Massive and rapid predominantly volcanic CO2 emission during the
end-Permian mass extinction
Abstract
The end-Permian mass extinction event (~252 Mya) is associated with
one of the largest global carbon cycle perturbations in the
Phanerozoic and is thought to be triggered by the Siberian Traps
volcanism. Sizable carbon isotope excursions (CIEs) have been found at numerous sites around the world, suggesting massive quantities of 13C-depleted CO2 input into the ocean and atmosphere system. The exact magnitude and cause of the CIEs, the pace of CO2 emission, and the
total quantity of CO2, however, remain poorly known. Here, we quantify
the CO2 emission in an Earth system model based on new
compound-specific carbon isotope records from the Finnmark Platform
and an astronomically tuned age model. By quantitatively comparing the modeled surface ocean pH and boron isotope pH proxy, a massive
(~36,000 Gt C) and rapid emission (~5 Gt C yr-1) of largely volcanic
CO2 source (~-15%) is necessary to drive the observed pattern of CIE,
the abrupt decline in surface ocean pH, and the extreme global
temperature increase. This suggests that the massive amount of
greenhouse gases may have pushed the Earth system toward a critical
tipping point, beyond which extreme changes in ocean pH and
temperature led to irreversible mass extinction. The comparatively
amplified CIE observed in higher plant leaf waxes suggests that the
surface waters of the Finnmark Platform were likely out of equilibrium
with the initial massive centennial-scale release of carbon from the
massive Siberian Traps volcanism, supporting the rapidity of carbon injection. Our modeling work reveals that carbon emission pulses are accompanied by organic carbon burial, facilitated by widespread ocean
anoxia.
https://www.pnas.org/content/118/37/e2014701118
Temporal Scaling of Carbon Emission and Accumulation Rates: Modern Anthropogenic Emissions Compared to Estimates of PETM Onset
Accumulation
Abstract
The Paleocene-Eocene thermal maximum (PETM) was caused by a massive
release of carbon to the atmosphere. This is a benchmark global
greenhouse warming event that raised temperatures to their warmest
since extinction of the dinosaurs. Rates of carbon emission today can
be compared to those during onset of the PETM in two ways: (1)
projection of long-term PETM rates for comparison on an annual time
scale and (2) projection of short-term modern rates for comparison on
a PETM time scale. Both require temporal scaling and extrapolation for comparison on the same time scale. PETM rates are few and projection
to a short time scale is poorly constrained. Modern rates are many,
and projection to a longer PETM time scale is tightly
constrained—modern rates are some 9–10 times higher than those during onset of the PETM. If the present trend of anthropogenic emissions
continues, we can expect to reach a PETM-scale accumulation of
atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human generations).
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018PA003379
On 9/15/2021 2:07 PM, Pandora wrote:
Massive and rapid predominantly volcanic CO2 emission during the
end-Permian mass extinction
Abstract
The end-Permian mass extinction event (~252 Mya) is associated with
one of the largest global carbon cycle perturbations in the
Phanerozoic and is thought to be triggered by the Siberian Traps
volcanism. Sizable carbon isotope excursions (CIEs) have been found at
numerous sites around the world, suggesting massive quantities of
13C-depleted CO2 input into the ocean and atmosphere system. The exact
magnitude and cause of the CIEs, the pace of CO2 emission, and the
total quantity of CO2, however, remain poorly known. Here, we quantify
the CO2 emission in an Earth system model based on new
compound-specific carbon isotope records from the Finnmark Platform
and an astronomically tuned age model. By quantitatively comparing the
modeled surface ocean pH and boron isotope pH proxy, a massive
(~36,000 Gt C) and rapid emission (~5 Gt C yr-1) of largely volcanic
CO2 source (~-15%) is necessary to drive the observed pattern of CIE,
the abrupt decline in surface ocean pH, and the extreme global
temperature increase. This suggests that the massive amount of
greenhouse gases may have pushed the Earth system toward a critical
tipping point, beyond which extreme changes in ocean pH and
temperature led to irreversible mass extinction. The comparatively
amplified CIE observed in higher plant leaf waxes suggests that the
surface waters of the Finnmark Platform were likely out of equilibrium
with the initial massive centennial-scale release of carbon from the
massive Siberian Traps volcanism, supporting the rapidity of carbon
injection. Our modeling work reveals that carbon emission pulses are
accompanied by organic carbon burial, facilitated by widespread ocean
anoxia.
