|Mean temperatures for December
Concord, NH, 1871-2007
The weekend was beautiful here in New Hampshire but today we’re back to what has over the past five years started to seem like normal for July: cool and cloudy. I’ve been taking an informal survey this month, asking friends whether they’ve gone swimming yet this summer. Almost nobody has, which we all agree is just weird, and which we all tend to attribute to climate change.
For me, our recent pattern of cool and cloudy summers is becoming a deal-breaker. Reliably nice summers used to be the payoff for living here through the winter, but if I can’t count on summer to be reliably nice, I’m tempted to consider other options. That’d be a big decision though, so I’d like to support it with hard data.
Given all that’s been said and written about climate change, it turns out to be surprisingly hard to get hold of historical climate data. I had to look around quite a while before I found this FTP site where NOAA has parked files full of raw temperature and precipitation data.
The files cover the whole world and they go back a long way. Here’s one line from the mean temperature file:
4257260500201993 -37 -73 -2 85 143 190 219 208 164 88 45 -13
I’ve marked the 3-digit country code in red, the 5-digit World Meteorological Organization station number in blue, and the year in green. What follows are twelve values which are monthly mean temperatures in tenths of degrees Celsius.
Since Concord, NH is the closest WMO station to me — 55 miles away — I uploaded the Concord data for mean temperatures (1871-2007) and precipitation (1859-2007) to Many Eyes, and looked for a recent pattern.
On the temperature front, we’re all very aware that this past December was freakily warm. And as this view shows, there hasn’t been an above-zero-Celsius December since 1982. But there were more (and warmer) above-zero-Celsius Decembers before the midpoint of the time series — 1939 — than there have been since.
I am not saying that the planet isn’t warming or that the climate isn’t changing. But we ought to be able to explore the evidence for these phenomena, and review the interpretations of them, in much more interactive and collaborative ways. Not only for reasons of global policy, but also so we can contextualize what we see happening around us.
Arguing about the weather has undoubtedly been a favorite pastime of our species since we learned how to talk. Now we can have those arguments in the context of actual data. And as questions about climate change grow more critical, it’s imperative that we do. Hats off to Martin Wattenberg, Fernanda Viégas, and their colleagues for creating Many Eyes and showing how we can.