A new temperature reconstruction indicates today’s sea surface temperatures are colder than all but a few millennia out of the last 156,000 years.
A Southern Ocean site analyzed in a new study (Ghadi et al., 2020) has averaged 1-2°C during glacials and 4°C during interglacials. Today, with a 410 ppm CO2 concentration, this location has again plummeted to glacial/ice age levels (2°C).
The site was 2°C warmer than now when CO2 concentrations were 180 ppm about 20,000 years ago, or during the peak of the last ice age. During the Early Holocene (10,000 to 8,000 years ago), summer sea surface temperatures were also 2°C warmer than today.
There is no indication that CO2 concentration changes are in any way correlated with temperature changes throughout this entire 156,000-year epoch.