If you’re looking for proof of climate change, consider that Londoners used to hold festivals on the frozen Thames that could go on for weeks. Of the 1683-84 “frost fair,” pictured above, diarist John Evelyn wrote:

Coaches plied from Westminster to the Temple, and from several other stairs too and fro, as in the streets, sleds, sliding with skates, bull-baiting, horse and coach races, puppet plays and interludes, cooks, tippling and other lewd places, so that it seemed to be a bacchanalian triumph, or carnival on the water.

Between 1400 and 1814 there are 23 documented cases of the Thames freezing over. The last fair lasted only four days, though; the climate was changing, and the river ran more swiftly as it was embanked during the 19th century.