Archives par mot-clé : History

Mercury Deposition, Climate Change and Anthropogenic Activities: A Review

by Li, F. et al. July 31, 2020 in Front. Earth.Sci.

As a toxic and harmful global pollutant, mercury enters the environment through natural sources, and human activities. Based on large numbers of previous studies, this paper summarized the characteristics of mercury deposition and the impacts of climate change and human activities on mercury deposition from a global perspective. The results indicated that global mercury deposition changed synchronously, with more accumulation during the glacial period and less accumulation during the interglacial period. Mercury deposition fluctuated greatly during the Early Holocene but was stable and low during the Mid-Holocene. During the Late Holocene, mercury deposition reached the highest value. An increase in precipitation promotes a rise in forest litterfall Hg deposition. Nevertheless, there is a paucity of research on the mechanisms of mercury deposition affected by long-term humidity changes. Mercury accumulation was relatively low before the Industrial Revolution ca. 1840, while after industrialization, intensive industrial activities produced large amounts of anthropogenic mercury emissions and the accumulation increased rapidly. Since the 1970s, the center of global mercury production has gradually shifted from Europe and North America to Asia. On the scale of hundreds of thousands of years, mercury accumulation was greater in cold periods and less in warm periods, reflecting exogenous dust inputs. On millennial timescales, the correspondence between mercury deposition and temperature is less significant, as the former is more closely related to volcanic eruption and human activities. However, there remains significant uncertainties such as non-uniform distribution of research sites, lack of mercury deposition reconstruction with a long timescale and sub-century resolution, and the unclear relationship between precipitation change and mercury accumulation.

New evidence that an extraterrestrial collision 12,800 years ago triggered an abrupt climate change for Earth

by C. Rotter, July 27, 2020 in WUWT

Christopher R. Moore, University of South Carolina

What kicked off the Earth’s rapid cooling 12,800 years ago?

In the space of just a couple of years, average temperatures abruptly dropped, resulting in temperatures as much as 14 degrees Fahrenheit cooler in some regions of the Northern Hemisphere. If a drop like that happened today, it would mean the average temperature of Miami Beach would quickly change to that of current Montreal, Canada. Layers of ice in Greenland show that this cool period in the Northern Hemisphere lasted about 1,400 years.

This climate event, called the Younger Dryas by scientists, marked the beginning of a decline in ice-age megafauna, such as mammoth and mastodon, eventually leading to extinction of more than 35 genera of animals across North America. Although disputed, some research suggests that Younger Dryas environmental changes led to a population decline among the Native Americans known for their distinctive Clovis spear points.

A collision from space would leave its mark on Earth. Vadim Sadovski/

What would an Earth impact leave behind?

Persistent warm Mediterranean surface waters during the Roman period

by Margaritelli G. et al., June20, 2020 in Nature OPEN ACESS


Reconstruction of last millennia Sea Surface Temperature (SST) evolution is challenging due to the difficulty retrieving good resolution marine records and to the several uncertainties in the available proxy tools. In this regard, the Roman Period (1 CE to 500 CE) was particularly relevant in the socio-cultural development of the Mediterranean region while its climatic characteristics remain uncertain. Here we present a new SST reconstruction from the Sicily Channel based in Mg/Ca ratios measured on the planktonic foraminifer Globigerinoides ruber. This new record is framed in the context of other previously published Mediterranean SST records from the Alboran Sea, Minorca Basin and Aegean Sea and also compared to a north Hemisphere temperature reconstruction. The most solid image that emerges of this trans-Mediterranean comparison is the persistent regional occurrence of a distinct warm phase during the Roman Period. This record comparison consistently shows the Roman as the warmest period of the last 2 kyr, about 2 °C warmer than average values for the late centuries for the Sicily and Western Mediterranean regions. After the Roman Period a general cooling trend developed in the region with several minor oscillations. We hypothesis the potential link between this Roman Climatic Optimum and the expansion and subsequent decline of the Roman Empire.

