Archives par mot-clé : History

Study shows that Vikings enjoyed a warmer Greenland

by Charles the moderator, February 7, 2019 in WUWT

Study shows that Vikings enjoyed a warmer Greenland

Chemistry of bugs trapped in ancient lake sediment shows a warm climate at a key time in Greenland’s history

Although TV and movies paint Vikings as robust souls, braving subzero temperatures in fur pelts and iron helmets, new evidence indicates they might have been basking in 50-degree summer weather when they settled in Greenland.

After reconstructing southern Greenland’s climate record over the past 3,000 years, a Northwestern University team found that it was relatively warm when the Norse lived there between 985 and 1450 C.E., compared to the previous and following centuries.

German Scientists Back Findings By Gebbie et al 2019, Believe Climate CO2 Sensitivity Even “Likely To Be Lower” Than 1.3°C

by P. Gosselin, January 29, 2019 in NoTricksZone

A paper very worth reading from the USA from January 2019 in Science (Geoffrey Gebbie of the Woods Hole Oceanographic Institution/Peter Huybers of Harvard University, hereinafter GH19) is titled “The Little Ice Age and 20th-century deep Pacific cooling”.

It shows fascinating science.

The authors evaluated temperature measurements made in the deep sea by the famous expedition of the “HMS Challenger” in the 1870s. The ship sailed the Atlantic and Pacific, and probably provided the first data on the oceans down to depths of over 2000 meters. The recalibration of the old data alone is a work of art! What the paper found: The Pacific down in depths has cooled from 1870 to today, the Atlantic not.

Concord and discord among Northern Hemisphere paleotemperature reconstructions from tree rings

by Scott St. George Jan Esper, December 19, 2018 in WUWT


  • Tree rings are the backbone of most last millennium temperature reconstructions.

  • Maximum density is a superior temperature proxy than ring-width but is less available.

  • The newest tree-ring reconstructions agree better with instrumental temperatures.

  • They also fit the memory structure of instrumental temperatures more closely.

  • It is imperative to develop new, long and up-to-date maximum density chronologies.


2 More New Climate Reconstructions Indicate Rapid COOLING In The Last 100+ Years

by K. Richard, November 22, 2018 in NoTricksZone

The evidence that “global” warming has not been global in scale continues to accumulate.  Two more new reconstructions from the Western Pacific (He et al., 2018) and subpolar North Atlantic (Orme et al., 2018)  indicate that modern temperatures have continued to decline since the onset of the Little Ice Age.

These add to the nearly 300 graphs published in the scientific literature since 2017 showing that there is nothing unusual, unprecedented, or remarkable about the temperatures changes in the last 150 years.

Scientists” Determine That the Worst Year in Human History Was… 536 AD.

by David Middleton, November 17, 2018 in WUWT

Why 536 was ‘the worst year to be alive’

By Ann Gibbons Nov. 15, 2018


Ask medieval historian Michael McCormick what year was the worst to be alive, and he’s got an answer: “536.” Not 1349, when the Black Death wiped out half of Europe. Not 1918, when the flu killed 50 million to 100 million people, mostly young adults. But 536. In Europe, “It was the beginning of one of the worst periods to be alive, if not the worst year,” says McCormick, a historian and archaeologist who chairs the Harvard University Initiative for the Science of the Human Past.

A mysterious fog plunged Europe, the Middle East, and parts of Asia into darkness, day and night—for 18 months. “For the sun gave forth its light without brightness, like the moon, during the whole year,” wrote Byzantine historian Procopius. Temperatures in the summer of 536 fell 1.5°C to 2.5°C, initiating the coldest decade in the past 2300 years. Snow fell that summer in China; crops failed; people starved. The Irish chronicles record “a failure of bread from the years 536–539.” Then, in 541, bubonic plague struck the Roman port of Pelusium, in Egypt. What came to be called the Plague of Justinian spread rapidly, wiping out one-third to one-half of the population of the eastern Roman Empire and hastening its collapse, McCormick says.

Extreme weather is the most likely and severe threat facing humanity!

by P. Homewood, November 8, 2018 in NotaLotofPeopleKnowThat

My very first foray into climate blogging was an analysis of extreme weather events in 1971. (I wrote it in 2011, so it was not a cherrypicked year, merely a nice round 40 years before.)

I won’t bore you with it again, as it was basically just a very long list. You can see it here though.

But here is a summary, which goes to show that extreme weather is the norm, not the exception:


Climate Book By Japanese Physics Professor: “The Globe Isn’t Warming Anymore”…IPCC “Scientifically Immoral”

by Kirye, October 23, 2048 in NoTricksZone

Dr. Fukai also points out that global vegetation coverage increased by 11% in 29 years, from 1982 to 2010, as increasing CO2 has helped the greening of the Sahel and Sahara Desert. He contradicts the often heard media claims that drought is spreading globally, writing: “The media spread the word that desertification is progressing globally, but practically the desert is greening through CO2.” […] “Everyone should be aware that increasing CO2 concentrations in atmosphere is not in itself harmful, but it’s a good thing.”

No correlation

Dr. Fukai also shows that the earth’s temperature change is not simple and does not correlate at all with CO2. He shows graphs from D. M. Etheridge et al., Mauna Loa Observatory and the temperature data from Moberg et al. (2005).


The retired Japanese professor writes that at around 1000 A.D. — the Medieval Warm Period — there were no signs showing CO2 concentration was higher. A temperature graph using data from Moberg et al. (2005) shows the Medieval Warm Period appears clearly and that CO2 was in fact around 280 ppm at that time.


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 :


Ocean Temperatures Have Been Rising Since 19thC

by P. Homewood, October 12, 2018 in NotaLotofPeopleKnowThat


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.


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.


* 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 (…)