Philadelphia Skating Club performing a rescue as others skate happily on the Schuylkill in Fairmount Park in the late 19th century; image courtesy Library Company of Philadelphia

This has been a winter to empower the global warming naysayers--with a few snowstorms and freezing temperatures, it's hard to believe that the plant is getting warmer, on average. But a look back in time shows that we've just gotten wimpy.

This past weekend's bitter cold doesn't approach the cold of winters past in Philadelphia. A low in the teens, like we had this weekend, is abnormally cold these days. But most of the record lows for the city are much, much colder--with many below zero. Imagine being in Philly on February 9th, 1934: it was -11 degrees Fahrenheit.

Images even show that people could ice skate on the Schuylkill River in the late nineteenth century, and one image from the winter of 1856 shows skaters on the Delaware. Overall, as this graph shows, the past 20 years have been trending warmer. That historical perspective isn't making me feel any warmer, though!