Why was the Pliocene so warm?

The Pliocene Epoch had roughly about the same amount of CO2 in the atmosphere as today, yet it was so much warmer than today all of the glaciers melted. Since man did not exist back then we know it was from natural causes.
What natural cause(s) warmed the planet during the Pliocene?

Originally posted by @metal-brain
The Pliocene Epoch had roughly about the same amount of CO2 in the atmosphere as today, yet it was so much warmer than today all of the glaciers melted. Since man did not exist back then we know it was from natural causes.
What natural cause(s) warmed the planet during the Pliocene?

How do you know it was warm back then?

Jimmy had it last and I think he went to the bathroom with it.

Originally posted by @metal-brain
The Pliocene Epoch had roughly about the same amount of CO2 in the atmosphere as today, yet it was so much warmer than today all of the glaciers melted. Since man did not exist back then we know it was from natural causes.
What natural cause(s) warmed the planet during the Pliocene?

It's really your opinion and nothing more. CO2 was high back then and temperatures were 3 or 4 degrees C higher, enough to melt all the ice.

And you find no problem in Earth having the same numbers today and we see an increase in global temperatures.

https://www.scientificamerican.com/article/ice-free-arctic-in-pliocene-last-time-co2-levels-above-400ppm/

Originally posted by @sonhouse
... CO2 was high back then and temperatures were 3 or 4 degrees C higher, enough to melt all the ice.
...
https://www.scientificamerican.com/article/ice-free-arctic-in-pliocene-last-time-co2-levels-above-400ppm/

As the link explains, it takes a while for the ocean and atmosphere to respond to a rapid rise in carbon dioxide thus "the Arctic today is not in equilibrium with the greenhouse gas settings, meaning that we have to expect significant increases in [Arctic] temperature and precipitation even if the level of greenhouse gases keeps constant,"

The more up-to-date scientific analysis indicates CO2 levels were (for the early and middle Pliocene but not for the late Pliocene when the climate was colder than what it was now) probably higher back then than now.

This isn't explained in this above link but previous estimates of CO2 levels back them where initially based on relatively pure quality disturbed samples considered as unreliable and open to some interpretation but these much more recent good quality core samples have increased that estimate. (there was a link to that but don't remember its address. Does anyone have it to give it here? )

Also, more CO2 is not the only explanation why it was warmer back then as there were multiple natural causes, not just CO2.
Another explanation for most of the Pliocene period being warmer than the present day ( except the late Pliocene ) is that the albedo of the Earth would have been lower than what it is today due to less glaciers at the poles. Less ice means less albedo which means more solar radiation absorbed at the Earth's surface which means higher average global temperatures maintained. The late Pliocene had more glaciers as well as less CO2 which at least partly explains why it was cooler.

Also note:
http://en.wikipedia.org/wiki/Pliocene_climate
"...decreasing carbon dioxide levels during late Pliocene may have contributed substantially to global cooling and the onset of northern hemisphere glaciation...."

In other words, there is evidence that CO2 decreased below 400ppm in late Pliocene and the temperature also decreased And by a significant amount as well. The evidence for the causal link between CO2 concentration and climate it just overwhelming.

Originally posted by @deepthought
How do you know it was warm back then?

The science says it was warmer in the early and middle Pliocene but not in the late Pliocene; that's the same science that, contrary to what he claims, now says CO2 levels were probably higher back then (for the early and middle Pliocene but not for the late Pliocene). No doubt, because the science contradicts his beliefs, he will now say the science must be wrong rather than change is beliefs. But none of the science really supported his beliefs in the first place and he merely twisted the interpretation of the links (those few he actually bothered to read) to fit in with whatever he wants to believe.

Originally posted by @humy
As the link explains, it takes a while for the ocean and atmosphere to respond to a rapid rise in carbon dioxide thus "the Arctic today is not in equilibrium with the greenhouse gas settings, meaning that we have to expect significant increases in [Arctic] temperature and precipitation even if the level of greenhouse gases keeps constant,"

The more up-to-da ...[text shortened]... ll. The evidence for the causal link between CO2 concentration and climate it just overwhelming.