See also  Roman Warm Period Was 3.6°F Warmer Than Today, New Study Shows

 See also here (GWPF)

Observations historiques d’inondations jusqu’à la fin du 19ème siècle (première partie)

by IRM, 2020

Nos observations historiques d’inondations font l’objet de trois articles. Voici le premier qui traite des inondations jusqu’à la fin du 19ème siècle.

En août 2019, nous avons introduit la possibilité d’envoyer vos propres observations via notre application météo. Cette nouvelle fonctionnalité semble avoir plu aux utilisateurs de notre app, puisque nous avons reçu près de 600.000 observations jusqu’à présent ! Etant donné ce succès, nous avons décidé en avril 2020 d’y ajouter deux nouveaux types d’observations à rapporter : les inondations et les phénomènes optiques. Ces phénomènes ont été observés de tous temps, c’est pourquoi nous avons décidé de nous plonger dans plus d’un millénaire d’anciennes observations de halos et d’arcs-en-ciel. Dans ce nouvel article, vous trouverez quelques observations d’inondations telles qu’elles ont été perçues et décrites dans d’anciens manuscrits, livres et journaux publiés en Europe de l’Ouest jusqu’au 19ème siècle.

Caricature représentant l’actuelle place Saint-Géry, lors de l’inondation de janvier 1820, Collection iconographique (ref. K-573), Archives de la Ville de Bruxelles.


See also Observations historiques d’inondations (deuxième partie)

and Observations historiques d’inondations (troisième partie)

Melting Glaciers Uncover Medieval Artefacts In Norway

by P. Homewood, April 16, 2020 in NotaLotofPeopleKnowThat

Melting glaciers in Norway have revealed ancient artefacts dropped by the side of a road more than 1,000 years ago.

Clothes, tools, equipment and animal bone have been found by a team at a lost mountain pass at Lendbreen in Norway’s mountainous region.

A haul of more than 100 artefacts at the site includes horseshoes, a wooden whisk, a walking stick, a wooden needle, a mitten and a small iron knife.

The team also found the frozen skull of an unlucky horse used to carry loads that did not make it over the ice.

The objects that were contained in ice reveal that the pass was used in the Iron Age, from around AD 300 until the 14th century.

Activity on the pass peaked around AD 1000 and declined after the black death in the 1300s, due as well to economic and climate factors.

The researchers say the melting of mountain glaciers due to climate change has revealed the historical objects, with many more to come.


Unfortunately neither the journalist nor the scientists seem to be capable of adding 2+2!


The existence of the Medieval Warm Period in Norway, followed by glacial advance in the Little Ice Age has been long known about, as HH Lamb wrote in 1982:


by H. Hardrada, March 8, 2020 in Electroverse

I [Harry Hardrada] recently unearthed an intriguing piece of literature from a 19th century periodical named ‘Ho! For the Pole!’ in Littell’s Living Age, Volume 66 (1860).

The paper highlights various voyages to the North Pole throughout the 17th-18th centuries with meticulous detail. It appears, according to the article, that many wooden ships penetrated as far north as the 89th latitude in ‘open iceless seas’ during this time — as in 1665 and 1675.

A bit far-fetched?

Perhaps, on the face of it… but there is some good evidence out there which may suggest otherwise.

The Rise and Fall of Central England Temperatures; Part 3 2000-2019

by Tony Brown, February 15, 2020 in WUWT

This is the third examination of Central England Temperatures (CET) in a series that commenced in 2015 and which has charted the recent decline in temperatures from their highest values. The two previous articles in this series are referenced here;

The Rise and Fall of Central England Temperatures; Part 1 covering 2000 to 2015

The Rise and Fall of Central England Temperatures; Part 2 covering 2000 to 2017

When referencing any ‘decline’ we need to put that into context against CET’s overall substantial rise in recent decades. The official CET dataset used in this article, which is compiled by the UK Met office is linked here and shown in Figure A);

It should be noted that the values between 1538 and 1658 are my own reconstruction and are not used at all in this current paper.

Note: Weather comprises the day to day events that we all experience. Climate is officially the trend of the weather (often temperature and rainfall) taken over a continuous thirty year period. The two terms have sometimes been used in an interchangeable manner here, when a period of more than a year is being examined.

