Central Greenland was nearly 14 °C (24.5 °F) colder during the Younger Dryas than it is today.
Notes on verification
Multiple independent peer-reviewed sources (PNAS, Science) and secondary references (Wikipedia/Britannica) corroborate a Younger Dryas cooling of roughly 9-15°C in central Greenland, consistent with the ~14°C claim, though exact magnitude varies by proxy and method.
Sources
- Younger Dryas | Definition, Causes, & Termination (britannica.com)
- https://www.pnas.org/doi/10.1073/pnas.1202183109 (pnas.org)
- https://www.science.org/doi/abs/10.1126/science.1254961 (science.org)