Also, I don't see mention of methane levels, since it is some 20X stronger greenhouse gas it would only take 1/40th the amount of methane to = 50% increase in greenhouse effect.

Originally posted by @humy
As the link explains, it takes a while for the ocean and atmosphere to respond to a rapid rise in carbon dioxide thus "the Arctic today is not in equilibrium with the greenhouse gas settings, meaning that we have to expect significant increases in [Arctic] temperature and precipitation even if the level of greenhouse gases keeps constant,"

The more up-to-da ...[text shortened]... ll. The evidence for the causal link between CO2 concentration and climate it just overwhelming.

"In other words, there is evidence that CO2 decreased below 400ppm in late Pliocene and the temperature also decreased And by a significant amount as well. The evidence for the causal link between CO2 concentration and climate it just overwhelming."

You are such a moron!

Yes, there is a causal link. Temps come first then CO2 follows. Temps cause CO2 levels to rise because the ocean cannot hold as much CO2 when the climate is warmer.

I have pointed out this before many times only for you to ignore it and embrace the falsehoods of Al Gore. Your cause and effect is backwards.......again!

http://www.co2science.org/articles/V6/N26/EDIT.php

Get it through your thick skull!

Originally posted by @humy
The science says it was warmer in the early and middle Pliocene but not in the late Pliocene; that's the same science that, contrary to what he claims, now says CO2 levels were probably higher back then (for the early and middle Pliocene but not for the late Pliocene). No doubt, because the science contradicts his beliefs, he will now say the science must be ...[text shortened]... the links (those few he actually bothered to read) to fit in with whatever he wants to believe.

Moron!

http://www.co2science.org/articles/V6/N26/EDIT.php

Originally posted by @metal-brain
"In other words, there is evidence that CO2 decreased below 400ppm in late Pliocene and the temperature also decreased And by a significant amount as well. The evidence for the causal link between CO2 concentration and climate it just overwhelming."

You are such a moron!

Yes, there is a causal link. Temps come first then CO2 follows. Temps cause C ...[text shortened]... again!

http://www.co2science.org/articles/V6/N26/EDIT.php

Get it through your thick skull!

So prove the cause and effect then, stop calling people moron's when atmospheric scientists say differently. Obviously there are more than one greenhouse effects going on, I mentioned one, methane, which is about 20X more potent greenhouse effect than CO2 and therefore even an increase of methane to 1/40th the amount of CO2, the affect would be a 50% increase in greenhouse effect.

Originally posted by @sonhouse
So prove the cause and effect then, stop calling people moron's when atmospheric scientists say differently. Obviously there are more than one greenhouse effects going on, I mentioned one, methane, which is about 20X more potent greenhouse effect than CO2 and therefore even an increase of methane to 1/40th the amount of CO2, the affect would be a 50% increase in greenhouse effect.

Henry's Law. There is your proof.

Atmospheric Physicists don't say differently.

Observe it for yourself. Take two cans or bottles of soda or beer out of the cooler and open them. Put one back in the cooler /fridge and leave the other out to warm while open. The one left out to warm will have less carbonation than the one in the fridge.

Also, this is why ocean acidification is limited. With a warmer climate the ocean cannot hold as much CO2 and that limits acidification (less alkaline). Notice that
alkalinization does not mean less acidic by definition. Acidification and ocean acidification are different. Notice ocean alkalinization does not exist in wikipedia. Just because wikipedia says something does not make it true. Calling something less alkaline to be acidification is just stupid. The only purpose is to mislead.


https://medical-dictionary.thefreedictionary.com/alkalinization

Originally posted by @metal-brain
Henry's Law. There is your proof.

Atmospheric Physicists don't say differently.

Observe it for yourself. Take two cans or bottles of soda or beer out of the cooler and open them. Put one back in the cooler /fridge and leave the other out to warm while open. The one left out to warm will have less carbonation than the one in the fridge.

Also, t ...[text shortened]... only purpose is to mislead.


https://medical-dictionary.thefreedictionary.com/alkalinization

You don't get my argument about methane?

Originally posted by @sonhouse
You don't get my argument about methane?

What argument? Source of information please.