Did an ice sheet collapse 120,000 years ago pushing sea levels up to 9m higher than today?

Proving that nature can outdo anything humans have done, a new paper shows that sea-levels off Western Australia may have risen as high as 9 m above the current level during the last warm period over a hundred thousand years ago. The authors (O’Leary et al) conclude that seas were 3-4 m higher for most of the last warm period (known as the Eemian) but towards the end of the period a large sudden rise occurred. They suggest that an ice shelf collapsed in Antarctica or Greenland or both, causing a 5m rise (17 feet).

The point of the paper was this double spiked shape of the sea level rise during the last warm interglacial known as the Eemian.

The Age interviewed O’Leary who said “he was confident that the 17-foot jump happened in less than a thousand years – how much less, he cannot be sure.”

Figure 3 j Relative sea-level curve for Western Australia. Ageomorphically defined palaeoMSL datum of C2:5m 120 kyr ago (Fig. 1c) anchors a predicted relative sea-level curve at Red Bluff, which includes a GIA signal based on the test calculation (see Methods) plus the following ESL history: ESL jumps from 0 to 3.4m […]