Figure A

According to the Met office; ‘Since 1974 the data have been adjusted to allow for urban warming: currently a correction of -0.2 °C is applied to mean temperatures.’

Climate Crisis Update–England As Warm As 1736 Last Month!

by P. Homewood, February 13, 2020 in NotaLotofPeopleKnowThat

It’s been a mild start to the year here in England. In fact, according to the CET, it’s been the 14th warmest January since the start of records in 1659.

No doubt fingers will be pointed at global warming, but as the above chart shows, we have simply had mild weather of the commonly seen before. The difference is that it lasted virtually all month.

Moreover we have had warmer Januaries way back in the past. The warmest was in 1916, followed by 1921, 1796 and 1834.

Continuer la lecture de Climate Crisis Update–England As Warm As 1736 Last Month!

The Insignificance of Greenland’s Ice Mass Loss in Five Easy Charts…

by David Middleton, February 5, 2020 in WUWT

This is a sort of a spin-off of Rutgers University Global Snow Lab and “the Snows of Yesteryear” and A Geological Perspective of the Greenland Ice Sheet. And, yes, there are a lot more than five charts in this post… And, none of them were all that easy.


There is a general scientific consensus that the Greenland Ice Sheet (GrIS) has been losing ice mass since the Little Ice Age (LIA). This should come as no surprise, since the LIA was quite likely the coldest climatic episode of the Holocene Epoch. Although it does appear that the GrIS may have gained ice mass during the mid-20th century global cooling crisis.

According to Mouginot et al, 2019, the GrIS was gaining an average of +47 ± 21 Gt/y from 1972–1980, then began to lose ice mass after 1980:

  • -51 ± 17 Gt/y from 1980–1990

  • -41 ± 17 Gt/y from 1990–2000

  • -187 ± 17 Gt/y from 2000–2010

  • -286 ± 20 Gt/y from 2010–2018


Figure 4. Central Greenland temperature reconstruction (Alley, 2000).

Longest-Ever S. Hemisphere Tree-Ring Reconstruction Finds The 1700s-1800s Were Warmer Than Today

by  K. Richard, February 3, 2020  in NoTricksZone

A new 5680-year tree-ring temperature reconstruction for southern South America (Lara et al., 2020) reveals (a) no clear warming trend in recent decades, and (b) the 18th and 19th centuries (and many centennial-scale periods from the last 5680 years) had much warmer temperatures than today.

In addition to finding modern temperature changes in southern South America fall well within the range of natural variability in the context of the last 5680 years, Lara et al. (2020) assess solar forcing to have contributed to climate variations for this region of the Southern Hemisphere.

Another New Study Finds The Canadian Arctic Was About 1-2°C Warmer During Medieval Times

by K. Richard, December 16, 2019 in NoTricksZone

Four reconstructions from the central and western High Arctic reveal July temperatures were about 1-2°C warmer than today during most of the 1st millennium and Medieval period (Tamo and Gajewski, 2019).

A few years ago, a chironomid reconstruction of Boothia Peninsula in the Canadian Arctic (Fortin and Gajewski, 2016) revealed not only were today’s temperatures the coldest of the last 7000 years, but the last 150 years “do not indicate a warming during this time.”


Cartology Affirms Relative Sea Levels Were Similar To Or HIGHER Than Now During The Little Ice Age

by K. Richard, December 5, 2019 in NoTricksZone

Surprisingly accurate nautical maps created the 17th to 19th centuries strongly suggest coastal land area in both hemispheres were quite similar to today’s. There is even evidence relative sea levels were higher than now back then.

Image Source:

Globally, coasts have grown since the 1980s

Between 1985 and 2015, satellite observations indicate the world’s coasts gained 13,565 km²  more land area than they had lost to the seas (Donchyts et al., 2016).

This means more coastal land area is above sea level today than in the 1980s.

This surprises scientists, as they “expected the coast would start to retreat due to sea level rise,” but instead they observed “coasts are growing all over the world.”

New Paper Presents Photo Evidence Affirming Equatorial Region Sea Levels Have FALLEN Since The 1600s

by K. Richard, November 29, 2019 in NoTricksZone

In a new paper (Mörner, 2019, expanding upon Mörner, 2017), photo evidence confirms sea levels in 5 studied equatorial regions have fallen by about 60 cm since the 17th century…and remained stable since the 1970s.

