How we talk about the weather
When the National Weather Service says "Once in 1000 years," do they mean the Middle Ages?
Between late July and late August of this year, there were six"1-in-1000 year" rainfall events in the U.S., according to the National Oceanic and Atmospheric Administration (NOAA). It’s a funny way to say there’s a “0.1% chance per year” of something occurring (which is what NOAA means by it), because that’s not what anyone hears when you say “once in a thousand years.” And of course over here at Modern Medieval, looking back a thousand years makes us think about the Middle Ages.
As we’re writing this, wave after wave of rain is pummeling the coast of California, a state that was (and still will be) experiencing an extreme drought. A few weeks ago, a winter storm smashed through the U.S., dropping over a foot of snow on David in Minnesota, before heading east towards Matt. It was a significant snowfall event in Minnesota, the fourteenth biggest ever and the fourth biggest for January. And of course, there was the deadly blizzard/ bomb cyclone that buried Buffalo (and shut down travel across the country, wreaking havoc) and killed at least 28 people and dumped four feet snow on the region. It was a “rare and deadly” combination of wind and snow that as it descended on the country was consistently described as: “Once-in-a-generation.” This phrase led the headlines across the country, a term picked up from the National Weather Service. But what is, in fact, a generation? How are we supposed to understand the phrase if next winter there is another similar weather event? How do these assertions of rarity work?
Language is less important than keeping the heat on, staying above the waters, surviving, mitigating harms, limiting the effects of climate change. But how we talk about extreme weather has a history just as the weather itself does. Until very recently, for example, professional meteorologists were discouraged from linking specific weather events to climate change, even when the probabilities of such a linkage were overwhelming. That’s really only changed in the last decade.
But our language that frames discrete events as unusual in the passing of time - “once a generation,” “once-a-century,” “once-a-millenium,” etc. - needs a lot of work. For example, NOAA says that 1-in-1000 years was never meant to mean literally only once in a thousand years, but “is given to an event that forecasters deem only to have a 0.1% chance of occurring in any given year -- a 1 in 1,000 chance. An 0.5% chance is deemed a "1-in-500-year" event, while a 1% chance is a "1-in-100-year" event, and so forth.” That sort of makes sense but it can confuse as much as it clarifies. Here, perhaps is where meteorologists need humanists (including folks expert in science communications). As medievalists anyway, we’re pretty sure that if someone says "one in 1000 years" event, people will hear that it's an event likely only to happen once in a thousand years - that the medieval has once again intruded into our own modern world.
Towards the end of his 9th-century CE history (written close to the end of his life), the Frankish historian, abbot, noble, warrior, and court advisor Nithard wrote about the horrors of the civil war that ripped the Carolingian Empire apart. And to convey that sense of doom, of disorder, he talked about the weather.
From this history, everyone may gather how mad it is to neglect the common good and to follow only private and selfish desires, since both sins insult the Creator so much, in fact, that He turns even the elements against the madness of the sinner…In the times of Charles the Great of good memory, who died almost thirty years ago, peace and concord ruled everywhere because our people were treading the one proper way, the way of the common welfare, and thus the way of God. But now since each goes his separate way, dissension and struggle abound. Once there was abundance and happiness everywhere, now everywhere there is want and sadness. Once even the elements smiled on everything and now they threaten, as Scripture which was left to us as the gift of God, testifies: And the world will wage war against the mad.
About this time, on March 20 , there occurred an eclipse of the moon. Besides, a great deal of snow fell in the same night and the just judgment of God, as I said before, filled every heart with sorrow. I mention this because rapine and wrongs of every sort were rampant on all sides, and now the unseasonable weather killed the last hope of any good to come.
Nithard is an interesting fellow. He was the advisor of Charlemagne’s grandson Charles the Bald and an illegitimate grandson of Charlemagne himself. We’ll be saying a lot more about Nithard’s Histories, and Charles the Bald, and Charles the Great, and the chaos of the 840s, and more in our new book Oathbreakers.
But how extreme weather is discussed, and how people react to that extreme weather, conveys meaning. For Nithard, the late snow was a sign of God’s displeasure with his new chosen people (the Franks) - that their sin had made even the elements turn against them and “killed the last hope of any good to come.”
The subtext of this, however, is quite different. Nithard despairs but there’s a remedy - returning to the “way of the common welfare” as had existed in the time of his grandfather, the great emperor Charlemagne. As he closes his Histories, this is weather that Nithard says his audience can’t do anything about, even as he’s saying they actually can.
In this, our own modern world, the “once in a thousand years” rhetoric should similarly perhaps adapt to the moment - to add context about what we can (or can’t do) in the face of nature’s fury. As we see from Nithard, the weather will come. It’s up to us humans to interpret it, to act.
Carolingian Chronicles, ed. and trans. Berhard Walter Scholz (University of Michigan Press, 1970), p. 174. https://archive.org/details/carolingianchron0000scho_j6w2
If you want to experience true weather obsession, read the diaries of Samuel Pepys: it was a thing for him. Also, the Tudor-era historians and letter writers commenting on the Thames freezing over and the sharp downturn in temps during the reign of Elizabeth, which of course some attributed to the horrors of have a FEMALE on the throne. Sigh.
Gosh, just the header amuses me!