noahs

Regardless of the politicisation by our idiotic leaders or utter denialism by some people, GLOBAL WARMING is happening — FAST. Not only we are burning fossil fuels that create gases that absorb extra heat in the atmosphere, we are experiencing a NATURAL weakening of the earth magnetic system and/or possible polarity change SOON … This would create some extra confusion and uncertainty in our future.

It has been noted that the strength of the earth magnetic field has been weakening, loosing about 9 per cent of the signal for the last 170 years, and its orientation has gone a bit walkabout. The magnetic north pole is wandering like a lost child. Lucky, most navigators rely on GPS. The magnetic north isn’t what it used to be...

Magnetic N/S reversals aren’t new. There was one about 42,000 years ago. It created some interesting changes to the climate of the planet, including some contrary effects (cooling) to warming, and a fast extension of the ice sheet over North America. This became the ice age until the last melt about ≥ 12,000 years ago. We know a lot about this melt through the folklore of biblical proportion: god wasn’t happy with his homo sapiens, so he picked a family of lesser sinners to survive a big flood. The reality is that the “big melt” (the end of the ice age) made the sea level rise by 100 metres in about 1,000 years. Half a metre per year… This is what we’re facing passed the threshold of the first 100 years from now… Not paying attention to the physical details of the earth dynamics, many budding civilisations thought this was a signs the gods were angry at something humans had done. Many sacrifices (humans and goats, no carrots) were made at the altars of ignorance. Unfortunately glorious ignorance through religious beliefs are still cultivated with intensity.

We all know now (we should all know) about the mechanics of NATURAL climate change. They are not much more complex than a microwave oven. Add some electromagnetic energy at specific wave length and the water boils. 

In the atmosphere, add EXTRA CO2 (and other warming gases) and the atmosphere warms up under specific electromagnetic wave lengths incoming from the sun. Simple.

So at this stage, some scientists have studied the change in the magnetic field of this little planet that happened 42,000 years ago. To do this, they need to look at specific markers, from tree rings to Carbon 14 concentrations, at different sites. Some of these magnetic happenings have been well known for a long time, but more details have been explored recently at the 42,000 mark, already noticed in the Lashamp event. The new indices give a picture of the conditions in which homo sapiens, already established in Europe (45,000 years ago) and around the planet — note: Aboriginal people have settled in Australia possibly around 60,000 years ago — had to make do with "changes” which might have been more subtle than the next big change — the big melt.

Laschamp event

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The Laschamps event was a geomagnetic excursion (a short reversal of the Earth's magnetic field). It occurred 41,400 years ago, during the end of the Last Glacial Period. It is known from geomagnetic anomalies discovered in the 1960s in the Laschamps lava flows in Clermont-Ferrand, France.[1]

The Laschamps event was the first known geomagnetic excursion and remains the most thoroughly studied among the known geomagnetic excursions.[2]

The Laschamps excursion occurred 41,400 (±2,000) years ago during the end of the Last Glacial Period; it was first recognised from a geomagnetic excursion discovered c. 1969 in the Laschamps lava flows in the Clermont-Ferrand district of France.[1]

The magnetic excursion has since been demonstrated in geological archives from many parts of the world.[2] The magnetic field was reversed for approximately 440 years, with the transition from the normal field lasting approximately 250 years. The reversed field was 75% weaker, whereas the strength dropped to only 5% of the current strength during the transition. This reduction in geomagnetic field strength resulted in more cosmic rays reaching the Earth, causing greater production of the cosmogenic isotopes beryllium 10 and carbon 14.[3]

The Australian Research Council is funding research to analyze a kauri tree uncovered in New Zealand in 2019. According to its carbon-dating, the tree was alive during the event (41,000–42,500 years ago).[4][5]