Another new study (Haryono et al., 2019) of sea level change in equatorial Indonesia also supplies photos of marine terrace biomarker evidence affirming sea levels were about 5 meters higher than they are today between 5000 to 3000 years before present, suggesting “it means it was warmer than the present day” back then.

Raw Data Bombshell: no change in Very Hot Days in Australia since World War I

by JoNova, November 20, 2019

After we were shocked at the latest ACORN changes to our Very Hot Days data, I asked Chris Gillham if we could see the effect of Bureau of Meteorology changes to the original raw data – and he replied it would be too time-consuming writing the code to calculate 40C+ days among the millions of daily temperatures from 112 weather stations across Australia since 1910. Then he did it anyway.

Wow. In 2011, the BoM’s ACORN 1 adjustments wiped out some of the “very hot days” recorded at weather stations in the early 1900s. These were records that had stood for a whole century. Then, quietly six years later, the ACORN 2 readjustments turned the statistical air conditioner on again and cooled people from 100 years in the future.

It’s all especially miraculous given that even the old World War I  data was recorded in official BoM-approved Stevenson screens. The BoM won’t consider pre 1910 data because it wasn’t standardized, but even when it is, they still have to “fix” it. And in the intervening years after 1910, the Urban Heat Islands have grown and electronic equipment that can record one-second-records have been introduced across the nation. With the old equipment, 40C+ extremes were harder to get than with today’s micro-minute spikes caused by gusts of hot air rolling off carparks and tarmacs.

What we see in the 60 longest running ACORN sites, all open in 1910, is that the raw temperature data had just as many “very hot days” in the World War I era as it does now. Oh boy.

No wonder the BOM was keen to move the “Very Hot Days” graphics and data and tuck them away in a remote page on their website.


170 Years of Earth Surface Temperature Data Show No Evidence of Significant Warming

by T. Bjorklund, October 16, 2019 in WUWT

Key Points

1. From 1850 to the present, the noise-corrected, average warming of the surface of the earth is less than 0.07 degrees C per decade.

2. The rate of warming of the surface of the earth does not correlate with the rate of increase of fossil fuel emissions of CO2 into the atmosphere.

3. Recent increases in surface temperatures reflect 40 years of increasing intensities of the El Nino Southern Oscillation climate pattern.


This study investigates the relationships between surface temperatures from 1850 to the present and reported long-range temperature predictions of global warming. A crucial component of this analysis is the calculation of an estimate of the warming curve of the surface of the earth. The calculation removes errors in temperature measurements and fluctuations due to short-duration weather events from the recorded data. The results show the average rate of warming of the surface of earth for the past 170 years is less than 0.07 degrees C per decade. The rate of warming of the surface of the earth does not correlate with the rate of increase of CO2 in the atmosphere. The perceived threat of excessive future global temperatures may stem from misinterpretation of 40 years of increasing intensities of the El Nino Southern Oscillation (ENSO) climate pattern in the eastern Pacific Ocean. ENSO activity culminated in 2016 with the highest surface temperature anomaly ever recorded. The rate of warming of the earth’s surface has dropped 41 percent since 2006.

Solar-Climate Theory Sheds New Light On History Of Chinese Civilization

by S. Chen, Sep; 24, 2019 in ClimateChangeDispatch

Scientists say they have found evidence beneath a lake in northeastern China that ties climate change and 500-year sun cycles to ups and downs in the 8,000 years of Chinese civilization.

According to the study by a team at the Institute of Geology and Geophysics in Beijing published in the science journal Nature Communications this month, whenever the climate warmed, Chinese civilization prospered and when it cooled, it declined.

While historians have used various social and economic factors to explain changes over the millennia, Dr. Xu Deke, lead author of the paper, and his colleagues said that while people played their part, their study indicated that cycles in solar activity influenced human activity.

“We just point out there is a natural constraint on human efforts,” Xu said.

Previous research linking Chinese history to climate relied on written records, but ancient texts contained only subjective descriptions of the weather and social development. The records also go back only so far – writing in China was not invented until 3,600 years ago.