https://www.pnas.org/content/118/37/e2014701118
Temporal Scaling of Carbon Emission and Accumulation Rates: Modern
Anthropogenic Emissions Compared to Estimates of PETM Onset
Accumulation
Abstract
The Paleocene-Eocene thermal maximum (PETM) was caused by a massive
release of carbon to the atmosphere. This is a benchmark global
greenhouse warming event that raised temperatures to their warmest
since extinction of the dinosaurs. Rates of carbon emission today can
be compared to those during onset of the PETM in two ways: (1)
projection of long-term PETM rates for comparison on an annual time
scale and (2) projection of short-term modern rates for comparison on
a PETM time scale. Both require temporal scaling and extrapolation for
comparison on the same time scale. PETM rates are few and projection
to a short time scale is poorly constrained. Modern rates are many,
and projection to a longer PETM time scale is tightly
constrained—modern rates are some 9–10 times higher than those during
onset of the PETM. If the present trend of anthropogenic emissions
continues, we can expect to reach a PETM-scale accumulation of
atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human
generations).
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018PA003379
So we get to see a new Great Dying in the near future? Hooray!
Massive and rapid predominantly volcanic CO2 emission during the
end-Permian mass extinction
Abstract
The end-Permian mass extinction event (~252 Mya) is associated with
one of the largest global carbon cycle perturbations in the
Phanerozoic and is thought to be triggered by the Siberian Traps
volcanism.
Sizable carbon isotope excursions (CIEs) have been found at
numerous sites around the world, suggesting massive quantities of 13C-depleted CO2 input into the ocean and atmosphere system. The exact magnitude and cause of the CIEs, the pace of CO2 emission, and the
total quantity of CO2, however, remain poorly known. Here, we quantify
the CO2 emission in an Earth system model based on new
compound-specific carbon isotope records from the Finnmark Platform
and an astronomically tuned age model. By quantitatively comparing the modeled surface ocean pH and boron isotope pH proxy, a massive
(~36,000 Gt C) and rapid emission (~5 Gt C yr-1) of largely volcanic
CO2 source (~-15%) is necessary to drive the observed pattern of CIE,
the abrupt decline in surface ocean pH, and the extreme global
temperature increase. This suggests that the massive amount of
greenhouse gases may have pushed the Earth system toward a critical
tipping point, beyond which extreme changes in ocean pH and
temperature led to irreversible mass extinction. The comparatively
amplified CIE observed in higher plant leaf waxes suggests that the
surface waters of the Finnmark Platform were likely out of equilibrium
with the initial massive centennial-scale release of carbon from the
massive Siberian Traps volcanism, supporting the rapidity of carbon injection. Our modeling work reveals that carbon emission pulses are accompanied by organic carbon burial, facilitated by widespread ocean anoxia.
https://www.pnas.org/content/118/37/e2014701118
Temporal Scaling of Carbon Emission and Accumulation Rates: Modern Anthropogenic Emissions Compared to Estimates of PETM Onset
Accumulation
Abstract
The Paleocene-Eocene thermal maximum (PETM) was caused by a massive
release of carbon to the atmosphere.
This is a benchmark global
greenhouse warming event that raised temperatures to their warmest
since extinction of the dinosaurs. Rates of carbon emission today can
be compared to those during onset of the PETM in two ways: (1)
projection of long-term PETM rates for comparison on an annual time
scale and (2) projection of short-term modern rates for comparison on
a PETM time scale. Both require temporal scaling and extrapolation for comparison on the same time scale. PETM rates are few and projection
to a short time scale is poorly constrained. Modern rates are many,
and projection to a longer PETM time scale is tightly
constrained—modern rates are some 9–10 times higher than those during onset of the PETM. If the present trend of anthropogenic emissions continues, we can expect to reach a PETM-scale accumulation of
atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human generations).
