[muawiyah]

The deal is that 3 million years ago is BEFORE the current Ice Age ~ which has been running for about 2 million years.

The ocean levels were higher and there was a greater current moving warm water into the Arctic.

One theory is that due to North America's tectonic plate moving further North this has blocked the flow of that warm water which then plunged the Earth into a very long ice age.

Until the plate rotates a different direction, North America will continue to move North and further reduce the flow of warmer water into the Arctic.

My simplistic, but most likely accurate estimation is that it's going to get colder for a very long time.

[o_zarkman44]

I have no disagreements with what you said.

[gleeaikin]

I seem to recall that about 3 million years ago was when the two hemispheres became connected by the isthmus of Panama, which caused major changes in ocean circulation and temperature distribution.

[colorado tanker]

I agree with you guys. Of course it was warmer in the Pliocene. The characteristic of the beginning of the Holocene is our cycle of glacial and interglacial periods. Taking the climate as a whole we've been in a kind of ice age the whole time.

Most scientists think this happened when the isthmus of Panama closed blocking global ocean currents.

So, the pattern is unlikely to break until plate tectonics breaks up the North/South America land mass.

Aren't geologists supposed to know this stuff?