Archives de catégorie : climate and geology

Solar forcing and climate variability during the past millennium as recorded in a high altitude lake: Lake Salda (SW Anatolia)

by I.B. Bauhi & S. Akçer-Ön, August 30, 2018 in QuaternaryInternational


Abstract

Climate variability is a well-known phenomenon and has been frequently, though complex, linked to solar forcing on different time scales. The importance of solar forcing related climate variability is crucial in our understanding of paleoclimate and future climate changes, as well as building climate models. Here in, we present the late Holocene (last ca 1400) climate records from Lake Salda in SW Anatolia using high-resolution micro X-ray Fluorescence (μ-XRF), magnetic susceptibility (MS), stable isotopes13C and δ18O) and TOC-TIC measurements. The age model is constructed by using radionuclide (210Pb, 137Cs and 14C) dating methods. The lake’s high-resolution multiproxy results revealed lake water level fluctuations associated with humid and dry spells during the last 1400 years. Periods of higher lake levels are consistent with solar maxima in total solar irradiance and vice versa. Moreover, the Lake Salda records clearly show dry Dark Ages Cold Period (DACP), humid Medieval Climatic Anomaly (MCA), dry Little Ice Age (LIA), and humid Modern Warm Period (MoWP). These records suggest that the solar forcing, through its influence on the atmospheric circulation, is the main mechanism of climate change during the DACP, MCA, LIA and MoWP in this region.

500 Million Years of Unrelatedness between Atmospheric CO2 and Temperature

by Davis W.J., 2017 in CO2Science


Davis, W.J. 2017. The relationship between atmospheric carbon dioxide concentration and global temperature for the last 425 million years. Climate 5: 76; doi: 10.3390/cli5040076.

Writing by way of introduction to his work, Davis (2017) notes that “a central question for contemporary climate policy is how much of the observed global warming is attributable to the accumulation of atmospheric CO2 and other trace greenhouse gases emitted by human activities.” If you talk to a climate alarmist, the answer you receive from such an inquiry will likely be “almost all.” A climate skeptic, on the other hand, will likely respond that the answer is “likely none.”

Hoping to provide some crucial information on this topic, Davis analyzed the relationship between historic temperature and atmospheric CO2 using the most comprehensive assemblage of empirical databases of these two variables available for the Phanerozoic period (522 to 0 million years before present; Mybp). In all, 6680 proxy temperature and 831 proxy CO2 measurements were utilized, enabling what Davis described as “the most accurate quantitative empirical evaluation to date of the relationship between atmospheric CO2concentration and temperature.” Multiple statistical procedures and analyses were applied to the proxy records and the resultant relationship is depicted in the figure below.

Egalement voir ici

Study: climate was more variable during the last inter-glacial period

by Anthony Watts, October 12, 2018 in WUWT


Century-scale climate variability was enhanced when the Earth was warmer during the Last Interglacial period (129-116 thousand years ago) compared to the current interglacial (the last 11,700 years), according to a new UCL-led study.

The findings, published today in Nature Communications and funded by the Natural Environment Research Council (NERC) and the Australian Research Council (ARC), reveal that the Last Interglacial period was punctuated by a series of century-scale arid events in southern Europe and cold water-mass expansions in the North Atlantic.

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.

Geologists: No Link Between Climate Warming And Rock Slides in European Alps!

by P. Gosselin, September 23, 2018 in NoTricksZone


Last year, August, 2017, a massive rockslide occurred on the north flank of the Piz Cengalo (3369 m) in the Swiss Alps, above the village of Bondo, located near the border to Italy.

No data suggesting warming is behind rock slides

In total some 4 million tonnes of rock and mud came tumbling down. The dramatic incident highlighted the hazards posed by rock slides for villages located near the picturesque mountains of the European Alps.

Though rockslides are not unusual, there has been growing scrutiny behind their causes lately. Unsurprisingly climate alarmists are opportunistically pointing the finger at climate warming.

 

 

A Geological Feud Over the Meghalayan? Or Just More Rubbish Published by the American Association for the Advancement of Science of America?

by David Middleton, September 24, 2018 in WUWT


Alternate Title: Yes, We Have No Anthropocene, We Have No Anthropocene Today! (Sung to the tune of Yes, We Have No Bananas)

 

Figure 4 from Finney & Edwards.  “Workflow for approval and ratification of a Global Standard Stratotype Section and Point (GSSP) proposal. Extensive discussion and evaluation occurs at the level of the working group, subcommission, and International Commission on Stratigraphy (ICS) Bureau. If approved at these successive levels, a proposal is forwarded to the International Union of Geological Sciences (IUGS) for ratification. This process is also followed for other ICS decisions on standardization, such as approval of names of formal units, of revisions to the units, and to revision or replacement of GSSPs.”

