03-20-23, 12:27 PM
From HERE
I should add that the historical climate seems to be better explained by the amount of ice that builds up at the poles (which depends on how much land-mass there is above sea level close to the poles and the Milankovitch Cycles as well).
The amount of sunlight reflected by the ice at the poles (which can also move down toward the equator if enough ice builds up) and by the cloud on the Earth can vary by between 25% to 50%.
The current amount reflected is 29.83% which puts us in a cold episode historically (still warmer than the 33% reflected during the ice ages) but go back to Pangea when there was very little land-mass near the poles and most of the land-mass was near the equator. You still have clouds reflecting the sunlight back but it is only 25% and there is no ice and the Earth is the hottest it has ever been at close to 25.0C versus today at 15.0C.
No CO2 needs to be involved in this explanation at all. In fact, in the early years of the Pangea hothouse, CO2 levels were lower than today. At other times, CO2 was 30 times higher than today and almost the entire Earth was frozen.
That signals a negative feedback for GHGs (clouds most likely) but a strong ice-Albedo feedback (which is still hard to change – it takes a lot of extra ice or a lot less ice at the poles to change the Albedo numbers by enough).
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EDITED to create paragraphs.
I should add that the historical climate seems to be better explained by the amount of ice that builds up at the poles (which depends on how much land-mass there is above sea level close to the poles and the Milankovitch Cycles as well).
The amount of sunlight reflected by the ice at the poles (which can also move down toward the equator if enough ice builds up) and by the cloud on the Earth can vary by between 25% to 50%.
The current amount reflected is 29.83% which puts us in a cold episode historically (still warmer than the 33% reflected during the ice ages) but go back to Pangea when there was very little land-mass near the poles and most of the land-mass was near the equator. You still have clouds reflecting the sunlight back but it is only 25% and there is no ice and the Earth is the hottest it has ever been at close to 25.0C versus today at 15.0C.
No CO2 needs to be involved in this explanation at all. In fact, in the early years of the Pangea hothouse, CO2 levels were lower than today. At other times, CO2 was 30 times higher than today and almost the entire Earth was frozen.
That signals a negative feedback for GHGs (clouds most likely) but a strong ice-Albedo feedback (which is still hard to change – it takes a lot of extra ice or a lot less ice at the poles to change the Albedo numbers by enough).
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EDITED to create paragraphs.
“A theory that is not refutable by any conceivable event is non-scientific.” – Karl Popper
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