20th July 2018 at this link here. If you’re reading this post after that date, you can download a pre-print here: Soon et al, 2018 ESR – China SAT trends (PDF)

The Supplementary Information and data for the paper is available here (Excel file) : Soon et al, 2018 ESR – China SAT trends – SI

The paper is quite technical and focuses specifically on Chinese temperature trends. But, we think that it will still be of interest to many readers here, especially anybody who is interested in any of the following topics:

  1. Urbanization bias

  2. The homogenization of temperature data

  3. The “early 20th century warm period” found in many parts of the Northern Hemisphere, and

  4. Comparing temperature proxies to instrumental records

Climate Cycles, Climate Mechanisms and Determining Accurate Dates

by Dr. Tim Ball, August 31, 2014 in WUWT


Lack of information is a major problem in reconstructing and understanding climate and climate mechanisms. H.H.Lamb gave it as his reason for creating the Climatic Research Unit (CRU).

Notice he is talking about “the facts”, which includes data and other measures. Chief among the other measures are accurate chronologies, which is why he discusses dates and dating methods at some length in Volume 2 of his Climate, Present, Past and Future.

Lamb also divided climate studies into three major areas based on time and method. The secular or instrumental period covers at most 100 years. Few stations are longer and almost all are in Western Europe or eastern North America. The historical period includes the recorded works of humans and covers at most 3000 years. The biologic/geologic record covers the remainder of time. The degree of accuracy diminishes both in measures, such as temperature and precision of dates, as you go back in time. One tragedy of the “hockey stick” rarely discussed was that it misused and demeaned the value of one of the few measures that transcends two or three of these divisions.

(…)

Changes in the Rate of Sea Level Rise

by Willis Eschenbach, May 22, 2018 in WUWT


There’s been some discussion of the rate of sea level rise lately, so I thought I’d take a look at some underlying data.

I started with a 2016 paper by the modern master of failed serial doomcasting, James Hansen. It has the frightening title of Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2°C global warming could be dangerous… yikes! Be very afraid!

In Figure 29 of that paper, Hansen claims to show that sea level rise has been accelerating, from 0.6 mm/year from 1900 to 1930, to 1.4 mm/year from 1930 to 1992, and 2.6 mm/year from 1993 to 2015.

(…)

No Long-term Warming in a 300-Year Temperature Reconstruction for the Tibetan Plateau

by Li M. et al., 2017 in CO2Science/Int.J.Biometeorology


In discussing the characteristics of their three-century temperature proxy, the authors report the existence of two prominent decadal-scale cold periods (1801-1833 and 1961-2003) and two prominent decadal-scale warm periods (1730-1800 and 1928-1960). They also note that “fifteen extreme cold years (< -1.5σ) were identified and most occurred within 1-2 years after major volcanic eruptions,” contrasting with the finding that the two decadal-scale warm periods both occurred during “gaps in volcanic activities.”

Perhaps the most significant observation made by the authors, however, is that “none of the extreme warm years [< 1.5σ] or decades occurred in the most recent 30 years,” which fact runs counter to anthropogenic global warming claims that temperatures of the past few decades have been the warmest of the past thousand years (…)

The Midwest Heatwave Of May, 1934

by Tony Heller, May 12, 2012 in TheDeplorableClimSciBlog


Ninety-five degree temperatures were common in the Midwest during May prior to 1940, but almost never happen any more. May afternoon temperatures have been declining in the Midwest since the 19th century. The hottest May (by far) was 1934, when 100 degree temperatures were widespread across the Midwest, including 101 degrees at Algona, Iowa on May 7th, 1934.

See also The Good News And The Bad News

Volcanic hazard scenarios: Mount Taranaki, New Zealand

by Geological Society of America, May 3, 2018 in ScienceDaily


Over the last 5000 years, Mount Taranaki volcano, located in the westernmost part of New Zealand’s North Island, produced at least 16 Plinian-scale explosive eruptions, the latest at AD 1655. These eruptions had magnitudes of 4 to 5, eruptive styles, and contrasting basaltic to andesitic chemical compositions comparable to the eruptions of Etna, 122 BC; Vesuvius, AD79; Tarawera, 1886; Pelée, 1902; Colima, 1910; Mount Saint Helens, 1980; Merapi, 2010; and Calbuco, 2015.

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

New study reveals increased snowfall in Antarctica over last two centuries

British Antarctic Survey, April 9, 2018


Presenting this week (Monday 9 April 2018) at the European Geosciences Union (EGU) meeting in Vienna, an international team, led by British Antarctic Survey, describes how analysis of 79 ice cores collected from across Antarctica reveals a 10% increase in over the last 200 years.  This is equivalent to 272 giga tonnes of water – double the volume of the Dead Sea.

Lead author and ice core scientist Dr Liz Thomas from British Antarctic Survey explains: (…)