Paleoclimate Reconstructions Continue To Document A Much Warmer-Than-Today Holocene

According to a new study, eastern Mediterranean summer temperatures were 1.5°C to 3°C “greater than the present” from about 11,000 to 7,000 years ago, when CO2 levels were approximately 265 ppm. Then the temperatures “followed a gradual decline towards present-day conditions”.

“The MTWA also showed an increasing trend from 9 ka and reached a maximum of ca. 1.5°C greater than the present at ca. 4.5 and 5 ka, followed by a gradual decline towards present-day conditions. … The TRACE-21k-I simulation shows peak summer temperatures between 11 and 9 ka, when the MTWA was ca. 3°C greater than the present”

Image Source: Cruz-Silva et al., 2023

Another new study indicates the climate average was much warmer (19.9°C) during the mid-Holocene than today (13°C) in Japan. The climate here was also warmer than today ~35-40,000 and ~55-60,000 years ago, when CO2 was said to be under 200 ppm.

“The average temperature during the period from 5.4 to 3.8 ka … is 19.9°C ± 6.0°C and is higher than the present cave temperature of 13°C.”