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018PA003379
On Thu, 16 Sep 2021 23:56:25 -0400, Oxyaena <oxy...@invalid.invalid>
wrote:
On 9/15/2021 2:07 PM, Pandora wrote:
Massive and rapid predominantly volcanic CO2 emission during the
end-Permian mass extinction
https://www.pnas.org/content/118/37/e2014701118
Temporal Scaling of Carbon Emission and Accumulation Rates: Modern
Anthropogenic Emissions Compared to Estimates of PETM Onset
Accumulation
Abstract
The Paleocene-Eocene thermal maximum (PETM) was caused by a massive
release of carbon to the atmosphere.
This is a benchmark global
greenhouse warming event that raised temperatures to their warmest
since extinction of the dinosaurs. Rates of carbon emission today can
be compared to those during onset of the PETM in two ways: (1)
projection of long-term PETM rates for comparison on an annual time
scale and (2) projection of short-term modern rates for comparison on
a PETM time scale. Both require temporal scaling and extrapolation for
comparison on the same time scale. PETM rates are few and projection
to a short time scale is poorly constrained.
Modern rates are many,
and projection to a longer PETM time scale is tightly
constrained—modern rates are some 9–10 times higher than those during >> onset of the PETM. If the present trend of anthropogenic emissions
continues, we can expect to reach a PETM-scale accumulation of
atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human
generations).
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018PA003379
So we get to see a new Great Dying in the near future? Hooray!
See also Whitmire hypothesis:
https://doi.org/10.1017/S1473550417000271
On Wednesday, September 15, 2021 at 2:07:51 PM UTC-4, Pandora wrote:
Massive and rapid predominantly volcanic CO2 emission during the
end-Permian mass extinction
Abstract
The end-Permian mass extinction event (~252 Mya) is associated with
one of the largest global carbon cycle perturbations in the
Phanerozoic and is thought to be triggered by the Siberian Traps
volcanism.
This seems to be well established from investigation of the
Siberian Traps themselves. On the other hand, I've never
seen any hypotheses as to what caused the PETM,
the subject of the second article whose abstract you
are providing for us, Pandora.
Sizable carbon isotope excursions (CIEs) have been found at
numerous sites around the world, suggesting massive quantities of
13C-depleted CO2 input into the ocean and atmosphere system. The exact
magnitude and cause of the CIEs, the pace of CO2 emission, and the
total quantity of CO2, however, remain poorly known. Here, we quantify
the CO2 emission in an Earth system model based on new
compound-specific carbon isotope records from the Finnmark Platform
and an astronomically tuned age model. By quantitatively comparing the
modeled surface ocean pH and boron isotope pH proxy, a massive
(~36,000 Gt C) and rapid emission (~5 Gt C yr-1) of largely volcanic
CO2 source (~-15%) is necessary to drive the observed pattern of CIE,
the abrupt decline in surface ocean pH, and the extreme global
temperature increase. This suggests that the massive amount of
greenhouse gases may have pushed the Earth system toward a critical
tipping point, beyond which extreme changes in ocean pH and
temperature led to irreversible mass extinction. The comparatively
amplified CIE observed in higher plant leaf waxes suggests that the
surface waters of the Finnmark Platform were likely out of equilibrium
with the initial massive centennial-scale release of carbon from the
massive Siberian Traps volcanism, supporting the rapidity of carbon
injection. Our modeling work reveals that carbon emission pulses are
accompanied by organic carbon burial, facilitated by widespread ocean
anoxia.
https://www.pnas.org/content/118/37/e2014701118
Temporal Scaling of Carbon Emission and Accumulation Rates: Modern
Anthropogenic Emissions Compared to Estimates of PETM Onset
Accumulation
Abstract
The Paleocene-Eocene thermal maximum (PETM) was caused by a massive
release of carbon to the atmosphere.
Release from where, I wonder. The article gives a great many refernces
to the hypothesized rates, but I couldn't find anything about possible causes.
