More Evidence Emerges That Mid-Holocene Sea Levels Were 1.5 to 3 Meters Higher Than Today

Two new studies indicate centennial-scale sea level rise rates ranged up to 29-45 mm/yr during the period between 14,500 and 8000 years ago, when CO2 levels were 250 to 265 ppm.

From NoTricksZone

By Kenneth Richard on 9. March 2023

Two new studies indicate centennial-scale sea level rise rates ranged up to 29-45 mm/yr during the period between 14,500 and 8000 years ago, when CO2 levels were 250 to 265 ppm.

Modern global sea level rise rates have been reported to be 1.56 mm/yr for 1900-2018, decreasing slightly to 1.3 to 1.5 mm/yr during 1958-2014 (Frederikse et al. (2020) and Frederikse et al., 2018).

But from 9000 to 8000 years ago sea levels in the East Vietnam Sea rose 29 meters – from -35 m to -6 m relative to present levels (Thanh et al., 2023). That’s 2.9 m per century, or 29 mm/yr. Sea levels then rose another 7.5 m from 8000 to 6700 years ago. At that time (6700 to 5500 years ago), sea levels were 1.5 m higher than present.

Image Source: Thanh et al., 2023

Another new study (a thesis) indicates global sea levels rose 13.5 m in 300 years (45 mm/yr), even 6.5 m in 140 years (>46 mm/yr), during the centuries centered around 14,500 years ago. Sea levels ultimately rose to 3 m higher than present throughout the Holocene’s sea level highstand.

At sites along the coasts of New Zealand sea levels were 1.2 to 2.5 m higher than today for much of the last 7000 years, or before sea levels fell to present levels in the last millennium.