Where is my Summer?

Ames, IA (July 28, 2013)

Unicorn Golden Bee

My father was commenting today that the temperatures in Italy (he lives in a small village in the Alps) are now unusually low (15ºC = 60ºF last night), for being close to "Ferragosto" (15 of August), and that the summer must be ending. If that's the case then summer in Iowa is also a goner: our minimum temperature yesterday night was below 12ºC (54ºF). Is this unusual? Well, it is a little on the cold side but it is not unprecedented (record minimum cold temperature in August according to Wikipedia has been 4ºC = 40ºF) and I would not be surprised if we get more hot sweltering weather (35ºC at night with 80% humidity) before the end of the month. So, where is it global warming when you need it? Well that's about the climate, not the weather. What is steadily increasing is the global average, and to see that you need to average over a sufficient number of years. Blaming individual data points (the weather here and today) to climate change is a little tricky: local weather does what it wants. In fact one of the consequences of climate change is precisely to increase the local variability: put more energy in the system and it will move out of equilibrium, enhancing its oscillations around a slowly increasing average. So, don't trust somebody saying that global warming must have stopped because today is cold: that's not what climate change is responsible for. On a separate note, I can officially announce the discovery that unicorns exist! They are golden and they fly, indeed.