The geomagnetic field was at low levels from 42,200–41,500 years ago. This period of low magnetic field has been termed the Adams Event or Adams Transitional Geomagnetic Event, a tribute to science fiction writer Douglas Adams, who wrote in The Hitchhiker's Guide to the Galaxy that "42" was the answer to life, the universe, and everything.[6][7] During this period, Earth's magnetic field dropped to below 6% of the current level, Carbon 14 production increased, ozone levels decreased, and atmospheric circulation changed.[8] This loss of the geomagnetic shield was also claimed to have caused the extinction of Australian megafauna, the extinction of the Neanderthals, and the appearance of cave art.[9][10][11] However, the lack of corroborating evidence of a causal link between the Laschamps event and population bottlenecks of many megafauna species and the relatively moderate radio-isotopic changes during the event have cast significant doubt on the real impact of the Laschamps event on global environmental changes [12]

Read more:

https://en.wikipedia.org/wiki/Laschamp_event#

The new study mentioned at top has discovered a few more interfering items, including that the event was far more significant in the lower latitudes, i.e. tropical and equatorials regions.

A global environmental crisis 42,000 years ago

Science  19 Feb 2021:

Vol. 371, Issue 6531, pp. 811-818

Reversing the field

Do terrestrial geomagnetic field reversals have an effect on Earth's climate? Cooper et al.created a precisely dated radiocarbon record around the time of the Laschamps geomagnetic reversal about 41,000 years ago from the rings of New Zealand swamp kauri trees. This record reveals a substantial increase in the carbon-14 content of the atmosphere culminating during the period of weakening magnetic field strength preceding the polarity switch. The authors modeled the consequences of this event and concluded that the geomagnetic field minimum caused substantial changes in atmospheric ozone concentration that drove synchronous global climate and environmental shifts.

Science, this issue p. 811

Abstract

Geological archives record multiple reversals of Earth’s magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the Laschamps Excursion [41 to 42 thousand years ago (ka)]. We use ancient New Zealand kauri trees (Agathis australis) to develop a detailed record of atmospheric radiocarbon levels across the Laschamps Excursion. We precisely characterize the geomagnetic reversal and perform global chemistry-climate modeling and detailed radiocarbon dating of paleoenvironmental records to investigate impacts. We find that geomagnetic field minima ~42 ka, in combination with Grand Solar Minima, caused substantial changes in atmospheric ozone concentration and circulation, driving synchronous global climate shifts that caused major environmental changes, extinction events, and transformations in the archaeological record.

Over the recent past, Earth’s magnetic field has steadily weakened (~9% in the past 170 years), and this, along with the current rapid movement of the magnetic North Pole, has increased speculation that a field reversal may be imminent (1, 2). The estimated economic impacts of such a reversal have focused on the increased exposure to extreme solar storms, with multibillion-dollar daily loss estimates (3) likely to be conservative. One of the best opportunities to study the impacts of extreme changes in Earth’s magnetic field is the Laschamps Excursion (hereafter Laschamps)—a recent, relatively short-duration (<1000 year) reversal ~41 thousand years ago (ka) (4). Sedimentary and volcanic deposits indicate a weakening of the magnetic field intensity to <28% of current levels during the reversed phase of the Laschamps and, notably, as little as 0 to 6% during the preceding transition as polarity switched (Fig. 1 and supplementary materials) (1, 2, 5).

Studies of Greenland ice cores have failed to reveal marked impacts in high-latitude paleoclimate associated with Laschamps (5, 6), and this observation has underpinned the current view that there is no relationship between geomagnetic reversals and climate or environmental changes. However, the markedly increased levels of solar and cosmic radiation reaching Earth’s atmosphere because of the weakened geomagnetic field are likely to have increased atmospheric ionization and decreased stratospheric ozone levels, potentially generating regional climatic impacts, particularly in lower latitudes (7–9). In this regard, it is notable that many environmental records around the Pacific Basin appear to detail a major (and often sustained) change in behavior ~40 to 42 ka, including local glacial maxima in Australasia and the Andes (7, 10), long-term shifts in atmospheric circulation patterns (11, 12), and continent-wide aridification and megafaunal extinction in Australia (4, 13–16). The same period in North America saw the rapid, pronounced expansion of the Laurentide Ice Sheet (LIS) from a local minimum close to 42 ka (17–19). Many of these records document a long-term phase shift into a glacial state that persisted until the transition into the Holocene (~11.6 ka), in direct contrast to the Atlantic Basin records of millennial-scale abrupt and extreme changes associated with stadial-interstadial events.

