Basically, my comment is that it's no surprise that there was ice melt during the height of
the warming during this interglacial.
Scientists Ellis and Palmer (2016) get right to the point and conclude CO2 plays «little or no» role in forcing
the warming during interglacial periods...
Chief Hydrologist refuses to accept that an abrupt
warming during an interglacial is not physically possible.
Not exact matches
Researchers from the Niels Bohr Institute have analysed the natural climate variations over the last 12,000 years,
during which we have had a
warm interglacial period and they have looked back 5 million years to see the major features of the Earth's climate.
Then they lugged them back to Ohio to begin independent study (IS) projects on characterizing the change in sea levels
during the last
interglacial warming period.
Instead, the fossil record indicates they vanished
during the Earth's glacial -
interglacial transition, which occurred about 12,000 years ago and led to much
warmer conditions and the start of the current Holocene period.
Many of the glaciers that jut out into the ocean are thinning, but whether the ice sheet itself has remained stable and intact, even
during warm interglacial periods, is a matter of considerable debate.
For example, the polar bear specimen from roughly 120,000 years ago survived in Svalbard
during a
warm interglacial period because that Arctic archipelago remained more frozen than other areas.
Previous estimates suggested that peak temperatures
during the
warmest interglacial periods — which occurred at around 125,000, 240,000 and 340,000 years ago — were about three degrees higher than they are today.
During «
interglacials», the temperature was somewhat
warmer and the ice retreated.
During the last 800,000 years, CO2 fluctuated between about 180 ppm during ice ages and 280 ppm during interglacial warm pe
During the last 800,000 years, CO2 fluctuated between about 180 ppm
during ice ages and 280 ppm during interglacial warm pe
during ice ages and 280 ppm
during interglacial warm pe
during interglacial warm periods.
The fact that ice sheets will respond to
warming is not in doubt (note the 4 - 6 m sea level rise
during the last
interglacial), but the speed at which that might happen is highly uncertain, though the other story this week shows it is ongoing.
No one says that there is anything mysterious about the relationship between raised CO2 levels and
warming / cooling
during glacial /
interglacial cycles.
This is because
warmer conditions
during interglacials encouraged the collapse of ice shelves.
The sequence of climatic forcings and responses
during deglaciations (transitions from full glacial conditions to
warm interglacials) are well documented.
Historically, methane concentrations in the world's atmosphere have ranged between 300 and 400 nmol / mol
during glacial periods commonly known as ice ages, and between 600 to 700 nmol / mol
during the
warm interglacial periods.
This article will use the term ice age in the former, glaciological, sense: glacials for colder periods
during ice ages and
interglacials for the
warmer periods.
Recent instrumental data spans 165 + years
during the past 11,000 + years of the Holocene
interglacial warm period as shown on figure 2.
David B. Benson says: «Somehow the climate survived
during the Eemian
interglacial despite global temperatures about 2 K
warmer than even now.»
The difference between the last glacial maximum (20,000 yrs ago) and today is about 120 meters (400 ft), but the high levels
during some of the
warmest interglacials were 6 - 9 meters (20 to 30 feet) higher than today.
[Response: If this reservoir existed and was so poised to release methane as you speculate, then it would have done something
during warmer conditions early in the Holocene, or in the last
interglacial.
You said: «If this reservoir existed and was so poised to release methane as you speculate, then it would have done something
during warmer conditions early in the Holocene, or in the last
interglacial.
--- What is of concern is what happens when the waters
warm at even greater depths, waters not
warmed enough to release
during prior
interglacials, where there are (presumably) vast quantities of methyl clathrates.
That might well be called nature's global
warming because what happens
during an
interglacial period is the Earth
warms up, the glaciers melt and life flourishes.
The explanation is global
warming and climate changes are now occurring 200 times faster than
during the much slower, Pleistocene
interglacial warming events.
During the previous
interglacial, the Eemian, temperatures were about 2 K
warmer than now and the sea highstand was 4 — 6 meters higher than the current level, depending upon location measured.
Wilmot McCutchen (26)-- We also know that
during the previous
interglacial, the Eemian, that global temperatures were about 2 K
warmer than «at present», i.e., 1950s, and
during that time considerable melt occurred in Greenland (and probably some of WAIS), resulting in a 4 — 6 m sea highstand (different in different locations).
