*** The mid-Pliocene was much warmer than today with CO2 levels similar to those caused by man today (400ppm or above). This is about as warm as most climate models predict the earth will be by 2100 – i.e. about +2C above current temperatures. The full 5 million year record of Benthic Fora data gives clear evidence of Milankovitch cycles throughout the period, including a 420K eccentricity cycle in earlier times. However by 3 million years ago glacial cycles had begun to follow a regular 41K obliquity cycle. It was only much later (< 1 million years) that 100k deep glacial cycles began.