For this latest study, the team and its leader, Chinese Academy of Sciences professor Lu Houyuan, took plant and lake bed sediment samples to track climate change over the centuries and compared them with written records.


Mann, Hayhoe Try To Erase To The Pesky Medieval Warm Period

by J. Taylor, October 3, 2019 in ClimateChangeDispatch

Climate alarmists Michael Mann and Katharine Hayhoe have been caught using dubious, revisionist temperature data in their attempt, as one Climategate email author put it,  to “deal a mortal blow” to the extensively documented Medieval Warm Period.

Before climate change became a political issue, it was scientifically well-established that a significant global warming event occurred between approximately 900 AD and 1200 AD.

For example, the United Nations Intergovernmental Panel on Climate Change (IPCC) First Assessment Report presented a temperature history and visual graph documenting that the Medieval Warm Period existed and that it brought temperatures at least as warm as today (at pg. 7).

Multiple peer-reviewed studies provided additional confirmation of the Medieval Warm Period.

The warming climate of the Medieval Warm Period spurred abundant crop production, fewer extreme droughts and floods, a growing human population, and improving living standards.

The Little Ice Age terminated the Medieval Warm Period and brought devastating weather extremes, widespread crop failures, famines, plagues like the Black Death, and a contracting human population.

For a good summary of the extensive benefits of the Medieval Warm Period and the devastating harms of the Little Ice Age, see the excellent book, “In the Wake of the Plague: The Black Death and the World It Created.”

Emmanuel Le Roy Ladurie A (re)lire absolument…

by Alain Préat,  3 octobre 2019 inScienceClimatEnergie

S’il est un livre, et un des premiers, à s’être penché de manière aussi détaillée sur l’évolution (récente) du climat, c’est celui d’Emmanuel Le Roy Ladurie ‘Histoire du climat depuis l’an mil’, publié en 1967.

Rappelons cependant le livre précurseur de Joseph-Jean-Nicolas Fuster publié en 1845 et récemment analysé ici même à SCE (et toujours disponible, voir ici).


1/ Introduction

A lire ou relire ce livre de 366 pages (Figure 1), on ne peut qu’être stupéfié par l’analyse rigoureuse qui met en évidence la variabilité naturelle du climat aux échelles pluriséculaire et décennale, qui décortique et privilégie  avec finesse le caractère local du climat par rapport à un climat global et fournit à partir d’indicateurs fiables des fourchettes de températures pour les variations climatiques observées à l’échelle pluriséculaire.

 Figure 1. Histoire du climat depuis l’an mil, Flammarion, publié en 1967

Avant d’aborder ce sujet en détail, il semble qu’aucun modèle sorti des ‘computers’ (GIEC) n’ait été jusqu’à présent capable de rendre compte des évolutions rapportées dans le livre d’ Emmanuel Le Roy Ladurie, ces modèles se prétendent ‘globaux’, contrairement à la conclusion du livre en question qui insiste particulièrement sur le caractère local des climats. Enfin il s’agit d’un livre de 366 pages bien illustré (photographies, cartes et graphiques) dans lequel il n’est pas mentionné une seule fois ‘le poison’ des temps modernes, à savoir le CO2. L’auteur, en 1967 (faut-il le rappeler …), propose ou explore quand  même des pistes pour rendre compte de la succession d’épisodes ‘froids’ et ‘chauds’, tout au long de ces 1000 années d’histoire, qui en fait  débutent il y a 3500 ans (mais pour ces temps historiques plus reculés, les données fiables sont moins nombreuses).


2/ Alors que dit Emmanuel Le Roy Ladurie ?

New Attempts To Erase The MWP & LIA

by P. Homewood, July 29, 2019 in NotaLotofPeopleKnowThat

There have been many attempts to get rid of the Medieval Warming Period and Little Ice Age, and here’s another one:

The science teams reconstructed the climate conditions that existed over the past 2,000 years using 700 proxy records of temperature changes, including tree rings, corals and lake sediments. They determined that none of these climate events occurred on a global scale.

