claim: Global average temperatures over land have plummeted by more than 1C since the middle of this year – their biggest and steepest fall on record.
evidence: The Paleocene–Eocene thermal maximum was an approximate 200,000 year long event where the global average temperature rose by some 5 to 8 °C ( 9 to 14 °F ), and mid-latitude and polar areas may have exceeded modern tropical temperatures of 24–29 °C ( 75–84 °F ).