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.
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.”
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).
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 ?
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:
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.
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).
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
by Willis Eschenbach, March 17, 2019 inWUWT
People often say that we’re heading into the unknown with regards to CO2 and the planet. They say we can’t know, for example, what a 2°C warming will do because we can’t do the experiment. This is seen as important because for unknown reasons, people have battened on to “2°C” as being the scary temperature rise that we’re told we have to avoid at all costs.
But actually, as it turns out, we have already done the experiment. Below I show the Berkeley Earth average surface temperature record for Europe. Europe is a good location to analyze, because some of the longest continuous temperature records are from Europe. In addition, there are a lot of stations in Europe that have been taking record for a long time. This gives us lots of good data.
So without further ado, here’s the record of the average European temperature.
by K. Richard, March 7, 2019 in NoTrickszone
Yet another scientific paper presents evidence that the Arctic region was warmer than recent decades during the 1930s, leading scientists to conclude there is “still-insufficient knowledge of the mechanisms governing the Arctic Climate System.”
by Y, S., Zheng et al., 2018, Marine Micropaleontology, in CO2Science
According to Yuan et al. (2018), “studies examining sea surface temperature variability over the past one century and their influence on climate change in China are seriously lacking.” And therefore, in an effort to remedy this information void, the team of eight Chinese scientists developed “the first tree-ring-based dendroclimatic sea surface temperature (SST) reconstruction for the South China Sea.”
In accomplishing their objective Yuan et al. cored 22 Pinus massoniana trees in the Changting Region of the Fujian Province, China. Analysis of the cores revealed a statistically significant relationship between the tree-ring series and gridded March SSTs (1°C resolution) of the South China Sea (16-20°N, 112-116°E). Ultimately, this relationship enabled them to produce a proxy temperature reconstruction over the period 1893-2011, which reconstruction is shown below.
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.
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.
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.
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.
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.