As with the other failed attempts, this latest one claims that the MWP and LIA were only localised phenomena. But nothing could be further from the truth.

These three new studies rely on proxies, but time and again hockey stick studies based on proxies are proven to be fake, based on cherry picked proxies and dodgy statistics.

In fact, we have no need to rely on proxies, because the actual evidence of warm and cold periods is very real and substantial across the world.

We are all familiar with the evidence from Greenland ice cores, which clearly show both the MWP and LIA:


Anti science L. A. Times hypes propaganda denying global wide Medieval Warm Period and Little Ice Age

by Larry Hamlin, July 28, 2019 in WUWT

The Los Angeles Times is at it again hyping anti science climate alarmist propaganda trying to conceal the global wide Medieval Warm Period and the Little Ice Age that are supported and justified by hundreds of scientific studies.

This climate alarmist propaganda Times article cites a new “study” that ridiculously attempts to deny these clearly established warm and cool periods in our past.

This alarmist hyped new “study” is addressed in a superb article at the JoNova website demonstrating the complete lack of scientific veracity of this studies claims.

There is nothing I can add to show how politically contrived and inane the claims are from this new “study” beyond the excellent presentation in the JoNova article.

Provided below are excerpts from this excellent article which demonstrate the lack of scientific credibility of the new “study” as well as the politically driven anti science climate alarmism bias of the Times.


1970s: Earth Warmed 0.6°C From 1880-1940 And Cooled -0.3°C From 1940-1970. Now It’s 0.1°C And -0.05°C.

by K. Richard, July 25, 2019 in NoTricksZone

About 45 years ago, the “consensus” in climate science (as summarized by Williamson, 1975) was quite different than today’s version.

1. The Medieval Warm Period was about 1°C warmer than present overall while the “largely ice-free” Arctic was 4°C warmer, allowing the Vikings to navigate through open waters because there was “no or very little ice” at that time.
2. The island of Spitsbergen, 1237 km from the North Pole and home to over 2000 people, “benefited” because it warmed by 8°C between 1900 and 1940, resulting in 7 months of sea-ice free regional waters. This was up from just 3 months in the 1800s.
3. Central England temperatures dropped -0.5°C between the 1930s to the 1950s.
4. Pack-ice off northern and eastern iceland returned to its 1880s extent between 1958 and 1975.
5. In the 1960s, polar bears were able to walk across the sea (ice) from Greenland to Iceland for the first time since the early 1900s. (They had somehow survived the 7 months per year of sea-ice-free waters during the 1920s-1940s).



Image Source: National Academy of Sciences,  Understanding Climatic Change

Medieval Climate Anomaly Now Confirmed In Southern Hemisphere On All Four Continents

by Lüning et al., July  6, 2019 in NoTricksZone

For a long time it has been said that the Medieval Warm Period was a purely North Atlantic phenomenon. This has proved to be wrong.

On 29 June 2019, a paper by Lüning et al. 2019 on the Medieval Warm Period in Antarctica appeared in the trade journal Palaeogeography, Palaeoclimatology, Palaeoecology. Here is the abstract:

With the publication of this paper, the Medieval Climate Anomaly (MCA) has now been confirmed on all four continents of the southern hemisphere.

While the largest part of the southern hemisphere apparently experienced a warm phase during the MCA, there were also isolated areas that cooled down. To the latter regions belong, for example, coasts, where cold water from the depth rose increasingly. In other areas so-called climate seesaws or dipoles were active, as we know them from today’s climate. One end of the “seesaw” heats up, the other end cools down.

Another result of the studies is that the medieval climate history of huge areas in the southern hemisphere is simply unknown. A task force urgently needs to be set up to fill in this climatic “empty space” with information on pre-industrial temperature development. This information is urgently needed to calibrate the climate models on the basis of which far-reaching socio-political planning is currently taking place.

What follows are publications on the Medieval Period climate of the southern hemisphere as an overview:

Lüning, S., M. Gałka, F. Vahrenholt (2019): The Medieval Climate Anomaly in Antarctica. Palaeogeogr., Palaeoclimatol., Palaeoecol., doi: 10.1016/j.palaeo.2019.109251