This is a benchmark global
greenhouse warming event that raised temperatures to their warmest
since extinction of the dinosaurs. Rates of carbon emission today can
be compared to those during onset of the PETM in two ways: (1)
projection of long-term PETM rates for comparison on an annual time
scale and (2) projection of short-term modern rates for comparison on
a PETM time scale. Both require temporal scaling and extrapolation for
comparison on the same time scale. PETM rates are few and projection
to a short time scale is poorly constrained. Modern rates are many,
and projection to a longer PETM time scale is tightly
constrained—modern rates are some 9–10 times higher than those during
onset of the PETM. If the present trend of anthropogenic emissions
continues, we can expect to reach a PETM-scale accumulation of
atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human
generations).
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018PA003379
The above criticisms notwithstanding, both of these are salutary
reminders of where we are headed if nothing drastic is done.
If the present massive rate of burning of fossil fuels continues
unabated, I predict a collapse of civilization before 2300,
not from global climate change -- drastic though that will be -- but from the inability to adjust
to the new realities of how all our energy-dependent devices will be powered. >Motor vehicles will be where the change will be most acutely felt.
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018PA003379
So we get to see a new Great Dying in the near future? Hooray!
Sounds like a Great Death Wish. :)
See also Whitmire hypothesis:
https://doi.org/10.1017/S1473550417000271
It talks a lot about the Principle of Mediocrity, which is ironic since the paper
is a case of "how to lie with statistics" [which is the title of a classic book
on the misuse of statistics]. It reminds me of the projections of the population
in the 1950's that assumed the rate of increase would continue indefinitely, >following an exponential curve.
The paper reads like it was written by some student of statistics trying
to put some ideas together for a term paper, with the professor more >interested in originality than in realism. If so, it must have held the professor's
attention much better than the usual term paper that had been turned in
for decades, and the professor would have been happy for the relief from >boredom that the other term papers may have occasioned.
If anyone disagrees with this assessment, I welcome reasoned criticisms,
but not hypocrisy from the usual sources about me criticizing people not present.
If I get that kind of pushback, I will be motivated to send the author
my reasons for the above assessment -- but not the assessment itself.
The assessment is based on the speculation that, as is the case with almost everything
in the Elite West, originality is valued above truth or beauty. [One need only >look at the acclaim given Serrano's "Piss Christ" to see how that can play out.]
But I have to take all such things on a case by case basis, and this could
be one of the exceptions.
On Friday, September 17, 2021 at 6:32:17 AM UTC-4, Pandora wrote:
On Thu, 16 Sep 2021 23:56:25 -0400, Oxyaena <oxy...@invalid.invalid>
wrote:
On 9/15/2021 2:07 PM, Pandora wrote:
Massive and rapid predominantly volcanic CO2 emission during the
end-Permian mass extinction
<snip of well written abstract>
https://www.pnas.org/content/118/37/e2014701118
Second article:
Temporal Scaling of Carbon Emission and Accumulation Rates: Modern
Anthropogenic Emissions Compared to Estimates of PETM Onset
Accumulation
Abstract
The Paleocene-Eocene thermal maximum (PETM) was caused by a massive
release of carbon to the atmosphere.
I wonder how this was determined in the absence of known causes
of the release. If the situation were like it is now, the unusual level of warming
could have triggered the release of vast amounts of methane from clathrates deep in the oceans, and the methane would have been a major contributor: methane, CH4, is a more potent greenhouse gas than CO2.
This is a benchmark global
greenhouse warming event that raised temperatures to their warmest
since extinction of the dinosaurs. Rates of carbon emission today can
be compared to those during onset of the PETM in two ways: (1)
projection of long-term PETM rates for comparison on an annual time
scale and (2) projection of short-term modern rates for comparison on
a PETM time scale. Both require temporal scaling and extrapolation for >>>> comparison on the same time scale. PETM rates are few and projection
to a short time scale is poorly constrained.
I'll have to read the article carefully to decipher the preceding sentence and also the next one:
Modern rates are many,
and projection to a longer PETM time scale is tightly
constrained—modern rates are some 9–10 times higher than those during >>>> onset of the PETM. If the present trend of anthropogenic emissions
continues, we can expect to reach a PETM-scale accumulation of
atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human
generations).
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018PA003379
So we get to see a new Great Dying in the near future? Hooray!
Sounds like a Great Death Wish. :)
Massive and rapid predominantly volcanic CO2 emission during the
end-Permian mass extinction
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