In 1923 it was warmer in Svalbard than it is now.
Romm says that current temperatures in Svalbard are the highest in 1,800 years, so we can deduce that 1923 was more than 1,800 years ago.
High Arctic Warmest In 1,800 Years: ‘The Medieval Warm Period Was Not As Uniformly Warm As We Once Thought’ | ThinkProgress
h/t to Marc Morano
Click to access past_models5.pdf
Romm must have read Dr. Dan Streetmentioner’s Time Traveler’s Handbook of 1001 Tense Transformations. Most readers get as far as the Future Semiconditionally Modified Subinverted Plagal Past Subjunctive Intentional before giving up; and in fact in later editions of the book all pages beyond this point have been left blank to save on printing costs.
Search H2G2 for more info.