Humans are very good at seeing patterns. We even find patterns where they don’t really exist, thus reminders such as “Correlation is not causation” and “post hoc ergo propter hoc.” We also build mental and mathematical models. We create structures to help us organize and predict what the world will do. Some of these are very durable and have stood the test of time and experience. Others . . . don’t do as well. And a few are so far out there that a lot of people enjoy listening to them but don’t believe them. [I.e. “I’m not saying that it was necessarily aliens, but . . .”]
One thing historians, archaeologists, and other people who live in the past do is look for patterns. Sometimes literally, so that we can identify the culture that created [thing], or for hints of written communication. We study aerial photos and satellite images searching for traces of missing or long-gone dwellings, forts, fields, and roads. We read accounts of events and goings on, hunting for hints about the bigger picture. A lot of environmental history, especially once you get to the centuries before modern thermometers, barometers, and the like, is combing through diaries, tax reports, inventories of foodstuffs and fiber, and government or corporate forms, trying to suss out what was going on in the background that no one bothered to write about because everyone knew what was happening. Like Dagomar Degroot pouring over ships’ logs and harbor reports to determine what the weather was in and around the Dutch Republic in the 1600s-1700s.
Our patterns are based on the past. We track recorded events and happenstances and compare them to modern, or make note of how people responded to storms, floods, freezes, and droughts. As Degroot points out, emperical data don’t tell us about how storms affected people’s lives, and how people adapted. The Dutch developed a number of adaptations that allowed them to survive the Little Ice Age in much better shape than did other places, but they still suffered. (The Wars of Independence [80-Years War and Anglo-Dutch Wars, and Louis XIV’s wars] didn’t help.) We’re looking at weather and climate events that already happened.
Weather forecasting tries to sort out, based on physics, chemistry, geology, and past events, what will happen in the near future. Anyone who puts their faith in a long-term weather forecast to, oh, plan a hiking trip, or an outdoor wedding, needs to have a back-up plan, unless he lives in one of those places with certain climates. No one in Jerusalem, for example, will plan an outdoor-only event for December that requires warm weather and sun, because winter is the rainy season. Likewise people who live in the Rocky Mountains know that thunderstorms form around two in the afternoon. Minnesotans assume that February will be cold and March-April will have mud. But to foretell on January 18 what will transpire on March 7th? Not likely. Even a week or 10 days from today is . . . fraught. If you are in Texas, it will be warm, possibly dry or not, perhaps windy or not, maybe humid or not. How warm? Above 60 F is as far as I’m willing to go, and I won’t put money on that.
Climate forecasting? Relies on models. Models are mathematical constructs of a very simplified world, with certain variables that can be adjusted. Emphasis on constructs and simplified. There is no climate prediction model yet that can deal with all the variables. Carbon Dioxide changes? Humidity changes? Heat islands? Effects of wind turbines? The occasional random equatorial volcano coughing sulfur dioxide and ash into the atmosphere? All at once? Splat! That was the model collapsing. Most of the most common models used by the IPCC and others can’t even retrocast accurately – that is, you can’t feed in the data for a date and location in the past and get the actual weather or climate for that time and place.
Models are very useful, so long as the user observes the limits in the model. The local weather guys and gals, especially the ones with several years of local experience, temper the models with “I’m just not entirely sure about this because of X, but here’s the National Weather Service/National Severe Storm Center Forecast/ European Model prediction.” Those of us with a lot of on-the-ground knowledge and regional research are not surprised when the models are off, or gee, winter can be very cold and still, or summer can be very hot and still, or that Texas gets freezes as far as Corpus Christi.
I’ve read through the diaries and reports of ranch managers and farmers from this region, going back as far as they exist, along with US Army documents and Indian Bureau reports. There were months where [due to a high pressure dome] the wind didn’t blow and windmills didn’t work. Cowboys had to wind ropes around the shaft and ride away from the thing, repeating that over and over to get the pump to bring up water for the cattle. Or there would be spells of miserable heat in an otherwise cold year. Or a hard, cold and wet winter in a decade of heat and drought. Snowvid 21 wasn’t all that unusual, really. High pressure building in and baking the Southwest, or Texas, or the Great Plains, isn’t too rare in the long-term. Even during the Little Ice Age.
Patterns and models. I work with patterns. I’m good at seeing patterns. I try not to make predictions, unless they are based on long experience and human nature. (Teenagers are going to be emotional. Toddlers will melt down. Someone’s going to tap the electric fence, because it might not really be live.) Models, especially models that claim they can determine what is going to happen and why a hundred years from now, or ten years from now? I fold my money and put it back in my pocket, as the gamblers say.