How much higher or lower was the sea level in the early Pliocene compared to today ?
The global average temperature in the mid-Pliocene ( 3.3 Ma–3 Ma ) was 2–3 °C higher than today , global sea level 25 m higher and the northern hemisphere ice sheet was ephemeral before the onset of extensive glaciation over Greenland that occurred in the late Pliocene around 3 Ma .