[Coral-List] Sea Level rise

Eugene Shinn eugeneshinn at mail.usf.edu
Fri Mar 4 18:05:44 UTC 2022

Dear Listers, What always bothers me about the relation between CO2 and 
temperature is how can we be sure anthropogenic CO2 is the cause of 
rising temperature and sea level rise. Ice cores are not my field of 
study but I know that abundant data from ice cores, such as the Vostok 
core, indicate a relationship between temperature and CO2. Clearly the 
CO2 associated with temperature increases in the past were not caused by 
burning fossil fuels. The ice cores show 4-distinct evenly spaced 
temperature rises during the Pleistocene. In addition, the rise in CO2 
usually peaks a few hundred years after the peak temperature. I suppose 
that can be explained by CO2 expelled from the oceans due to increasing 
warmth. But what caused the temperature increase in the first place?

Cores of the Pleistocene limestone that built the Florida Keys also show 
3 to 4 periods of climate temperature change. The changes are marked by 
iron rich red/brown soil layers caping each sedimentary unit. These 
layers are identical to the well-studied soil stone layers presently 
forming on the surface of Florida Keys limestone. It is clear the 
Pleistocene layers represent periods of limestone exposure and thus 
indicate lowered sea level. I am guessing these sea level fluctuations 
are analogous to the fluctuations indicated in ice cores. I think we can 
safely conclude the red/brown layers in the Pleistocene Keys limestone 
indicate sea level fluctuations caused by something other than burning 
fossil fuel.

How much sea level fluctuation the Pleistocene ice core temperature 
changes represent is not generally known, but there is good geological 
evidence that the last one, the 125,000 year-old temperature increase 
(known as isotope stage 5 e) raised sea level around 27 ft above 
present. I live on land formed at that time as are people living in the 
Florida Keys. That the land formed when sea level was around 27 ft 
higher than today could not have been caused by humans burning fossil 
fuel. This may suggest the present sea level rise might also go as high 
as it did 125,000 years ago. So how do we explain all this. Presumably 
the Carbon isotopes in the present atmospheres CO2 identify some as the 
result of burning fossil fuel. Can we identify those same isotopes in 
the 125,000 year old temperature rise? I suspect the answer is no. There 
were not enough people back then to create excess CO2. This suggests we 
still do not know what caused stage 5 e. What ever caused sea level rise 
back then may also be the cause of the present sea level rise. Or maybe 
rising CO2 is not what is causing the present rise. I am just asking the 
question? I think we have a long way to go before we truly know what is 
causing the present sea level rise? And, will it rise as high as it did 
during stage 5 e? Possibly we need to remove politics from the question 
before we have the correct answer? Gene

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