Although the Pacific Basin environmental changes appear broadly coincident with the Laschamps, the lack of knowledge about the exact timing and duration of the geomagnetic excursion has greatly limited the ability to examine whether it played any role. In addition, chronological uncertainties are complicated in radiocarbon-dated terrestrial and marine records around the Laschamps because of the elevated production of 14C and 10Be, cosmogenic radionuclides resulting from the substantial increase in high-energy cosmic radiation reaching the upper atmosphere. The high 10Be flux has been well described from Greenland and Antarctic ice core records (6, 20, 21), which reveal synchronous century-long 10Be peaks across the Laschamps that appear to reflect a series of pronounced Grand Solar Minima (GSM; prolonged periods of low solar activity similar to the Spörer and Maunder Minima: 1410 to 1540 CE and 1645 to 1715 CE), with unknown climate impacts (20, 21). By contrast, the associated atmospheric 14C changes remain poorly constrained (22), preventing precise calibration (23).

Radiocarbon changes across the Laschamps

In this study, we performed detailed radiocarbon analyses of ancient kauri (Agathis australis) trees preserved in northern New Zealand wetlands (24) to generate a contiguous reconstruction of atmospheric 14C across the Laschamps (see supplementary materials). We compared a series of radiocarbon measurements across multiple kauri trunk cross sections to identify variations in atmospheric radiocarbon at a highly resolved level. A 1700-year record from a tree recovered from Ngāwhā, Northland, is particularly important because it spans the period of greatest change in 14C, including an apparent weakening of the magnetic field before the Laschamps. The growth of the Ngāwhā tree is relatively suppressed compared with both modern kauri and other late Pleistocene kauri, and there is a marked decrease in tree-ring width that coincides with the weakest phase of the geomagnetic field (supplementary materials). We spliced the kauri tree 14C series into the radiocarbon dataset reported from the 230Th-dated Hulu Cave speleothem (22) to provide an absolute (calendar) time scale (Fig. 1). Our 40-year–resolved reconstruction (Fig. 1) shows major changes in atmospheric radiocarbon before and during the Laschamps (23), closely matching reconstructions of the virtual geomagnetic pole [positions and geomagnetic intensity (1, 5)]. A comparison of the kauri-Hulu 14C with the paleomagnetic intensity data indicates that the reversed phase of the geomagnetic field (and associated partial recovery) defining the Laschamps sensu stricto occurred at 41.56 to 41.05 ka (supplementary materials).

By modeling 14C-production rates from our kauri Δ14C record, it is possible to precisely align to the ice core time scale by using 10Be records (21). Across this period, we infer that the Greenland ice core 2005 (GICC05) time scale is 265 years younger than the Hulu Cave time scale (95.4% range: 160 to 310 years) (Fig. 1 and fig. S15), which is considerably more precise than previous comparisons (21). Notably, the steep rise in ∆14C commences at 42.35 ka, with a peak value of 782 per mil (‰) occurring at 41.8 ka, 300 years before the full Laschamps reversal. This is the highest atmospheric 14C concentration yet reported of the pre-anthropogenic radiocarbon time scale (22, 23, 25) (see supplementary materials). The peak ∆14C value reported here occurs during the most weakened phase of the geomagnetic field (5) and is associated with a prominent GSM recorded by 10Be flux (20) (Fig. 1 and supplementary materials), when the weakened solar interplanetary magnetic field allowed enhanced input of galactic cosmic rays (GCRs) into the upper atmosphere. This kauri-Hulu record provides a precise radiocarbon calibration curve for this period, permitting a detailed recalibration of wider environmental changes to test synchrony between events while also enabling us to investigate the potential climate drivers during the Laschamps.