However, although the Arctic is still not as
warm as it was
during the Eemian
interglacial 125,000 years ago [e.g., Andersen et al., 2004], the present rate of sea ice loss will likely push the system out of this natural envelope within a century.
The new results... show that the climate in Greenland was around 8 degrees C. [14.4 degrees F.]
warmer than today
during the last
interglacial period, the Eemian period, 130,000 to 115,000 thousand years ago.
Why should
warming during the current Holocene
Interglacial be significantly different / less than
during the previous Eemian
Interglacial (MIS5e), when sea levels were, per the IPCC's own comments, above modern levels or for that matter above the purported mid-Holocene highstand?
I look at the transitions from glacial to
interglacial and see that
warming is extremely rapid, overshoots by a bit, then never again exceeds the initial overshoot
during the rest of the
interglacial period.
The 12 — 21 cm higher sea level stand
during the MWP is likely the highest sea level since the previous
interglacial period 110,000 years ago, and was produced by an extended period of
warming, allowing time for glaciers and thermal expansion to reach a climatic balance.
It seems likely to me that the level
warming we have had in many periods of this
interglacial period are likely to occur again in the future centuries: And it seems
during most the current of the
interglacial temperatures have as
warm or
warmer than current temperatures, therefore it seems as
warmer or
warmer is most likely.
The planet went from
interglacial warm to glacial cold
during the Younger Dryas period with cooling for around 1000 years.
For example, atmospheric carbon dioxide grew by approximately 30 %
during the transition from the most recent cold glacial period, about 20,000 years ago, to the current
warm interglacial period; the corresponding rate of decrease in surface ocean pH, driven by geological processes, was approximately 50 times slower than the current rate driven largely by fossil fuel burning.
Before the industrial revolution, the natural level of atmospheric CO ₂
during warm interglacials was around 280 ppm.
During the Eemian (the
interglacial before this one about 100,000 or so years ago) sea level was about 9 meters higher than now, presumably because the Earth was
warmer than now and there was then enough water.
During this period, global temperatures were 1.5 - 2.0 °C
warmer than the peak warmth of the present
interglacial, or Holocene, in which we are now living.
It is not accidental that human development has occurred primarily
during the current (
warmer)
interglacial period.
And in terms of our current
interglacial period, there has much
warmer periods
during this time, and that the long trend over 8000 year period has been a slight cooling.
Both panels are reconstructions of oxygen concentrations in the California Margin
during a cold, glacial climate (left, 18,000 years ago) and a
warm,
interglacial climate (right, 14,000 years ago; Moffitt et al. 2015a).
However, we know that severe and abrupt climate shifts of global extent have occurred (infrequently)
during glaciations, and almost never
during warmer interglacial periods such as the current Holocene.
If we have real - world evidence that temperatures were
warmer than today
during most of the past 10,000 years (and also
during several
interglacial warm periods
during the past few million years), and if we also have real - world evidence that human civilization thrived
during these
warmer temperatures and the
warmer temperatures did not trigger so - called «tipping points» sending the planet into a climate catastrophe, then we have very little reason to believe that our presently and moderately
warming temperatures are now poised to send the planet into a climate catastrophe.
We are undeniably in an
interglacial period,
during which the planet
warms.
Study «finds Greenland was resistant to melting
during last
interglacial, despite temps much
warmer than present.
Matthiessen, J. & Knies, J. Dinoflagellate cyst evidence for
warm interglacial conditions at the northern Barents Sea margin
during marine oxygen isotope stage 5.
Based on the empirical evidence of the laboratory experiments, it is quite possible that the increasing CO2 in the atmosphere
during interglacial periods could have amplified the
warming already occurring.
Warm Greenland
during the last
interglacial: the role of regional changes in sea ice cover.
Even if it has been
warmer at times
during the current and previous
interglacials, showing that the forcing is unprecedented, rising and currently overwhelming natural variation can be seen of itself to be sufficient cause for alarm (that it be overwhelming is not quite what the IPCC report states but the more than half post 1950 claim is similar).
http://www.nbi.ku.dk/english/news/news13/greenland-ice-cores-reveal-warm-climate-of-the-past/ «The new results from the NEEM ice core drilling project in northwest Greenland, led by the Niels Bohr Institute at the University of Copenhagen show that the climate in Greenland was around 8 degrees C
warmer than today
during the last
interglacial period, the Eemian period, 130,000 to 115,000 thousand years ago.»