Turns out the CO2 levels were much less than originally thought for the Eocene. Add in the unusual temperature claims and there is much to consider. My first concern is that the ten to even twenty degree shift appears grossly exaggerated and only possible at the poles. In out own experience, a half degree global warming trend promoted a five degree shift during the past generation at the pole. By the same token, a one degree shift could produce those ten degree polar changes.
That is a lot of doubt on those Eocene claims. Just as surely, a ten degree shift at the equator, already maxed out would drive massive extinctions and massive biological adjustments as well. I do not think that happened at all. Then the reversal into the ice age would have decimated those changes. It did not happen that way.
Accepting Eocene temperature claims as is happens to be seriously problematic but expensive to properly redress. In the meantime it provided a convenient 'proof' of the climate warming CO2 hypothesis. This is scientific rubbish that demands extreme evaluation simply because the central claims are extraordinary. Now one of its core findings is crumbling on its own.
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Climate models to be scrapped? Scientists “retract” previous belief about carbon dioxide levels during last warming period
Wednesday, October 18, 2017 by: Isabelle Z.
Tags: atmosphere, carbon dioxide, carbon dioxide levels, climate change, climate models, climate science, early Eocene period, Earth, research, Super Greenhouse period, temperatures
https://www.naturalnews.com/2017-10-18-climate-models-scrapped-carbon-dioxide-levels-warming.html
(Natural News)
As if the conflicting information and endless debates about climate change and carbon dioxide levels
were not confusing enough, a new study has found that carbon dioxide
levels were actually much lower than previously believed during the last
“warm” period on the planet, illustrating just how difficult it is to
make conclusive statements about the topic.
Earth’s early Eocene period, also known as the Super Greenhouse
period, was commonly believed to have concentration levels of carbon
dioxide of as much as 2,000 parts per million (ppm). However, Dartmouth
College researchers have discovered that it could have been less than
1,000 ppm – a difference of half!
This could also mean that carbon dioxide is not the primary driver of
planetary warming events, as other factors now have stronger weight on
the final result.
To put this in perspective, the levels of carbon dioxide that are
currently observed at the Mauna Loa Observatory of the National Oceanic
and Atmospheric Administration (NOAA) are roughly 400 ppm.
The Super Greenhouse period is often studied by climate researchers
to gain a clearer understanding of how the planet has historically
responded to carbon dioxide level changes and to help form climate
projections. It began around 60 million years ago and ended roughly 40
million years ago. During this time period, the Antarctic and Arctic
were believed to be free of ice, and temperatures were around 10 degrees
Celsius warmer than they currently are.
Five extreme warmth periods occurred during the early Eocene when the
planet’s temperatures rose by as much as 8 degrees Celsius further on
top of the 10-degree hotter average that characterized the period. This
means that the temperature was 32 degrees Fahrenheit hotter on average
than today, which is not an insignificant difference. Even though power
plants and cars were very much unheard of 56 million years ago, the
same carbon was released into the atmosphere. Researchers could never
quite explain where that carbon had come from and how it was released
until now.
Novel method led to surprising finding
The researchers turned to a new method to help reconstruct the levels
of carbon dioxide that have been associated with the rises in
temperature during the early Eocene period. They used sediment samples
taken from deep-sea and land drilling sites and assessed their carbon dioxide concentrations.
Using the carbon-12 to carbon-13 isotope ratio from these samples, they
determined that the carbon most likely can be traced to thawing
permafrost at the time.
Dartmouth College Obering Postdoctoral Fellow Ying Cui said, “This
changes our understanding of what the concentration of carbon dioxide
should be in relationship to global temperature as well as how we should
revisit climate models in order to better project future climate
change.”
Despite their useful finding, it is still uncertain what could have triggered the warming that spurred the release of the extra carbon into the planet’s atmosphere. Other research shows that water vapor and extreme volcanic activity in earlier warming periods plays a role.
Could this technique be used to provide valuable insight on a wider scale?
Now, Cui says the challenge is reconstructing past carbon dioxide
concentrations and using the knowledge gleaned to inform current
thinking. Despite taking place more than 50 million years ago, Cui says
the research is directly related to modern efforts to understand current
trends and predict how natural dynamics and human activities might
affect the planet’s temperatures in the future.
Next, the team is hoping to use their new technique to help expand the present understanding of carbon dioxide’s role
across a much bigger stretch of the planet’s history. They are hoping
to come up with useful information for economists and policy makers
regarding how ecosystems can evolve after rapid periods of climate
change.
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