Global chemistry-climate modeling

To explore the impacts of a greatly weakened geomagnetic field on atmospheric ionization, chemistry, and dynamics, we undertook a series of simulations using a global chemistry-climate model, SOCOL-MPIOM (8) (see supplementary materials). First, the global conditions before the Laschamps were modeled by using modern values of the geomagnetic dipole moment (M) and average solar modulation potential (ɸ) of 800 MV (equivalent to the modern value). After a 398-year spin-up, three 72-year–long simulations (from which the last 60 years were used for analysis) were branched off to study the Laschamps and two additional solar states likely to influence atmospheric ionization: a reference run keeping M = 100% current and ɸ = 800 MV (experiment REF); the Laschamps with weakened geomagnetic field (M = 0% current, ɸ = 800 MV; experiment M0P800) (2); and a Laschamps weakened geomagnetic field plus GSM when the decreased geomagnetic field and the reduced solar modulation potential greatly increase the GCR ionization rate in Earth’s atmosphere (M = 0% current, ɸ = 0 MV; experiment M0P0).

Although our simulation for the weakened magnetic field during the Laschamps (M0P800) showed modest but significant changes in atmospheric chemistry and climate (see supplementary materials), the scenario for Laschamps plus GSM (M0P0) showed greatly amplified impacts, most notably during the boreal winter and austral summer (December to February) (Figs. 2 and 3 and figs. S18 to S30). Our results yield a large increase in atmospheric ionization from GCRs, resulting in an enhanced production of hydrogen and nitrogen oxides (HOx and NOx, respectively) (Fig. 2, A and B) (8) down to very low altitudes. The increased HOx and NOx concentrations influenced ozone levels over the entire atmosphere, decreasing the O3 mixing ratio in the stratosphere (~5%) while increasing the O3 mixing ratio in the troposphere, with the greatest changes observed over Antarctica (~5%)

(insert chart)

“Modern” homo sapiens arrived in Europe around 45,000 years ago…

Some 55,000 years ago, a person — whether female or male, we don't know — lived in Manot Cave in the western Galilee area of what is now Israel. Judging from the partial skull recovered from the cave, and described in Nature last week by Israel Hershkovitz of Tel Aviv University and his co-authors, the person was anatomically modern and closely related to the first modern humans who went on to colonize Europe.

Greedy for any solid evidence that sheds light on the migration of anatomically modern humans (AMH) out of Africa and into Europe, paleoanthropologists welcome detailed analysis like this one about the Manot Cave person (known as "Manot 1").

For the rest of us, there's something exciting about scientific announcements like this because they afford us new glimpses of our very own evolutionary path.

Let's consider what paleoanthropologists knew already, before the discovery of the Manot 1 skull.

AMH — people like us — evolved in Africa right around 200,000 years ago from earlier human-like ancestors. For many millennia, Africa remained the center of our evolution — and not just anatomically: The fascinating paint factory found at Blombos Cave in South Africa, dated to 100,000 years ago is just one illustration of the behavioral and cognitive sophistication that developed in Africa.

Read more:

https://www.npr.org/sections/13.7/2015/02/05/383976105/fossil-provides-evidence-of-early-human-migration-to-europe#

The Neanderthals were extinct by 30,000 years ago, but their disappearance started by 40,000 years ago — very soon after the Laschamp excursion… The question is which had more importance in the process: Homo sapiens invading their space, interbreeding with Humans (like donkeys and horses), or the Laschamp excursion increasing the UV through depletion of the ozone layer. as noted by scientists… Increase UV, increases the chance of skin cancers. Who knows...