500 Million Years of Unrelatedness between Atmospheric CO2 and Temperature

by Davis W.J., 2017 in Climate/CO2Science


One final gem from Davis’ work is a pronouncement that follows a discussion on the lack of correlation between CO2 and temperature across the historical record, where he aptly reminds us that “correlation does not imply causality, but the absence of correlation proves conclusively the absence of causality.” Consequently, there should be no more doubt regarding the ineffectiveness of atmospheric CO2 to control or drive climate change. It is simply nothing more than a bit player, whose influence has been continually overestimated by climate alarmists. The big question now is whether or not 500 million years of these data will convince them otherwise!

from Davis 2017

Egalement: Le changement climatique : la règle en géologie

Iceland’s monster volcano charging up for eruption

by Anthony Watts, September 20, 2018 in WUWT


The Katla volcano, hidden beneath the ice cap of Mýrdalsjökull glacier in Iceland, has historically erupted violently once every 40-80 years.  In-as-much as it’s last such eruption took place one hundred years ago, in 1918, Katla’s next eruption is long overdue.

An eruption in Katla would dwarf the 2010 Eyjafjallajökull eruption, scientists have warned.

A new study by Icelandic and British geologists showed that Katla is emitting enormous quantities of CO2 – at least 20 kilotons of CO2 every day. Only two volcanoes worldwide are known to emit more CO2, Evgenia Ilyinskaya a volcanologist with the University of Leeds told the Icelandic National Broadcasting Service RÚV.

N ICE CAULDRON IN MÝRDALSJÖKULL Geothermal activity in the volcano’s caldera melts the glacier, creating cauldrons in the ice. Photo/Fréttablaðið

Out with the Anthropocene – in with the Meghalayan

by Anthony Watts, September 11, 2018 in WUWT


WUWT readers may recall that climate activists wanted the current epoch we live in to be named the “Anthropocene”, because they believe humans are the dominate force on the planet. The official organization that decides such things, The International Commission on Stratigraphy, would have none of it, and nixed the naming recently. Now, here’s a summary of the the Meghalayan.


Welcome to the new Meghalayan age – here’s how it fits with the rest of Earth’s geologic history

Steve Petsch

Associate Professor of Geosciences, University of Massachusetts Amherst

Jurassic, Pleistocene, Precambrian. The named times in Earth’s history might inspire mental images of dinosaurs, trilobites or other enigmatic animals unlike anything in our modern world.

….

10 New Reconstructions Show Today’s Temperatures Still Among The Coldest Of The Last 10,000 Years

by K. Richard, September 10, 2018 in NoTricksZone


Even though CO2 concentrations hovered well below 300 ppm throughout most of the Holocene, newly published paleoclimate reconstructions affirm that today’s surface temperatures are only slightly warmer (if at all) than the coldest periods of the last 10,000 years.  This contradicts the perspective that temperatures rise in concert with CO2 concentrations.

 

Bottom Graph Source: Rosenthal et al. (2013)

Claim: Episodic and intense rain was caused by ‘ancient global warming’

by Anthony Watts, September 4, 2018 in WUWT


From the University of Bristol and the “models before measurements” department comes this highly speculative claim that is entirely based entirely on climate models. There’s no actual measured data from any sort of paleo research. It’s science, but not as we know it.


A new study by scientists at the University of Bristol has shown that ancient global warming was associated with intense rainfall events that had a profound impact on the land and coastal seas.

The Palaeocene-Eocene Thermal Maximum (PETM), which occurred about 56 Million years ago, is of great interest to climate scientists because it represents a relatively rapid global warming event, with some similarities to the human-induced warming of today.

Although there have been many investigations of how much the Earth warmed at the PETM, there have been relatively few studies of how that changed the hydrological cycle.

Seabed Volcanoes Can Influence West Antarctic Glacier Melts Read Newsmax: Seabed Volcanoes Can Influence West Antarctic Glacier Melts

by Larry Bell, September 3, 2018 in Newsmax


New evidence now updates and confirms a column I wrote in June 2014 that some or all of the highly publicized melting of western coastal Antarctic glaciers may be caused by seabed volcanoes rather than having much or anything to do with climate change.

An article published in June 22 edition of the journal Nature Communications reports that an international team of scientists tracing a chemical signature of helium in the seawater discovered that contemporary volcanic heat is causing observed melting beneath the massive west Antarctic Ice Sheet (WAIS.)

 

A Second Letter to the Geological Society

by Andy May, August 29, 2018 in WUWT


In June of this year, Howard Dewhirst, a fellow of The Geological Society (London), wrote a letter to the President of the Society voicing the concern of 33 current and former fellows of the society, as well as other concerned geoscientists, that the Society’s position on climate change is outdated and one-sided. As of this writing, receipt of the letter has been acknowledged, but no reply has been received. Given the long period of time, Howard has sent a second letter to the Society, it is reproduced below.

Dear President

We understand that the council is reviewing the The Geological Society’s 2010 and 2013 position papers on climate change which was the subject of the letter we wrote to the society in early June. We also understand that despite the clear interest amongst Fellows – and other scientists, that the society will not be publishing further letters until the new position paper has been agreed. If true, we (the contributors to the first letter) think this is unfortunate, as now would be the very time to solicit informed opinion from Fellows and others as there clearly is not a consensus. …