Global warming update
April warmer, but overall the world a tad cooler since Jan. 1.
We noted in today's Inquirer article that officially the first four months of the year constituted the warmest Jan. 1 through April 30 period on record in Philadelphia.
Yet again we learn that the weather in Philadelphia or any other locality is not necessarily a bellwether of what is happening worldwide.
The most recent world climate report by the National Climate Data Center states that globally those first four months were the coolest such period in four years.
As for April, while things were cooling down somewhat around here, it was the fifth-warmest April in the period of record dating to 1880.
The April world temperature, 57.9 degrees Fahrenheit, was 1.17 degrees above 20th Century averages, but not quite as toasty as April 2011, which came in at 58.1.
The Northern Hemisphere was on fire last month, registering the warmest April on record, according to NCDC. Again, Philadelphia was on the tepid side of that trend, with temperatures a mere 1.5 degrees above the 30-year normal.
The general warming in April probably had to do with the dissipation of the La Nina cooling of sea-surface temperatures in the tropical Pacific.
Right now, temperatures out that way are close to normal, and what happens next is a crap-shoot.
About half the models see conditions remaining "neutral," and half foresee the onset of El Nino, an anomalous warming, acccording to the lastest update from the World Meteorological Ogranization.
El Nino might be splendid news for Gulf and East Coast residents: That warming generates strong upper-air winds that can snuff out incipient hurricanes.