The last appearance date of Neanderthals is commonly cited as ca. 30 thousand years ago (ka). This date follows the emergence of modern humans in Europe by several millennia, but our understanding of the exact timing and duration of this interval is obscured by the limitations of our dating methods. For example, peaks in atmospheric radiocarbon production during this time result in a large degree of uncertainty in the relevant radiocarbon dates (Conard & Bolus 2008). The two species may have coexisted in Europe for up to ten millennia, and possibly came across each other during this time, although the duration of this coexistence is debated, as is contact between the two (e.g., Finlayson 2000, Pinhasi et al. 2011). The question of what may have happened during these encounters and what the role of the early modern humans could have been in the Neanderthal extinction, have been the subject of intense discussion and a focal point in Neanderthal research.

The Neanderthal disappearance is viewed by some as a true extinction. Others however, contend that Neanderthals did not become extinct, but instead were assimilated into the modern human gene pool. The fossil record is ambiguous on this point: a few European Upper Paleolithic modern human specimens have been proposed as potential Neanderthal-modern human hybrids, but this interpretation has been questioned (e.g., see Smith 2005, Harvati et al. 2007). Analysis of Neanderthal and Upper Paleolithic modern human mitochondrial DNA shows no indication of interbreeding (e.g., Ghirotto et al. 2011). However, recent research on Neanderthal nuclear DNA has found evidence for limited admixture: a small portion (up to ~4%) of the genomes of non-Africans so far examined may derive from Neanderthals, suggesting that interbreeding probably occurred in the Near East during the earliest dispersal of modern humans out of Africa, but prior to their arrival in Europe (Green et al. 2010). Demographic modeling of admixture combined with territorial expansion, however, indicates that this level of introgression would be produced under very low (<2%) interbreeding rates and strong barriers to reproduction between Neanderthals and modern humans, arguing against assimilation (Currat & Excoffier 2011). Pending the completion of the Neanderthal genome and ancient DNA analyses of early modern Europeans dating to the Upper Paleolithic, and following the recent discovery of a third possibly coexisting species from Denisova cave (Krause et al. 2010), it is premature to conclude that the currently observed level of admixture constitutes assimilation. Regardless of this small contribution to the modern human gene pool, Neanderthal populations across Europe vanished abruptly in the fossil record, and several scenarios have been proposed to account for this observation. Most invoke a degree of competition, either direct or indirect, with modern humans, or alternatively, deteriorating environmental conditions, as major factors.

Read more:

https://www.nature.com/scitable/knowledge/library/what-happened-to-the-neanderthals-68245020/#:

Earth's Magnetic Field Flipped 42,000 Years Ago. The Consequences Were Dramatic

MICHELLE STARR       19 FEBRUARY 2021

A global period of upheaval 42,000 years ago was the result of a reversal in Earth's magnetic field, new research has found.

According to radiocarbon preserved in ancient tree rings, several centuries' worth of climate breakdown, mass extinctions, and even changes in human behaviour can be directly linked to the last time Earth's magnetic field changed its polarity.

The research team has named the period the Adams Transitional Geomagnetic Event, or Adams Event, after sci-fi writer Douglas Adams, who famously declared the number 42 the ultimate answer to life, the Universe, and everything.

"For the first time ever, we have been able to precisely date the timing and environmental impacts of the last magnetic pole switch," said Earth scientist Chris Turney of the University of New South Wales in Australia. 

"The findings were made possible with ancient New Zealand kauri trees, which have been preserved in sediments for over 40,000 years. Using the ancient trees we could measure, and date, the spike in atmospheric radiocarbon levels caused by the collapse of Earth's magnetic field."

Read more:

https://www.sciencealert.com/earth-s-magnetic-field-flipped-42-000-years-ago-with-dramatic-consequences

So. In conclusion, we know that the surface of planet earth has dynamic changes that can suit us or not be pleasant. Imagine an increase of temperature 5 degrees Celsius above those of present. Imagine having a day in pleasant Sydney at 53 degrees Celsius. This likely to happen in the next century due to our burning of fossil fuels. Idiots like Angus Taylor and Scott Morrison can’t see beyond the next 24 hours — or say the next election, so they can fudge the politics of global warming some more… Idiots! Did I say idiots? well, the future will confirm this aspect of Aussie politics...